EP0720565B1 - Process for producing a container from thermoplastics material - Google Patents

Abstract

PCT No. PCT/AT94/00137 Sec. 371 Date Mar. 28, 1996 Sec. 102(e) Date Mar. 28, 1996 PCT Filed Sep. 26, 1994 PCT Pub. No. WO95/09111 PCT Pub. Date Apr. 6, 1995A container made of thermoplastic material has a bottom, a lid and a wall that extends between the bottom and the lid. The wall is substantially less thick than the bottom and the lid and is designed as a film soldered along a longitudinal seam and welded to the bottom and the lid.

Description

The invention relates to a method for producing a container made of thermoplastic material according to the preamble of claim 1.

Such a container in the form of a screw-top plastic bottle can be found, for example, in EP-A-483 976. It has a handle and is made from a tubular element in the blow molding process. The thickness of the middle wall part is about a third to a quarter of the thickness of the bottom and the cover part. If the container is to be labeled, a label is applied to the container or this is placed in the blow mold.

EP-A-126 575 shows a screw-lock plastic flap composed of a base, jacket and cap, the jacket of which represents an extruded, in particular multi-layered piece of pipe on which the base and the cap are locked and then welded. Labeling is done by labeling.

FR-A-874 080 shows a container which also consists of three parts. Here, a possibly two-layer container wall, which is rolled from a flat sheet, is connected to a base and a lid. The individual parts are made of metal, with folded edges of the bottom and the lid being at least simply folded over the edge of the container wall.

From FR-A-2 289 394 a method for closing a container filled with a product made of thermoplastic material is known, the wall of which consists of a film web provided with a longitudinal weld seam. The lid and base have mutually facing flanges that overlap the wall. After filling the goods and putting the lid on, the container is covered by a heat-shrinking film connected. This additional covering allows a thinner film to be used for the wall of the container.

The invention has set itself the task of creating a container of the type mentioned, the middle wall part can be printed directly, so that the application of labels is unnecessary.

According to the invention this is achieved in that a flat, in particular printed film web is closed to form a tube and is welded along the two longitudinal edges, that alternately a cover part and a base, each having an apron, are introduced into the closing tube with the same orientation of the aprons and are each welded to a container in the already closed area with the tube forming the wall part, and that the tube is then cut between a bottom and a subsequent cover part. The production of the container wall from a flat film web allows the majority of the film web to be printed in any way, since the subsequent container production processes this film web only at its edges, but not at the printed area. Both the welding of the longitudinal seam and the welding to the bottom and the cover part only require heating of a narrow strip.

The flat film web is fed via a shaped shoulder and corresponding guide elements to a thin-walled tube which forms a core and serves as a counter-holder for the welding device which produces the longitudinal seam and acts from the outside. Since each container is preferably manufactured with the cover part in advance, a first cover part is fed from a magazine through the core tube, the closable opening of the cover part pointing in the feed direction, so that the feed tool, which simultaneously forms an inner counter-holder for the transverse seam welding can attack within the apron of the cover part. After pushing the cover part through the core tube, the cover part is welded to the hose. The tube feed and the longitudinal welding are continued and the counter holder is pulled back out of the cover part through the core tube. The feed length of the tube forming, which determines the filling volume of the container, is controlled, for example, by recognizing markings printed on the film. Finally, a bottom is fed through the core tube from a magazine by means of the feed tool, the skirt of which is also on the side facing the feed tool, which later represents the outside of the container. The counter holder of the feed tool can therefore also support the floor. The film feed is stopped again and the tube is welded to the floor. Now the hose is cut off and a finished container is ejected. Another cover part is fed from the magazine and welded to the hose and the next container is manufactured in the manner described.

For the use of the container as a refill in soap dispensers or the like. It is further provided that the cover part is provided with a container neck which has a slide-on guide that is open at least on one side for a sliding closure. This allows the container to be inserted into the dispenser from the side.

The invention will now be described in more detail below with reference to the figures in the drawings, without being limited thereto.

Fig. 1

einen Längsschnitt durch einen Behälter,

Fig. 2

einen Schnitt durch den verschlossenen Deckteil,

Fig. 3

einen Schnitt nach der Linie III-III von Fig. 2,

Fig. 4

eine schematische Vorderansicht einer Fertigungsvorrichtung,

Fig. 5

eine schematische Seitenansicht der Fertigungsvorrichtung, und

Fig. 6

eine schematische Draufsicht auf die Quernahtschweißeinrichtung gemäß Fig. 1.

Show it:

Fig. 1

a longitudinal section through a container,

Fig. 2

a section through the closed cover part,

Fig. 3

2 shows a section along the line III-III of FIG. 2,

Fig. 4

1 shows a schematic front view of a production device,

Fig. 5

is a schematic side view of the manufacturing device, and

Fig. 6

2 shows a schematic top view of the transverse seam welding device according to FIG. 1.

A container has a base 1, in particular made of polyethylene, with an apron 6 projecting downwards. A wall part 2 consisting of a film is welded to the apron 6. The thickness of the film is preferably between 0.08 mm and 0.1 mm. At the upper end, the wall part 2 is welded to an apron 7 of a cover part 4. The opening of the container is formed in an upstanding container neck 5, which is provided with a slide-on guide 8 for a sliding closure 9 that can be pushed on from the side. In an annular groove of the container neck 5, a sealing insert 33 is inserted, which has raised ring webs 34 on the top. The sliding closure 9 engages with inwardly directed webs 32 side flanges 31 of the container neck 5. An end stop, not shown, can be provided in order to limit the depth of displacement.

The wall part 2 is made of a flat sheet of film and therefore has a longitudinal weld 3. This flat film web is preferably printed, so that the application of a label on the container is unnecessary. The closed container, for example filled with liquid soap, is stable because it has its largest volume only in the upright position, and collapses when emptied due to the small thickness of the film, so that its empty volume is reduced to a minimum. The thickness of the bottom 1 and the cover part 4 is preferably between 0.6 and 0.8 mm.

A production system 10 according to FIGS. 4 to 6 has a thin-walled tube 11 forming a mandrel, to which a flat, in particular printed film web 2 is fed from a roll 20. The film web 2 'reaches the core tube 11 via a shaped shoulder 12 and is closed around it to form a tube, passing through a longitudinal welding device 16, the counter-holder of which forms the core tube 11. A magazine 13 for bottom 1 and a magazine 14 for cover parts 4 are provided on the side of a feed device 15. A cover part 4 from the magazine 14 and a base 1 from the magazine 13 are alternately pushed by means of transverse sliding devices 25 and 26 in front of the feed device 15, which has an inner counter-holder 18. The latter detects the part that is pushed in within the aprons 6, 7 and leads it through the core tube 11 to a transverse welding direction 17 arranged below the core tube 11, which welds the tube first to a cover part 4 and then to a base 1. The cross welding device 17 is provided with a cutting device which cuts the hose along each base 1, so that a container is ejected. The hose length determining the filling volume is controlled via a feed device 19 which has, for example, a sensor that detects printed markings. The cross section of the container can be of any design. For a rectangularly rounded cross section, the transverse welding device 17 can be designed, for example, according to FIG. 6. It has a welding jaw 21, 22 assigned to a quadrant, which is alternately displaceable in the diagonals and pressed from the outside against the areas of the wall part 2 and the base 1 or the cover part 4 to be welded, which are pressed against the counter-holder 18 of the feed device arranged inside 15 are supported. If appropriate, the counter-holder 18 can be composed of expandable individual elements.

Claims (3)

1. A process for the production of a container of thermoplastic material, in particular polyethylene, having a bottom, a cover portion having an opening, and a wall portion which extends between the bottom and the cover portion and which is of a substantially smaller thickness than the bottom and the cover portion, characterised in that a flat foil web (2'), in particular with printing thereon, is closed to form a tubular portion and welded along the two longitudinal edges, that a cover portion (4) and a bottom (1) which each have an apron (6, 7) are alternately introduced into the closing tubular portion in the same positional orientation of the aprons (6, 7) and are each welded in the already closed region to the tubular portion forming the wall portion to constitute a container, and that then the respective tubular portion is cut between a bottom (1) and a following cover portion (4).
2. A container produced by the process according to claim 1 characterised in that the cover portion (4) is provided with a container neck (5) which has a push-on guide means (8), open towards one side, for a sliding closure (9).
3. A container according to claim 2 characterised in that a sealing insert (33) is arranged in the cover portion (4).

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