Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D7/00—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal
  • B65D7/12—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls
  • B65D7/34—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls with permanent connections between walls
  • B65D7/36—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls with permanent connections between walls formed by rolling, or by rolling and pressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B7/00—Closing containers or receptacles after filling
  • B65B7/16—Closing semi-rigid or rigid containers or receptacles not deformed by, or not taking-up shape of, contents, e.g. boxes or cartons
  • B65B7/28—Closing semi-rigid or rigid containers or receptacles not deformed by, or not taking-up shape of, contents, e.g. boxes or cartons by applying separate preformed closures, e.g. lids, covers
  • B65B7/2842—Securing closures on containers
  • B65B7/2878—Securing closures on containers by heat-sealing

Definitions

• the invention relates to the field of rigid or semi-rigid packaging consisting of containers, typically box bodies, closed by crimped lids.
• the invention relates more specifically to a method of closing a container comprising crimping and heat sealing the lid and the box body.
• Crimping includes the formation of a double hook by winding the edge of the cover and the crimping edge of the box body, double hook obtained by several sets of crimping wheels.
• the closure of semi-rigid containers that is to say whose metal wall thickness is of the order of 0.10 mm up to 0.15 mm, uses either the technique of heat sealing or crimping a cover.
• the problem posed concerns the final quality of containers filled with packaged products as they are delivered to consumers.
• This final quality is partly linked to the lid and to the crimping of the lid and of the can body once filled.
• the lid manufacturer is faced with a problem of formation of the seal on the lids:
• the deposition of the seal remains conditioned by a flow of a liquid seal through an orifice in movement relative to the cover, with openings and closings of the orifice for each cover.
• Deposition irregularities and manufacturing incidents require strict control of the deposition of the seal. Indeed, a lack of seal subsequently means possible bacterial contamination of the contents of the container, with the possibly very serious consequences which may result therefrom.
• the crimping remains a critical operation for the same reasons as those seen previously (risk of bacterial contamination if the crimping is insufficient, ie if the covering of the hooks on the edge of the cover and the edge to be crimped is insufficient).
• the cover once crimped plays a big role, like the bottom of the container, during the heat treatment phase, typically high temperature sterilization, for example between 110 and 130 ° C.
• a first object of the invention is constituted by a method of closing a container comprising a skirt and a fallen edge, with a cover comprising a bowl and a crimping edge, comprising a crimping of the edge of said cover with the fallen edge of said container, characterized in that, a) a container and a cover, free of seals, are supplied, said container and said cover each comprising an interior coating chosen so that the interior coating of one is heat-sealable with the interior coating on the other, b) crimping said cover and said container so as to form at least one crimping hook, c) and heat sealing said inner coating of said container in contact with said inner coating of said lid.
• a meniscus of material is formed by heat-sealing said interior coating of said container with said interior coating of said cover, ensuring the welding of the interior coatings of said container and said cover and forming a junction of said bowl and said skirt. All of these means make it possible to solve all of the problems posed.
• Figures la to ld illustrate the method according to the invention.
• Figure la shows, in axial section, a container (2) comprising a skirt (3) and a dropped edge (4a).
• FIG. 1b represents, in axial section, a cover (5) comprising a central panel (6) forming a bowl, and a crimping edge (7a).
• FIG. 1d represents, in axial section, a modality of the process in which the heat sealing is carried out, after the crimping, by placing the crimped packaging (la) on a support (13), and applying a heating jaw (14) on the crimp formed by the hook (9) of the cover and the fallen edge (4) of the container, so to obtain the packaging (1) according to the invention.
• Figure 2 shows, in partial view in an axial section, the connection, by crimping and heat sealing according to the invention, the cover (5) and the container (2), after sterilization heat treatment.
• the cover (5) comprises a crimping edge (7) and a central cup-forming panel (6).
• the crimping edge (7) consists of an internal slope (8) and a hook (9).
• Figure 3 shows, in a view similar to that of Figure 2, the connection by crimping according to the prior art, of the cover (5) with seal (15), after sterilization heat treatment and irreversible deformation of the cover to this opportunity.
• the position of the cover before sterilization is shown in dotted lines.
• the heat sealing operation can be carried out after that of crimping, as shown in Figures la to ld, or simultaneously with that of crimping.
• said inner coating of said container and that of said cover externally comprises a thermoplastic film, the thermoplastic film of said container and that of said cover being heat-sealable.
• This thermoplastic film can be a polyolefin film from 5 to 50 ⁇ m thick.
• PP polypropylene
• one of said interior coatings comprises a thermoplastic film, the other of said interior coatings comprises a heat-sealable varnish to said thermoplastic film.
• said thermoplastic film is a polyolefin and said varnish is a varnish loaded with grains of a thermoplastic material heat sealable with said polyolefin.
• Said polyolefin can be PP and said varnish can be an epoxy varnish.
• said container is coated on the inside with said varnish, and said cover is coated on the inside with said polyolefin, but it is also possible to have the reverse, said container being coated on the inside with said polyolefin, and said cover being coated on the inside with said varnish.
• a second object of the invention consists of the packaging obtained according to the method of the invention.
• This packaging containing a product to be packaged, formed by a container comprising a skirt and a dropped edge, and a cover comprising a bowl and a crimping edge, said cover being crimped to said container, is characterized in that the internal coating of said cover is , for the facing parts, heat-sealed to the interior coating of said container.
• said container and / or said cover are metallic, the thickness of metal being between 0.10 and 0.25 mm.
• Said metal may be aluminum or aluminum alloys, or steel, the container may be made of a material different from that of the cover.
• said container can be made of steel and said cover made of aluminum.
• Said internal coating of said container and of said lid can be chosen from films of thermoplastic material, or varnishes containing grains of thermoplastic material.
• Said inner coating of said container and said inner coating of said lid can both be films of thermoplastic material, preferably films of polyolefin.
• said interior coating of said container can be a varnish containing grains of thermoplastic material and said interior coating of said cover can be a film of thermoplastic material heat-sealable to said varnish.
• said film of thermoplastic material has a thickness of 10 to 50 ⁇ m, and said varnish has a thickness of 3 to 15 ⁇ m.
• the invention relates more particularly to containers of the box body type or trays, with a lid which may or may not be easy to open.
• the covers were first crimped in a standard manner, then, as shown in FIGS. 1a to 1d, the crimp was heat sealed by applying a heating jaw (14) to the crimp formed by the cooperation of the hook (9) of the cover and from the fallen edge (4) of the box body.
• Heat sealing conditions :
• ** "-" means that there is no leakage / deformation at
• a "facet” designates a deformation in the plane of the cover.
• a "spoiler” designates a deformation (more serious than the previous one) which also affects the periphery of the cover and therefore the crimp.
• FIG. 2 represents a typical example according to the invention which is characterized by the presence of a meniscus (12) of thermoplastic material.
• thermoplastic material (12) modifies and improves the mechanical behavior of the cover and its resistance to corrosion.
• the invention in addition to solving all the problems posed, and which will not be repeated here, also makes it possible to widen the technical possibilities of packaging with crimped lids, in particular in the field of mechanical strength of the cover, and in that of corrosion resistance. These possibilities can, for equal performance, reduce the thickness of these covers, and therefore their material cost.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Closures For Containers (AREA)
• Closing Of Containers (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9483300

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (4)

Family Cites Families (5)

• 1995
  • 1995-10-02 FR FR9511751A patent/FR2739354B1/fr not_active Expired - Fee Related
• 1996
  • 1996-10-01 CZ CZ981008A patent/CZ100898A3/cs unknown
  • 1996-10-01 AU AU72190/96A patent/AU7219096A/en not_active Abandoned
  • 1996-10-01 WO PCT/FR1996/001526 patent/WO1997012808A1/fr not_active Application Discontinuation
  • 1996-10-01 ES ES96933465T patent/ES2136430T3/es not_active Expired - Lifetime
  • 1996-10-01 DE DE69603869T patent/DE69603869T2/de not_active Expired - Lifetime
  • 1996-10-01 EP EP96933465A patent/EP0853578B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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