GB2189220A - Suspension pack - Google Patents

Abstract

A suspension pack for a product eg meat or cheese is formed by use of a packaging bag having a closed end at which a seal line 2 is spaced from the extreme edge 3 of the bag to leave between them a space in which suspension holes 5 are formed. The open end 4 of the bag can then subsequently be closed after introduction of a product into the bag, and if necessary surplus material can be cut away from the open end. After shrinking, the holes 5 become reinforced and serve as suspension means for the finished package. <IMAGE>

Description

SPECIFICATION Flexible packaging container The present invention relates to a flexible packaging container, and in particular to one which is adapted for suspension of a packed product enclosed by the container.

It is known to provide packaging containers which have means for suspending the container from an overhead support. For example, plastic bags enclosing liquids for drip application to patients to have a hole in one corner to support the bag from a drip transfusion stand.

Another known form of container with a hole serving as a suspension means is disclosed in US Patent No. 4,555,025 in which one panel of the bag is longer than the other at the open end of the bag and has a hole which, in the sealed configuration of the bag, serves as a carrying handle.

Other packaging containers which are relevant to the field of suspension packaging are disclosed in US Patents Nos. 2,983,087, 3,087,610, 3,516,537, and 3,863,837.

It is an object of the present invention to provide an improved packaging bag which, at the time of making the bag available to the customer, includes suspension means which, when a product has been packaged in the container, facilitates suspension of the package. It is also desirable for such a bag to be able to support heavy products in excess of 5 kg.

Accordingly, one aspect of the present invention provides a flexible packaging container formed of plastic film and comprising a product-enclosing space having a margin defined by a seal area, and film material between said seal area margin and an edge of the container, with at least one hole having a closed periphery formed in the material between the edge of the margin, to define suspension means for a finished package formed from the container.

A second aspect of the present invention provides a method of storing and/or displaying a product, comprising loading the product into a flexible packaging bag having a closed end formed by a seal line spaced from the bag edge and with at least one suspension hole of closed periphery formed between the edge and the seal line, the bag further having an open end through which the product is introduced; closing said open end of the bag; and suspending the loaded bag by means of the said at least one hole.

In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which: Figure 1 shows a plan view of a flexible packaging bag, of the shrink film type, before being subjected to the packaging process; Figure 2 shows the bag of Fig. 1 after being loaded with a product and having been shrunk; and Figure 3 shows a plan view of a suspension fitting for use with the bag of Figs. 1 and 2.

Fig. 1 shows a shrink film type of packaging bag, in this case made from a laminated barrier film construction.

One preferred bag size is 300 mm wide and 770 mm long, but the container in accordance with the present invention can have any other dimensions, larger or smaller than the preferred size, as desired.

It is intended that the packaging bag illustrated should be capable of carrying a product having a weight of up to 12 kg. The product article may, for example, be a large body of perishable food such as cheese or meat.

The bag 1 shown in Fig. 1 is formed from a continuous extruded tube by transverse sealing at 2 to define a closed end of the bag, and severing at 3 to separate that particular bag 1 from the open end or mouth 4 of the next successive bag formed from the same tube. It will be appreciated that between the seal line 2 and the severed end 3 at the closed end of the bag there will be a quantity of film comprising a double thickness of the bag wall material since it is derived from both the upper panel, nearer the observer in Fig. 1, and the lower panel further from the observer.

It is normal for such packaging bags to be formed from multi-layer films, so where we refer to a panel of the bag this in itself may comprise several different layers. However, it is within the scope of the present invention for a single such layer to form each panel.

In the case of the bag 1 of Fig. 1, each panel of the bag is a three layer construction in which the innermost layer of the finished bag is an irradiated layer of 9% ethylene vinyl alcohol (EVA), and the outer layer of the bag is also of 9% EVA, and between these two layers of EVA there is sandwiched a layer of polyvinylidene chloride which is blended so as to make it processable and this sandwiched inner layer serves as a barrier layer for the bag panel. The overall thickness of the bag may be in excess of 100 micrometers, for example up to 120 micrometers. A preferred range for the bag thickness is from 50 to 70 micrometers, embracing the most preferred thickness of approximately 60 micrometers.

It is possible for a four layer packaging material to be used for the bag, in which case the layers quoted above are supplemented by an additional inner layer of linear low density polyethylene (LLDPE) where both the inner LLDPE layer and the next adjacent layer of the EVA are irradiated. If desired more than four layers may be used.

Selective irradiation can be carried out by sequential extrusion followed by irradiation of the just-extruded layer before the next layer is extruded onto it.

The bag 1 shown in Fig. 1 has three holes 5 formed in the area between the seal line 2 and the severed end 3 at the closed end of the bag.

As can be seen from Fig. 2, once the bag 1 has been closed around an enclosed product article 6, the three holes 5 remain in the bag material.

In fact, Fig. 2 shows the configuration after not only evacuation and closing of the bag but also heat shrinking, which causes the parts of the bag around the periphery of the product article 6 to be shrunk into close contact with the product article to give a more tidy appearance to the pack. Nevertheless, the three suspension holes 5 remain visible and accessible.

It is important to note that when the bag material is shrunk to arrive at the configuration shown in Fig. 2 there will also be shrinkage of the film area 7 in which the holes 5 are formed, and hence the holes themselves will decrease in size but equally the material forming the area 7 will increase in thickness giving a reinforcement of the holes 5.

By virtue of this reinforcing effect, the holes 5 can be used for suspending the product article 6 (having a weight of up to 12 kg) from horizontal suspension bars 8 shown in plan view in Fig. 3 and carried by a common carrier member 9. It will of course be appreciated that several packages such as the one shown in Fig. 2 can be suspended side-byside on the same set of bars 8.

Although three suspension holes 5 have been shown in Figs. 1 and 2, there is no particular importance to this number and any number of suspension holes from one upwards may be contemplated.

It should of course be borne in mind that the finished pack has four edges of which one is the line of severance 3 shown in Fig. 1, two others are the fold lines 10 extending along the margins of the flat-folded film tube from which the bag is made, and a final one is the sealed edge 11 formed as the bag is closed. In practice, the seal 11 does not occur along the edge 4 since the seal is formed as close as possible to the end of the product article 6 and at the same time surplus bag neck material is cut away and either scrapped or salvaged.

The advantage of having the suspension holes at the closed end of the bag is that they can be precisely manufactured in accordance with the manufacturers specification for the film material used for the bag and their strength, after reinforcing shrinkage, can be predetermined. Furthermore, the holes 5 are then positioned outside the product-enclosing space of the bag defined by the seal line 2 and the two fold lines 10 and maximum strength of the finished package (shown in Fig. 2) can be ensured.

Although, as shown in Fig. 2, it is envisaged that the packaging bag may be closed by hat sealing, other suitable closing methods may be used, for example clipping of the open end of the bag.

As indicated above, when the bag is of heat-shrinkable material it offers considerable advantages in being subject to reinforcing shrinkage of the area 7 in which the holes 5 are formed, so that the holes in the finished package are as strong as possible. However, it is not essential for heat shrinkage to take place.

The step of evacuating the bag 1 may be carried out in a vacuum chamber, before or during the bag closing step.

Claims (17)

1. A flexible packaging container formed of plastic film and comprising a product-enclosing space having a margin defined by a seal area, and film material between said seal area margin and an edge of the container, with at least one hole having a closed periphery formed in the material between the edge of the margin, to define suspension means for a finished package formed from the container.

2. A flexible packaging container according to claim 1, in the form of a plastic bag of generally rectangular construction having two superposed panels joined along side edges of th4 bag and a closed bottom of the bag formed by a transverse seal line spaced from the edge of the bag and leaving a film area within which said at least one suspension hole is located.

3. A flexible packaging container according to either of the preceding claims, when formed from a heat-shrinkable film.

4. A flexible packaging container according to any one of the preceding claims, wherein the plastic film is of multi-layered construction to give multiple functions to the bag material.

5. A flexible packaging bag according to claim 4, wherein at least one of the layers of the plastic film has been cross-linked.

6. A flexible packaging bag according to claim 5, wheein the cross-linking has been achieved by irradiation.

7. A flexible packaging container according to any one of the preceding claims, wherein there is a plurality of said holes along an edge of the container.

8. A method of storing and/or displaying a product, comprising loading the product into a flexible packaging bag having a closed end formed by a seal line spaced from the bag edge and with at least one suspension hole of closed periphery formed between the edge and the seal line, the bag further having an open end through which the product is introduced; closing said open end of the bag; and suspending the loaded bag by means of the said at least one hole.

9. A method according to claim 8, and including the step of evacuating the interior of the bag before or during the closing step.

10. A method according to claim 9, wherein the bag material has been crosslinked by irradiation.

11. A process according to claim 9 or 10, wherein the bag is formed of a heat-shrinkable film, and including the step of heat-shrinking the bag before suspending the package.

12. A process according to any one of claims 8 to 11, wherein the bag has a width of at least 300 mm and a length of at least 770 mm, and wherein the product has a weight of up to 12 kg.

13. A process according to claim 12, wherein the product weight is from 7 to 12 kg.

14. A package formed by the process of any one of claims 8 to 13.

15. A flexible packaging container substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.

16. A method of storing and/or displaying a product, substantially as hereinbefore described with reference to the accompanying drawing.

17. A package substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawing.