AU621693B2 - Packaging - Google Patents

Description

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1 62169 3 COMMONWEALTH OF AUSTRALIA The Patents Act 1952 Name of Applicant(s): TRANSPAK INDUSTRIES LIMITED Address of Applicant(s): 23-25 PORANA ROAD GLENFIELD, AUCKLAND NEW ZEALAND Actual Inventor(s): Address for Service: 44 4:( 4: 1 (4:4:4: 4 4: 4: 4:4: 4: (4:4:4: 4: 4.

4:44:4: 4: 4:4: 4:4 4: 4:4:4:1 4:4 #4 4:4:4:, JOHN CAMERON SADLER G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, Dalgety House, 79 Eagle Street, Brisbane, Qld. 4000, Australia.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: C f t C t :C V: 4. 4

PACKAGING

The following statement is a full description of the invention including the best method of performing it known to

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h To: The Commissioner of Patents Signature of Declarant(s) \i -2- This invention relates to the wrapping and/or packaging of articles.

The present invention has application to the wrapping or packing of articles of all kinds, but has particular (but although not exclusive) application to the wrapping and packaging of articles in the meat and dairy industry. For example, the packaging of meat cuts, meat carcasses, cheese, dairy products and the like.

There are numerous disadvantages with the methods and apparatus that have been used up until this time, for the packaging ar wrapping of articles. In particular this applies to the methods and apparatus that have been available for what is known as shrink wrapping.

•e Up until this time, where articles such as for example t g 15 meat products, poultry, diary products and the like have been t 4. packed (such as by vacuum packaging), it is desirable to have the packaged or wrapped product to be essentially shrink treated, so as to meet in some cases governmental and industry requirements and in other cases packaging, storage t 20 and consumer requirements.

In many cases hot air shrink tunnels are used, which are particularly expensive insofar as power is concerned, given 4 a excessive heat loss. It is also known to shrink package by the use of hot water, wherein articles that have already been packaged (such as vacuum packaged) are inserted in heated water for a predetermined period of time, in order for the 1.- 1 i; -3packaging or wrapping to be shrink treated. There are substantial disadvantages with this method in that there is excessive heat loss and at the same time the product is wet when it exits from a hot water tank or container, so that it has to be dried out either manually or by forced air or the like, this being time consuming, expensive and inefficient.

The present invention sets out to overcome or at least minimise these problems and to provide the industry and public with a useful choice.

According to one aspect of this invention there is provided a method of packaging an article, including at least partially packing an article in a wrapping or packaging material; thereafter subjecting said at least partially wrapped article to a fluidised bed of heated beads, each 15 having a diameter of between 20mm and 100mm and having a density of between .07 and .3 gm/cc.

According to a further aspect of the invention there is S. provided an apparatus for performing the above defined method.

According to a still further aspect of the invention C'c there is provided an article packaged by the above defined I method or apparatus.

This invention will now be described by way of example only. It should be appreciated that modifications and improvements may be made to the invention without departing from the scope or spirit thereof. The invention is described with reference to certain foodstuffs such as meat and -o42 Te; -4poultry, but it should be appreciated that the invention has equal application to the packaging and/or wrapping of other articles.

A method of packaging or wrapping articles, and in particular articles in the meat industry, is described and illustrated in our New Zealand patent specification number 211171, (Australian patent specification number 55966/86) but it should be appreciated that the method and apparatus described and illustrated in said New Zealand patent specification number 211171 is equally applicable to all articles, including all meat articles, poultry, dairy products and the like. It should also be appreciated that the present invention is carried out essentially in trrr accordance with the parameters and steps described and 7 15 illustrated in New Zealand patent specification number 211171, except insofar as the present invention is particularly applicable to the shrink wrapping of articles.

I r i Thus, the present disclosure should be read as part of and in conjunction with the disclosure of the New Zealand patent specification number 211171, the contents of which is Iii incorporated herein, by way of reference.

In using the method described and illustrated in New Zealand patent specification number 211171, an article which 'has already been at least partially wrapped, is placed in or passed through a fluidised bed of beads, so that the heat of the particles causes the packaging material to contract and shrink about the article being packaged.

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ii For example, a cut of meat may have been already packaged such as by vacuum packaging. The vacuum packaged cut of meat is then placed into a fluidised bed, for a predeterminded or desired period of time, the heated beads of the fluidised bed acting upon the flexible or semi flexible wrapping material, so that it shrinks and contracts, thus effectively encapsulating and shrink wrapping the article concerned.

The invention applies equally to all other articles, carcasses, dairy products, poultry and the like.

It should be appreciated that in the present invention, the action of the heated beads of the fluidised bed, act on the flexible or semi flexible wrapping material so that it is contracted and shrunk around the article. The disclosure of New Zealand patent specification number 211171, refers in particular to the heat and pressure of the beads, in causing an essential secondary seal of the plastic material, about the article to be wrapped, thus causing the article to be essentially and substantially encapsulated within the wrapping material.

While the present invention is described with reference to shrink wrapping products which have already been vacuum packed, it is envisaged that the invention has equal application to products which are already partially packaged or wrapped, which can then be placed into a heated fluidised bed, such as in the manner described and illustrated in patent specification number 211171, so that the action of the C t A c~ b ~CI o ii :X I i -i -6heated beads will cause the wrapping material or packaging material to shrink wrap the article or articles concerned.

The invention is not therefore limited to the packaging of articles which have already been vacuum packed.

Referring now to the attached drawing, this graphically illustrates the shrink characteristics of known barrier packaging films, the graph being a plot of shrinkage in percentage terms against temperature in degrees centigrade.

The graph shows the plot of shrinkage against temperature for two samples. Sample 1 is typically an existing shrink structure consisting of a co-extrusion of 4 4 EVA/PVDC/EVA while Sample 2 is typically a shrink structure consisting of a co-extrusion of nylon/LLDPE.

It needs to be mentioned here that in existing hot water ,i 15 shrink tunnels the temperature of operation will be below C and would usually be about 85 0 C. It is seen therefore that at such a temperature of about 85°C the developmental off& A shrink material of Sample 2 would not achieve the desired C shrinkage, this only being achieved at above 100 C, typically 105 C to 110 C.

It is thus seen that with the use of a fluidised bed which can efficiently operate at a temperature of above 100 C, shrink materials which cannot be used in existing hot water baths can now be used such as the developmental shrink structure of Sample 2.

With regard to the fluidised bed itself it has now been found that the beads of the bed need to be of a larger iSfVf- 4 4 i; i :i .1 -7size from about 20mm to about 100mm. It has been found in experiments that below that size range, the beads can be entrapped in the product itself while above about 100mm efficiency of operation is substantially reduced due to the amount of air needed and the velocity of that air to maintain the bed in operation and the heat transfer of the bed has been found to reduce dramatically.

Moreover, the density of the beads in the bed should, it has been found, be within the range of .07 to .3 gm/cc and preferably about .1 gm/cc.

In a preferred fluidised bed the bead size would be about 50mm at a density of about .1 gm/cc.

ii c Moreover, in a preferred embodiment of the invention the beads would suitably be in the form of balls and the surface 15 of the balls should preferably be substantially soft so as to avoid indentation or abrasion on the plastic shrink film.

The present invention with the use of the fluidised bed for shrink wrapping thus enables the preferred 30% shrinkage in both directions of the wrapping material to be achieved using a wide variety of materials which previously would not have been able to have been used in existing hot water baths.

A It has been found that the present invention has substantial advantages of the prior known methods and apparatus, in that it has a far more effective temperature transfer, and is more efficient and straightforward in use and operation.

kL -11 11 1 -8- Where in the aforegoing description reference has been to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.

The present invention has been described by way of example only and improvements and modifications may be made without departing from the scope thereof as defined in the appended claims.

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Claims (9)

1. A method of packaging an article including at least partially packing an article in a wrapping or packaging material: thereafter subjecting said at least partially wrapped article to a fluidised bed of heated beads, each having a diameter of between 20mm and 100mm and having a density of between .07 and .3 gm/cc.

2. A method of packaging as claimed in claim 1 wherein said step of at least partially packing an article includes vacuum packing said article.

3. A method as claimed in claim 2 wherein the said step of at least partially packing an article includes wrapping about it a flexible wrapping or packaging material.

4. A method of packaging an article as claimed in any one of the preceding claims wherein the said heated beads act on said wrapping or packaging material to shrink said material about said article.

A method of packaging an article as claimed in any one of the preceding claims wherein each said particle is of a diameter of about 50mm and has a density of about .1 gm/cc.

6. A method of packaging an article as claimed in any one of the preceding claims wherein each bead comprises a soft surfaced ball.

7. A method of packaging an article substantially as herein before described. ii i. L P

8. A packaging apparatus which performs the method of any one of the preceding claims comprising a fluidised bed of heated beads each having a diameter of between and 100mm and having a density of between .07 and .3gm/ CC.

9. An article packaged by a method or apparatus of any one of the preceding claims. A packaged article as claimed in claim 9 wherein said article comprises a meat, dairy or poultry product. DATED this 8th day of January 1992 TRANSPAK INDUSTRIES LIMITED By their Patent Attorneys CULLEN CO. 44 f t 44 t I tt 'iH j~~r Y,-h iii4 9 4/ ~t 6 D