GB2528308A

GB2528308A - Packaging

Info

Publication number: GB2528308A
Application number: GB1412738.5A
Authority: GB
Inventors: Alan John Davey; Ben Elkington
Original assignee: Linpac Packaging Ltd
Current assignee: Linpac Packaging Ltd
Priority date: 2014-07-17
Filing date: 2014-07-17
Publication date: 2016-01-20
Also published as: EP3169605A1; WO2016009212A1; GB201412738D0

Abstract

An article 6 is placed on a folded blank 1 and vacuum sealed with plastic film 7. Ideally the blank 1 has four side walls 3, 4 hingedly attached to a base via fold lines. The film can have a structural layer and an adhesive layer. The blank can have an internal layer, a thermo laminated external layer and several printed ink or adhesive layers inbetween, some of which are masking. The folded blank with a base and side wall is separately claimed. A layer of the blank may be peelable polyethylene. The print can create patterns on both sides of the masking layer. There can be an ethylene vinyl acetate adhesive layer. The other layer can be multilayer co extruded polyethylene terephthalate.

Description

PACKAGING

The present invention relates to lood packaging, more particularly the present invention relates to vacuum packed food products, such as meat, fish and cheese.

Conventionally, food products such as meat and fish sold in supermarkets are packaged in a rigid plastic tray which is covered with cling film or a lidding film. The Former option is relatively inexpensive but does not provide the sufficient shelf life from the packaging of the product to the end consumer and lidding films are increasingly favoured.

Another type of packaging adopted by food packers is based on vacuum sealing technology, in which the food product is vacuum sealed into a plastic skin film. The gas free environment extends the shelf life of the product and the end consumer is able to readily see the shape, dimensions and state of the product thus packed. Typically, product specifications are printed onto an adhesive paper label which is then &ued directly onto the skin film Such labels are unprotected and tend to be easily damaged and scratched so that the information printed thereon becomes unreadable. In addition, such labels create a cheap-looking appearance which may render the product unattractive to the end consumers.

To improve the appearance of vacuum sealed products, the product is placed onto a flat support, then a plastic skin film is applied around both the product and the support. Firstly, the support is usually a piece of laminated cardboard, which provides no substantive rigidity. In addition, despite the lamination, the cardboard has a tendency to absorb moisture from the product itself and from outside, thereby becoming soggy and soft. Printed labels placed onto the skin film or the cardboard suffer the same disadvantages as descnbed above.

Cardboard hackings have been rep'aced with plastic trays. generally comprising a base and sidewalls extending from the base. The trays can be closed with a lidding film as described above or vacuum sealed. Such plastic trays are sufficiently rigid to provide suitable support.

However. rigid plastic trays are heavy and shaped so that, even when the empty trays can be nested into one another, considerable space is required for storage and transport.

It is an object of this invention to mitigate problems such as those described above.

According to a first aspect of the invention, there is provided a process for packaging an arlicle comprising the steps of providing a foldaffle blank, placing the artide onto the Idded blank and vacuum sealing the article and the blank with a plastics film. Preferably, in its unfolded state, the blank is substantially flat and, in its folded, the blank comprises a base and one or more side walls extending from the base. hi a prefelTed embodiment, the blank, in its folded state, comprises a base and four side walls extending substantially perpendicuhirly from the base.

The flat blanks are lighter, less bulky and easier to store and transport than rigid plastic trays as they can simply he stacked on top of each other. The blanks can he folded into their intended fokled configuration at the point of packing the article. The blanks according to the present invention will typically have a thickness of around 350 microns. compared with a thickness of around 650 microns for conventional rigid trays. Conventional rigid plastic trays. in particuhir PET trays, are prone to distort during vacuum sealing processes because of the inherent stress of the trays and the industry has encountered many issues in trying to decrease this built-in stress without much success.

In addition, the side walls provide rigidity to the overall structure of the fokied blank so that unlike cardboard sheets, the folded blanks will not easily lose their shape. This is particularly advantageous when displaying the packed products on a shelf, where a cardboard supporting a vacuum sealed product will buckle upon itself partly due to the weight of the product and partly because of the lack of rigidity of cardboard material. Furthermore, the blank can be held and supported in its folded state (i.e. with the side walls extending upwards from the base) by the vacuum scaled cover film, in particular at the corner points.

Preferably, the process further comprises the step of forming one or more folding lines in the blank. Preferably, the process further comprises the step of folding the blank about the folding line(s). In a preferred embodiment, the blank is substantially rectangular or square and the folding lines are substantially parallel to the lateral and longitudinal sides. The pre-folded lines allow accurate and easy folding of the blank into its folded configuration. The blanks can be folded manually or automatically using a folding apparatus. The folding apparatus may comprise one or more support elements to hold the blank in its folded configuration during the vacuum sealing step.

In a preferred embodiment, die plastics hIm (or skin film) is a multilayer film. Prelerally.

the multilayer film compnses an external support layer and an internal adhesive or seal layer.

The external support layer may comprise one or more layers, depending on the desired film properties and provides protection for the packed article from the outside atmosphere. The interna' adhesive layer enables the plastics film to adhere onto the blank. Preferably. the plastics film has a thickness of 100-150 microns. Within the context of this invention, the numerical value ranges provided herein include the lowest and highest values.

Preferably, the process further comprises the step of forming the foldable blank.

Preferably, the blank has a multilayer structure and comprises an internal layer for contact with the article and an external support layer. More preferably, the contact layer and/or the support layer are made of a transparent material. Prelerably. the blank lurther comprises an intermediary print layer (coloured layer) between (lie internal layer and the exiernal layer.

Preferably, the process comprises the step of applying one or more layers of ink to form the intermediary print layer. The layers of ink or print may he applied hy means of one or more rollers. Typically, around 9-10 colours are available and each colour is applied in turn.

Preferably, the process comprises the step of applying one or more internal layers of ink onto the surface of the contact layer facing away from the article, thereby creating the colour pattern to appear on the side of the blank facing the packaged article. Thus, the printed colour pattern and information can be seen through a transparent contact layer.

Preferably, die process comprises the step of applying two or more intermediary layers of ink to form a masking layer. Preferably two or three layers of ink are applied to create an opaque masking layer. PrefelTed colours to create this masking layer are white and silver. The masking layer provides an opaque canvas onto which layers of ink can be applied to create the desired colour pattern or image. Images can he printcd on one or both sides of the masking layer.

Preferably, the process comprises the step of applying one or more external layers of ink onto the masking layer, thereby creating the colour pattern to appear on the underside of the blank. Thus, the printed colour pattern and information can be seen through a transparent external support layer.

Preferably, the process further comprises the step of applying a layer of adhesive between the intermediary print layer and the external support layer. More preferably, the adhesive comprises or consists of ethylene vinyl acetate (EVA).

Preferably, the process compnses the step of applying the external support layer onto the intermediary print layer or the adhesive layer, more preferably by thermo-laminating the external support ayer onto the intermediary print layer or the adhesive ayer. A preferred material for the external support layer is polyethylene terephthalate (PET). The external support layer may he a monofilin or a multilayer film. More preferably, the external support layer comprises a layer of recycled PET between two layers of PET, although the layer of recycled PET may be replaced with another materia' depending on the desired film properties. Most preferably, the external support layer is a co-extruded multilayer film, !or example a co-extruded PET multilayer film.

Preferably, the external support layer is thermo-laminated onto the intermediary print layer or the adhesive layer, at the time of manufacture of the external support layer. Freshly co-extruded film will be naturally hot and this heat ca activate the adhesive in the adhesive layer so that no additional source of heat is required.

In a preferred embodiment, the article is a food product, such as meat, fish or cheese.

According to a second aspect of the invention, there is provided a foldable blank for use in the process described above which, in its unfolded state, is substantially flat and, in its folded state, comprises a base and one or more side walls extending from the base.

Preferably, the blank, in its folded state, comprises four side walls extending substantially perpendicularly from the base.

Preferably, the blank comprises one or more folding lines.

Preferably, the blank comprises an internal layer for contact with the article (a contact layer or internal layer) and an external support layer. More preferably, the internal layer comprises a peelahle layer and a hacking ayer. Most preferably, (lie internal layer comprises polyethylene. In a preferred embodiment, the internal layer is a peelable polyethylene layer.

Preferably, the blank lurther comprises an intermediary print layer between the internal layer and the externa' support layer. Preferably, the intermediary print layers comprises one or more layers of ink forming a masking layer, one or more layers of ink forming a colour pattern on a first side of the masking layer, and/or one or more layers of ink forming a colour pattern on the second side of the masking layer.

Preferably, the blank further comprises an adhesive layer between the intermediary print layer and the external layer. Preferably, the layer of adhesive comprises ethylene vinyl acetate (EVA).

Preferably, the external support layer is a multilayer co-extruded film. Preferably, the external support layer comprises or consists of polyethylene terephthalate.

According to a third aspect of the present invention, there is provided a method for manufacturing a blank as descnbed above comprising the step of forming a print or coloured layer, preferably a double-sided printed layer.

Preferably, the method comprises the step of forming an internal layer for contact with the article and an external support layer. More preferably, the method comprises the step of forming an intermediary print layer between the internal layer and the external layer.

Preferably, the method comprises the step of applying one or more layers of ink to form the intermediary print layer. Preferably. the method comprises the step of applying one or more internal layers of ink onto the surface of the contact layer facing away from the article.

Preferably. the method comprises the step of applying two or more intermediary layers of ink to form a masking layer. Preferably, the method comprises the step of applying one or more external layers of ink onto the masking layer.

Preferably, the method comprises the step of applying a layer of adhesive between the intermediary print layer and (he externa' support layer.

Preferably, the method comprises the step of thermo-laminating the external support layer onto the intermediary print layer or the adhesive layer, most preferably at the time of manufacture of (he external support layer.

Preferably, the method comprises the step of forming one or more folding lines in a flat blank.

The invention wifi he further described by way of examples and with reference to die drawings and figures, in which figure 1 is a schematic representation of a blank according to the present invention in its unioMed state; figure 2 is a schematic representation ol the blank oF ligure I in its folded state; and figure 3 is a schematic representation of a article vacuum scaled onto a blank according to the present invention.

Referring to figures, there is illustrated a foldable blank 1 according to the present invention which is, in its unfolded state, substantially flat as shown in figure 1 and, in its folded state, comprises a base 2 and one or more side walls 3,4 extending from the base. The blank 1 is foldable athng pre-formed folding lines The blank I shown in the figures comprises two opposed longitudinal walls 3 and two opposed lateral walls 4.

An article 6 is placed onto the base 2 of the folded blank 1. A vacuum sealing film or skin Film 7 is applied and the article 6 and (lie Hank I are vacuum sealed together. The film 7 comprises one or more external layers 7A and the choice of material for each layer 7A depends on the required properties (e.g. liquid barrier, gas barrier, shrinkability etc). The film 7 also comprises an internal adhesive film 7B so that (he film 7 adheres to the blank 1.

The blank 1 comprises an internal contact layer 8 for direct contact with the article 6 to be packaged and with the seal layer 7B of the skin film 7; an intermediary print layer 9, an optional adhesive layer 10 and an external support layer 11.

In this preferred embodiment, the contact layer 8 has a two-layer structure of polyethy'ene.

The top layer SA in contact with the article 6 to he packaged and with the seal layer 7B of the skin film 7 comprises a peelable formulation. This is the layer 8A which will he peeled off when the consumer opens the packaging by peeling off the film 7 from the blank 1. The peelable formulation comprises or consists of polyethylene and one or more additives to modify the polyethylene and render the ayer 8A pedahlc from the skin film 7. The second layer SB is a structural layer to provide support to the peelable formulation of top layer 8A. This second layer comprises or is macic of polyethylene, preferably low density polyethylene (LDPE). Enhanced and controlled peel effect has been observed with this type of two-layer structure, and in particifiar polyethylene two-layer structure. The overall thickness of the contact layer 8 is preferably around 40 microns.

The intermediary print layer 9 comprises three layers 9A, 9B, 9C. Printing is typically achieved using a range of around 9-10 colours. Each colour is applied in turn, for example by means of rollers. Layer 9A facing the article 6 comprises one or more layers (preferably 3-4 layers) which creates the colour pattern of the surface of the blank 1 facing the article 6. Thus, printed patterns, images andlor information can he read on the article side through the transparent skin film 7 and transparent contact layer 8. Similarly, layer 9C facing away from the article 6 comprises one or more layers (preferably 3-4 layers) which creates the colour pattern of the underside surface of the blank 1. Thus, printed patterns, images and/or information can be read on the underside of the blank I through the transparent external layer II.

Layer 9B is a masking layer positioncd between laycrs 9A and 9C so that layers 9A and layers 9C can be printed on either side of layer 9B. Opacity is achieved by printing two to three colours, for examp'e white-silver or white-silver-white. The Hank I can therefore have printed information on one side or both sides.

The external support layer 11 can be a monolayer or a multilayer structure. For example.

the support layer 11 comprises three co-extruded layers of polyethylene tcrephthalate (PET), e.g. a layer 1 lB of recycled PET between two layers 1 1A. 1 1C of PET. The choice of materials will depend on the properties required. For example, the middle layer 1 lB can comprise colouring or materials with specific properties (gas-or liquid-barrier etc). The overall thickness of the external support layer 11 is in the range of from 350 microns to 400 microns for lighter blank 1.

The thickness can he increased to around 600 microns for a premium appearance and robustness.

The blank I also optionally comprises a layer of adhesive 10 between the intermediary print layer 9 aM the external support layer 11. The adhesive comprises or consists of ethylene viny] acetate (EVA).

The process for manufacturing a blank 1 according to the present invention will now be described by way of example.

The contact layer S is prepared by applying a layer of pee]ahle formulation SA onto a support laycr SB.

The print layer 9 is printed in three steps. Firstly. one or more colours are printed (e.g. using one or more printing rol]ers) onto the support]ayer SB to form the desired colour pattern 9A to show on the article side of the blank 1. Secondly, one or more colours are printed (typically two or three, e.g. white and silver) to form an opaque masking layer 9B. which will separate the colour patterns 9A, 9C on each side of the blank. Third]y, one or more colours are prnted onto the masking layer 9B to form the desired colour pattern 9C to show on the underside of the blank 1.

An adhesive ayer 10 for example of EVA is apphed onto the print layer 9 to affix the external support layer 11. The external support layer 11 for example a PET multilayer film is thermo-laniinatcd onto the adhesive laycr 10. The EVA laycr 10 needs to bc heated at temperature around 90°C to be activated. However, if the thermolamination of the PET film onto the adhesive ayer is carried out at the time ol manufacture/co-extrusion ol the PET film, then there is no need to apply heat. This is because the PET film will be naturally hot at the time of niaiiufacture.

The h]anks I are cut out and one or more fo]ding Unes are formed at the desired thcations by conventional means.

ffi use, a blank 1 with pre-foimed folding lines 5 is prepared for example through the manufacturing process described above. The blank I is then fed into an automated folding apparatus, which will fold the hlank I about the folding hnes 5 so that die folded blank I has a base 2 and fou side walls 3.4 extending substantially perpendicularly from the base 2.

The artide 6 to he packaged for examp'e meat or fish is placed onto the base 2. The article 6 and the folded blank I are then vacuum sealed with a skin film 7, surrounding both the artide 6 and the blank 1. If required, the side walls 3,4 are supported in the folded position during the vacuum sealing process. The vacuum sealed film 7 therefore holds the side walls 3,4 in the folded position. in particular at the corner points.

Thus, from the above description, it can be seen that the present invention provides a simple and promising alternative to eulTently available packaging solutions, in particular in the fleld of food packaging.

The flat blanks can easily he laid on top of each other, stored and/or transported. The inherent stress of the blanks is lower than that of rigid plastic trays so that the blanks do not distort when the vacuum seal is applied. The Nanks provide a more hygienic. more stable support than traditional cardboard backings. with enhanced appearance.

The present invention also offers a printing process in which a masking layer is formed onto which an image can he printed on one or both sides of the masking layer. This present a more hygienic and less damage prone alternative to pr nted adhesive paper labels.

Claims

CLAIMSI. A process for packaging an artide comprising the steps ol (a) providing a foldable blank; (b) placing the llhicle onto the folded blank; and (c) vacuum sealing the article and the blank with a plastics film.
2. The process according to claim 1. wherein the blank is foldable from an unfolded state in which the blank is substantially flat and a folded state in which the blank comprises a base and one or more side walls extending from the base.
3. Thc process according to claim 2, wherein the blank, in its folded state, comprises a base and four side walls extending substantially perpendicularly from the base.
4. The process according to claim 2 or 3, further comprising the step of forming one or more folding lines in the blank.
5. The process according to daim 4, further comprising the step of folding the blank about the folding line(s).
6. The process according to any preceding claim, wherein the plastics film is a niultilayer film.
7. Thc process according to claim 6, whercin the plastics film comprises an external support layer and an internal adhesive layer.
8. The process according to any preceding claim, further comprising the step of forming the foldable blank.
9. The process according to claim 8, wherein the blank comprises an internal layer for contact with the article and an external support layer.
10. The process according to claim 8. wherein the blank further comprises an intermediary print layer between the internal layer and the external layer.
II. The process according to claim 10, further comprising the step of applying one or more layers of ink to form the intermediary print layer.
12. The process according to claim II, comprising the step of applying onc or morc internal layers of ink onto the surface of the contact layer facing away from the article.
13. The process according to claim 11 or 12, comprising the step of applying two or more intermediary layers of ink to form a masking layer.
14. The process according to claim 12. comprising the step of applying one or more external layers of ink onto the masking ayer.
15. The proccss according to any one of claims 9 to 14, further comprising the stcp of applying a layer of adhesive between the intermediary print layer and the external support layer.
16. The process according to any one of claims 9 to 15, further comprising the step of thermo-laminating the external support layer onto the intermediary print layer or the adhesive layer.
17. The process according to claim 16, wherein the external support layer is thermo-laminated onto the intermediary print layer or the adhesive layer, at the tinie of manufacture of the external support layer.
18. The process according to any preceding claim, wherein the article is a food product.
19. A foldable blank for usc in thc process according to any onc of claim I to 18.wherein the blank is, in its unfolded state, substantially flat and, in its folded state, comprises a base and one or more side walls extending from the base.
20. The blank according to claim 19. wherein the blank, in its folded state.comprises lour side walls extending substantially perpendicularly from the base.
21. The blank according to claim 19 or 20, wherein the blank comprises one or more folding lines.
22. The blank according to any one of claims 19 to 21, comprising an internal layer for contact with the article and an external support layer.
23. The blank according to claim 22, wherein the internal layer comprises a peelahle ayer and a backing layer.
24. The blank according to claim 22 or 23. wherein the internal layer comprises polyethylene.
25. The blank according to any one of claims 19 to 24, further comprising an intermediary print layer between the internal layer and the external support layer.
26. The blank according to claim 25, wherein the intermediary print layers compnses one or more layers of ink forming a masking layer, one or more layers of ink forming a colour pattern on a first side of the masking layer, and one or more layers of ink forming a colour pattern on the second side of the masking layer.
27. The blank according to claim 25 or 26, further comprising an adhesive laycr between the internal print layer and the external layer.
28. The blank according to claim 27, wherein the layer of adhesive comprises ethylene vinyl acetate (EVA).
29. The blank according to any onc of claim 22 to 28. whcrcin thc cxternaI support layer is a multilayer co-extruded film.
30. The blank according to claim 29. wherein the external support layer comprises or consists of poyethy1ene terephthahile.
31. A process for manufacturing a hlank according to any one of claims 19 to 30 comprising the step of forming a printed layer.
32. A process substantially as described herein with reference to the accompanying drawings aM examples.
33. A blank substantially as described herein with reference to the accompanying drawings and examples.
34. A printing process substantially as described herein with reference to the accompanying drawings and examples.