GB2199284A

GB2199284A - Packaging material

Info

Publication number: GB2199284A
Application number: GB08725640A
Authority: GB
Inventors: Alistair John Mcintyre; Frank George Grundman
Original assignee: UEB PACKAGING Ltd
Current assignee: UEB PACKAGING Ltd
Priority date: 1986-11-05
Filing date: 1987-11-02
Publication date: 1988-07-06
Also published as: AU8066787A; GB8725640D0; NZ218176A

Abstract

A packaging material 1 comprises a plurality of layers which include at least a plastics layer 2 such as polyolefin having some porosity to liquid flow backed by a layer or layers 3 absorbent to liquid such as tissue paper. At least one layer 2,3 has a porosity to the flow of carbon dioxide gas. Optionally there is an innermost layer 4, e.g. of paper, layer 4 being also porous to liquid flow, a reinforcing layer 5 e.g. non woven rayon, polypropylene, polyethylene or polyester and a further layer 14 of for example polyethylene. The construction allows exudate from meat to pass through the plastics layers to be absorbed in the tissue thereby reducing discolouration of the meat by the exudate. <IMAGE>

Description

IMPRCNEMEN?S IN OR REIATIS O TO A PACKAGING MXTERIAL This invention relates to a packaging material and has been devised particularly though not solely for use in packaging meat.

Wrapping meat at present has some inadequacies in that exudate from the meat often lies on the surface of the meat. This exudate often discolours the meat leading to unacceptability of the meat to the purchasing public. This is clearly disadvantageous.

It is therefore an object of the present invention to provide a packaging material which will obviate or minimise the foregoing disadvantages or which will at least provide the public with a useful choice.

Accordingly in one aspect the invention consists in a packaging material comprising a plurality of layers including a layer of plastics material having some porosity to liquid flow, one or more layers of liquid absorbent material outside said plastics material layer, one of said layers or a further layer of plastics material having a controlled porosity to the flow of carbon dioxide gas.

In a further aspect the invention consists in a method of wrapping comprising the steps of placing a cut of meat onto the inner surface of a sheet of packaging material according to the preceding paragraph and forming said sheet about said cut of meat in a manner such that at least a double thickness of said wrapping material is provided over any sharp points in said cut of meat.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

One preferred form of the invention will now be described with reference to the accompanying drawings in which; Figure 1 is a diagrammatic cross-sectional view of part of a packaging material in use according to one preferred form of the invention, Figures 2 to 7 show a wrapping sequence for using the material of Figure 1, and Figure 8 is a diagrammatic cross-sectional view on A-A in Figure 7.

In the preferred form of the invention a packaging material 1 is provided which is formed from a plurality of layers. A layer 2 is provided which has at least some porosity to liquid flow. This layer may be formed of a plastics material, suitably a polyolefin, for example by a layer of polyethylene for example about 20 microns thick although it is believed that this thickness could be reduced to as low as 8 microns. The necessary porosity for the intended purpose of the material can be achieved by treating the polyethylene electrically for example by applying a high voltage thereto which disturbs the surface molecules so as to cause minor pin holes through the thin layer of the polyethylene film. Alternatively it can also be achieved by physically perforating or puncturing small holes through the polyethylene film.

Outside the layer 2 is an absorbent layer or layers and this can be provided for example by layers of tissue paper 3 there being six such layers shown in Figure 1. However the number of layers can, depending upon the conditions in which the material is to be used, be increased or decreased as desired and for example it is believed that up to eight-plys of tissue paper can reasonably be provided. The tissue layers could be for example 17g m2 weight. Other absorbent material such as kraft paper can be used.

An innermost layer 4, of for example, paper such as 21g m2 paper may be provided. This layer 4 also has porosity to fluid flow. Non-woven material could be used but this is likely to be more expensive.

In order to reinforce the construction a reinforcing layer 5 may be provided and this may comprise an outer layer although this layer could be otherwise located if desired. The reinforcing layer may comprise a non-woven material such as a non-woven rayon fabric and may be for example about 30 grams in weight per square meter up to for example about 50 grams per square meter. Such a fabric is absorbent but non-absorbent material such as polypropylene, polyethylene or polyester could be used. It will be appreciated that each of the integers above is set forth by way of a guide only and the particular weights of the material or thicknesses or number of plys will be determined by the circumstances and conditions of use or the material intended to be wrapped.

In a particular use of the invention the packaging material 1 can be wrapped around a cut of meat 6. In such a construction the intention is to substantially totally encase the meat 6 thus providing for example protection against puncturing of the outer barrier package by bones in the meat as well as the other functions that will be discussed further herein. In particular the construction may be used in relation to the packaging of cuts of meat.

Thus a cut of meat 6 may be placed on a sheet of the material 1 of the invention as shown in Figure 2. The end 7 is then wrapped around meat cut 6 as shown in Figure 3.

This wrapping is continued by rolling the cut 6 along the material 1 until end 8 is positioned as shown in Figure 6.

This can be held in place with pressure sensitive tape strips 9. The end 10 can then be folded over and held in place with further pressure sensitive tape strips 11, thus providing at least two and preferably at least four thicknesses of wrapping material 1 over the corners of the package 12 as formed. The paper layer 4 if provided or the polyethylene layer 2 lies against the surface of the meat 6 thus not allowing the liquid exudate from the meat to lie on the fat surface to thereby discolour that surface. The porosity achieved in the polyethylene allows the exudate to flow through the polyethylene layer 2 and to be absorbed in the layers 3 of absorbent material therebehind. The absorbent material 3 collects the exudate and thus substantially prevents discolouration of the meat surface which occurs when the liquid is allowed to remain in contact with the surface.

The layer of film 2 or a further layer 14 of, for example, polyethylene restricts-the rate of flow of carbon dioxide into the meat and substantially reduces the probability of bleaching of the meat caused by denaturing of the muscle fibre proteins which can be caused by a very high concentration of carbon dioxide, for example 100% CO2, while allowing the package atmosphere to maintain a sufficient level of carbon dioxide to achieve the desired storage conditions.

The wrap hereinbefore described is able to be used with carbon dioxide flushing packaging and also inside vacuum barrier bags.

The present invention is primarily intended to be used as a wrapping material for packaging individual pieces of fresh meat which are subsequently packaged either individually or preferably with other similarly wrapped pieces of meat into a larger package where a desired atmosphere is maintained by high barrier packaging materials. This package concept allows maintenance of desired fresh meat quality for an extended period without freezing of the meat.

Thus it can be seen that at least in the preferred form of the invention a packaging material is provided which has some advantages. In particular the packaging allows exudate to pass through a layer 2 of plastics material adjacently surfaced so that the exudate is absorbed by layers 3 of absorbent material behind the plastics film layer 2. The absorbent material collects the exudate and avoids or substantially reduces discolouration of the surface of the meat. The method of wrapping described also provides at least a double thickness of material at sharp edges such as at points 15 shown in Figure 8, and preferably four thicknesses of material at the package corners thus reducing any tendency of the bone to puncture the packaging material.

Claims

CLAIMS:

1. A packaging material comprising a plurality of layers including a layer of plastics material having some porosity to liquid flow, one or more layers of liquid absorbent material outside said plastics material layer, one of said layers or a further layer of plastics material having a controlled porosity to the flow of carbon dioxide gas.

2. A packaging material as claimed in claim 1 wherein said layer of plastics material having some porosity to liquid flow comprises a polyolefin.

3. A packaging material as claimed in claim 1 or claim 2 wherein said layer of plastics material having some porosity to liquid flow comprises polyethylene.

4. A packaging material as claimed in any one of claims 1-3 wherein said liquid absorbent material comprises one or more layers of tissue paper.

5. A packaging material as claimed in any one of the preceding claims having a paper layer forming the innermost layer.

6. A packaging material as claimed in any one of claims 1-4 wherein said plastics layer having some porosity to liquid flow forms the innermost layer.

7. A packaging material as claimed in any one of the preceding claims wherein said further layer of plastics material having a controlled porosity to carbon dioxide is formed from polyethylene.

8. A packaging material as claimed in any one of the preceding claims wherein said packaging material can be used in the form of a wrapper or can be formed to the shape of a bag, said plastics material layer having some porosity to liquid flow forming the innermost surface or the layer adjacent to the innermost surface of said wrapper or bag.

9. A packaging material substantially as herein described with reference to the accompanying drawings.

10. A method of wrapping comprising the steps of placing a cut of meat onto the inner surface of a sheet of packaging material according to any one of the preceding claims and forming said sheet about said cut of meat in a manner such that at least a double thickness of said wrapping material is provided over any sharp points in said cut of meat.

11. A method as claimed in claim 10 wherein at least four thicknesses of said wrapping material are provided over any sharp points in said cut of meat.

12. A method of wrapping substantially as herein described with reference to the accompanying drawings.