GB2295815A

GB2295815A - A container for produce

Info

Publication number: GB2295815A
Application number: GB9424525A
Authority: GB
Inventors: Norman Shutler
Original assignee: MARDEN WOLFE Ltd; CVP Systems Inc
Current assignee: MARDEN WOLFE Ltd; CVP Systems Inc
Priority date: 1994-12-05
Filing date: 1994-12-05
Publication date: 1996-06-12
Also published as: GB9424525D0

Abstract

In the field of plastics trays for the storage and displaying of e.g. meat products, a problem is that bubbles of gas trapped in the containers beneath a shrinkable enclosure therefor are detrimental to the appearance of the meat. To avoid such trapped gas, a container (10) has a flange (17) which is perforated at intervals about the periphery of the container (10). Each perforation (20) is formed in a respective recess (19) formed in the flange (17). The presence of the recesses assists in the manufacture of the perforations (20). <IMAGE>

Description

A CONTAINER FOR PRODUCE This invention relates to a container for produce. In particular, but not exclusively, the invention relates to a tray suitable for the storage, distribution and displaying of e.g.

joints of fresh meat in supermarkets. The invention is also suitable for use with many other kinds of produce, such as fruit, vegetables, dough-based products, cook-chill dishes, part-cooked or part baked produce, fish and fish products and also cuts of meat other than joints. The invention may be used for the displaying etc. of many other products including many foodstuffs not specifically mentioned in the foregoing list.

It is known for supermarkets to display joints of meat in clear plastic trays that are impermeable to liquids.

The trays are open at their upper ends. Prior to distribution of the joints of meat to the supermarkets, each tray receives an absorbent pad and a freshly cut joint of meat. Each tray is then placed in a thermoplastic sleeve or bag that is shrunk onto the tray e.g. by means of a heat treatment process, to form a shrink-wrapping.

The shrink-wrapping seals about the open upper end of the tray to prevent the ingress of dirt, bacteria, liquids, etc., and to prevent the egress from the tray of liquid produced by the joint of meat.

A batch of thus completed display trays may optionally then be sealed into a further container, (e.g. a further bag) containing an inert gas. The further container is sealed for the duration of the storage and transportation of the meat, to prevent degradation of the meat until the meat is placed on display in the supermarket. The step of sealing the trays into such a further container is not essential to the practising of the invention.

It is desirable for the supermarkets to display the meats in an attractive way. In particular, it is desirable for the shrink-wrapping to press tightly against the surface of the meat adjacent the upper end of the tray, so that the shrink-wrapping appears smooth. If the shrink-wrapping does not press tightly against the meat, the completed pack of meat can appear cloudy or opaque and consequently less attractive to consumers.

Known heat treatment processes for the application of the shrink-wrapping tend initially to result in the trapping of a bubble of gas beneath the portion of the shrink-wrapping material that overlies the open upper end of each tray. In the heated condition of the shrink-wrapping, the bubble of gas is under pressure and consequently the shrink-wrapping material is forced clear of the joint of meat in the tray. When the bubble of gas cools after heat treatment of the shrink-wrapping, the shrinkwrapping collapses towards the surface of the meat but fails to attain the tight, smooth finish referred to above. As a result the opacity or cloudiness of the pack can occur.

Even when the trays are used to display items that do not protrude beyond the open end of the tray the trapping of a bubble of gas as aforesaid causes stretching of the shrink-wrapping.

When the gas contracts on cooling of the tray the shrink-wrapping lacks tautness and hence is unattractive.

Consequently, there is a need for a display pack for e.g.

joints of meat in which the problem of trapped bubbles of gas does not arise.

According to the invention, there is provided a container for produce comprising a base; and one or more side walls upstanding therefrom to form an open end, e.g. an upper end, spaced from the base; the container being suitable for receiving produce therein and suitable for sealing by means of a shrinkable closure, or within a shrinkable enclosure, capable of sealing against the open end on shrinking of the shrinkable closure or enclosure, wherein the container includes one or more perforations therein permitting the passage of fluid between the interior and exterior of the container after such sealing of shrinkable material against the open end, the perforations being so located as to minimise the passage of liquid under gravity from the interior to the exterior of the container.

A container of this kind does not suffer from the trapping of a bubble between the shrink-wrapping material and the end of the tray. The presence of apertures or perforations in the tray permits an equalisation of gas pressures between the interior of the tray and the exterior of the tray that lies within the shrinkable enclosure.

Preferably, the container includes a flange extending along an upper portion of a sidewall, including one or more perforations formed in the flange.

Preferably, the flange includes one or more recesses formed therein whereby portions of the flange are spaced from a shrinkable closure or enclosure applied thereto, the one or more perforations being formed in a respective said recess.

This feature advantageously assists in the production of the trays having perforations in the flange thereof.

Conveniently, the container includes a wall extending downwardly from the outer edge of the flange whereby to form a channel on the underside of the flange, the recesses extending downwardly into the channel between the downwardly extending wall and an upstanding wall of the container.

This feature advantageously ensures that the recesses, which extend downwardly in a preferred embodiment, do not interfere with the sealing of the shrinkable closure or enclosure about the flange.

Preferably the flange is substantially continuous about the upper end of the container. It is also preferable that the upper end of the container is generally rectangular in plan. However other container shapes are possible, in particular triangular and circular containers.

There now follows a description of preferred embodiments of the invention, by way of example, with reference being made to the accompanying drawings in which: Figure 1 is a perspective representation of a first embodiment of a container according to the invention; Figure 1A is a sectional view through the region of the flange of the container of Figure 1; Figure 2 is a perspective, partial view of a second embodiment of the invention; and Figure 3 is a perspective, partial view of a third embodiment of the invention.

In Figure 1 there is shown a container 10 having a substantially planar base 11 and four inclinedly upstanding sidewalls 12, 13, 14, and 15. The sidewalls 12 - 15 are interconnected at their adjacent edges to form a container having an open, upper end.

The open upper end of the container terminates in a generally horizontally extending, rim-like flange 17. Flange 17 extends about the entire periphery of the open, upper end of container 10 in the embodiment shown.

Flange 17 terminates about its outer periphery in a downwardly extending wall 18 that defines, with flange 17 and the sidewalls 12 to 15 of the container, a channel formed on the underside of flange 18.

A series of recesses 19 extends downwardly into the aforesaid channel at the junction of flange 17 with the respective sidewalls 12 to 15. A perforation or aperture 20 is formed in each recess 19.

When the container 10 is enclosed in a shrinkable enclosure after the insertion therein of e.g. a joint of meat, the presence of the perforations 20 allows an equalisation of pressure between the interior of the container and the exterior thereof. This in turn avoids the trapping of a large bubble of gas within the interior of container 10, thereby ensuring that the shrinkable enclosure shrinks tightly onto the joint of meat contained within container 10. Consequently, the opacity or cloudiness caused by rippling of the shrinkable enclosure does not arise.

This beneficial effect occurs even when the container 10 is completely enclosed in a shrinkable enclosure, since the perforations still function to permit a degree of equalising of pressure between the interior and exterior of the container, within the shrinkable enclosure.

The embodiment of the invention shown in Figure 1 is generally rectangular in plan view. Of course, many other shapes are possible including square, triangular and rectangular trays.

Many other shapes, including entirely irregular shapes and shapes that mimic known articles, are possible. Moreover, the arrangement of strengthening ribs and depressions shown in the base and sidewalls of the container 10 in the drawing maybe varied or even dispensed with, as desired.

Some foodstuffs are not packed by means of a shrinkable enclosure, but instead a shrinkable cover is added to the container 10. In other words, in some cases it is not necessary for the shrinkable material to extend about the entire container 10 so as to encircle it. In such cases the perforations 20 are still of benefit in allowing the exhausting of pressurised gas from within the container 10, thereby avoiding the creation of a rippled or opaque effect in the finished product.

Figure 2 shows an embodiment, similar to the Figure 1 embodiment, from which the recesses 19 are absent. In the Figure 2 embodiment the perforations 20 are formed in the flat, upper surface of flange 17.

In Figure 3 there is shown a further embodiment including a series of strengthening ribs 40 extending upwardly from the base 11 towards the flange 17, on the interior side of each wall 12-15. Each rib 40 terminates in a respective horizontally extending shoulder 41 in which the respective perforations 20 are formed.

In each of the embodiments described, the perforations 20 are so located and directed that liquid e.g. produced from a joint of meat in the container 10 would not normally pass through the perforations 20.

In embodiments such as that of Figure 3, the flange 17 may optionally be dispensed with.

The invention is also considered to reside in tooling for forming the container 10. Specifically, such tooling would include shaped portions for producing the base and side walls, the flange 17 (if present), the recesses 19 (if present) and the perforations 20. Parts of the tooling may optionally be moveable relative to one another where this assists in the production of the container 10.

The invention is further considered to reside in a method of forming the container 10 comprising the steps of forming the container with a base, one or more side walls upstanding therefrom to form an, open upper end spaced from the base and (optionally) a flange extending along an upper portion of a side wall; and perforating the container in at least one location.

The step of forming the recesses may optionally be carried out prior to perforating of the container, although the forming of the recesses 19 may not be absolutely necessary for the successful perforation of the flange. Typical production methods for the container include thermoforming and injection moulding.

Claims

1. A container for produce comprising: a base; and one or more side walls upstanding therefrom to form an open end spaced from the base, the container being suitable for receiving produce therein and suitable for sealing by means of a shrinkable closure or within a shrinkable enclosure capable of sealing against the open end on shrinking of the shrinkable closure or enclosure, wherein the container includes one or more perforations therein permitting the passage of fluid between the interior and exterior of the container, the perforations being so located as to minimise the passage of liquid under gravity from the interior to the exterior of the container when the container is upright.

2. A container according to Claim 1 including a flange extending along an upper portion of a sidewall, including one or more perforations formed in the flange.

3. A container according to Claim 2 wherein the flange includes one or more recesses formed therein whereby portions of the flange are spaced from a shrinkable closure or enclosure applied thereto, the one or more perforations being formed in a respective said recess.

4. A container according to Claim 3 including a wall extending downwardly from the outer edge of the flange whereby to form a channel on the underside of the flange, the recesses extending downwardly into the channel between the downwardly extending wall and an upstanding wall of the container.

5. A container according to any of Claims 2 to 4 wherein the flange is substantially continuous about the upper end of the container.

6. A container according to any preceding claim including one or more perforations formed in a side wall of the container.

7. A container according to any preceding claim wherein the upper end thereof is generally rectangular in plan.

8. Tooling for producing a container according to any of Claims 1 to 7.

9. A method of manufacturing a container according to any of Claims 1 to 7 comprising the steps of: (i) forming a container having a base, one or more side walls upstanding therefrom to form an open end spaced from the base; and (ii) perforating the container in at least one location.

10. A method according to Claim 9 including the step of forming a flange extending along an upper portion of a side wall of the container.

11. A method according to Claim 10 including the step of forming one or more recesses in the flange prior to forming of the perforations, and perforating the flange in the or a said recess.

12. A container generally as herein described, with reference to or as illustrated in the accompanying drawings.

13. Tooling generally as herein described.

14. A method generally as herein described.