GB2107291A

GB2107291A - Closure assembly for a tubular container

Info

Publication number: GB2107291A
Application number: GB08228989A
Authority: GB
Inventors: David E R Haughton
Original assignee: Haughton W & E W Ltd
Current assignee: Haughton W & E W Ltd
Priority date: 1981-10-12
Filing date: 1982-10-11
Publication date: 1983-04-27
Also published as: IE812391L

Abstract

A closure assembly for an open end of a tubular container includes an endless frame 13, a captive removable lid 14 and a protective membrane 15. The endless frame 13 comprises two coaxial cylindrical walls 16, 17 connected by a web 18 and an annular flange 19 which limits the depth of insertion of the frame 13 into the container 10 and also provides an annular platform to support another container thereon. The membrane 15 is a conventional laminate, the upper face of which is of metal foil, the lower or product-contacting face being of polyethylene with a layer of paper between the faces. The membrane 15 is secured to the lower or free edge of the wall 17 by means of a hot melt adhesion of the peripheral region of the polyethylene layer. The container is supplied to the filling establishment complete with a bottom and the closure assembly is inserted and pushed home after the container has been filled. <IMAGE>

Description

SPECIFICATION Closure assembly for a tubular container This invention relates to a closure assembly for a tubular container, being an assembly of the kind which includes a rupturable membrane for the ultimate consumer to break or remove, and a removable lid to protect the intact membrane and to protect the container contents once the membrane has been ruptured. Such containers may be of plastics material, but they are more commonly made from a board composite wound helically around a former, and may comprise several laminations for different purposes, as is well known. They are used for packaging solid products in powdered or granular form, such as coffee, cocoa, spices, herbs, cleaning and scouring compositions, chemicals etc., They are normally filled through the open bottom, since the top is occupied by a conventional closure assembly intended for broaching only by the consumer.A container bottom is applied after filling, and is hermetically sealed or seamed to the container by means of relatively expensive machinery. The reduction of this expense is among the objects of the invention.

The invention accordingly provides a closure assembly for an open end of a tubular container, which assembly comprises an endless frame having an outer peripheral portion which is a sealing push fit in said open end, the frame having a first inner peripheral portion defining a first aperture for access to the container contents, a rupturable membrane-type closure being supported by said first inner peripheral portion to seal said first aperture, and the frame having a second inner peripheral portion defining a second aperture for access to the membrane-type closure and the second aperture being adapted to receive a removable lid, the apertures being in parallel planes, of similar sizes and in mutual register.

The closure assembly is preferabiy made from plastics material, such as polypropylene, apart from the membrane-type closure which is of conventional structure including at least one layer of metal foil such as aluminium foil with or without further layers such as plastics material and paper laminated thereto. The membrane-type closure is attached to the first inner peripheral portion by heat sealing or by adhesive bonding.

Heat sealing involves the use of a foil having a fusible polymer coating. Adhesive bonding includes the use of hot-melt adhesive of a polymer layer. Each of these methods is used so as to effect hermetic sealing of the container in use.

The closure assembly is presented for preference complete with a removable lid, which may be a push fit in the second aperture or alternatively may be adapted to encompass an externally projecting rim of said second aperture.

The lid is desirably captive to the closure assembly and is conveniently moulded together with the endless frame and a flexible connecting strip as a single component.

The endless frame is provided for preference with a peripheral flange extending in a plane parallel to the planes of the apertures, which flange serves to limit the extent of penetration of the frames into the end of the tubular container in use. The upper surface of the flange may be adapted to render the filled containers stackable.

The outer peripheral portion of the endless frame may be chamfered around the exterior of the leading edge thereof (referred to its direction of insertion into the end of the tubular container in use) to facilitate insertion of the closure assembly into the tubular container.

The tubular containers for which the invented closure is intended are, for the most part, cylindrical in form, and thus the closure assembly including the endless frame normally has a circular cross-section transversely of its proper direction of insertion into the container end.

In conventional practice, such containers are often manufactured with a non-removable access closure assembly fixed (as e.g. by seaming) to one end of the container, the other end being left open for later application and attachment of a container bottom after a charge of product has been filled into the container. The product filling establishment is obliged to invest in machinery for applying and sealing the container bottoms.

When the closure assembly of the invention is used, in contrast, the containers are normally supplied to the filling establishment complete with bottoms, and the closure assembly needs merely to be inserted and pushed home after the container has been filled, a much simpler operation requiring little or no special equipment.

The capital and running expenditure economies that result will be readily appreciated.

The endless frame may be provided with one circumferential rib or more on the normally cylindrical push-fit surface thereof, to assist in obtaining a hermetic seal. The quality of the hermetic seal may be enhanced by reason of the container having an inmost lamination of ductile material such as metal alloy foil, which cooperates with said circumferential ribs by spreading in close contact therewith. The bulk layers of the container will further cooperate in achieving a hermetic seal by virtue of their eiastic properties. The push-fit of the closure assembly in the container should be of a strength sufficient to prevent accidental dislodgement, even with relatively rough handling, as e.g. when a substantial effort proves necessary to remove the lid that covers the membrane.

The closure assembly of the invention, when made, preferably complete with the removable lid, of plastics material, eliminates the corrosion problems attendant on the use of tinplate and the like in conventional practice, at least as far as the access end of the container is concerned.

The invention and its advantages will be appreciated in greater detail from the following description of a particular and preferred embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which Figure 1 is a plan view of a closure assembly; Figure 2 is a section of the closure assembly of Figure 1, taken along the line Il-Il and viewed in the direction of the associated arrows; and Figure 3 is a partially cutaway perspective representation of a tubular container with the closure member of Figure 1 in position therein.

Referring now to the drawings, a cylindrical container 10 of pulpboard laminate, holding a retail quantity of granular coffee extract and ready for sale, is closed at the bottom by a conventional tinplate end (not shown) seamed into thesedge of the container wall in known manner. A closure assembly 1 2 is a hermetically sealing, mechanicaily firm push fit in the top end 11 of the container 10.

The closure assembly 12 comprises an endless (annular) frame 13 of injection-moulded polypropylene, a captive removable lid 14 integrally moulded therewith, and a protective membrane 1 5 hermetically sealed thereto.

The endless frame 13 comprises an outer, substantially cylindrical depending wall 1 6 and an inner, coaxial, substantially cylindrical depending wall 1 7 connected to the wall 16 by an annular bridging web 18. The web 18 extends radially outward to afford an annular flange 19 for limiting the depth of insertion of the frame 1 3 into the container 10, for orienting the frame 1 3 in the desired transverse abutting relationship with the container, and for providing an annular platform to support another container similar to the container 10 in a stable upright stance thereupon.

The web 18 also comprises an upstanding annular rib 20 coaxial with the walls 16, 17 and of uniform axial height above the plane of the web 18, but broken by gaps 21, 22 at diametrically opposite locations for purposes which will appear.

The removable lid 14 comprises a closure disc 141, a lifting tab 142, a flexible hinge 143 and a closure spigot 144. In use the removable lid fits into the endless frame by insertion of the closure spigot 144 inside the depending wall 1 7 of the endless frame 1 3. Said parts desirably fit together as a firm push fit. The gap 21 serves to accommodate the hinge 143, and the gap 22 the lifting tab 142. The closure disc 141 projects externally of the closure spigot 144 to form a flange 145. Abutment of the flange 145 and the annular rib 20 serves to limit the penetration of the closure spigot 1 44 into the endless frame 13, to orient the lid 14 correcting in the closed position thereof, and to yield a neat and aesthetically pleasing external appearance of the closure assembly.

The closure spigot 144 bears an external peripheral rib 146 and the depending wall 1 7 an internal groove 24. These formations are adapted to cooperate in use giving a snap fit to the lid 14.

The membrane 1 5 is a conventional laminate, the upper face of which, seen in Figure 3, is of metal foil, the lower or product-contacting face, seen in Figure 1, being of polyethylene with a layer of paper between the faces. The membrane 1 5 is secured to the lower or free edge of the depending wall 17 by means of hot melt adhesion of the peripheral region of the polyethylene layer.

The membrane is broached by the consumer for access to the container contents, the rupturable nature thereof being illustrated in Figure 3 by a torn edge.

The depending wall 1 6 is externally bevelled at 25 to assist in inserting the closure assembly into the container 10. It is provided with external ribs 23 to deform the internal surface of the container wall, which surface is provided by an interior lamination of metal foil. The ductility of the metal foil leads to the formation of a substantially airand moisture-proof seal when the closure member of the invention is used.

The closure member of the invention is of light weight and hygienic finish. It is immune from corrosion and compatible with sensitive materials commonly packaged in board containers. It has a low manufacturing cost and has a pleasing appearance leading to improved acceptability to the consumer. The captive lid is a convenient feature. The prime advantage of the closure member lies in the elimination of expensive closure affixing machinery at the product filling station.

A bottom closure may of course be fixed in conventional manner (by seaming or otherwise) to a container equipped with a closure of the invention, thereby sacrificing the said prime advantage. Alternatively a plug-type bottom closure may be applied to such a container, similarly to the manner in which the closure of the invention is applied. It will be clear that the scope of the invention is unaffected by such variations of procedure and design.

Claims

1. A closure assembly for an open end of a tubular container which assembly comprises an endless frame having an outer peripheral portion which is a sealing push fit in said open end, the frame having a first inner peripheral portion defining a first aperture for access to the container contents, a rupturable membrane-type closure being supported by said first inner peripheral portion to seal said first aperture, and the frame having a second inner peripheral portion defining a second aperture for access to the membrane-type closure and the second aperture being adapted to receive a removable lid, the apertures being in parallel planes, of similar sizes and in mutual register.

2. A closure assembly as claimed in claim 1 wherein the closure assembly is made from plastics material, such as polypropylene, apart from the membrane-type closure which is of conventional structure including at least one layer of metal foil such as aluminium foil with or without further layers such as plastics material and paper laminated thereto.

3. A closure assembly as claimed in claim 1 or claim 2 wherein the foil has a fusible polymer coating.

4. A closure assembly as claimed in claim 3 wherein the closure is attached to the first inner peripheral portion by heat sealing.

5. A closure assembly as claimed in any of claims 1-3 wherein the closure is attached to the first inner peripheral portion by adhesive bonding.

6. A closure assembly as claimed in claim 5 wherein the adhesive bonding includes the use of hot-melt adhesion of a polymer layer.

7. A closure assembly as claimed in any of claims 1-6 wherein the assembly is presented complete with a removable lid which may be a push fit in the second aperture.

8. A closure assembly as claimed in any of claims 1-6 wherein the assembly is presented with a removable lid which may be adapted to encompass an externally projecting rim of said second aperture.

9. A closure assembly as claimed in claims 7 or 8 wherein the lid is captive to the closure assembly and is conventionally moulded together with the endless frame and a flexible connecting strip as a single component.

10. A closure assembly as claimed in any of claims 1-9 wherein the endless frame is provided with a peripheral flange extending in a plane parallel to the planes of the apertures which flange serves to limit the extent of penetration of the frame into the end of the tubular container in use.

11. A closure assembly as claimed in claim 10 wherein the upper surface of the flange is adapted to render the filled container stackable.

12. A closure assembly as claimed in any of claims 1-11 1 wherein the outer peripheral portion of the endless frame is chamfered around the exterior of the leading edge thereof (referred to its direction of insertion into the end of the tubular container in use) to facilitate insertion of the closure assembly into the tubular container.

13. A closure assembly as claimed in any of claims 1-12 wherein the closure assembly including the endless frame has a circular crosssection transversely of its proper direction of insertion into the container end.

14. A closure assembly as claimed in any of claims 1--13 wherein the endless frame is provided with one or more circumferential ribs on the normally cylindrical push-fit surface thereof to assist in obtaining a hermetic seal.

15. A tubular container in combination with a closure assembly of the type as claimed in any of claims 1-14.

1 6. A tubular container in combination with a closure assembly of the type as claimed in claim 14 wherein the container has an inmost lamination of ductile material such as metal alloy foil, which cooperates with said circumferential ribs by spreading in close contact therewith.

1 7. A method of filling a container with a solid product in powdered or granular form which method comprises supplying the container with a bottom to a filling station; filling the container to the desired level with the product through the top of the container; and attaching the closure assembly as claimed in any of claims 1-14 to the top of the container.

1 8. A closure assembly substantially as herein described with reference to the accompanying drawings.

1 9. A tubular container in combination with a closure assembly substantially as herein described with reference to the accompanying drawings.

20. A method of filling a container with a solid product in powdered or granular form substantially as herein described with reference to the accompanying drawings.