JPS63203324A - Preparation of can body - Google Patents

Abstract

PURPOSE:To make it possible to produce continuously a laminated blank from a metal foil web, by slitting in the longer direction a laminated web formed by adhering a part of wide width on both faces of a thermoplastic plastic web, and forming a laminated blank by cutting it in a length equal to the height of a can body. CONSTITUTION:A metal foil web 9 to become an outer layer (wherein an adhesive layer is formed on the upper face and a printed layer is usually formed on the lower face) is slitted by means of a slitter so that a part of wide width 27 whose width is w and a part of narrow width 28 whose width is x may be alternately arranged, and a laminated web 29 is formed by heat-bonding the art of wide width 27 on the upper face of a plastic web 19 of an one-side laminated web 20 which is sent through a guide roll 21, by means of a heat- bonding roll apparatus 24 after the part of narrow width 28 is removed. The laminated web 29 is slitted along the face 30 by means of a slitter 32 while it is being transferred in a horizontal direction by, being bent at a guide roll 31, and it is cut in the same length as the height of a can body by means of a cutter 33 to prepare a laminated blank 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a perforation-resistant and buckling-resistant product whose inner and outer layers are made of metal foil and whose center layer is made of thermoplastic plastic.

This invention relates to a method for manufacturing a can body that has excellent container performance such as amphibious properties and gas barrier properties.

(Prior Art) The present inventors previously disclosed in Japanese Utility Model Publication No. 60-28587 that the inner and outer layers are made of metal foil, the center W is made of a thermoplastic plastic film, and the opposite ends are made of a laminate made of metal foil. A can body formed by overlapping the opposing edges of a leafy vegetable whose central layer is exposed on different grades of edges and heat-sealing the exposed central layer to form a side joint. It was shown that the container has excellent container performance such as cold porosity resistance, buckling resistance, hygiene, and gas barrier properties.

First, as a manufacturing method for the above-mentioned grade, first, a first metal foil sheet is placed on one side of a thermoplastic web at a constant interval X (equal to the overlapping width), and has a large number of vacuum suction holes. Thermal bonding is performed using an adhesive roll, and then the second metal foil sheet is shifted from the opposing first metal foil sheet by a fixed distance X to the other side of the web, and the same adhesive roll as above is used to thermally adhere the second metal foil sheet. The above-mentioned publication proposed a method for forming a laminated web by doing this, and then cutting this laminated web to the dimensions of the above-mentioned element.

However, in this method, the metal foil web is first cut into metal foil sheets of a predetermined size, and the metal foil sheets are thermally bonded to the plastic web using an adhesive roll having a large number of vacuum suction holes, and the resulting laminate is Since the web is cut into even smaller dimensions, the process and equipment become complicated, and the productivity is also low.

(Problems to be Solved by the Invention) The present invention relates to a method for manufacturing a can body in which the inner and outer layers are made of metal foil and the center layer is made of thermoplastic plastic. It is an object of the present invention to provide a method for manufacturing the above-mentioned can body, in which a can body (laminate blank) can be formed with high productivity using relatively simple steps and equipment.

(Means for Solving the Problems) The method for manufacturing a can body of the present invention is such that the inner and outer layers are made of metal foil, the center layer is made of thermoplastic, and the thermoplastic is formed by overlapping and heat-sealing the thermoplastic. A method of manufacturing a can body having a side joint, the method comprising: a first metal foil web having a width substantially equal to the circumference of the can body and a width of the side joint; A plurality of alternating first narrow portions of substantially equal width are longitudinally slit, the first narrow portions are removed and the first wide portion is inserted into the first wide portion of the thermoplastic web. a plurality of second wide parts and a plurality of second narrow parts each having a width equal to the first wide part and the first narrow part, respectively. alternatingly, and the first side end surface of the plastic web of the second wide section is substantially flush with the second side end surface of the plastic web of the first wide section. Slit in the longitudinal direction to form
removing the second narrow section and adhering a second wide section to the second side of the plastic web to form a laminate web; and then slitting the laminate web along the same side. and then cut to a length equal to the height of the can body to form a laminate blank, and a first narrow portion and a second narrow portion of opposing edges of the laminate blank. overlap the corresponding exposed thermoplastic parts,
It is characterized by heat fusion.

(Operation) A metal foil web is slit in the longitudinal direction so that a plurality of wide parts and a plurality of narrow parts alternate, the narrow parts are removed, and the wide parts are bonded to both sides of a thermoplastic web. The continuous production of laminate blanks from metal foil webs is possible because the laminate web formed by the process is longitudinally slit and then cut into lengths equal to the height of the can body to form laminate blanks. is possible, the process and equipment are relatively simple, and high productivity can be obtained.

The width of the wide portion of the metal foil is substantially equal to the circumference of the can body;
The width of the narrow portion is substantially equal to the width of the side joint of the can body, and the right (left) end surface of the wide portion bonded to one side of the plastic web is bonded to the other side of the wide portion. Since the laminate web is slit along this same plane, the opposing edges of the resulting laminate blank have different edges. A thermoplastic layer is exposed on the surface with the width of the side joint. By overlapping and heat-sealing the exposed portions of the opposing edges, a can body having side joints can be manufactured.

(Example) In FIG. 1, 1 is a can body, and the outer layer 2 and inner layer 3 are made of metal foil, and the center layer 4 is made of thermoplastic plastic. Reference numeral 5 in FIG. 2 shows a longitudinal cross-sectional view of a laminated body blank for manufacturing the can body 1. Among the opposing edge portions 5a and 5b of the blank 5, the edge portion 5
The constant width X (overlapping width) of a is not covered by the metal foil of the inner surface layer 3, and the constant width X of the edge portion 5b is not covered by the metal foil of the outer surface F layer 2. The thermoplastic of the central layer 4 is exposed.

The can body 1 is formed by rolling up a blank 5 and forming an end edge 5a.

5b are stacked so that the exposed portions of the center layer 4 are in contact with each other, and the edge portions 5a*5b are heated using a heat bar type, high frequency induction heating method, etc., and the center layer 4 of the core portion is heated.
is melted or softened, then pressurized and rapidly cooled to form the side joint portion 6 by a so-called heat fusion method.

As the metal foil forming the outer layer 2 and the inner layer 3, iron foil, steel foil, tin foil, tin-free steel foil, aluminum alloy foil, etc. having a thickness of about 10 to 100 μm are preferably used. As the thermoplastic plastic forming the center layer 4, stretched or unstretched polyethylene, polyzolopyrene, polyamide, linear polyester, polycarbonate, etc. having a thickness of approximately 50 to 300 μm, and those to which fillers are added are preferably used. It will be done. Preferably, the thickness of the blank 5 is approximately 100-500 μm.

FIG. 3 shows an example of an apparatus for manufacturing the laminate blank 5. As shown in FIG. Reference numeral 11 is a web of metal foil that is to become the inner layer 3, and on the upper surface of the figure is an adhesive layer (e.g. epoxy phenol type, urethane type, maleic anhydride modified polyolefin, polyamide type).

A corrosion-resistant baked coating film (for example, epoxy/phenol type, etc.: not shown) is formed on the lower surface. Reference numeral 12 denotes a slitter, as shown in FIG. The metal foil web 11 is slit in the longitudinal direction so that the narrow width portions 14 of the metal foil web 11 alternate in the width direction. After slit, 5th
As shown in the figure, the wide part 13 goes around the lower roll 15a of the pinch roll 15 and descends, but the narrow part 14 and the ear part 10 (if present) move around the upper roll 15a of the pinch roll 15.
It is rolled up and removed by a roller (not shown) along the line 5b.

Among the above combinations, the first preferred example (particularly from the viewpoint of industrial cost) is the combination of aluminum foil, maleic anhydride-modified polypropylene adhesive, and polypropylene; There is a combination of steel foil (still based on tin-free steel), epoxy phenolic adhesive, and nylon 12.

The adhesive strength of the film to the metal foil is sufficient as long as it does not cause peeling between the two materials during the subsequent can body manufacturing and processing steps, and is 200 g in T-shaped beer measurement.
It would be good if it was 15mm or more.

Reference numeral 16 denotes a thermal adhesive roll device, which includes a heating roll 17 with a built-in heater and a presser roll 18 lined with elastic rubber (not shown).

A plurality of (three in the figure) wide width portions 13 are attached to one side of a thermoplastic web 19 fed from the presser roll 18 side by a thermal bonding roll device 16 at a mutual spacing of X.
Then, they are thermally bonded together to form a single-sided laminated web 20, as shown in FIG.

22 and 23 are a slitter and pinch roll having the same structure as 12 and 15, respectively.

Further, 24 is a thermal adhesive roll device having the same structure as 16, 25 is a heating roll, and 26 is a presser roll. A web 9 of metal foil (on which an adhesive layer is formed on the upper surface and a printed film is usually formed on the lower surface) which is to become the outer surface layer 2 is separated by a slitter into a wide part 27 having a width W and a narrow part 27 having a width X. After the sections 28 are alternately slit and the narrow sections 28 are removed in the same manner as the narrow sections 14, the wide section 27 is formed into a single-sided layer which is fed through the guide rolls 21 in a thermal bonding roll device 24. Web 20 is thermally bonded to the top surface of plastic web 19 to form laminate web 29 . As shown in FIG. 7, the slit has an end face 27a on the first side end 19a side of the plastic web 19 of the wide part 27, and an end face 13a on the second side end 19b side of the plastic web 19 of the wide part 13. This is done in such a way as to form substantially the same surface 30.

The laminate web 29 is bent through a guide roll 31 and transferred horizontally to the surface 3 by a slitter 32.
After being slit along 0, the laminate blank 5 is produced by cutting it into a length equal to the height of the can body 1 by a cutter 33.

Note that instead of forming an adhesive layer on the metal foil webs 11 and 9, adhesive layers may be formed on both sides of the plastic web 19. Further, 11 may be a web of metal foil to be the outer layer 2, and 9 may be a web of metal foil to be the inner layer 3.

(Effects of the Invention) The method of manufacturing a can body in which the inner and outer layers of the present invention are made of metal foil and the center layer is made of thermoplastic plastic can be used to prepare a laminate blank for producing the can body in a relatively simple process. The device has the advantage that it can be formed with high productivity.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an example of a can body manufactured by the method of the present invention, FIG. 2 is a longitudinal cross-sectional view of a laminate blank used to manufacture the can body of FIG. 1, and FIG. FIG.
5 is a side view taken along the line V-V in FIG. 3, and FIGS. 6 and 7 are the vi-vi line and vii-vi line in FIG. 3, respectively. FIG. 3 is a cross-sectional view taken along line vii. 1...Can body, 2...Outer layer, 3...Inner layer, 4
... center layer, 5 ... laminate blank, 5a*5b.
...Edge, 6...Side joint, 9,11...Metal foil web, 12t22-...Slitter, 13.27
-j・Wide part, 13a, 27a... End surface, 14.28
... Narrow width part, 16.24 ... Thermal adhesive roll device, 1
9... Thermoplastic plastic web, 29... Laminate web, 30... Same surface. Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] (1) In a method for manufacturing a can body, the inner and outer layers are made of metal foil, the center layer is made of thermoplastic plastic, and the can body has a side joint part formed by overlapping and heat-sealing the thermoplastic plastics, the first metal foil The web is configured to alternate between a plurality of first wide portions having a width substantially equal to the circumference of the can body and a plurality of first narrow portions having a width substantially equal to the width of the side joint. longitudinally slit the thermoplastic web, removing the first narrow section and adhering the first wide section to the first side of the thermoplastic web, and attaching the second metal foil web to the first side. a plurality of second wide portions and a plurality of second narrow portions, each having a width equal to the wide portion and the first narrow portion, alternate; A slit is formed in the longitudinal direction so that the end face on the side end side of the first wide part forms substantially the same plane as the end face on the second side end side of the plastic web of the first wide part, and the second narrow part is slit in the longitudinal direction. removing and adhering a second wide section to the second side of the plastic web to form a laminate web, and then slitting the laminate web along the same side before slitting the can body. cutting to a length equal to the height to form a laminate blank with exposed edges corresponding to the first narrow portion and the second narrow portion, respectively, of opposite edges of the laminate blank; A method for manufacturing a can body having a side joint, characterized by overlapping and heat-sealing thermoplastic plastic parts.