NZ202572A - Lid,adhesive situated between rim bead and channel-shaped rib - Google Patents

Description

202572 Priority Date(s): Complete Specification Filed: #9.3..•$£' Class: Publication Date: !???, P.O. Journal, No: Q9& NEW ZEALAND PATENTS ACT J 953 No.: Date: COMPLETE SPECIFICATION "CONTAINER LID" | JK/We, W. R. GRACE AUSTRALIA LIMITED, a company incorporated under the laws of the State of Victoria, Australia, of 1126-1134 Sydney Road, Fawkner, in the State of Victoria, Commonwealth of Australia, Australia, hereby declare the invention for which Jc / we pray that a patent may be granted to Rife/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 1 (followed by page la) 1<X 202572 "CONTAINER LID" This invention relates to a reclosable or resealable container, and more particularly to a container and a lid for said container which can be 5 initially sealed across the opening of the container, and which may be used to reclose or reseal the container, preferably in a liquid tight manner, after the initial seal has been broken to give access to the contents of the container. Such resealable containers 10 are particularly useful, and are widely used, in the packaging for sale of foodstuffs, the foodstuff being sold to the consumer in the initially-sealed container and the container being particularly adapted to be resealed after a portion of the contents have been 15 used by the consumer. 202572 2 Australian Patent Specification No. 505,749 discloses a formed stackable lid for application to a container, the opening of which has a foil seal membrane adhered across it, the lid being formed with 5 a flat central portion which when the lid is applied to the container rests on the surface of the foil seal membrane, the central portion being surrounded by an upstanding annular rib which is surrounded by a flat annular portion adapted to bear on a portion of the 10 foil seal membrane overlying an external annular flange formed around the opening of the container, the flat annular portion being surrounded by a skirt adapted to clip over and engage the flange of the container and the skirt terminating in a flared 15 portion, the height and form of the annular rib and the form of the flared portion of the skirt being such as to support an identical lid stacked concentrically on top of the lid with the flared portion of the skirt of the stacked lid clear of the outer periphery of the 20 lid below.

Whilst the lid of Specification No. 505,749 is adapted to be resealable, it is designed for use I with a container having an opening which has a foil 25 seal membrane adhered across it to provide the initial I sealing of the contents within the container, the lid being of such a construction that it may be used to reclose or reseal the container after the foil seal \ membrane has been removed. It is an object of the I present invention to provide an improved reclosable or I I resealable container and formed stackable lid I < 6 I 202572 therefor, in which the lid provides both the initial sealing of the contents within the container and is adapted to be used to reclose or reseal the container after the initial seal has been broken. In this way, the need to provide a separate foil seal membrane across the opening of the container is avoided with the consequent saving both in assembly time and in materials. At the same time, it is an object of the invention to provide a reclosable or resealable lid which is designed to be stackable to allow automatic printing of lids and dispensing thereof when used in automatic filling lines.

In one aspect the invention consists in a lid for a container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, said lid comprising a substantially planar central portion, a channel-shaped rib having a substantially rectangular cross-section with the outer wall of the channel-shaped rib tapering inwardly at its upper extremity, said rib surrounding said central portion and adapted in use to be received within said opening and engage said container wall portion defining said opening, and a rim surrounding said channel-shaped rib outwardly of said rib, said rim being adapted in use to engage the flange surrounding said opening in the container and having an integral bead or lip, said bead or lip together with said channel-shaped rib defining an area on the ritn within which an adhesive or sealing material is retained or contained so that during application of the lid to the container when said lid is stacked vertically upon a second identical lid one channel-shaped rib will not nest into the next channel-shaped rib thereby providing easy removal and ensuring that sealing material on said lid will be separate from said second.lid in the stack.

In another aspect of this invention, there is a lid for a container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, said lid comprising a substantially planar central portion, a channel-shaped rib surrounding said central portion and adapted in use to be eceived within said opening and engage said container wall portion fining said opening, and a rim surrounding said channel-shaped rib 202572 outwardly of said rib, said rim being adapted in use to engage the flange surrounding said opening in the container and having an integral bead or lip, said bead or lip together with said channel-shaped rib defining an area on the rim of said lid within which an adhesive or sealing material is retained or confined during application of the lid to the container.

In another aspect of this invention, there is provided a container and lid combination comprising a container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, and in combination therewith a lid for said container, said lid comprising a substantially planar central portion, a channel-shaped rib portion surrounding said central portion and received within said opening and engaging said container wall portion defining said opening, and a rim surrounding the channel -shaped rib outwardly of said rib, said rim engaging the flange surrounding said opening in the container, and having an integral bead or lip, said bead or lip together with said channel-shaped rib defining an area on the rim of said lid within which an adhesive or sealing material is retained or confined during application of the lid to the container. wo particularly preferred aspect- of this invention, the rim fX/the lid is provided with an integral bead or 1 ipj^jjj^kr-i^gether with * the channel-shaped rib of the 1 id de^i^«^anarea on the contacting - surface of the rim of the^MtTwiithin which the adhesive or sealing >materiaj^J__s HW . or confined during application of the lid to the 2 SfEBms 202572 In another particularly preferred aspect of the invention, the outer wall of the channel-shaped rib of the lid is provided with engaging means which, in use, positively engages the container wall portion defining the opening of the container. In one embodiment of this aspect, the container wall portion defining the opening is provided with an inwardly sloping portion, and the engaging means engages this inwardly sloping portion. The engaging means may, for example, comprise a plurality of spaced, outwardly extending lugs or a continuous or discontinuous bead portion formed in the outer wall of the channel-shaped rib of the lid.

Further features of the present invention will be apparent from the following description with reference to the accompanying drawings, in which:- Figure 1 is a vertical cross-section through a container and reclosable or resealable lid combination in accordance with the present invention; Figure 2 is a detailed cross-section of portion of the container and reclosable or resealable lid combination of Figure 1 generally designated by the letter A in Figure 1, prior to sealing of the lid to the container; Figure 3 is a similar view to that shown in Figure 2, after sealing of the lid to the container; 2025 Figure 4 is a part cross-sectional view of two reclosable or resealable lids in accordance with this invention in a stack; and Figure 5 is a cross-sectional view of portion of an alternative construction of a reclosable or resealable lid in accordance with this invention.

Referring firstly to Figure 1, there is shown a container 10 which may be of any standard shape and, as illustrated, comprises a base portion 11 having a raised central area, and upstanding wall portion 12 having an upper edge portion 13 which defines an opening 14 in the container. The upper edge portion 13 of the wall 12 is surrounded by a generally planar flange 15 extending outwardly from the opening 14. Further details of upper edge portion 13 and flange 15 will be described in greater detail hereinafter. At the lower end of the upper edge portion 13, container 10 is provided with a stacking ledge 16 which enables a plurality of containers 10 to be stacked for use in automatic machinery. The container 10 may be formed in any suitable manner, for example by thermoforming or injection moulding, from any suitable polymeric material, for example polystyrene.

As shown in greater detail in Figures 2 and 3, the internal surface of the upper edge portion 13 of the wall 12 slopes inwardly at its upper end m 202572 7 adjacent to opening 14 as shown to form an inwardly sloping portion 17 which forms a bulge or overhang in the container wall inwardly of the flange 15. As will be described in greater detail hereinafter, this bulge assists in the reclosing or resealing of the lid in the container.

Lid 20 is received within the opening 14 of the container 10 as generally depicted in Figure 1. This lid comprises a generally planar central portion 21, a channel-shaped rib 22 surrounding the central portion 21 and a generally planar rim 23 surrounding the channel-shaped rib 22 outwardly of the rib. As central portion 21 is generally planar, it is 15 particularly suited for application of printed or similar material thereto to assist in labelling of the products within the container for marketing purposes. The lids 20 may, for example, be fed to an automatic printing machine prior to application to the 20 containers. Channel-shaped rib 22, as shown, is generally U-shaped, however the lower portion of the rib is chamfered on the outer base corner thereof as shown at 24 to ensure stable stacking of each lid on top of a similar lid as shown particularly in Figure 25 4. The outer wall of the channel-shaped rib 22 is provided with means 25 to engage the inwardly sloping portion 17 on the upper edge portion 13 of the wall 12. Means 25 may, for example, comprise a plurality of spaced, outwardly extending deformed portions or lugs as shown in Figure 1, or alternatively means 25 may comprise a continuous or discontinuous bead 202572 8 portion extending around the outer wall of the channel-shaped rib 22. The engagement of means 25 with the inwardly sloping portion 17 provides a positive closing action on resealing of the lid 20 to 5 container 10 after the initial seal has been broken.

As is depicted in Figures 2 and 3, the under-surface of the rim 23 which contacts the flange 15 of the container may be provided with a bead or 10 layer of adhesive material 26. Suitable adhesive materials include known adhesives which can be activated by heat, ultrasonics or pressure, or any combination thereof, and by way of example the adhesive material may be a polyvinyl acetate/polyvinyl 15 alcohol adhesive material which is heat activated at about 70°C.

The adhesive material 26 may be applied to the under-surface of the rim 23 by automatic means, 20 for example as a hot melt or as a 30 percent solid solution in a hydrocarbon solvent, by spin lining or by a printing process. Preferably, means are provided to retain the material 26 in its proper position during application thereof to the lid and during 25 sealing of the lid to the container. In Figures 2 and 3, this means comprises a bead 27 which surrounds the material 26 on the underside of the rim 23. Figure 5 illustrates an alternative configuration in which the outer edge of the rim 23 is deformed to form a lip 28 30 to achieve this function. 2025 7? 9 In an alternative embodiment of the invention, not shown, a sealing material of the soft, rubbery type may be applied to the upper surface of the flange 15 of the container 10. Such a sealing 5 material does not adhere to the under-surface of the rim 23, however it can act as a seal between the contacting surfaces because of its soft and rubbery properties which enable it to fill any voids between those surfaces, particularly if the lid is applied to 10 the container at elevated temperatures at which the ; sealing material has lower viscosity. This embodiment is particularly useful in containers which are loaded i; with a product while it is hot and the lid then \ applied. Cooling of the product with the lid in place I t produces a lower pressure within the container and the S lid is held in place by the pressure differential. In < this embodiment, reclosing or resealing of the lid is ensured by engagement of means 25 on the lid with the inwardly sloping portion 17 of the wall 12 as I described above. j I s I < Lids 20 may be formed by any suitable means I from any suitable material. By way of example, the lids may be thermoformed from sheet polymeric material 25 or formed by injection moulding. One suitable material which is mentioned by way of example is \ I acrylonitrile/butadiene/styrene co-polymer. j ( It is an important feature of the present i { invention that the adhesive material 26 is applied ! only in the area of need for the material, and not, j i 2025 for example, over the complete under-surface of the lid. Thus, the material 26 shown in Figures 2 and 3 is provided in a restricted annular band on the underside of the rim 23 defined between the 5 channel-shaped rib 22 and the bead 27. This configuration of the adhesive material is of considerable economic benefit in that it allows trim generated during production of lids by the thermoforming process to be fully re-used, whereas it would have to be dumped if it was coated with adhesive material. Since the trim can amount to up to 30 to 50 percent of the sheet used in the thermoforming process, the ability to reuse this trim is of particular importance to the economy of the process. 15 Furthermore, the use of the adhesive material configuration described above, particularly the application of this material subsequent to the formation of the lid, enables lids to be formed by injection moulding if desired.

It will be apparent from the foregoing description of one embodiment of the invention that the present invention provides a stackable lid which, by use of an appropriate adhesive or sealing material, 25 can be hermetically sealed to the container by the application of heat, ultrasonics and/or pressure, and after it has been initially sealed the lid can be peeled from the container to allow access to the contents thereof. Once peeled from the container, the 30 lid can, however, be replaced on the container and reclosed or resealed thereon as described above. 7? >vAV •v* A»» ? * 202575 11 If desired, in order to assist in the peeling of the lid from the container after it has been initially sealed thereon, the upper surface of the flange of the container or the lower surface of 5 the outer rim of the lid may be knurled or otherwise textured to ensure that the seal is broken and the lid peels from the container in a controllable manner on application of a steady removal force.

It will be apparent from the foregoing description that the present invention provides a reclosable or resealable lid for a container, and a container and lid combination, which can provide a strong initial seal so that the lid will not be 15 accidentally dislodged during handling of the container, and which will provide a positive reclosing or resealing function after the initial seal has been broken. Furthermore, this initial sealing and resealing function is achieved by the use of a single 20 lid instead of the more complex system comprising a foil seal membrane and a separate resealable lid as is described, for example, in Specification No. 505,749.

It will, of course, be readily apparent to 25 persons skilled in this art that many modifications and variations may be made to the particular embodiments of the present invention which are illustrated in the accompanying drawings without departing from the spirit and scope of the present 30 invention as broadly described above. The present 202572 12 invention is intended to encompass all such modifications and variations.

Claims (16)

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1. A lid for a container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, said lid comprising a substantially planar central portion,

a channel-shaped rib having a substantially rectangular cross-section with the outer wall of the channel-shaped rib tapering inwardly at its upper extremity, said rib surrounding said central portion and adapted in use to be received within said opening and engage said container wall portion defining said opening, and a rim surrounding said channel-shaped rib outwardly of said rib, said rim being adapted in use to engage the flange surrounding said opening in the container and having an integral bead or lip, said bead or lip together with said channel-shaped rib defining an area on the rim within which an adhesive or sealing material is retained or contained so that during application of the lid to the container when said lid is stacked vertically upon a second identical lid one channel-shaped rib will not nest into the next channel-shaped rib thereby providing easy removal and ensuring that sealing material on said lid will be separate from said second lid in the stack.

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2. A lid according to Claim 1, wherein said rim surrounding said channel-shaped rib of said lid is substantially planar.

3. A lid according to Claim 1, wherein the outer wall of said channel-shaped rib is provided with engaging means which, in use, positively engages the container wall portion defining the opening of the container.

4. A lid according to Claim 3, wherein said engaging means comprises a plurality of spaced,

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outwardly extending lugs in the outer wall of said channel-shaped rib, and said lugs are adapted to engage an inwardly sloping portion of the container wall portion defining the opening of the container.

engaging means comprises a continuous or discontinuous bead portion extending around the outer wall of said channel-shaped rib, and said bead portion being adapted to engage an inwardly sloping portion of the container wall portion defining the opening of the container.

'6. A lid for a container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, said lid comprising a substantially planar central portion, a channel-shaped rib surrounding said central portion and adapted in use to be received within said opening and engage said container wall portion defining said opening, and a rim surrounding said channel-shaped rib outwardly of said rib, said rim being adapted in use to engage the flange surrounding said opening in the container and having an integral^bead or lip,' said bead or lip together with said channel-shaped rib defining an area on the rim of said lid within which an adhesive or sealing material is retained or confined during application of the lid to the container.

5.A lid according to claim 3, wherein said

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7. A container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, and in combination therewith a lid for said container according to claim 1.

8. A container and lid combination according to claim 7, wherein both said flange extending outwardly from said opening of the container and said rim surrounding said channel-shaped rib of said lid are substantially planar.

9. A container and lid combination according to claim 7, wherein the outer wall of said channel-shaped rib is provided with engaging means which, in use, positively engages the container wall portion defining the opening of the container.

10. A container and lid combination according to claim 9, wherein said container wall portion defining

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P \i JUN 1985m

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the opening in said container is provided with an inwardly sloping portion, and said engaging means comprises a plurality of spaced, outwardly extending lugs in the outer wall of said channel-shaped rib,

said lugs engaging said inwardly sloping portion of said container.

11. A container and lid combination according to claim 9 , wherein said container wall portion defining the opening in said container is provided with an inwardly sloping portion, and said engaging means comprises a continuous or discontinuous bead portion extending around the outerwall of said channel-shaped rib, said bead portion engaging said inwardly sloping portion of said container.

container having an opening therein defined by a container wall portion and surrounded by a flange extending outwardly from said opening, and in combination therewith a lid for said container, said lid comprising a substantially planar central portion, a channel-shaped rib portion surrounding said central portion and received within said opening and engaging said container wall portion defining said opening, and a rim surrounding said channel-shaped rib outwardly of said rib, said rim engaging the flange surrounding said opening in the container, and having an integral bead or lip7 said bead or lip together with said channel-shaped rib defining an area on the rim of said lid within which an adhesive or sealing material is

12.

A container and lid combination comprising a

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/retained or confined during application of the lid to the container.

13. A lid for a container substantially as herein described with reference to Figures 1 to 4.

14. A lid for a container substantially as herein described with reference to Figure 5.

15.. A container and lid combination substantially as herein described with reference to Figures 1 to 4.

16. A container and lid combination substantially as herein described with reference to Figure 5 of the accompanying drawings.

DATED THfsQlj^ OF A. J. PARK & SON

pea L o

AGENTS FOR THE APPLICANTS

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