WO1995015284A1 - Procede de fabrication d'une structure metal-polymere - Google Patents

Procede de fabrication d'une structure metal-polymere Download PDF

Info

Publication number
WO1995015284A1
WO1995015284A1 PCT/US1994/013920 US9413920W WO9515284A1 WO 1995015284 A1 WO1995015284 A1 WO 1995015284A1 US 9413920 W US9413920 W US 9413920W WO 9515284 A1 WO9515284 A1 WO 9515284A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal
plastic
zone
construction
thickness
Prior art date
Application number
PCT/US1994/013920
Other languages
English (en)
Inventor
Robert J. Mchenry
Dominique Petit
Original Assignee
Mchenry Robert J
Dominique Petit
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mchenry Robert J, Dominique Petit filed Critical Mchenry Robert J
Priority to US08/737,813 priority Critical patent/US5862939A/en
Priority to AU13349/95A priority patent/AU1334995A/en
Publication of WO1995015284A1 publication Critical patent/WO1995015284A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects
    • B21D51/16—Making hollow objects characterised by the use of the objects
    • B21D51/38—Making inlet or outlet arrangements of cans, tins, baths, bottles, or other vessels; Making can ends; Making closures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects
    • B21D51/16—Making hollow objects characterised by the use of the objects
    • B21D51/26—Making hollow objects characterised by the use of the objects cans or tins; Closing same in a permanent manner

Definitions

  • the invention falls in the technical area of the fabrication by drawing or drawing and ironing starting from a layered metal-plastic construction, of cans for use for example in packaging of beverages or foods and of containers for aerosols or of can ends, whether easy-open or not.
  • the metal-plastic construction used in the present invention is of the type metal-polymer- metal, that is in which a layer of polymer is interposed between two metal sheets to which it is adhered.
  • This patent describes a metal-plastic construc ⁇ tion composed in its simplest form of realization of a polyethylene (called for abbreviation PE) film attached to a foil or plate of metal.
  • Another method of realization consists of two films of PE attached to opposite surfaces of a metal plate to form a complex PE-metal-PE.
  • a third method of realization consists of two plates or foils of metals attached to opposite surfaces of a PE film.
  • the PE used obtained by copolymerization under a low pressure of ethylene and of butene-1, is of the type linear low density and it has been found that this particular type, whose characteristics are described in the applica ⁇ tion, has the interesting property of adhering directly to the metal without needing to use an adhesive. It suffices to adhere it to the metal by the simultaneous application of heat and pressure (heat sealing) .
  • the metallic substrate can be steel, steel having a coating of tin, or of chrome, or of chrome/chrome oxide, or of zinc, of aluminum treated or not with nickel, copper, or zinc. It can have undergone a chemical conversion treatment.
  • the films of different types of polyethylene of 100 microns thickness are thus heat sealed on the plates of different metals; steel, tin plated steel, steel coated with chrome-chrome oxide, or aluminum of a thickness of 2310 microns.
  • the specimens obtained are then formed into hollow articles by folding, stamping, drawing, wall-ironing. The adhesion of the coatings is compared and demonstrates the superiority of linear low density polyethylene.
  • the French patent FR2665887 (Pechiney Emballage Alimentaire) describes a capsule to fit over a cork made by drawing, drawing and ironing, or flow turning, character ⁇ ized in that it is comprised of two layers of aluminum bound together by an adhesive layer of shore hardness less than 80.
  • the adhesive layer can be constituted of an ethylene acrylic acid or of polyethylene, or of polypro ⁇ pylene modified with acid functionality.
  • the total thick ⁇ ness of the complex is comprised between 120 and 400 microns with the following percentage distribution of the total thickness:
  • the problem presented to the inventors was that of improving drawn can bodies, in particular for food, of drawn and ironed cans intended for beverages and their ends, whether they be easy-open or standard.
  • the forming process for food cans is the drawing- redrawing process, that of beverage cans is drawing and ironing, that of ends is drawing. All of these processes permits very high production rates.
  • this disc is drawn in a single pass.
  • the first pass gives an intermediate form in the shape of a cup which is then redrawn to reduce its diameter and increase its height.
  • the form in the shape of a cup obtained by drawing in one or several passes is then ironed with the aid of a series of ironing rings, generally three in number, of decreasing internal diameters. There results from this a thinning and a corresponding elongation of the wall. All of these techniques are well known to one skilled in the art.
  • the cost of the metal despite its slight weight, constitutes a preponderant portion.
  • the cost of the usual polymers, polyolefins such as polyethylene (PE) or polypropylene (PP) , polyesters (PET) , polyamides is generally less, for an equal thickness than that of aluminum alloys.
  • the inventors have found that the plastic layer ought to be placed between two metal layers and ought to be thicker than those attained up until now in the containers made of metal-plastic constructions.
  • the inventors have developed a metal-plastic construction constituted of a central layer of thermo ⁇ plastic polymer of thickness P coated on each of its internal and external faces with metal foils of respective thicknesses Mi and Me, such that the ration P/(Mi+Me) is greater than 0.5.
  • the thickness P of the polymer is between 100 and 500 microns and the thick ⁇ ness Mi or Me of each of the metal foils is between 25 and 150 microns.
  • the thick- ness P of the polymer is between 100 and 500 microns and the thickness Mi or Me of each of the metal foils is between 25 and 150 microns.
  • the thickness P of the polymer is between 80 and 300 microns and the thick ⁇ ness Mi or Me of each of the metal foils is between 25 and 100 microns.
  • the total thickness in the brim is, in general, higher than that of the thinnest part of the wall, which gives a margin of safety. It is also possible for reinforcing the can to choose for the external foil a higher thickness or a stronger alloy than for the internal layer. Finally, the exterior appearance of the can will not be affected since the broken part of the metal foil will be covered by the folded edge of the end in such a way that the final user of the can will not even notice it. On the contrary, for the ends of which the rims ought also to be rolled to a small radius in view of seaming, the problem remains undiminished.
  • the object of the invention is a process permitting rolling the rims of an end made of a MPM construction to a small diameter without provoking cracks in the metal layer brought into extension in the course of this folding operation.
  • This process consists of reducing locally the thickness of the plastic in the zone which ought to be rolled in order that the construction reduced to a thin layer of plastic between two metal foils acts pretty nearly like a foil of homogeneous metal.
  • this process in the same way as has been explained above, is not indis- pensable for rolling the upper part of the can body, it could equally be applied to it.
  • the ends will be nearly exclusively mentioned, but the process applies also to the can bodies.
  • the can bodies and ends fabricated by the above process equally constitute an object of the invention.
  • Figure 1 represents one of the variants of the invention in which a local reduction of the plastic thickness occurs by flow towards the exterior; and Figure 2 represents one of the variants of the invention in which the local reduction of the plastic thickness occurs by flow towards the center of the end.
  • the process used consists of flowing in exercis ⁇ ing a pressure, the central plastic in a fashion so that at the place where this pressure is exerted, the thickness of the polymer would be reduced in a proportion of a least 50% such that folding becomes possible without rupture of the external layer of metal.
  • the plastic be sufficiently fluid that it can flow. It is necessary therefore to bring it to a tempera ⁇ ture above its softening point and, preferably, above its melting point. This is achieved easily by a localized heating on an exterior ring of the end.
  • a rapid mode of heating for example induction heating.
  • the process includes two successive and nearly simultaneous steps.
  • the first consists of expelling the plastic towards the exterior.
  • the plastic thus expelled proceeds to add itself to the plastic already present in the annular exterior zone. It contributes then to increasing the thickness of it, thus forming an annular bulge of a diameter greater than the diameter of the zone corresponding to the thickness reduction.
  • this ring of plastic will be used to improve the leak proofing of the end on the can or it will be trimmed in a manner to separate it from the end.
  • the second solution consists of flowing the plastic towards the center of the end where it will form a light annular bulge which will permit the improvement of the mechanical qualities of the end and, in particular, its rigidity.
  • FIGS 1 and 2 illustrate the one and the other of these two solutions.
  • Figure 1 represents the elimination of a part of the plastic towards the exterior.
  • a form of circular end viewed in cross section along a diameter (1) is constituted of a core in plastic material (2) and of two metal foils
  • zone (5) and (6) One heats the circular rim of the form on all of its circumference: zone (5) and (6) in a fashion to soften or even to melt the plastic. This zone corresponds to that where the end will be rolled on a small diameter.
  • zone (5) and (6) One then applies on all of the periphery of the form a pressure represented by the arrows.
  • the liquid or at least softened plastic flows toward the exterior and forms a bulge toward the exterior of the end.
  • the zone where a part of the plastic material has been eliminated can then be folded on a small radius without fissures being observed.
  • Figure 2 represents the elimination of the plastic towards the center of the end.
  • a form of circular end viewed in cross section along a diameter (11) is constituted of a core of plastic material (12) and of two metal foils (13) and (14) .
  • the liquid or at least softened plastic is not able to flow toward the exterior since the brim itself is not heated and that the plastic there, therefore, has remained solid.
  • the easy-open or standard open ends and the cans of a metal-plastic construction of the type metal-polymer- metal, according to the invention, are characterized in that at the place where, in view of seaming, the end or the can ought to be rolled on a small diameter, the thickness of the plastic material forming the core has been reduced at least 50%.
  • Example 1 A strip of polypropylene of 140 microns thickness has been coated on each of its faces with a layer of 5 microns thick adhesive constituted of a film of maleic acid modified polypropylene. The two films of adhesive have been applied on the film by cold passage between rollers. The composite strip thus obtained has then been introduced continuously between two foils* of 80 microns thickness of aluminum alloy 3003, alloy of manganese according to the "Aluminum Association" standards and preheated by passage in an oven at a temperature of 200°C in a fashion to melt the adhesive. The MPM construction obtained has then been introduced between rollers for heat sealing it. Starting from this construction, circular discs of 75.4 mm diameter have been cut out. These discs have then been drawn to give ends of 65 mm diameter.
  • these brims Before proceeding to roll the brims, these brims have been treated according to the scheme of Figure 1 in heating them by induction to a temperature of 200°C in a fashion to melt the plastic. A pressure of 1500 Kpa has been applied on the perimeter of the end in a fashion to expel a part of the central plastic of the heated zone. The brims of the covers have then been rolled in view of seaming. In the course of this opera ⁇ tion, no cracks of the metal nor of the plastic has been put in evidence.
  • Example 2 A layer of low density polyethylene of 150 micron thickness has been extruded between two foils of 80 microns thickness of aluminum preheated by passage in an oven at a temperature of 200°C without interposition of adhesive. The MPM construction obtained was then passed between rollers for heat sealing. Starting from this construction, circular discs of 75.4 mm diameter were cut out. Before proceeding to the rolling of the brims, these brims have been treated according to the scheme of Figure 2 in heating them by induction to a temperature of 200°C in a fashion to melt the plastic in a zone near the edge but at a small distance.
  • Example 3 A layer of polyester of 150 microns of thickness has been extruded between two foils of 80 microns thickness of aluminum preheated by passage in an oven at a tempera ⁇ ture of 280°C without interposition of adhesive. The MPM construction obtained was then passed between rollers for thermosealing it. Starting from this construction circular discs of 75.4 mm diameter have been cut out.
  • these brims Before proceeding to roll the brims, these brims have been treated according to the scheme of Figure 2 in heating them by induction to a temperature of 280°C in a fashion to melt the plastic in a zone near the edge, but at a small distance.
  • a pressure of 1500 Kpa has been applied on the perimeter of the end in a fashion to expel a part of the plastic of the core from the zone heated towards the center of the end.
  • the brims of the ends have been then rolled in the zone emptied of its plastic core in view of this seaming. In the course of the operation, no cracks of the metal nor of the plastic have been put in evidence.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rigid Containers With Two Or More Constituent Elements (AREA)
  • Laminated Bodies (AREA)

Abstract

Procédé permettant de rouler le rebord d'une extrémité ou d'une boîte de structure métal-plastique-métal de faible diamètre sans provoquer de fissure dans la couche métallique (3) lors du pliage. Le procédé consiste à réduire localement l'épaisseur du plastique (2) dans la zone (5 ou 6) qui doit être roulée de façon à réduire la structure à une mince couche de plastique (2) comprise entre deux feuilles de métal (3 et 4) afin que ladite structure se comporte presque comme un métal homogène. Le plastique qui reflue vers l'extérieur de la zone à rouler forme un bourrelet saillant soit à l'extérieur, soit à l'intérieur (18) de la zone (7). Le procédé s'applique à des boîtes de conserve ou de boissons de structure métal-plastique-métal, ainsi qu'à leurs extrémités. Les corps et les extrémités des boîtes obtenus par ce processus sont également l'objet de cette invention.
PCT/US1994/013920 1993-12-01 1994-11-30 Procede de fabrication d'une structure metal-polymere WO1995015284A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08/737,813 US5862939A (en) 1993-12-01 1994-11-30 Fabrication process for metal-polyester construction
AU13349/95A AU1334995A (en) 1993-12-01 1994-11-30 Fabrication process for metal-polymer construction

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9314618A FR2713113B1 (fr) 1993-12-01 1993-12-01 Procédé de fabrication de couvercles et de boîtes en complexes métal-polymère-métal munis d'un bord roulé.
FR93/14618 1993-12-01

Publications (1)

Publication Number Publication Date
WO1995015284A1 true WO1995015284A1 (fr) 1995-06-08

Family

ID=9453614

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1994/013920 WO1995015284A1 (fr) 1993-12-01 1994-11-30 Procede de fabrication d'une structure metal-polymere

Country Status (3)

Country Link
AU (1) AU1334995A (fr)
FR (1) FR2713113B1 (fr)
WO (1) WO1995015284A1 (fr)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1179589A (fr) * 1980-06-26 1984-12-18 Dominic I. Nelson-Ashley Ouvrages comprenant un element de polyethylene liaisonne a un support metallique, et methode de fabrication connexe
FR2665887B1 (fr) * 1990-08-14 1992-10-16 Cebal Capsule de surbouchage pouvant etre decoupee sans risque de blessure et son procede de fabrication.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
No relevant documents disclosed. *

Also Published As

Publication number Publication date
FR2713113B1 (fr) 1996-01-19
FR2713113A1 (fr) 1995-06-09
AU1334995A (en) 1995-06-19

Similar Documents

Publication Publication Date Title
US4403710A (en) Easily-openable heat seal lid
US6098829A (en) Can components having a metal-plastic-metal structure
US5059460A (en) Laminated metal sheet
US5782375A (en) Drawn and ironed cans of a metal-plastic construction and their fabrication process
DK166574B1 (da) Laminat af metalfolie og polymere, beholder eller komponent til samme fremstillet af dette laminat og fremgangsmaade til fremstilling af laminatet
JPH0755552B2 (ja) 深絞り缶の製造方法
EP0683110A1 (fr) Ensemble récipient-fermeture
CN101232959B (zh) 层压钢板制的2片罐用罐体及其制造方法
JPH0757386B2 (ja) 薄肉化絞り缶の製造方法
EP2493774A1 (fr) Ensemble de contenant comportant une extrémité métallique thermoscellée, extrémité métallique pour celui-ci, et procédé pour sa fabrication
NZ233805A (en) Laminate of aluminium sheet and film of amorphous polyester
EP0731752B1 (fr) Elements de boites de conserve a structure metal-plastique-metal
US5862939A (en) Fabrication process for metal-polyester construction
EP0731738B1 (fr) Boites embouties/etirees de structure metalloplastique et leur procede de fabrication
WO2007020951A1 (fr) Feuille d’acier stratifiée pour boîte en deux parties, procédé de fabrication de boîte en deux parties, et boîte stratifiée en deux parties
WO1995015284A1 (fr) Procede de fabrication d'une structure metal-polymere
JP2504164B2 (ja) 薄肉化深絞り缶の製造方法
EP0132468B1 (fr) Corps de récipient
CA2618461A1 (fr) Feuille d'acier stratifiee pour corps de boite en deux parties et boite en deux parties comprenant une feuille d'acier stratifiee
KR20050110701A (ko) 성형용 시트 재료, 상기 시트 재료로 제조된 금속 용기 및상기 시트 재료의 제조 방법
JPH0631362A (ja) 密着性の優れたラミネート鋼板製多段絞り缶の製造方法
CA2065426A1 (fr) Materiaux composites metal-plastique et procede de fabrication et applications correspondants
JP6753557B1 (ja) 樹脂金属複合容器用樹脂ラミネート鋼板製缶蓋、樹脂金属複合容器用樹脂ラミネート鋼板製缶底、及び樹脂金属複合容器
JPH05269920A (ja) 加工性、密着性、耐熱性及び耐食性に優れた容器用樹脂被覆鋼板及びその製造方法
WO2007020955A1 (fr) Feuille d’acier stratifiée pour boîte en deux parties et feuille stratifiée en deux parties

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU CA JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 08737813

Country of ref document: US

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase in:

Ref country code: CA