WO2020012190A1

WO2020012190A1 - Apparatus and method for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner

Info

Publication number: WO2020012190A1
Application number: PCT/GB2019/051958
Authority: WO
Inventors: John-Paul GROGAN; Stewart Huxley; Peter Gough
Original assignee: Frugalpac Limited
Priority date: 2018-07-12
Filing date: 2019-07-12
Publication date: 2020-01-16
Also published as: GB201811424D0; GB2576866A

Abstract

This invention relates to a machine for manufacturing a liner for a container. In particular this invention relates to a machine for manufacturing a liner from a thin film polymeric material that is used to line a container made from a paperboard material. An apparatus for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner comprises an applicator for applying a force to the area of the first polymeric sheet in a direction substantially parallel to a plane of the first sheet to move at least a portion of the area of the first polymeric sheet with respect to a portion of the area of the second polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along an edge of the area of the first sheet; and a nozzle for directing a jet of air at the edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet.

Description

APPARATUS AND METHOD FOR SELECTIVELY SEPARATING AN AREA OF A FIRST POLYMERIC SHEET

FROM AN AREA OF A SECOND POLYMERIC SHEET IN FACE TO FACE CONTACT WITH THE FIRST POLYMERIC SHEET IN A MACHINE FOR MANUFACTURING A CONTAINER LINER

BACKGROUND

This invention relates to a machine for manufacturing a liner for a container. In particular this invention relates to a machine for manufacturing a liner from a thin film polymeric material that is used to line a container made from a paperboard material.

Disposable or paper cups are often made from pre-laminated card comprising a paper- based substrate layer and a polymeric coating. The use of laminated card has the benefits of being more resource and energy efficient than using plastic alone, however, combining materials in this way prevents the cups being recycled with unlaminated cardboard or pure plastic, and therefore, most disposable cups end up in landfill.

There is, therefore, a need to find a more environmentally friendly alternative. It is known to manufacture containers having a separable cardboard or paperboard shell and a thin polymeric liner. The liner is at least partially adhered to the paperboard shell in such a way that the liner and the shell can be separated and disposed of or recycled separately.

Commercial considerations, however, mean that it is desirable for any alternative containers to be able to be manufactured at similar speeds and in similar volumes to existing paper cups and also with the same degree of reliability and consistency. Current paper cup making machines typically output at a rate of up to 100-200 cups per minute with a failure/leakage rate of about one cup in every million.

It is, therefore, an object of the invention to provide a machine for manufacturing a liner for a container that is able to operate reliably and at high speeds.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided an apparatus for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner, the apparatus comprising:

an applicator for applying a force to the area of the first polymeric sheet in a direction substantially parallel to a plane of the first sheet to move at least a portion of the area of the first polymeric sheet with respect to a portion of the area of the second polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along an edge of the area of the first sheet; and

a nozzle for directing a jet of air at the edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet.

Preferably the applicator is configured to apply the force proximate the edge of the area of the first sheet. The applicator may be configured to apply the force in a direction substantially perpendicular to the edge of the area of the first sheet.

In preferred embodiments the nozzle is configured such that the jet of air flows in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

In some embodiments the edge of the area of the first polymeric sheet is a peripheral edge of the first polymeric sheet. The edge of the area of the second polymeric sheet may be a peripheral edge of the second polymeric sheet. In other embodiments the edge of the area of the first polymeric sheet is spaced from a peripheral edge of the first polymeric sheet so as to define a margin between the edge of the area of the first polymeric sheet and the peripheral edge of the first polymeric sheet. A first edge of the area of the first polymeric sheet may be spaced from a first peripheral edge of the first polymeric sheet so as to define a first margin and a second edge of the area of the first polymeric sheet may be spaced from a second peripheral edge of the first polymeric sheet so as to define a second margin.

In some embodiments the apparatus preferably comprises:

a first applicator for applying a force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the first edge of the area of the first sheet;

a second applicator for applying a force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the second edge of the area of the first sheet;

a first nozzle for directing a first jet of air at the first edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet; and

a second nozzle for directing a second jet of air at the second edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet.

The first applicator may be configured to apply a force in a direction towards the second edge and said second applicator may be configured to apply a force in a direction towards the first edge, and the first nozzle may be configured to direct the first jet of air in a direction towards the second edge and the second nozzle may be configured to direct the second jet of air in a direction towards the first edge.

The or each applicator preferably comprises a foot that contacts the first polymeric sheet to apply the force to said sheet and an actuator configured to move the foot into contact with the first polymeric sheet. The actuator may be configured to move the foot in a direction substantially perpendicular to the plane of the first sheet. The foot preferably comprises a friction surface for applying a gripping force to the first polymeric sheet. The friction surface may be disposed on a foot pad of the foot.

In preferred embodiments the foot is connected to the actuator so that during movement of the actuator the friction surface initially moves in a direction towards the first sheet to contact the first sheet and subsequently the friction surface moves in a direction parallel to the plane of the first sheet. The foot preferably comprises a foot plate connected to the actuator at a pivot and the friction surface is disposed on a first side of said pivot. A biasing member may be connected to the foot plate to bias the foot plate in a direction such that the friction surface moves in a direction towards the first polymeric sheet. The biasing member is preferably connected to the foot plate on a second side of the pivot.

In some embodiments the apparatus comprises:

a first pair of applicators for applying a force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the first edge of the area of the first polymeric sheet, the applicators of the first pair being spaced apart in a direction parallel to the first edge; and

a second pair of applicators for applying a force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the second edge of the area of the first polymeric sheet, the applicators of the second pair being spaced apart in a direction parallel to the second edge,

the first nozzle being disposed between the applicators of the first pair of applicators, and the second nozzle being disposed between the applicators of the second pair of applicators. The apparatus preferably further comprises a support surface for supporting the first and second polymeric sheets. Preferably the apparatus further comprises a retaining member configured to constrain movement of the first and second sheets away from the support surface. In some embodiments the retaining member may be disposed between the first and second applicators to constrain movement of at least a central part of the first and second polymeric sheet away from the support surface. The retaining member is preferably spaced from the support surface such that the first and second polymeric sheets are receivable between the retaining member and the support surface.

In preferred embodiments the apparatus further comprises an assembly for applying a tensile force to the first and second polymeric sheets in a direction substantially parallel to the edge of the area of the first polymeric sheet. The assembly for applying a tensile force parallel to the edge may comprise a roller.

In some embodiments the apparatus may further comprise an assembly for applying a tensile force to the first and second polymeric sheets in a direction substantially perpendicular to the edge of the area of the first polymeric sheet. The assembly for applying a tensile force perpendicular to the edge may comprise a roller.

According to a second aspect of the present invention there is provided a method for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner, the method comprising:

applying a force to the area of the first polymeric sheet in a direction substantially parallel to a plane of the first sheet to move at least a portion of the area of the first polymeric sheet with respect to a portion of the area of the second polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along an edge of the area of the first polymeric sheet; and

directing a jet of air at the edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet.

The method preferably comprises applying the force to the area of the first polymeric sheet proximate the edge of the first area. In some embodiments the method comprises applying the force in a direction substantially perpendicular to the edge of the area.

The method may comprise directing the jet of air in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

The edge of the area of the first polymeric sheet may be spaced from a peripheral edge of the first polymeric sheet so as to define a margin between the edge of the area of the first polymeric sheet and the peripheral edge of the first polymeric sheet. Preferably a first edge of the area of the first polymeric sheet is spaced from a first peripheral edge of the first polymeric sheet so as to define a first margin and a second edge of the area of the first polymeric sheet is preferably spaced from a second peripheral edge of the first polymeric sheet so as to define a second margin.

In some embodiments the method comprises:

applying a first force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the first edge of the area of the first polymeric sheet;

applying a second force to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the second edge of the area of the second polymeric sheet;

directing a first jet of air at the first edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet; and

directing a second jet of air at the second edge of the area of the first polymeric sheet such that at least some of the jet of air flows between the two sheets within the area of the first polymeric sheet.

The first force may be applied in a direction towards the second edge and the second force may be applied in a direction towards the first edge, and the first jet of air preferably flows in a direction towards the second edge and the second jet of air preferably flows in a direction towards the first edge.

In some embodiments the method may comprise:

applying a first pair of forces to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the first edge of the area of the first polymeric sheet, the forces of the first pair being spaced apart in a direction parallel to the first edge; and

applying a second pair of forces to the area of the first polymeric sheet to at least partially separate the areas of the first and second polymeric sheets along the second edge of the area of the first polymeric sheet, the forces of the second pair being spaced apart in a direction parallel to the second edge.

The method preferably further comprises supporting the first and second polymeric sheets on a support surface.

The method preferably further comprises applying a tensile force to the first and second polymeric sheets in a direction substantially parallel to the edge of the area of the first polymeric sheet. The method may further comprise applying a tensile force to the first and second polymeric sheets in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 is a block diagram of a machine for manufacturing a container including a first section for manufacturing a lining of the container and a second section for assembling the lining with a shell of the container;

Figure 2 illustrates the pattern of bond lines formed when two webs of polymeric material are bonded together in one step in the manufacture of the lining of the container;

Figure 3 shows a single pair of the bond lines formed in the web of Figure 2 and shows the cut lines formed in a further step in the manufacture of the lining;

Figure 4 shows a part of the machine for manufacturing a liner for a container from a sleeve of plastic material, Figure 4 showing in particular a first station for separating first and second halves of the sleeve and a second station for opening the sleeve and placing it over a former; Figure 5 is a further view of the second station of Figure 4 showing a pair of assemblies for opening sleeves;

Figure 6 shows the second station of Figure 5 with an open sleeve held by each one of the pair of assemblies, the sleeves being positioned over a respective pair of formers;

Figure 7 shows a further part of the machine for manufacturing a liner for a container from a sleeve of plastic material, Figure 7 showing in particular a station for cutting and holding a base of the liner prior to attachment to a sleeve of the liner;

Figure 8 shows the station of Figure 7 with two formers positioned so as to bring a sleeve of the liner into contact with a respective base of the liner;

Figure 9 is a perspective view of the first station of Figure 4 showing a separation assembly;

Figure 10 is a side view of the separation assembly of Figure 9;

Figure 1 1 is a perspective view of the separation assembly of Figure 9 from above;

Figure 12 is a perspective view of the separation assembly of Figure 9 from below;

Figure 13 is a view of the separation assembly of Figure 9 with a support structure removed;

Figure 14 shows a displacement unit of the separation assembly of Figure 13 in a first configuration;

Figure 15 shows the displacement unit of Figure 14 in a second configuration;

Figure 16 shows an assembly for opening a sleeve in a first configuration;

Figure 17 is an end view of the assembly of Figure 16 in the first configuration;

Figure 18 is a further view of the assembly of Figure 16 in the first configuration;

Figure 19 is a view from below of the assembly of Figure 16 in the first configuration; Figure 20 shows an assembly for opening a sleeve in a second configuration;

Figure 21 is an end view of the assembly of Figure 20 in the second configuration;

Figure 22 is a further view of the assembly of Figure 20 in the second configuration;

Figure 23 is a view from below of the assembly of Figure 20 in the second configuration;

Figure 24 is a view of the assembly of Figure 16 in the first configuration and with a support carriage removed;

Figure 25 is a view of the assembly of Figure 20 in the second configuration and with a support carriage removed;

Figure 26 is a view of a support surface of the second station of Figure 4 showing a plurality of cutting units disposed below the support surface;

Figure 27 is a view of the plurality of cutting units of Figure 26, with the support surface removed for clarity;

Figure 28 shows one of the cutting units of Figure 26 with a cutting element of the unit in a deployed or raised position;

Figure 29 is a view of the station for cutting and holding a base of the liner of Figure 7 showing a pair of cutting assemblies cutting bases from a length of plastics material;

Figure 30 is a view of one of the cutting assemblies of Figure 29;

Figure 31 is a view of one of the cutting assemblies of Figure 29 showing a cutting ring recessed into a support plate;

Figure 32 is a view of a part of the cutting assembly of Figure 30;

Figure 33 is a view of a carousel of the cutting assembly of Figure 30, the carousel comprising a support ring and a plurality of retaining tabs; Figure 34 shows the support ring of the carousel of Figure 33;

Figure 35 shows the retaining tabs of Figure 33 and a plurality of pins, each pin being in an engaged position and in contact with a respective one of the retaining tabs; and

Figure 36 shows a heat sealing assembly arranged to heat seal the base of the liner to the sleeve of the liner, the sleeve of the liner being supported on a former.

DETAILED DESCRIPTION

Figure 1 is a block diagram of a machine for manufacturing containers 2 and, in particular, for manufacturing disposable cups. The containers 40 comprise an outer shell 42 made of a cardboard or paperboard material and an inner liner that is made from a thin sheet of polymeric material. The polymeric material preferably has a thickness of less than 100 pm, and more preferably less than 70 pm. The polymeric material preferably has a thickness of more than 20 pm. Most preferably the polymeric material has a thickness of about 30 pm.

The machine 2 comprises a first section 4 for forming the liner of the container and a second section 6 for conforming and adhering the liner to the shell.

At a first step 8, two webs 44 of polymeric material are brought together such that edges 46 of the webs are aligned with each other and a first face of one web is in contact with a first face of the second web. Tension is applied to the webs by suitable tensioning means to ensure that the two webs remain parallel and in contact with each other.

At a second step 10 the two webs 44 are heat welded together along discrete bond lines 48. The bond lines 48 traverse the polymeric webs at inclined angles to the edges 46 of the webs. Figure 2 illustrates one preferred pattern of bond lines 48. In the illustrated embodiment the bond lines 48 do not extend fully across the webs 44 of polymeric material; however, in some embodiments it is preferable if the bond lines 48 do extend fully across the webs 44 between the edges 46 of the webs. The bond lines 48 are disposed in pairs; the bond lines 48 in each pair converging proximate one edge 46 of the webs. In particular a first end 50a of each of the bond lines 48 in a pair is disposed proximate a first edge 46a of the webs and a second end 50b of each of the bond lines 48 in a pair is disposed proximate a second edge 46b of the webs, and the second ends 50b of the bond lines 48 are closer together than the first ends 50a of the bond lines 48. Each pair of bond lines 48 forms a sleeve or tube 52 of polymeric material that, at this stage, is connected to and integral with the remainder of the webs 44 of material.

At a third step 12 the polymeric webs 44 are cut along discrete cut lines. Figure 3 illustrates a preferred configuration of cut lines 54 associated with one pair of bond lines 48, the cut lines being indicated by dashed lines. A first cut line 54a extends generally in a direction substantially parallel to the first edge 46a of the webs 44. A first end of the first cut line 54a intersects a first bond line 48a of a pair of bond lines 48 proximate the first end 50a of the bond line 48a and a second end of the first cut line 54a intersects a second bond line 48b of a pair of bond lines 48 proximate the first end 50a of the bond line 48b. In a preferred embodiment the first cut line 54a is curved. The first cut line 54a extends in an arc such that a central region of the first cut line 54a is closer to the first edge 46a of the webs 44 than the first and second ends of the first cut line 54a. A second cut line 54b extends generally in a direction substantially parallel to the second edge 46b of the webs 44. A first end of the second cut line 54b intersects the first bond line 48a proximate the second end 50b of the bond line 54b and a second end of the second cut line 54b intersects the second bond line 48b proximate the second end 50b of the bond line 48b. In a preferred embodiment the second cut line 54b is curved. The second cut line 54b extends in an arc such that a central region of the second cut line 54b is further from the second edge 46b of the webs 44 than the first and second ends of the second cut line 54b. In other embodiments the first and second cut lines 54a, 54b may be straight and may extend parallel to the first and second edges 46a, 46b of the webs 44. Each of the first and second cut lines 54a, 54b is spaced from the respective first and second edge 46a, 46b of the webs 44 so that a first web margin 56a is formed between the first cut line 54a and the first edge 46a of the webs and a second web margin 56b is formed between the second cut line 54b and the second edge 46b of the webs. The first and second cut lines 54a, 54b define, respectively, first and second ends 58, 59 of the polymeric sleeve 52.

A third cut line 54c extends parallel to and is coincident with the first bond line 48a. A fourth cut line 54d extends parallel to and is coincident with the second bond line 48b. The third and fourth cut lines 54c, 54d therefore define longitudinal edges 60 of the sleeve 52 in its folded or collapsed configuration.

The third and fourth cut lines 54c, 54d extend through the first and second bond lines 48a, 48b respectively but do not extend for the full length of the bond lines. Furthermore, the third and fourth cut lines 54c, 54d do not insect the first and second cut lines 54a, 54b. In this way four uncut spurs 62 of material extend between the sleeve 52 defined by the bond lines 48 and the surrounding polymeric webs 44. A first spur 62 extends between a first end of the third cut line 54c and the first cut line 54a, a second spur 62 extends between a first end of the fourth cut line 54d and the first cut line 54a, a third spur 62 extends between a second end of the third cut line 54c and the second cut line 54b, and a fourth spur 62 extends between a second end of the fourth cut line 54d and the second cut line 54b.

During these initial steps the first and second polymeric webs 44 become attracted to each other or stuck to each other due to electrostatic forces that have built up between the webs. Furthermore, the first and second webs 44 can also become attached to each other along the first and second cut lines 54a, 54b due to the pressure applied to the webs 44 by a cutting blade used to form the cut lines 54.

Accordingly, at a fourth step 14 in the manufacture of the liner, with the sleeve 52 still attached to the remainder of the polymeric webs 44, a force is applied to the sleeve portion 52 of the webs 44 to move the first web with respect to the second web to break any unwanted connection between the webs that may have formed. In a preferred embodiment a first force is applied to the sleeve portion of a first one of the webs proximate the first cut line and a second force is applied to the sleeve portion of the first one of the webs proximate the second cut line. Preferably the first force is applied in a direction towards the second cut line and the second force is applied in a direction towards the first cut line.

In preferred embodiments a stream, jet or blast of air is directed between the first and second webs between the pair of bond lines 48. The jet or blast of air is preferably directed substantially perpendicular to at least a part of the first and second cut lines 54a, 54b. In particularly preferred embodiments a first jet of air is directed from the first end 58 of the sleeve portion 52 towards the second end 59 of the sleeve portion 52 and a second jet of air is directed from the second end 59 of the sleeve portion 52 towards the first end 58 of the sleeve portion 52. The jet(s) of air are configured to urge apart the first and second webs in the sleeve portions so as to break the electrostatic forces between the webs 44.

At a fifth step 16 the sleeve portions 52 are separated from the remainder of the web 44 and the sleeves 52 are opened and placed over a mandrel or former. In preferred embodiments the spurs 62 of polymeric material are cut and the sleeve 52 lifted away from the remainder of the webs 44. The sleeve 52 is then opened to form a substantially cylindrical or truncated conical shape and slid 18 over a former; an external shape of the former corresponding to an internal shape of the sleeve 52. The sleeve is preferably retained over the former by means of a partial vacuum which is applied to the sleeve through the former and acts to suck or draw the sleeve into contact with the external circumferential surface of the former.

With the liner located over the former, an end region of the sleeve extends beyond an end face of the former. A length of the end region of the sleeve is preferably less than half the diameter of the end face.

At a sixth step 20 the end region of the sleeve is heated to conform this region around a perimeter edge of the end face of the former. Preferably a source of hot air is used to heat the end of the sleeve, with the hot air being directed towards the end face of the former so as to evenly heat the end region of the sleeve around its full circumference. Due to the orientation of the polymer chain molecules in the polymeric material of the sleeve, the heat causes the polymeric sheets to shrink in such a way that the end region wraps around the end of the former to lie in contact with the end face. The heat shrunk end region thereby forms a substantially flat bonding surface onto which a further piece of material is bonded to form a base of the liner in a further step in the method of manufacturing the liner.

Substantially circular bases of the liner are cut 22 from a web of polymeric material. The polymeric material used to make the bases is preferably the same polymeric material as that used to form the sleeve. A diameter of each of the bases is not greater than a diameter of the end of the former such that the diameter of the base is not greater than an external diameter of the heat shrunk end region of the sleeve.

In a subsequent step 24 each base is bonded to a respective sleeve. Each base is preferably heat welded to the end region of the sleeve. A bonding means preferably bonds the plastic material of the base to the plastic material of the end region of the sleeve around the full perimeter of the end region. In preferred embodiments a heat welding means is brought into contact with the base such that the base and the end region of the sleeve are sandwiched between the heat welding means and the end face of the former.

The fully formed liner, with the base bonded to the sleeve remains attached to the former and is then, in a subsequent step 26, inserted into a shell 42. The shell 42 is preferably made from a paperboard material with no laminated plastic layers. In preferred embodiments the shell is in the shape of a disposable cup. Accordingly, the shell comprises a generally circular base, a side wall extending from the base and an opening defined by an upper edge of the side wall. The upper edge of the side wall includes a rolled rim that extends fully around the opening. A plurality of shells to be lined may be held in a stack before processing in the machine. A single shell may be removed, or de- nested, from the stack, using any suitable means.

In a further step 30 an adhesive is applied to internal surfaces of the shell. The adhesive is preferably sprayed into the shell so as to apply an even coating of adhesive to the internal surfaces of the side wall and base of the shell. The adhesive is preferably a heat activated adhesive, but may be a pressure activated adhesive or a heat and pressure activated adhesive. The adhesive is preferably a water soluble adhesive.

A pre-formed liner, made according to the method described above, is then inserted 26 into the shell. In some embodiments the pre-formed liner may be inserted into the shell with the adhesive in a non-activated state. In these embodiments the liner is then adhered to the internal surfaces of the shell by activating the adhesive. This may be achieved by inserting a heated former into the lined shell. Alternatively, the liner may be adhered to the internal surfaces of the shell as the liner is inserted into the shell. The liner is constructed so that the external shape of the liner conforms to the internal shape of the shell such that the liner does not have to be stretched to bring the liner into contact with the internal surfaces of the shell.

The former carrying the liner is fully inserted into the shell so that the base of the liner is in contact with the internal surface of the base of the shell. With the liner inserted in this way an upper edge region of the liner protrudes from the opening of the shell. With the former fully inserted into the shell, the partial vacuum that was retaining the liner on the former is removed or switched off. In preferred embodiments air is then blown out of the former so as to force the sleeve in a radially outwards direction away from the former and into contact with the shell. The former is then removed from the shell.

In an optional subsequent step means may be inserted into the lined shell to smooth the lining against the internal surfaces of the shell. The means for smoothing the liner may include resilient means such as an elastomeric or sponge former or may include bristles or brush heads. In a further step 34 in the method, the upper edge region of the liner is drawn or folded over the rolled rim of the shell such that the upper edge region of the liner extends down the external surface of the side wall of the shell around the rim. An expandable tool may be used to stretch the upper edge region of the liner radially outwardly and then draw the upper edge region of the liner downwards over the side wall of the shell such that the upper edge region of the liner wraps over the rim of the container.

To firmly secure the upper edge region of the liner to the shell, in a subsequent step 36 this region is preferably heat shrunk around the external surface of the shell. In preferred embodiments a heating element applies hot air to a region around the outside of the shell to heat shrink the liner around the shell. Preferably the heating element is annular and has an internal diameter greater than the outer diameter of the rim of the shell.

In preferred embodiments the method further includes checking 37 that the upper edge region of the liner has been corrected folded over the rim of the shell and has been correctly heat shrunk around the external surface of the shell. This method step may be performed at a rim check station. Incorrect positioning or locating of the shell during insertion and manipulation of the liner may cause the tool used to stretch and wrap over the upper region of the liner to only grip part of the liner, which may result in a loose part of the liner spanning or partially overlapping the opening of the shell. This checking step 37 may include inserting an object through the opening of the shell to determine if there is an obstruction. If it is determined that the liner has been incorrectly inserted into the shell, the container is rejected.

With the liner fully secured to the shell, the finished container 40 is then ejected 38 from the machine.

It will be appreciated that at various stages in the machine 2, following at least some of the method steps described above, sensors may be positioned and configured to detect whether the method step has been successfully completed. For example, sensors may determine if the sleeve of the liner has a base attached, if a liner has been inserted into a shell and/or if an edge region of a liner has been heat shrunk around the rim of the shell. If the sensors detected that there has been a fault and that at least one of the method steps has not been completed then that container is rejected.

In some embodiments it may be desirable to locate and attach a secondary sleeve or double wall around the finished container. A paperboard sleeve may be secured around external surfaces of the finished container to conceal or cover the upper edge region of the liner. The paperboard sleeve preferably locates below the rolled rim of the shell. An external surface of the paperboard sleeve may be printed.

Figure 4 shows a separation assembly 66 according to a preferred embodiment of the invention configured to apply a force to the sleeve portion 52 of the webs 44 to move the first web with respect to the second web to break any unwanted connection between the webs that may have formed, as described above. Figures 4 to 6 show a sleeve opening assembly 68 according to a preferred embodiment of the invention configured to separate sleeve portions 52 from the remainder of the webs 44, open the sleeves 52 and place them over a former 238, as described above.

The polymeric webs 44 including the sleeves 52 moves between these two assemblies 66, 68 supported on a generally horizontal support surface 70. In this way a plane of the polymeric webs is substantially horizontal. To aid in the further description of these assemblies 66, 68, the orientation of parts of the assemblies will be referred to with respect to orthogonal X, Y and Z axes. The plane of the support surface 70 is in the X-Y plane, with the X axis extending along the length of the support surface 70, and therefore parallel to the length of the webs 44, and the Y axis extending across the support surface 70, and therefore parallel to a width of the webs 44 between the edges 46 of the webs 44. The Z axis extends perpendicularly from the support surface 70.

Tension is applied to the webs 44 by a series of rollers or wheels 72. The rollers 72 are mounted above the support surface 70 and the webs pass between the rollers 72 and the support surface 70. The rollers 72 are disposed near edges 74 of the support surface 70 such that the rollers 72 contact the webs 44 near the edges 46 of the webs 44. In particular, the rollers 72 preferably contact margins 56 of the webs between the first cut line 54a and the first edge 46a of the webs 44 and between the second cut line 54b and the second edge 46b of the webs 44. The rollers 72 are set at an angle to the edge of the support surface 70 such that an axle of each of the rollers 72 is at an angle of between 45° and 90° to the edge of the support surface 70 and such that a leading edge of each roller 72, i.e. the part of the roller 72 moving downwards into contact with the webs 44, is closer to a centreline of the support surface 70 than a trailing edge of each roller 72, i.e. the part of the roller 72 moving upwards and losing contact with the webs 44.

The rollers 72 are preferably arranged in pairs across the width of the support surface 70. Each of the rollers 72 applies a force to an upper surface 76 of the webs 44 such that a tension is applied to the webs 44 in a direction substantially parallel to the Y axis, i.e. across the width of the webs 44.

The tension applied by the rollers 72 is in addition to a tension being applied to the webs 44 by a mechanism (not shown) for drawing the webs 44 along the support surface 70. The tension applied to the webs 44 by this mechanism is in a direction substantially parallel to the X axis.

As described above, the webs 44 that are drawn onto the support surface 70 includes a plurality of sleeves 52 that have been bonded and partially cut from the surrounding remainder of the webs 44. The webs 44 are initially drawn into a position in which one of the sleeves 52 is in alignment with or in registration with the separation assembly 66. At the same time, a further sleeve 52, at a distance along the webs 44, will be in alignment or registration with the sleeve opening assembly 68.

An embodiment of the separation assembly 66 will now be described with reference to Figures 9 to 15. The separation assembly 66 comprises a support structure or gantry 78 that extends over the support surface 70. Legs 80 of the support structure 78 are disposed at each edge 74 of the support surface 70 and a support member or beam 82 extends between the two legs 80 across the full width of the support surface 70.

A pair of skids 84 is mounted to the support beam 82 in a substantially central position across the width of the support beam 82. Each skid 84 comprises a bracket 86 and a skid plate 88. A first, upper end 90 of the bracket 86 is attached to the support beam 82 and a second, lower end 92 of the bracket 86 is attached to the skid plate 88. The skid plate 88 is, therefore, suspended from the support beam 82 by the bracket 86. A plane of the skid plate 88 extends substantially parallel to the plane of the support surface 70. The skid plate 88 is disposed at a fixed distance above the support surface 70, this distance being substantially equal to or slightly greater than the thickness of the webs 44. In operation, the webs 44 pass under the skid plate 88 and the skid plate 88 retains a central portion of the webs 44 in contact with the support surface 70. The skids 84 therefore act as retaining members to retain the webs 44 in contact with the support surface 70.

The skid plate 88 is elongate and has a first, leading edge 94 and a second, trailing edge 96. A first end 93 of the skid plate 88, including the leading edge 94, is upturned or bent upwardly with respect to the rest of the skid plate 88. As such, the distance between the leading edge 94 and the support surface 70 is greater than the distance between the trailing edge 96 and the support surface 70. This prevents the webs 44 getting caught on the leading edge 94 of the skid plate 88 as the webs 44 pass under the skid plate 88.

In this embodiment the separation assembly 66 includes two skids 84 adjacent each other; however, it will be appreciated that in other embodiments the separation assembly 66 may only include one skid 84. In some embodiments the separation assembly 66 may include alternative means for retaining the webs 44 in contact with the support surface 70.

The separation assembly 66 further comprises a plurality of displacement units 98. In this embodiment there are two pairs of displacement units 98; however, in other embodiments there may be more than or fewer than four displacement units 98. For example, there may be one pair of displacement units 98.

Each displacement unit 98 is attached to the support structure 78. In each pair of displacement units 98, a first one of the pair is disposed between the skid(s) 84 and a first leg 80 of the support structure 78 and a second one of the pair is disposed between the skid(s) 84 and a second leg 80 of the support structure 78. In this way, the displacement units 98 are disposed on opposite sides of the skid(s) 84 and each of the displacement units 98 is disposed proximate a respective edge 74 of the support surface 70.

Each displacement unit 98 comprises an actuator 100 and a foot 102 connected to the actuator 100. The actuator 100 is attached to the support structure 78 and the foot 102 is connected to a lower end of the actuator 100. In this embodiment the actuator 100 is a linear actuator. The foot 102 includes a foot pad 104 which provides a non-slip or friction surface. Preferably the foot pad 104 is made from a rubber material or other resilient material, or includes a tacky contact surface.

The foot 102 comprises a mounting block 106, a foot plate 108 and the foot pad 104, shown most clearly in Figures 14 and 15. The mounting block 106 is rigidly attached to the end of the linear actuator 100. The foot plate 108 is pivotally attached to the mounting block 106 at a pivot 1 10, and the foot pad 104 is attached to a first end 1 12 of the foot plate 108. A biasing means 1 16 is connected between a second end 1 14 of the foot plate 108 and the mounting block 106. In this embodiment the biasing means 1 16 is in the form of an extension spring. The pivot 1 10 is disposed between the biasing means 1 16 and the foot pad 104.

The foot 102 moves between a disengaged position, in which the foot pad 104 is not in contact with the polymeric webs 44, and an engaged position, in which the foot pad 104 is in contact with the polymeric webs 44. In the disengaged position the foot 102 is suspended from the actuator 100, and no part of the foot 102 is in contact with the support surface 70 or the polymeric webs 44. The biasing means 1 16 applies a force to the second end 1 14 of the foot plate 108 which holds the second end 1 14 of the foot plate 108 in a raised position. Because the foot pad 104 is on an opposite side of the pivot 1 10 to the second end 1 14 of the foot plate 108, the foot pad 104 is in a lowered position with respect to the second end 1 14 of the foot plate 108, i.e. the first end 1 12 of the foot plate 108 is closer to the support surface 70 than the second end 1 14 of the foot plate 108. In the engaged position the foot pad 104 is in contact with the support surface 70 or polymeric webs 44, and the first end 1 12 of the foot plate 108 is further from the support surface 70 than the second end 1 14 of the foot plate 108. In this embodiment the extension spring is stretched such that additional energy is stored in the biasing means 1 16 compared to when the foot 102 is in the disengaged position.

In use, as the foot 102 moves from the disengaged position to the engaged position, the linear actuator 100 extends to bring the foot pad 104 into contact with the upper surface 76 of the polymeric webs 44. Further extension of the linear actuator 100 causes the foot plate 108 to rotate about the pivot 1 10. This in turn causes the foot pad 104, while in contact with the polymeric webs 44, to move in a direction substantially perpendicular to the direction of movement of the linear actuator 100. The attachment of the displacement unit 98 to the support structure 78 is such that this movement of the foot pad 104 is substantially parallel to the plane of the support surface 70 and, therefore, substantially parallel to the plane of the polymeric webs 44.

As the foot 102 moves from the engaged position to the disengaged position, the linear actuator 100 is retracted. As the foot 102 is lifted away from the support surface 70, the biasing means 1 16 applies a force to the second end 1 14 of the foot plate 108, which causes the foot plate 108 to rotate about the pivot 1 10. Preferably the speed of retraction of the actuator 100 is such that the foot pad 104 is lifted clear of the polymeric webs 44 before significant rotation of the foot plate 108 has occurred.

As shown most clearly in Figures 10 to 13, the displacement units 98 are attached to the support structure 78 such that the movement of the foot pad 104 while in contact with the polymeric webs 44 is in a direction across the width of the polymeric webs 44, i.e. in a direction substantially parallel to the Y axis. Furthermore, in each pair of displacement units 98, the first and second displacement units 98 are arranged in opposite orientations. In particular, the first displacement unit 98 of a pair, proximate the first edge 46a of the polymeric webs 44, is configured such that movement of the foot pad 104 while in contact with the polymeric webs 44 is in a direction away from the first edge 46a of the webs 44 and towards the second edge 46b of the webs 44. The second displacement unit 98 of the pair, proximate the second edge 46b of the polymeric webs 44, is configured such that movement of the foot pad 104 while in contact with the polymeric webs 44 is in a direction away from the second edge 46b of the webs 44 and towards the first edge 46a of the webs 44. In other words, foot pads 104 of a pair of displacement units 98 while in contact with the polymeric webs 44 moves in directions towards each other and towards the centreline of the polymeric webs 44.

While in contact with the polymeric webs 44 the foot pads 104 grip or apply a force to the upper layer of the webs 44. The upper layer of the webs 44 in contact with the foot pad 104 is, therefore, moved with respect to the respective part of the lower layer during engagement of the foot 102 with the webs 44. This causes any bond or attachment between the upper and lower layers of the webs 44 to be disturbed and broken.

An attachment between the upper and lower layers of the webs 44 may exist along the first and second cut lines 54a, 54b due to the cutting blade pressing the upper layer of the webs into the lower layer of the webs along the cut lines 54a, 54b. A bond may also exist between the upper and lower layers of the webs 44 due to static between the polymeric layers.

In preferred embodiments, and as shown most clearly in Figures 12 to 14, the separation assembly 66 comprises a conduit or nozzle 1 18 for directing a jet of de-ionised air between the two layers of the polymeric webs 44. The conduit or nozzle 1 18 is preferably connected to a compressed air supply. The separation assembly 66 preferably comprises two nozzles 1 18, a first one 1 18a disposed proximate the first edge 46a of the webs 44 and a second one 1 18b disposed proximate the second edge 46b of the webs 44. The first nozzle 1 18a is configured such that an end of the nozzle 1 18a is disposed proximate the first cut line 54a of the webs 44 and directs a jet of air in a direction substantially across the webs 44 towards the second edge 46b of the webs 44 and downwardly towards the support surface 70. Similarly, the second nozzle 1 18b is configured such that an end of the nozzle 1 18b is disposed proximate the second cut line 54b of the webs 44 and directs a jet of air in a direction substantially across the web towards the first edge 46a of the webs 44 and downwardly towards the support surface 70. The end of each nozzle 1 18 is in a fixed position with respect to the support surface 70 and is positioned a small distance above the polymeric webs 44.

In operation, when the feet 102 of the displacement units 98 are in an engaged position and applying a force to the upper layer of the polymeric webs 44, a jet or pulse of air is directed by the nozzle 1 18 at the cut line 54 in the polymeric webs 44. Because the upper layer of the webs 44 is displaced with respect to the lower layer at the cut line 54, at least a part of the jet of air is forced between the upper and lower layers of the polymeric webs 44. This air flows between the upper and lower layers over the area of the sleeve 52 and assists in disturbing or breaking any bond between the layers due to static forces. In preferred embodiments a pulse of air of limited duration is directed at the webs 44 only while the feet 102 of the displacement units 98 are in the engaged position.

In embodiments comprising two pairs of displacement units 98, the first nozzle 1 18a is preferably disposed between the two displacement units 98 proximate the first cut line 54a and the second nozzle 1 18b is preferably disposed between the two displacement units 98 proximate the second cut line 54b.

The displacement units 98 and the nozzles 1 18 may be moveably attached to the support structure 78 such that the displacement units 98 and the nozzles 1 18 can each be moved with respect to the support structure 78 and the edges 74 of the support surface 70. This allows the displacement units 98 and the nozzles 1 18 to be moved into appropriate positions to accommodate different sizes of polymeric webs 44. In particular the displacement units 98 and the nozzles 1 18 may be moved to accommodate different distances between the first and second cut lines 54a, 54b if the sleeves 52 are sized to line different sizes of shell 42.

In the above description the displacement units 98 and nozzles 1 18 have been described in relation to the webs 44 being supported on the support surface 70 in the X-Y plane, with the X axis parallel to the length of the webs 44 and the Y axis parallel to a width of the webs 44 between the edges 46 of the webs 44, and with the foot pads 104 applying a force to the upper layer of the webs 44. It will be appreciated, however, that in other embodiments the webs 44 may be supported in a different orientation, and the foot pads 104 may be arranged to apply a force to the lower layers of the webs 44 to move the lower layer with respect to the respective part of the upper layer during engagement of the foot 102 with the webs 44 to cause any bond or attachment between the upper and lower layers of the webs 44 to be disturbed and broken.

An embodiment of the sleeve opening assembly 68 will now be described with reference to Figures 16 to 28. The sleeve opening assembly 68 comprises a support structure or carriage 120 to which is mounted a manipulation assembly 122. The manipulation assembly 122 comprises a carrier 124 connected to the support structure 120 and configured for movement with respect to the support structure 120. The manipulation assembly 122 further comprises a coupling assembly 126 configured to apply a force to a part of the sleeve 52 of polymeric material and retain the sleeve 52 in connection with the sleeve opening assembly 68 during manipulation of the sleeve 52 and an engagement mechanism 128 connected between the carrier 124 and the coupling assembly 126.

In use the manipulation assembly 122 moves between an engagement configuration and a holding configuration. When a polymeric sleeve 52 is coupled to the coupling assembly 126, movement of the manipulation assembly 122 from the engagement configuration to the holding configuration moves the sleeve 52 from a first configuration, in which the sleeve 52 has a first three dimensional shape, to a second configuration, in which the sleeve 52 has a second three dimensional shape. In the first configuration the sleeve 52 preferably has a closed or planar configuration.

The support structure 120 comprises a frame 130 and a guide post 132. In this embodiment the frame 130 includes four legs 134, each leg 134 disposed at a corner of the frame 130, and at least two arched support members 136. A first, lower end 138 of each of the legs 134 lies in a contact plane 140. A first arched support member 136a is disposed at a first end of the frame 142 and a second arched support member 136b is disposed at a second opposite end of the frame 144. A foot portion 146 of each of the arched support members 136 is connected to one of the legs 134. In some embodiments the legs 134 at the first end of the frame 142 may be further apart than the legs 134 at the second end of the frame 144. A longitudinal axis 148 of the support frame 130 extends between the first and second ends of the frame 142, 144, and generally perpendicular to the arched support members 136. A first side of the frame 150 extends between a first one of the legs 134 at the first end of the frame 142 and a second one of the legs 134 at the second end of the frame 144, and a second side of the frame 152 extends between a third one of the legs 134 at the first end of the frame 142 and a fourth one of the legs 134 at the second end of the frame 144.

The guide post 132 is rigidly connected to the frame 130 between the arched support members 136 and extends upwardly in an opposite direction to the legs 134. The carrier 124 is engaged with the guide post 132 and is configured to move along a longitudinal axis 154 of the guide post 132, in directions generally towards and away from the contact plane 140, between first and second positions. In this embodiment the carrier 124 includes a recess 156 within which the guide post 132 is seated and which constrains the carrier 124 to linear movement along the post 132.

The carrier 124 is biased to return to the first position. In preferred embodiments a biasing member 158, which is preferably a spring, is connected between a part of the guide post 132 and the carrier 124. The biasing member 158 is configured to apply a force to the carrier 124 to urge the carrier 124 towards the first position.

In a preferred embodiment, and as illustrated in Figures 16 to 25, the coupling assembly 126 comprises a plurality of suction cups 160. Means are provided for applying a partial vacuum between each of the suction cups 160 and the polymeric sleeve 52 when the suction cups 160 are in contact with the sleeve 52. As shown most clearly in Figures 19, 23, 24 and 25, in this embodiment the coupling assembly 126 comprises a first outer coupling bar 162, a second outer coupling bar 163 and a third central coupling bar 164. The first outer coupling bar 162 is disposed proximate and extends along the first side of the frame 150, the second outer coupling bar 163 is disposed proximate and extends along the second side of the frame 152, and the third central coupling bar 164 is disposed between the first and second coupling bars 162, 163. Each of the coupling bars 162, 163, 164 includes at least two suction cups 160 and at least one connector 166 for connection to the means for applying a partial vacuum to the suction cups 160.

Each of the coupling bars 162, 163, 164 is elongate and extends between first and second ends 168, 170. A first end 168 of each of the coupling bars 162, 163, 164 is disposed proximate the first end of the frame 142 and a second end 170 of each of the coupling bars 162, 163, 164 is disposed proximate the second end of the frame 144. The suction cups 160 are spaced along the length of each of the coupling bars 162, 163, 164. In embodiments in which each coupling bar 162, 163, 164 includes two suction cups 160, a first one of the suction cups 160 is preferably proximate the first end of the bar 168 and a second one of the suction cups 160 is preferably proximate the second end of the bar 170. In embodiments in which each coupling bar 162, 163, 164 includes more than two suction cups 160, a first suction cup 160 is preferably proximate the first end of the bar 168, a second one of the suction cups 160 is preferably proximate the second end of the bar 170, and the remainder of the suction cups 160 are spaced along the bar 162, 163, 164 between the first and second suction cups 160. In preferred embodiments a greater number of suction cups 160 may be proximate the first end 168 than the second end 170.

A longitudinal axis 172 of each bar 162, 163, 164 extends substantially parallel to the longitudinal axis 148 of the support frame 130. In preferred embodiments, in which the legs 134 at the first end of the frame 142 are further apart than the legs 134 at the second end of the frame 144, the first and second coupling bars 162, 163 are preferably further apart at their first ends 168 than at their second ends 170.

The first and second coupling bars 162, 163 are pivotally connected to the support structure 120. In particular, the pivotal connection 174 is configured such that the first and second coupling bars 162, 163 pivot about an axis parallel to the longitudinal axis 172 of the coupling bar 162, 163. The first and second coupling bars 162, 163 are preferably pivotally connected to the support structure 120 at their first and second ends 168, 170.

The engagement mechanism 128 comprises an actuating member 176 that is connected at a first end 178 to the carrier 124. The actuating member 176 is connected to the carrier 124 such that the actuating member 176 moves linearly with the carrier 124. A second end 179 of the actuating member 176 is connected to the central coupling bar 164 by a linkage 180. A first end 182 of the linkage 180 is pivotally connected to the actuating member 176 and a second end 183 of the linkage 180 is pivotally connected to the central coupling bar 164. The linkage 180 is preferably connected to the coupling bar 164 approximately mid-way along its length.

A guide plate 184 is attached to the support structure 120. A plane of the guide plate 184 is substantially parallel to the longitudinal axis 148 of the frame 130 of the support structure 120. The guide plate 184 has two elongate slots 186, 188, each slot 186, 188 extending between a first end 190 and a second end 191 . The first and second slots 186, 188 are substantially the same length. The first end 190 of each slot 186, 188 is further from the contact plane 140 than the respective second end 191 of the slot 186, 188. An axis of each of the slots 186, 188, extending between the first and second ends 190, 191 , is inclined with respect to the longitudinal axis 154 of the guide post 132. In particular each of the slots 186, 188 extends at an angle of between 2° and 30° to the longitudinal axis 154 of the guide post 132. A first one of the slots 186 is preferably closer to the second end 144 of the support structure 120 than a second one of the slots 188. Furthermore, in this preferred embodiment, the first end 190 of the first slot 186 is further from the contact plane 140 than the first end 190 of the second slot 188.

A pair of followers 192 is connected to the central coupling bar 164. The connection between each of the followers 192 and the central coupling bar 164 is positioned between the linkage 180 and the second end 170 of the central coupling bar 164. Each of the followers 192 locates in and engages with a respective one of the slots 186, 188 in the guide plate 184. When the manipulation assembly 122 is in the holding configuration the followers 192 are disposed at or proximate the first ends 190 of the slots 186, 188 and when the manipulation assembly 122 is in the engagement configuration the followers 192 are disposed at or proximate the second ends 191 of the slots 186, 188.

In use, the movement of the followers 192 along the slots 186, 188 changes the angle of the central coupling bar 164 with respect to the contact plane 140 of the support structure 120. In particular, when the followers 192 are located at the second ends 191 of the slots 186, 188 the central coupling bar 164 extends substantially parallel to the contact plane 140. When the followers 192 are located at the first ends 190 of the slots 186, 188 the central coupling bar 164 is inclined with respect to the contact plane 140 such that the first end 168 of the central coupling bar 164 is further from the contact plane 140 than the second end 170 of the central coupling bar 164.

The engagement mechanism 128 further comprises a first series of linkages 194 connected at a first end to the carrier 124 and at a second end to the first coupling bar 162 and a second series of linkages 195 connected at a first end to the carrier 124 and at a second end to the second coupling bar 163. In this embodiment, each of the first and second series of linkages 194, 195 comprises a first linkage arm 196, a second linkage arm 198 and a third linkage arm 200. Each linkage arm 196, 198, 200 extends between respective first and second ends. In each of the series of linkages 194, 195 a first end 202 of the first linkage arm 196 is pivotally connected to the carrier 124, a second end 203 of the first linkage arm 196 is pivotally connected to a first end 204 of the second linkage arm 198, a second end 205 of the second linkage arm 198 is pivotally connected to a first end 206 of the third linkage arm 200 and a second end 207 of the third linkage arm 200 is pivotally connected to the respective outer coupling bar 162, 163. The second linkage arm 198 is also pivotally connected to a part of the support frame 130 at a position between the first and second ends 204, 205 of the second linkage arm 198. In this embodiment a pivot 208 between the second linkage arm 198 and the support frame 130 is closer to the second end 205 than to the first end 204 of the second linkage arm 198.

The first linkage arms 196 and the third linkage arms 200 extend in directions substantially aligned with the axis 154 of the guide post 132. The second linkage arms 198 extend in directions transverse to the axis 154 of the guide post 132. Preferably the second linkage arms 198 extend in a direction at an angle of between about 30 ° and about 150 ° to the axis 154 of the guide post 132 during movement of the manipulation assembly 122 between the engagement and holding configurations.

The series of linkages 194, 195 are configured to cause each of the outer coupling bars 162, 163 to pivot between a first position and a second position as the carrier 124 moves linearly along the guide post 132. In the first position the suction cups 160 attached to the outer coupling bars 162, 163 all lie in a plane parallel to the contact plane 140. In the second position the outer coupling bars 162, 163 are rotated such that the suction cups 160 attached to each of the first and second outer coupling bars 162, 163 face in a direction generally or substantially towards each other.

The sleeve opening assembly 68 further comprises at least one non-contact gripper or non- contact suction device 210. The non-contact gripper 210 may be of a cyclone type or a Bernoulli type. In both types a layer of air is present between the gripper 210 and the object being held by the gripper 210. The movement of air through and out of the gripper 210 creates a zone of partial vacuum enabling an object to be lifted by the gripper 210 with no physical contact between the gripper 210 and the object.

In a preferred embodiment a pair of non-contact grippers 210 is connected to the support structure 120. The non-contact grippers 210 are preferably secured to the arched support member 136 at the first end of the frame 142. When the manipulation assembly 122 is in the holding configuration a first one of the non-contact grippers 210 is preferably located substantially between the first outer coupling bar 162 and the central coupling bar 164 and a second one of the non-contact grippers 210 is preferably located substantially between the second outer coupling bar 163 and the central coupling bar 164.

In the engagement configuration the rims of the suction cups 160 of the first, second and third coupling bars 162, 163, 164 define a planar surface. In the holding configuration the rims of the suction cups 160 of the first, second and third coupling bars 162, 163, 164 and front faces of the non-contact grippers 210 define part of a truncated conical surface.

As the manipulation assembly 122 moves from the holding configuration to the engagement configuration the carrier 124 moves along the guide post 132 in a direction towards the contact plane 140. The actuating member 176 applies a force to the central coupling bar 164 which also moves in a direction towards the contact plane 140. The engagement of the followers 192 in the slots 186, 188 of the guide plate 184 means that, as the central coupling bar 164 moves towards the contact plane 140, the angle of the central coupling bar 164 with respect to the contact plane 140 changes and decreases, as described above. Movement of the carrier 124 along the guide post 132 also causes the first linkage arms 196, and in particular the second ends 203 of the first linkage arms 196, to move in a direction towards the contact plane 140. This causes each of the second linkage arms 198 to rotate or turn about the pivotal connection 208 between the second linkage arm 198 and the support frame 130. This rotation or pivoting causes the second end 205 of each of the second linkage arms 198 to move in a direction generally away from the contact plane 140, which in turn pulls the third linkage arms 200 in a direction away from the contact plane 140. Movement of each of the third linkage arms 200 in this direction rotates the respective outer coupling bar 162, 163 about the pivotal connection 174 between the outer coupling bar 162, 163 and the support frame 130 until the rims of the suction cups 160 of the outer coupling bars 162, 163 lie in a plane parallel to the contact plane 140.

Movement of the manipulation assembly 122 between the holding configuration and the engagement configuration may be actuated by mechanical and electrical means or by pneumatic means. In preferred embodiments the movement of the carrier 124 with respect to the support structure 120 is effected by an arrangement of an electrical motor and actuating members and/or pulleys. In other embodiments the movement of the carrier with respect to the support structure is effected by a suitable arrangement of pneumatic pistons, air conduits and an air source. The biasing means 158 connected between the carrier 124 and the support structure 120 is configured to retain the manipulation assembly 122 in the holding configuration when the sleeve opening assembly 68 is at rest, i.e. there is no actuation of the manipulation assembly 122.

Referring again to Figure 5 and 6, the sleeve opening assembly 68 is connected to a mounting structure or gantry 212 disposed above the support surface 70 for the polymeric webs 44. In preferred embodiments two sleeve opening assemblies 68 are connected to the gantry 212 and are positioned adjacent each other in the same orientation. This allows two polymeric sleeves 52 to be manipulated simultaneously. It will be appreciated that in these embodiments each of the sleeve opening assemblies 68 operates in the same way and, accordingly, the following description describes the movement and operation of a single sleeve opening assembly 68.

The sleeve opening assembly 68 is connected to the gantry 212 via a guide assembly 214. In this embodiment the guide assembly 214 comprises a drive member 216, a follower arm 218 and a slot 220. The drive member 216 is connected to a part of the gantry 212 for linear movement with respect to the gantry 212. In particular the drive member 216 is configured to move in a linear direction substantially perpendicular to the plane of the support surface 70. The follower arm 218 is connected at a first end 222 to the drive member 216 and at a second end 223 is engaged with the slot 220.

The slot 220 includes a bend 224 having an angle of about 90°, such that the slot 220 is generally L-shaped. A first portion of the slot 226 extends generally in a direction parallel to the Y axis and a second portion of the slot 228 extends generally in a direction parallel to the Z axis, with the bend 224 between the first and second portions of the slot 226, 228. A first end 230 of the slot 220 is located at the end of the first portion of the slot 226 furthest from the bend 224 and a second end 231 of the slot 220 is located at the end of the second portion of the slot 228 furthest from the bend 224.

The connection of the sleeve opening assembly 68 to the guide assembly 214 and the configuration of the guide assembly 214 permits both translational and rotational movement of the sleeve opening assembly 68 with respect to the gantry 212. In particular the arrangement permits movement of the sleeve opening assembly 68 from a first, separation position in which, in use, the sleeve opening assembly 68 couples with the polymeric sleeve 52 on the support surface 70 with a longitudinal axis of the sleeve 52 parallel to the Y axis, to a second, lifted position in which, in use, the sleeve 52 is lifted a distance from the support surface 70 and is orientated such that the longitudinal axis of the sleeve 52 is substantially parallel to the Z axis.

As shown most clearly in Figure 6, in this embodiment, a first end of the drive member 232 is connected to the gantry 212 by a slider 234 that is engaged with a vertical track 236. The follower arm 218 extends perpendicularly from the drive member 232 proximate a second end of the drive member 233. In the second, lifted position the second end 223 of the follower arm 218 is engaged with the slot 220 at the first end of the slot 230 and an axis of the follower arm 218 extends substantially parallel to the Y axis. To move the sleeve opening assembly 68 from the lifted position to the separation position the slider 234 moves linearly in a direction towards the support surface 70 along the vertical track 236. This in turn causes movement of the drive member 216 and the follower arm 218. The second end 223 of the follower arm 218 moves along the first portion of the slot 226 towards the bend 224. During this movement the first end 222 of the follower arm 218 has moved in a direction towards the support surface 70. Because the second end 223 of the follower arm 218 is constrained by the slot 220, the axis of the follower arm 218 rotates through about 90° so that, when the second end 223 of the follower arm 218 reaches the bend 224, the axis of the follower arm 218 is substantially vertical and parallel to the Z axis.

The follower arm 218 and drive member 216 are connected to the sleeve opening assembly 68 such that, during this first phase of movement of the guide assembly 214, the sleeve opening assembly 68 also rotates through an angle of about 90 °. In particular, in the lifted position the longitudinal axis 154 of the guide post 132 of the sleeve opening assembly 68 is substantially horizontal and parallel to the Y axis and the contact plane 140 is substantially vertical and parallel to an X-Z plane. When the second end 223 of the follower arm 218 is at the bend 224, the longitudinal axis 154 of the guide post 132 of the sleeve opening assembly 68 is substantially vertical and parallel to the Z axis and the contact plane 140 is substantially horizontal and parallel to an X-Y plane.

During a second phase of movement of the guide assembly 214 the drive member 216 continues to move vertically in a direction towards the support surface 70 and the second end 223 of the follower arm 218 moves along the second portion of the slot 228 to the second end 231 of the slot 220. During this second phase of movement, therefore, the sleeve opening assembly 68 moves vertically in a direction towards the support surface 70 with the contact plane 140 horizontal. The second end 231 of the slot 220 is located relative to the support surface 70 such that, when the second end 223 of the follower arm 218 is at the second end 231 of the slot 220, the legs 134 of the sleeve opening assembly 68 contact the support surface 70 or the polymeric webs 44 overlying the support surface 70.

In use, the or each sleeve opening assembly 68 is initially in the lifted position at a distance above the support surface 70, with the contact plane 140 substantially vertical. The manipulation assembly 122 is in the holding configuration. The sleeve opening assembly 68 is then moved into the separation position with the legs 134 of the support frame 130 in contact with the polymeric webs 44 on the support surface 70. The legs 134 contact the polymeric webs 44 outside or beyond a perimeter edge of the polymeric sleeve 52 as defined by the cut lines 54.

The manipulation assembly 122 is then actuated to move into the engagement configuration. In this configuration the suction cups 160 of the coupling assembly 126 are in contact with the upper surface of the polymeric webs 44. The suction cups 160 of the outer coupling bars 162, 163 contact the polymeric webs 44 along longitudinal edges 60 of the sleeve 52 proximate the third and fourth cut lines 54c, 54d. A partial vacuum is created in the suction cups 160 so as to apply a lifting force to the polymeric sleeve 52.

The manipulation assembly 122 is then moved to the holding configuration. The lifting force applied by the suction cups 160 to the polymeric sleeve 52 lifts the upper layer of the polymeric sleeve 52 and forms it into a curved or partially conical shape. The non-contact grippers 210 are activated which further draws the upper layer of the polymeric sleeve 52 into a partially conical shape.

At a subsequent step the sleeve opening assembly 68 is moved to the lifted position. Initially, upon upward movement of the sleeve opening assembly 68, gravity causes the lower layer of the sleeve 52 to separate from the upper layer of the sleeve 52 in a central region of the sleeve 52 between the bonded longitudinal edges 60. The speed of movement of the sleeve opening assembly 68 and the rotation of the sleeve opening assembly 68 into the lifted position causes a flow of air between the polymeric layers of the sleeve 52, which causes the sleeve 52 to open into a generally conical shape. Movement of the sleeve opening assembly 68 effectively scoops air into the sleeve 52 causing it to open fully.

In some embodiments a jet of de-ionised air may be directed between the layers of the sleeve 52 to maintain the sleeve 52 in an open configuration. In some embodiments a suction force is applied to the lower layer of the sleeve 52, for example by means of a partial vacuum. This may be used to retain the lower layer of the sleeve 52 in contact with the support surface 70 during an initial phase of lifting of the upper layer of the sleeve by the sleeve opening assembly 68. The partial vacuum may then be switched off and the suction force removed from the lower layer of the sleeve 52 to allow the sleeve 52 to be fully lifted clear of the support surface 70.

As the sleeve opening assembly 68 reaches the lifted position a former 238 is inserted into the sleeve 52. As described above, the external size and shape of the former 238 is substantially the same as the internal size and shape of at least a part of the sleeve 52. In some embodiments wheels or rollers are provided that engage with an outer surface of the sleeve 52 as the former 238 is inserted into the sleeve 52. The rollers apply a force to the sleeve 52 to urge it fully onto the former 238. An external surface of the former 238 may be coated in a suitable low-friction coating. In preferred embodiments at least a part of the external surface of the former 238 is coated in polytetrafluoroethylene (PTFE).

Once the sleeve 52 is correctly located on the former 238 air is drawn through the former 238 to suck or draw the sleeve 52 against an external surface of the former 238. Simultaneously, the suction applied to the sleeve 52 by the sleeve opening assembly 68 is switched off or removed. The sleeve 52 is now entirely supported on the former 238.

It will be appreciated that in other embodiments the location of the former 238 relative to the support surface 70 may be such that the sleeve opening assembly 68 does not rotate as described above. For example, in some embodiments the sleeve opening assembly 68 may move in a linear direction, for example horizontally or parallel to the support surface, to cause a flow of air between the polymeric layers of the sleeve 52 and to locate the sleeve 52 over the former 238.

Referring now to Figures 26 to 28, the region of the support surface 70 corresponding to the sleeve opening assembly or assemblies 68 has a plurality of openings or slots 240. When the polymeric webs 44 are drawn onto this region of the support surface 70 the four uncut spurs 62 of material extending between a sleeve 52 and the surrounding polymeric webs 44 align with the slots 240.

Below the support surface 70 is a plurality of cutting units 242. As shown most clearly in Figure 28, each cutting unit 242 comprises an actuator 244, a cutting blade 246 and a blade guide 248. The actuator 244 is preferably a linear actuator. Each cutting unit 242 is disposed beneath the support surface 70 such that the cutting blade 246 is aligned with one of the slots 240. The actuator 244 is configured to move the cutting blade 246 between a withdrawn position and an extended position. In the withdrawn position the entire cutting blade 246 is located below or beneath the support surface 70. In the extended position the blade 246 extends through the slot 240 in the support surface 70 and at least a distal portion or tip 250 of the cutting blade 246 protrudes upwardly from the support surface 70. The blade guide 248 maintains the cutting blade 246 in alignment with the slot 240 and guides the cutting blade 246 through the slot 240 during movement of the blade 246. Furthermore, the blade guide 248 forms a protective shield or guard around the cutting blade 246 when the cutting blade 246 is in the withdrawn position.

In use, the cutting blades 246 are initially in the withdrawn position to allow the polymeric webs 44 to be drawn across the support surface 70. Once the polymeric webs 44 are in the correct position, so that uncut spurs 62 of the polymeric material are aligned with the slots 240, the sleeve opening assembly 68 is lowered to the separation position and the manipulation assembly 122 is moved into the engagement configuration, as described above. In this position parts of the polymeric webs 44 surrounding the sleeve 52 are clamped between the legs 134 of the sleeve opening assembly 68 and the support surface 70. This retains the sleeve 52 and the polymeric webs 44 in a fixed position. The cutting blades 246 of the cutting units 242 are then moved into the extended position. This causes the cutting blades 246 to extend through the slots 240 and cut or sever the spurs 62 of polymeric material between the sleeve 52 and the surrounding polymeric webs 44. Once the spurs 62 of polymeric material have been cut, the cutting blades 246 are withdrawn again. The sleeve 52 is then fully separated from the surrounding polymeric webs 44.

Following cutting of the spurs 62 of polymeric material the manipulation assembly 122 may then be moved to the holding configuration and the sleeve opening assembly 68 moved to the lifted position, as described above.

Figures 7 shows a sub-assembly 252 of a machine for forming a liner of a container. The sub-assembly 252 includes a first section 254 for cutting the bases of the liner from a continuous web 64 of polymeric material and a second section 256 for bonding the bases to the rest of the liner, as described above. The first section 254 includes two cutting stations 258 so that two bases can be cut simultaneously from the web 64 and the second section 256 includes two bonding stations 260 so that two bases can be bonded simultaneously to respective liner sleeves. Each of the cutting stations 258 operates in the same way and, accordingly, in the following description the features and operation of only a single cutting station 258 will be described. Similarly, each of the bonding stations 260 operates in the same way and, accordingly, in the following description the features and operation of only a single bonding station will be described. It will further be appreciated that in some embodiments of the sub-assembly 252 only one cutting station 258 and one bonding station 260 may be provided, and in further embodiments more than two cutting stations and more than two bonding stations may be provided.

Figure 29 illustrates a pair of cutting stations 258 according to a preferred embodiment. In use, a web 64 of polymeric material is drawn over a support plate 262 and each of the cutting stations 258 cuts a circular disc from the web 64. The support plate 262 includes a circular hole 264 aligned with each of the cutting stations 258. The circular hole 264 in the support plate 262 has a slightly larger diameter than the polymeric base disc to be cut. Once the disc has been cut it is separated from the surrounding web 64. The web 64 is then drawn over the support plate 262 by a predetermined distance such that a further two discs can be cut from the polymeric web 64. The support plate 262 is preferably substantially horizontal.

An embodiment of the cutting station 258 is shown in Figures 30 to 33. The cutting station 258 comprises a carousel 266, a cutting ring 268 and a plurality of press elements 270. In use, the carousel 266 and cutting ring 268 are located on a first side or below the polymeric web 64 and the press elements 270 are located on a second side or above the polymeric web 64.

The carousel 266 is shown most clearly in Figure 32. The carousel 266 comprises an annular support ring 272 and a plurality of retaining tabs 274. The annular support ring 272 has an outer peripheral edge 276 and an inner peripheral edge 277. A plurality of raised lips 278 are spaced apart around the inner edge 277 and project from a first, upper surface 280 of the support ring 272. The retaining tabs 274 are connected to the first surface 280 of the support ring 272 and are spaced apart around the support ring 272. There is the same number of retaining tabs 274 as raised lips 278 and each retaining tab 274 is aligned with a respective one of the lips 278. A first end 282 of each of the retaining tabs 274 is attached to the support ring 272 proximate the outer edge 276 and the retaining tabs 274 extend radially inwardly towards the inner edge 277. A second end 283 of each of the tabs 274 is seated on the respective one of the raised lips 278. The second end 283 of each of the retaining tabs 274 is not attached to the support ring 272 such that the retaining tabs 274 are effectively cantilevered. The support ring 272 further includes a plurality of apertures 284 extending through the thickness of the support ring 272 between the first surface 280 and an opposite second surface 296. Each aperture 284 is aligned with one of the retaining tabs 274 such that the retaining tab 274 extends over the aperture 284. The apertures 284 are located proximate the inner edge 277 of the support ring 272. The carousel 266 is disposed below the support plate 262.

A carrier mechanism 286 is disposed below the carousel 266. The carrier mechanism 286 comprises an outer annular member 288 and an inner annular member 290. An outer diameter of the inner annular member 290 is smaller than an inner diameter of the outer annular member 288 such that the inner annular member 290 fits within the central hole of the outer annular member 288.

A plurality of pins 292 extends from a first, upper surface 294 of the outer annular member 288. Each pin 292 is aligned with a respective one of the apertures 284 in the support ring 272 of the carousel 266. The pins 292 are sized to extend through the apertures 284 in use. The outer annular member 288 is connected to a linear actuator or push rod which is configured to move the outer annular member 288 in axial directions towards and away from the second surface 296 of the carousel support ring 272.

The outer diameter of the inner annular member 290 is smaller than the inner diameter of the support ring 272 such that the inner annular member 290 is able to pass through the central hole of the support ring 272. The inner annular member 290 is connected to a linear actuator or push rod which is configured to move the inner annular member 290 in an axial direction.

The cutting ring 268 is mounted in the hole 264 in the support plate 264. The cutting ring 268 includes an annular cutting edge 298. The cutting ring 268 is mounted in the support plate 262 such that the cutting edge 298 is flush with a first, upper surface 300 of the support plate 262. A diameter of the cutting edge 298 is smaller than the diameter of the hole 264 in the support plate 262 such that an annular groove or channel 302 extends around the cutting ring 268 between the cutting edge 298 and a circumferential edge of the hole 264.

A press assembly 304 comprises the plurality of press elements 270 and a clamp member 306. In this embodiment the cutting station 258 comprises three press elements 270; however, other embodiments may include fewer than three or more than three press elements 270. A cutting station may include only one press element.

In this embodiment each of the press elements 270 comprises a body or block 308 to which is attached a wheel or roller 310. The roller 310 is free to rotate about an axle 312 which extends from the body 308 of the press element 270 and the rollers 310 include an outer circumferential press surface 314. The press elements 270 are attached to a mounting disc 316 such that the press elements 270 are spaced apart around the circumference of the mounting disc 316 and extend from a first surface 318 of the mounting disc 316. The mounting disc 316 is disposed above the support plate 262 and the first surface 318 of the mounting disc 316 is parallel to the upper surface 300 of the support plate 262. The press elements 270 extend from the mounting disc 316 such that the axles 312 of the rollers 310 are at an angle of between about 30° and 60°, and most preferably about 45°, to the first surface 318 of the mounting disc 316. A generally radially inwardly facing portion of the press surface 314 of each of the rollers 310 defines a circle having a diameter substantially the same as the diameter of the annular cutting edge 298. The mounting disc 316 is configured to move in axial directions towards and away from the support plate 262. Furthermore, the mounting disc 316 is rotatable about its axis.

The clamp member 306 comprises a clamping surface 320 that extends parallel to the upper surface 300 of the support plate 262 and faces in a direction towards the upper surface 300 of the support plate 262. The clamping surface 320 has a substantially circular perimeter and may be in the form of a complete circular disc or an annular surface. The diameter of the clamping surface 320 is smaller than an inner diameter of the cutting ring 268 such that, in use, the clamp member 306 is able to pass through the cutting ring 268. The clamp member 306 also includes a retraction surface 322 which is configured to contact a part of each of the press elements 270. In this embodiment the retraction surface 322 is an annular surface extending from the circumferential of the clamping surface 320. The retraction surface 322 is inclined with respect to the clamping surface 320 and extends in a direction generally away from the support plate 262.

The clamp member 306 is connected to a linear actuator or push rod 324 which is configured to move the clamp member 306 in axial directions towards and away from the support plate 262. ln operation, the cutting station 258 has an initial configuration in which the press elements 270 are seated on the retraction surface 322 of the clamp member 306 and the press assembly 304 is raised, such that there is a gap between the upper surface 300 of the support plate 262 and the clamping surface 320 and rollers 310.

A web 64 of polymeric material is positioned on the upper surface 300 of the support plate 262 so that a part of the web 64 is aligned with the hole 264 in the support plate 262. The outer annular member 88 and the inner annular member 290 of the carrier mechanism 286 are raised or moved in a direction towards the support plate 262. The inner annular member 290 is raised through the hole 264 in the support plate 262 until an upper surface of the inner annular member 290 contacts a first, lower surface of the polymeric web 64. The outer annular member 288 is raised until the pins 292 protrude through the apertures 284 in the support ring 272 of the carousel 266. The pins 292 apply a force to the retaining tabs 274 and lift the second end 283 of the retaining tabs 274 from their initial position in which the second end 283 of the retaining tabs 274 are in contact with the raised lips 278 of the support ring 272 to a position in which the tabs 274 are flexed and there is a gap between each of the second ends 283 of the retaining tabs 274 and the corresponding raised lip 278.

The press assembly 304 is lowered or moved in a direction towards the support plate 262. The rollers 310 contact a second, upper surface of the polymeric web 64 such that parts of the polymeric web 64 are disposed between the press surface 314 of each of the rollers 310 and the cutting edge 298 of the cutting ring 268. The clamp member 306 is lowered further such that the retraction surface 322 is no longer in contact with the press elements 270 and the clamping surface 320 is in contact with the upper surface of the polymeric web 64. A circular disc-shaped region of the polymeric web 64 is then clamped between the inner annular member 290, disposed below the web 64, and the clamp member 306, disposed above the web 64.

With the web 64 clamped between the inner annular member 290 and the clamp member 306 the rollers 310 apply a force to press the polymeric web 64 against the cutting edge 298. The pressure applied by the rollers 310 causes the cutting edge 298 to cut or pierce the polymeric web 64 in the regions between each of the rollers 310 and the cutting edge 298. The mounting disc 316 is rotated so that the rollers 310 contact the polymeric web 64 around the full length of the cutting edge 298. In this way a complete circle or disc of polymeric material is cut from the polymeric web 64. The disc of polymeric material has an outer diameter larger than the outer diameter of the inner annular member 290 and the outer diameter of the clamp member 306. Furthermore, the outer diameter of the disc of polymeric material is larger than the diameter of the inner peripheral edge 277 of the carousel 266. With the retaining tabs 274 in a raised position due to the force applied by the pins 292, the bending of the retaining tabs 274 means that the second end edges 283 of the retaining tabs 274 lie on a circle having a diameter larger than the diameter of the inner peripheral edge 277 of the support ring 272 of the carousel 266. Furthermore, the position of the second end edges 283 of the retaining tabs 274 in this bent or flexed configuration is such that they lie on a circle having a diameter larger than the diameter of the polymeric disc.

Once the disc of polymeric material has been cut from the remainder of the web 64, the inner annular member 290 and the clamp member 306 are then lowered to draw the disc of polymeric material though the hole 264 in the support plate 262. The disc of polymeric material is lowered until a circumferential edge region or margin of the polymeric disc is in contact with an inner peripheral edge region of the support ring 272 of the carousel 262, and in particular the raised lips 278 of the support ring 272.

The outer annular member 288 of the carrier mechanism 286 is then lowered in a direction away from the support ring 272 such that the pins 292 no longer protrude through the apertures 284 in the support ring 272 of the carousel 266. The pins 292 therefore no longer apply a force to the retaining tabs 274 and the retaining tabs 274 return to their initial position. The edge region or margin of the polymeric disc is therefore clamped between each of the retaining tabs 274 and the corresponding raised lip 278.

With the polymeric disc held by the carousel 266, the inner annular member 290 is lowered or moved in a direction away from the polymeric disc and the clamp member 306 is raised or moved in an opposite direction away from the polymeric disc. The polymeric disc is then held and supported entirely by the carousel 266 around an edge region of the polymeric disc.

The clamp member 306 is raised until the retraction surface 322 contacts the press elements 270. Continued raising of the clamp member 306 then also lifts the press elements 270 away from the cutting ring 268 and returns the press assembly 304 to the raised position. The polymeric disc, held by the carousel 266, may now be moved to a further station 260 of the machine at which the polymeric disc is bonded to a sleeve of polymeric material to form a base of a lining for a container. At the same time the web 64 can be advanced such that the cutting station 258 can cut and separate a further polymeric disc from the web 64. In this way, the machine preferably includes more than one carousel 266 so that a first carousel 266 can be positioned at the cutting station 258 for receiving a cut polymeric disc and a second carousel 266 can be transporting a polymeric disc to a bonding station 260.

To form a liner a polymeric disc is bonded to a heat shrunk end region of a polymeric sleeve extending over and preferably in contact with an end face of a former. The polymeric sleeve and disc, once bonded together, thereby form a liner for a container as described above. In preferred embodiments the diameter of the polymeric disc is equal to or smaller than the diameter of the end face of the former. The polymeric disc is preferably bonded to the end region of the sleeve around the full perimeter of the disc so that the sleeve and disc form a liquid tight liner.

An embodiment of a bonding station 260 is shown in Figure 36. The bonding station 260 comprises a bonding element 326 and a release assembly 328. In this embodiment the bonding element 326 comprises an annular heating element 330 for heat welding the polymeric disc to the polymeric sleeve. The release assembly 328 comprises a base ring 332 and a plurality of pins 334 extending from a first surface 336 of the base ring 332. The base ring 332 has an outer peripheral edge 338 and an inner peripheral edge 339. An external diameter of the heating element 330 is smaller than a diameter of the inner peripheral edge 339 of the base ring 332.

In use a carousel 266 holding a polymeric disc is located at the bonding station 260 so that the carousel 266 is aligned with the bonding element 326 and the release assembly 328. In particular the carousel 266 is located such that the annular heating element 330 and carousel 266 are co-axial.

The bonding element 326 is disposed below the carousel 266 and the annular heating element 330 is configured to move axially in directions towards and away from the carousel 266. Similarly, the release assembly 328 is disposed below the carousel 266 and is configured to move axially in directions towards and away from the carousel 266. The pins 334 of the release assembly 328 are aligned with the apertures 284 in the support ring 272 of the carousel 266 and the pins 334 are sized to extend through the apertures 284 in use. Once a carousel 266 has been located at the bonding station 260, a former 238 with a surrounding sleeve 52 is lowered towards the carousel 266. The sleeve 52 around the former 238 has a heat shrunk end region in contact with the end face of the former 238. As the former 238 is moved towards the carousel 266 the end face of the former faces or opposes the upper surface 280 of the support ring 272 of the carousel 266. The former 238 is coaxial with the support ring 272 of the carousel 266 so that the end face of the former is aligned with the polymeric disc held by the retaining tabs 274 of the carousel 266.

The release assembly 328 is raised to move the base ring 332 and pins 334 towards the carousel 266. The release assembly 328 is raised until the pins 334 protrude through the apertures 284 in the support ring 272 of the carousel 266. The pins 334 apply a force to the retaining tabs 274 and lift the second end 283 of the retaining tabs 274 from their initial position in which the second end 283 of the retaining tabs 274 are in contact with the raised lips 278 of the support ring 272 to a position in which the tabs 274 are flexed and there is a gap between each of the second ends 283 of the retaining tabs 274 and the corresponding raised lip 278. Accordingly the polymeric disc is no longer held or retained by the carousel 266.

The bonding element 326 is also raised towards the carousel 266. The bonding element 326 is raised until the annular heating element 330 contacts the polymeric disc. The polymeric disc is brought into contact with the end region of the sleeve 52 overlying the end face of the former 238. Heat applied to the polymeric disc by the heating element 330 then bonds or welds the polymeric disc to the polymeric sleeve 52 to form a base of the liner. The polymeric disc is preferably bonded to the polymeric sleeve 52 fully around the heat shrunk end region of the sleeve 52 so that a liquid tight seal is formed between the base and the sleeve of the liner.

Once the polymeric disc has been heat welded to the end region of the sleeve 52, the former 238 is raised in a direction away from the carousel 266. Because the polymeric disc is no longer held by the retaining tabs 274 of the carousel 266, the polymeric disc is free to be lifted together with the former 238 and the sleeve 52. After the heat welding step both the bonding element 326 and the release assembly 328 are lowered in a direction away from the carousel 266.

The empty carousel 266 can then be moved to another station of the machine. In preferred embodiments the empty carousel 266 returns to the cutting station 258.

Although in this embodiment the bonding element 326 comprises the annular heating element 330, in other embodiments the polymeric disc may be bonded to the end region of the sleeve 52 by other means. For example the polymeric disc may be bonded by ultrasonic welding to the end region of the sleeve 52.

Claims

1 . Apparatus for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner, the apparatus comprising:

2. An apparatus as claimed in Claim 1 , wherein the applicator is configured to apply the force proximate the edge of the area of the first sheet.

3. An apparatus as claimed in Claim 1 or Claim 2, wherein the applicator is configured to apply the force in a direction substantially perpendicular to the edge of the area of the first sheet.

4. An apparatus as claimed in any preceding claim, wherein the nozzle is configured such that the jet of air flows in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

5. An apparatus as claimed in any preceding claim, wherein the edge of the area of the first polymeric sheet is a peripheral edge of the first polymeric sheet.

6. An apparatus as claimed in any preceding claim, wherein the edge of the area of the second polymeric sheet is a peripheral edge of the second polymeric sheet.

7. An apparatus as claimed in any one of Claims 1 to 4, wherein the edge of the area of the first polymeric sheet is spaced from a peripheral edge of the first polymeric sheet so as to define a margin between the edge of the area of the first polymeric sheet and the peripheral edge of the first polymeric sheet.

8. An apparatus as claimed in Claim 7, wherein a first edge of the area of the first polymeric sheet is spaced from a first peripheral edge of the first polymeric sheet so as to define a first margin and a second edge of the area of the first polymeric sheet is spaced from a second peripheral edge of the first polymeric sheet so as to define a second margin.

9. An apparatus as claimed in Claim 8, comprising

10. An apparatus as claimed in Claim 9, wherein said first applicator is configured to apply a force in a direction towards the second edge and said second applicator is configured to apply a force in a direction towards the first edge, and the first nozzle is configured to direct the first jet of air in a direction towards the second edge and the second nozzle is configured to direct the second jet of air in a direction towards the first edge.

1 1 . An apparatus as claimed in any preceding claim, wherein the or each applicator comprises a foot that contacts the first polymeric sheet to apply the force to said sheet and an actuator configured to move the foot into contact with the first polymeric sheet.

12. An apparatus as claimed in Claim 1 1 , wherein the actuator is configured to move the foot in a direction substantially perpendicular to the plane of the first sheet.

13. An apparatus as claimed in Claim 1 1 or Claim 12, wherein the foot comprises a friction surface for applying a gripping force to the first polymeric sheet.

14. An apparatus as claimed in Claim 13, wherein the friction surface is disposed on a foot pad of the foot.

15. An apparatus as claimed in Claim 13 or Claim 14, wherein the foot is connected to the actuator so that during movement of the actuator the friction surface initially moves in a direction towards the first sheet to contact the first sheet and subsequently the friction surface moves in a direction parallel to the plane of the first sheet.

16. An apparatus as claimed in Claim 15, wherein the foot comprises a foot plate connected to the actuator at a pivot and the friction surface is disposed on a first side of said pivot.

17. An apparatus as claimed in Claim 16, wherein a biasing member is connected to the foot plate to bias the foot plate in a direction such that the friction surface moves in a direction towards the first polymeric sheet.

18. An apparatus as claimed in Claim 17, wherein the biasing member is connected to the foot plate on a second side of the pivot.

19. An apparatus as claimed in Claim 9, comprising

the first nozzle being disposed between the applicators of the first pair of applicators, and the second nozzle being disposed between the applicators of the second pair of applicators.

20. An apparatus as claimed in any preceding claim, further comprising a support surface for supporting the first and second polymeric sheets.

21 . An apparatus as claimed in Claim 20, further comprising a retaining member configured to constrain movement of the first and second sheets away from the support surface.

22. An apparatus as claimed in Claim 21 when dependent on Claim 9, wherein the retaining member is disposed between the first and second applicators to constrain movement of at least a central part of the first and second polymeric sheet away from the support surface.

23. An apparatus as claimed in Claim 21 or Claim 22, wherein the retaining member is spaced from the support surface such that the first and second polymeric sheets are receivable between the retaining member and the support surface.

24. An apparatus as claimed in any preceding claim, further comprising an assembly for applying a tensile force to the first and second polymeric sheets in a direction substantially parallel to the edge of the area of the first polymeric sheet.

25. An apparatus as claimed in Claim 24, wherein the assembly for applying a tensile force parallel to the edge comprises a roller.

26. An apparatus as claimed in any preceding claim, further comprising an assembly for applying a tensile force to the first and second polymeric sheets in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

27. An apparatus as claimed in Claim 26, wherein the assembly for applying a tensile force perpendicular to the edge comprises a roller.

28. A method for selectively separating an area of a first polymeric sheet from an area of a second polymeric sheet in face to face contact with the first polymeric sheet in a machine for manufacturing a container liner, the method comprising:

29. A method as claimed in Claim 28, comprising applying the force to the area of the first polymeric sheet proximate the edge of the first area.

30. A method as claimed in Claim 28 or Claim 29, comprising applying the force in a direction substantially perpendicular to the edge of the area.

31 . A method as claimed in any one of Claims 28 to 30, comprising directing the jet of air in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.

32. A method as claimed in any one of Claims 28 to 31 , wherein the edge of the area of the first polymeric sheet is spaced from a peripheral edge of the first polymeric sheet so as to define a margin between the edge of the area of the first polymeric sheet and the peripheral edge of the first polymeric sheet.

33. A method as claimed in Claim 32, wherein a first edge of the area of the first polymeric sheet is spaced from a first peripheral edge of the first polymeric sheet so as to define a first margin and a second edge of the area of the first polymeric sheet is spaced from a second peripheral edge of the first polymeric sheet so as to define a second margin.

34. A method as claimed in Claim 33, comprising:

35. A method as claimed in Claim 34, wherein the first force is applied in a direction towards the second edge and the second force is applied in a direction towards the first edge, and the first jet of air flows in a direction towards the second edge and the second jet of air flows in a direction towards the first edge.

36. A method as claimed in Claim 33, comprising:

37. A method as claimed in any one of Claims 28 to 36, further comprising supporting the first and second polymeric sheets on a support surface.

38. A method as claimed in any one of Claims 28 to 37, further comprising applying a tensile force to the first and second polymeric sheets in a direction substantially parallel to the edge of the area of the first polymeric sheet.

39. A method as claimed in any one of Claims 28 to 38, further comprising applying a tensile force to the first and second polymeric sheets in a direction substantially perpendicular to the edge of the area of the first polymeric sheet.