GB2526548A

GB2526548A - Laminate for forming a package

Info

Publication number: GB2526548A
Application number: GB1409332.2A
Authority: GB
Inventors: Mark Shaw; John Dixon
Original assignee: Parkside Flexibles Europe Ltd
Current assignee: Parkside Flexibles Europe Ltd
Priority date: 2014-05-27
Filing date: 2014-05-27
Publication date: 2015-12-02
Also published as: GB201409332D0; WO2015181523A1; EP3148794A1

Abstract

A laminate has multiple layers with adhesive therebetween, each layer has an aperture offset from the aperture of another layer, and a channel extends between the layers to form a vent through the packaging. The adhesive in the channel can be different from the surrounding adhesive, for example because it is releasable rather than permanent, because it is a thinner layer, because it is less sticky or because it is missing altogether. There can be two or three layers in the laminate, one of which is metallic. The sheet can surround tobacco, either around or within a box.

Description

LAMINATE FOR FORMING A PACKAGE

Technical Field

This disclosure relates to a wrapper for forming a package.

Background

It is desirable that packaged commodities remain fresh for consumption for as long as possible. Examples of commodities which are packaged to remain fresh are cigarettes and other tobacco industry products. A conventional way of packaging cigarettes is to wrap the cigarettes within a foil paper, with the foil paper lying within a card box. A plastic wrapper may surround the card box. The plastic wrapper is typically discarded when the pack is first opened, and provides an indication that the pack has not previously been opened.

More recently, cigarettes have been packaged with a multi-layer laminate wrapper.

The laminate wrapper can be provided with a resealable opening. The laminate wrapper can be provided within a card box or can be provided around the outside of a card frame. The laminate can remain in place after the package has been opened.

A further way of preserving the contents of a package is by removing some, or all, of the atmospheric air from the interior of the package. The interior of the package can be pressurised with an inert gas (e.g. nitrogen) or can be sealed at a sub-atmospheric pressure.

The package can comprise a valve to maintain a pressure differential between the interior of the package and the exterior of the package.

There is a requirement for alternative packaging which can help to preserve a packaged commodity.

Summary

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

There is provided a laminate for forming a package comprising a first layer; a second layer; a &st adhesive layer between the first layer and the second layer; a fWst opening in the first layer; a second opening in the second layer at a position laterally offset from the first opening; a flow channel between the openings which is openable and closable in response to a pressure differential.

The first adhesive layer may comprise a resealable adhesive where the flow channel is formed.

The first adhesive layer may comprise a resealable adhesive having a first tack strength where the flow channel is formed and a resealable adhesive having a second tack strength where the flow channel is not formed, wherein the first tack strength is lower than the second tack strength.

The first adhesive layer may comprise a first thickness of adhesive where the flow channel is formed and a second thickness of adhesive where the flow channel is not formed, wherein the first thickness is less than the second thickness.

The first adhesive layer may comprise a resealable adhesive where the flow channel is formed and a permanent adhesive where the flow channel is not formed.

The first adhesive layer may comprise a region free of adhesive where the flow channel is formed and an adhesive where the flow channel is not formed.

The first adhesive layer may comprise one of a permanent adhesive and a resealable adhesive.

The laminate may further comprise a third layer, a second adhesive layer between the second layer and the third layer; and a third opening in the third layer.

The third opening in the second layer may be at a position laterally offset from the second opening and the laminate may further comprise a second flow channel between the second and third openings which is openable and closable in response to a pressure differential.

The second adhesive layer may comprise a resealable adhesive where the second flow channel is formed.

The second adhesive layer may comprise a resealable adhesive having a third tack strength where the second flow channel is formed; and a resealable adhesive having a fourth tack strength where the second flow channel is not formed, wherein the third tack strength is lower than the fourth tack strength.

The second adhesive layer may comprise a third thickness of adhesive where the second flow channel is formed; and a fourth thickness of adhesive where the second flow channel is not formed, wherein the third thickness is less than the fourth thickness.

The second adhesive layer may comprise a resealable adhesive where the second flow channel is formed; and a permanent adhesive where the second flow channel is not formed.

The second adhesive layer may comprise a region free of adhesive where the second flow channel is formed; and an adhesive where the second flow channel is not formed.

The second adhesive layer may comprise one of a permanent adhesive and a resealable adhesive.

One of the layers may be a foil layer or a metallised polymer layer.

There is also provided a package comprising a laminate wrapper.

The package may further comprise a container for containing a quantity of a product, wherein the wrapper is an outer wrapper located around the container.

The wrapper may be located around a quantity of a product. The package may further comprise a container with an openable portion, wherein the quantity of the wrapper-enclosed product is within the container and wherein the openable portion of the wrapper is located beneath the openable portion of the container.

The product may be a tobacco industry product.

There is also provided a method of manufacturing a laminate for forming a package comprising: providing a first layer of sheet material; providing a second layer of sheet material; applying a first adhesive layer between the first layer and the second layer; forming a first opening in the first layer; forming a second opening in the second layer at a position laterally offset from the first opening; wherein the step of applying a first adhesive layer forms a flow channel between the openings which is openable and closable in response to a pressure differential.

An advantage of this laminate is that there is no need to provide a separate valve on the wrapper. Instead, a valve function is performed by the layers of the laminate wrapper used to form a package. This saves an additional valve fitting step, and machinery required to fit the valve to a laminate. It also has an advantage of reducing the quantity of materials required to form the package.

The preferred features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the invention.

Brief Description of the DrawinQs

Embodiments of the invention will be described, by way of example, with reference to the following drawings, in which: Figure 1A shows an assembled package; Figure 1 B shows a container which fits within the package; Figure 1C shows the assembled package in an opened state; Figure 2A shows a plan view of the outer wrapper of the package; Figure 28 shows a cross-section along A-A' of Figure 2A; Figure 2C shows a plan view of a second (inner) layer of Figure 28; Figure 2D shows a plan view of the adhesive layer between the first and second layers of Figure 28; Figure 3 shows a flow channel with a variable thickness of adhesive between layers; Figure 4A shows one example of a flow channel formed in a three-layer laminate; Figure 48 shows another example of a flow channel formed in a three-layer laminate; Figure 5 shows a production process using two types of adhesive; Figure 6 shows a production process using a variable thickness of adhesive; Figure 7 shows a web of laminate resulting from the process of Figure 5 or 6; Figure 8 shows a method of packaging tobacco industry products.

Common reference numerals are used throughout the figures to indicate similar features.

Detailed Description

Embodiments of the present invention are described below by way of example only.

These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.

Figures lA-iC show an example packageS. The package in Figures lA-iC is for tobacco industry products, such as cigarettes. More generally, a package can be provided for any type of packaged commodity. The packageS has a wrapper 10 of a flexible sheet material which has multiple layers. This will be described as a multi-layer laminate.

The packageS also comprises a container 50 containing a quantity of tobacco industry products. The container 50 is shown in Figure lB. The wrapper 10 shown in Figure 1A is wrapped around the container 50. The container 50 can comprise, for example, a box, a frame or any other structure for containing the products. The container may not enclose the products on all faces. For example, it may lack at least part of a top end face. The container can be formed of card, a polymer material, or any other suitable material. The material may be biodegradable. The example container 50 shown in Figure 16 has a front panel Si, a back panel 52, two side panels 53, 54, a base 55 and a partial top panel 58. A cut-out 58 is located in an upper central part of the front panel 51 and in a central part of the top panel 56.

The cut-out 58 corresponds to the location of an openable portion 20 of the wrapper 10.

The outer wrapper lois sealed in an airtight manner (i.e. hermetically sealed) around the container 50. The outer wrapper 10 shown in Figure 1A is intended to remain around the container after the package has been opened for the first time. The outer wrapper 10 has an openable portion 20 which can be opened, by a user, to define an opening in the wrapper 20 to provide access to the cigarettes. The openable portion 20 can be defined by a line of weakness 45 in at least one layer of the wrapper 10. In this example, the openable portion 20 is a flap. Figure 1A shows the flap 20 in a closed configuration, in which the flap 20 seals the outer wrapper 10. Figure 1 C shows the flap 20 in an open configuration, in which the flap 20 is pulled back to allow access to the interior of the wrapper 10. The flap 20 remains connected to the remainder of the wrapper 10 after the flap has been opened. The container has a cut-out 48 in a region corresponding to the location of the openable portion 20.

The openable portion 20 can be reclosable or resealable. An advantage of this arrangement is that the products remain fresh after the package has been opened for the first time, as the outer wrapper 10 and the openable portion 20 continue to provide protection to the contents. An advantage of providing a wrapper 10 around a container 50 is that the container can be a simpler, lower cost, item as it no longer forms the exterior of the package.

For example, the exterior finish of the container can be a simpler, lower cost, finish (e.g. matt instead of glossy) and does not need to be printed.

The outer wrapper 10 also comprises a valve 30. There is no separate valve device filled to the laminate. Instead, the function of a valve 30 is unitary with, or integral with, the laminate wrapper 10. There is no need to provide a separate valve, orto secure a separate valve to the wrapper. Figure 1A generally shows a possible location for the valve 30.

The valve 30 is openable and closable in response to a pressure differential across the layers of the laminate in the region where the valve is formed. The pressure differential is between opposing sides of the laminate. For example, the valve 30 opens in response to a positive pressure differential (e.g. above a threshold value) between an interior of the package formed using the laminate and an exterior of the package formed using the laminate.

The valve 30 can close again in response to a pressure differential falling below a particular threshold value. For example, the valve 30 may close in response to the pressure differential between an interior of the package and an exterior of the package falling below a positive threshold value, or in response to a negative pressure differential, e.g. when the pressure surrounding the package is greater than the pressure within the package. The valve 30 can be used to evacuate gas from the interior of the package when the package is placed in a low pressure chamber. Thereafter, the valve 30 maintains the interior of the package at a sub-atmospheric pressure and prevents air from entering the interior of the package. This can help to preserve the freshness of the packaged products, by reducing the amount of atmospheric air in contact with the packaged products. During packaging, some of the atmospheric air is evacuated from the interior of the package 5. Some of the air within the package can be replaced by an inert gas, such as nitrogen, if desired, to further preserve freshness of the contents. The valve 30 can be located anywhere on the package, such as on an end face of the package, on a front face, back face or side face of the package.

Another possible location for the valve is the openable portion 20. The valve may be limited to one planar surface of the package, or may extend around two (or more) planar surfaces of the package. The valve may be re-used if needed, such that the interior of the package can be restored to a sub-atmospheric pressure after the package has first been opened.

The valve 30 functions as a one-way valve. When the interior of the package is at a higher pressure than the exterior of the package, pressure is exerted on the valve area from within the package and a flow channel of the valve opens to release air from within the package. When the interior of the package is at a lower pressure than the exterior of the package, external pressure is exerted on the valve area and the contents of the pack support the inner surface of the wrapper and prevent the flow channel of the valve from opening.

The container 50 provides support during a period when the interior of the wrapper is partially evacuated, and resists deformation of the package. The outer wrapper 10 provides a hermetic seal between an interior of the package and an exterior of the package when the interior of the package is at a sub-atmospheric pressure.

Figures 2A-2D show a region of the laminate wrapper where the valve 30 is formed within the layers of the laminate wrapper 10. Figure 2A shows the outside of the wrapper in plan view. The valve is hidden within the structure of the laminate layers. A small opening 35 is located on the outside of the package and another small opening 36 is located on the inside of the package. Figure 2B shows a cross-section through the laminate, along line A-A' of Figure 2A where the valve 30 is formed. Figure 2C shows the second (inner) layer 32 of the laminate in plan view. Figure 2D shows an adhesive layer 33 in plan view. It is important to note that a function of a one-way valve is provided within the layers 31, 32 of the laminate.

There are no additional layers added to the laminate in the region of the laminate where the valve is formed. Layers 31, 32 extend across the wrapper.

Referring to Figure 2B, the laminate used for the wrapper 10 comprises a first layer 31 and a second layer 32. The first layer 31 can be formed, for example, of a polymer material, such as a 20 micron orientated polypropylene (OFF). The second layer 32 can be formed of a polymer material, which may be the same as the first outer layer, ora different polymer material. The layers 31, 32 are laminated using an adhesive layer 33.

There are various possibilities for the adhesive used to laminate the layers 31, 32 together. A first possibility is to secure the layers 31, 32 together utilising a permanent lamination adhesive. In the region 34 of the laminate where the valve is formed, the permanent adhesive is not used. Instead, in the region 34 of the laminate where the valve 30 is formed, a non-permanent adhesive such as a Pressure Sensitive Adhesive (PSA) can be used or no adhesive is used at all. Another possibility is to secure the layers 31, 32 together utilising a non-permanent lamination adhesive, such as a Pressure Sensitive Adhesive (PSA).

In the region 34 of the laminate where the valve 30 is formed, the non-permanent adhesive can be varied in some way. For example, a PSA having a weaker bond can be used, or a reduced amount of PSA can be used. These options are described in more detail below.

An opening 35 is provided in the first layer 31. An opening 36 is provided in the second layer 32 at a position which is laterally offset from the opening 35 in the first layer 31.

A flow channel 34 is defined between the opening 35 and the opening 36. The flow channel 34 can comprise a resealable adhesive, such as Pressure Sensitive Adhesive (PSA) which can seal the flow channel 34 until a pressure differential between an interior of the package and the exterior of the package exceeds a predetermined value. In use, gas can pass from the interior 15 of the wrapper to the exterior via the opening 36, the flow channel 34 and the opening 35 when there is a suitable pressure differential between the interior 15 and the exterior. Atmospheric pressure at sea level is around l000mbar. The pressure within the package can be lower than atmospheric pressure. An example non-limiting range of pressures within the package is 300-700mbar. The valve of Figures 2A and 2B allows air to flow when the pressure within the wrapper 20 is greater than the pressure outside the wrapper by a predetermined amount. When the pressure within the wrapper 10 is lower than the pressure outside the wrapper by a predetermined amount, the flow channel will close and the interior space 15 is sealed.

Figure 2C shows the second layer 32 of the laminate in plan view. Figure 2D shows the adhesive layer of the laminate in plan view, with adhesive patterned on top of the second layer 32. The position of openings 35, 36 is shown for reference, but the openings are not formed in the layer shown in Figure 2C. An area 34 defines the flow channel of the valve between openings 35, 36. Area 34 can be left free of adhesive. Alternatively, area 34 can comprise a non-permanent, resealable, adhesive such as PSA. Area 34 can be an adhesive having a lower tack composition compared to the adhesive used across area 33.

Alternatively, area 34 can be an adhesive having the same tack composition compared to the adhesive used across area 33, but the thickness of adhesive can be reduced in area 34 compared to area 33. Figure 3 shows an example of a valve 30 with a reduced thickness of adhesive in the region 34 of the fluid channel of the valve. Another possibility is to use a combination of different adhesive composition and thickness.

Figures 2A-2D show a simple case of a single flow channel 34 between openings 35, 36. There can be multiple flow channels formed in the adhesive layer. Each flow channel can have a respective pair of openings 35, 36. Aternatively, flow channels may share a common opening. For example, each flow channel may have a respective opening 35 in the first layer 31, and the flow channels may share a common opening 36 in the second layer (or vice versa).

A possible, non-limiting, range of layer thicknesses for duplex laminates incorporating the valve 30 is 20 micron (first layer)/20 micron (second layer) up to 40 micron (first layer)/100 micron (second layer), where the "first laye(' can be the inner layer or the outer layer of the laminate.

The valve 30 shown in Figure 26 is one possible example of a one-way valve. The valve 30 shown in Figures 28 and 38 is formed in a laminate with two-layers 31, 32. The laminate can comprise further layers.

Figures 4A and 48 show examples of valves formed in a laminate with three layers 31, 32, 41. A third layer 41 and a further adhesive layer 42 are provided in the laminate. In Figure 4A there is a third layer 41 adjacent layer 32 and a further adhesive layer 42 between the second layer 32 and the third layer 41. In Figure 4A and Figure 46 a fluid channel of the valve is formed between the first layer 31 and the second layer 32. Opening 36 extends through the second layer 32 and the third layer 41. Adhesive between the laminate layers which do not contain the fluid channel can be a permanent adhesive or a strong resealable adhesive (e.g. strong PSA). Another possibility (not shown) is for a second fluid channel between the other pair of laminate layers. For example, in Figure 4A a second fluid flow channel can be provided between the second layer 32 and the third layer 41. The position of the hole in the third layer 41 can be laterally offset from the hole in the second layer 32. As with the first fluid flow channel, the region where the second fluid flow channel is formed can be left free of any adhesive, or can include a resealable adhesive (e.g. PSA) or a reduced thickness of resealable adhesive compared the rest of the adhesive layer. The adhesive(s) used in the adhesive layer 42 can be the same, or can be different to, the adhesive(s) used for the other adhesive layer. The relative strengths of the adhesive(s) used in the adhesive layer 42 can be the same, or can be different to, the relative strengths of the adhesive(s) used for the other adhesive layer. The thicknesses of the adhesive used in the adhesive layer 42 can be the same, or can be different to, the thicknesses of the adhesive used for the other adhesive layer.

In a three layer laminate, the intermediate layer (e.g. layer 41 in Figure 4A, 46) can be a metal layer foil, such as an Aluminium foil. A foil layer is particularly advantageous at providing a moisture barrier to maintain freshness. Alternatively, the intermediate layer can be a metallised filmic layer, e.g. Polyethylene terephthalate (PET), oriented polypropylene (OFF), compostable polymer or any alternative metallic film. These can be a single layer without adhesive between the film and metal as they are generally produced by metal deposition. In a two layer laminate, one of the two layers can be a metallised filniic layer.

In one possible embodiment the outer wrapper 10 can incorporate a tear-oft strip and the entire outer wrapper, or a part of the outer wrapper, can be disposed of when the package is first opened. A possible location of the one-way valve 30 is within the tear-off strip on the outer wrapper. The tear-off strip may be provided on the outer wrapper to provide evidence that the package has not been tampered with.

Figure 5 schematically shows a manufacturing process for producing a laminate with a valve integrated into the layers of the type where a different adhesive is used for the region where the valve is located. A first (strong) adhesive is used for the region where the valve is not formed. A second (weak) adhesive is used for the region where the valve is formed. The process uses a quantity 101 (e.g. a roll) of sheet material of the first layer 31 and a quantity 103 of sheet material of the second layer 32. At stage 102 the strong adhesive is applied to the first layer 31 in a region where the valve is not to be formed. At stage 104 the weak adhesive is applied to the second layer 32 in a region where the valve is to be formed. The first adhesive can be a permanent adhesive and the second adhesive can be a resealable adhesive (e.g. PSA). Alternatively, the first adhesive and the second adhesive can be different compositions of resealable adhesives having different tack strengths. At stage 105 the wet" sides of the two layers 31, 32 are brought together. Pressure is applied to seal the layers 31, 32 together. The resulting laminate is stored 106. Before storage, the laminate can be processed to form the openings 35, 36 of the valve in the laminate. The openings can be formed by laser cutting or by a mechanical process. In a laser cutting process, a laser forms a cut using a wavelength which is tuned to a particular layer of the laminate. Before storage, the laminate can be processed to form any other cuts or other lines of weakness required in the laminate, such as a cut of line of weakness to define an openable portion of the wrapper.

Figure 6 schematically shows a manufacturing process for producing a laminate with a valve integrated into the layers of the type where a different thickness of adhesive is used for the region where the valve is located. A first thickness of adhesive is used for the region where the valve is not formed. A second, reduced, thickness of adhesive is used for the region where the valve is formed. The process uses a quantity 101 (e.g. a roll) of sheet material of the first layer 31 and a quantity 103 of sheet material of the second layer 32. At stage 110 the adhesive is applied to the first layer 31. The adhesive is applied from an engraved gravure cylinder which delivers differing adhesive thickness areas to the layer 31.

At stage 105 the two layers 31, 32 are brought together. Pressure is applied to seal the layers 31, 32 together. The resulting laminate is stored 106. As with Figures, the laminate can be processed to form the openings 35, 36 of the valve in the laminate and to form any other cuts or other lines of weakness required in the laminate.

Figure 1 shows a web 120 of laminate for forming packages. The web can result from one of the processes shown in Figure 5 or 6. The web 120 comprises a plurality of laminate segments 121, each for forming a package. Each laminate segment 121 includes a valve 30 formed within the layers of the laminate structure and openings on respective sides of the web. Each segment 121 can also include one or more lines of weakness for defining an openable portion of the package. At a packaging line, the web 120 is separated into the laminate segments 120 and each segment is used to form packages. The laminate segment 121 may be used to form a sealed package. Packages may be formed by heat sealing, adhesive or any other techniques.

The package can be designed for any quantity of tobacco industry products and is not limited to standard shapes and sizes.

The lines of weakness described above may be formed by cutting a laminate material using lasers. Other cutting techniques may be utilised as appropriate, for example the cuts may be formed in the layers prior to lamination, or different cutting technologies may be used.

Figures lA-iC show a package where the wrapper 10 is sealed around the container 50. In an alternative example, the wrapper 10 can be located within a container, such as a conventional flip-top box.

In Figures 1A and 1C the sheet is used as a wrapper. The sheet can be used to form other types of package, such as a bag or pouch.

A method of packaging a commodity will now be described with reference to Figure 8.

At step 701 a quantity of a commodity (e.g. tobacco industry products such as cigarettes) are fitted within a container, such as a frame or box. At step 702 an outer wrapper is added around the container. The outer wrapper comprises at least a single layer flexible sheet material. The outer wrapped is sealed, such as by induction heating or adhesive, to provide a hermetic seal between an interior of the package and an exterior of the package. At step 703 the interior of the package is partially evacuated to a sub-atmospheric pressure. A one-way valve is provided in, or on, the outer wrapper, wherein the one-way valve is capable of maintaining a pressure differential between the interior of the package and the exterior of the package when the interior of the package is at the sub-atmospheric pressure. The one-way valve can be provided as part of the wrapper. One way of partially evacuating the interior of the package to a sub-atmospheric pressure comprises evacuating an environment surrounding the package to a sub-atmospheric pressure. This causes a pressure differential between the interior of the package and the surrounding environment (i.e. interior pressure higher than surrounding pressure). This causes air to flow out of the package, through the one-way valve. Subsequently, the package is moved to an environment with a normal atmospheric pressure. The one-way valve prevents air from flowing into the package, as the pressure within the package is lower than the pressure surrounding the package.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

Any reference to an' item refers to one or more of those items. The term comprising' is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

It will be understood that the above description of a preferred embodiment is given by way of example only and that various modifications may be made by those skilled in the art.

Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention.

Claims

Claims 1. A laminate for forming a package comprising: a first layer; a second layer; a first adhesive layer between the first layer and the second layer; a first opening in the first layer; a second opening in the second layer at a position laterally offset from the first opening; a flow channel between the openings which is openable and closable in response to a pressure differential.
2. A laminate according to claim 1 wherein the first adhesive layer comprises a resealable adhesive where the flow channel is formed.
3. A laminate according to claim 2 wherein the first adhesive layer comprises: a resealable adhesive having a first tack strength where the flow channel is formed; and a resealable adhesive having a second tack strength where the flow channel is not formed, wherein the first tack strength is lower than the second tack strength.
4. A laminate according to claim 2 or 3 wherein the first adhesive layer comprises: a first thickness of adhesive where the flow channel is formed; and a second thickness of adhesive where the flow channel is not formed, wherein the first thickness is less than the second thickness.
5. A laminate according to claim 1 wherein the first adhesive layer comprises: a resealable adhesive where the flow channel is formed; and a permanent adhesive where the flow channel is not formed.
6. A laminate according to claim 1 wherein the first adhesive layer comprises: a region free of adhesive where the flow channel is formed; and an adhesive where the flow channel is not formed.
7. A laminate according to claim 6 wherein the first adhesive layer comprises one of: a permanent adhesive and a resealable adhesive.
B. A laminate according to any one of the preceding claims further comprising: a third layer; a second adhesive layer between the second layer and the third layer; a third opening in the third layer.
9. A laminate according to claim 8 wherein the third opening in the second layer is at a position laterally offset from the second opening and the laminate further comprises a second flow channel between the second and third openings which is openable and closable in response to a pressure differential.
10. A laminate according to claim 9 wherein the second adhesive layer comprises a resealable adhesive where the second flow channel is formed.
11. A laminate according to claim 10 wherein the second adhesive layer comprises: a resealable adhesive having a third tack strength where the second flow channel is formed; and a resealable adhesive having a fourth tack strength where the second flow channel is not formed, wherein the third tack strength is lower than the fourth tack strength.
12. A laminate according to claim 10 or 11 wherein the second adhesive layer comprises: a third thickness of adhesive where the second flow channel is formed; and a fourth thickness of adhesive where the second flow channel is not formed, wherein the third thickness is less than the fourth thickness.
13. A laminate according to claim 9 wherein the second adhesive layer comprises: a resealable adhesive where the second flow channel is formed; and a permanent adhesive where the second flow channel is not formed.
14. A laminate according to claim 9 wherein the second adhesive layer comprises: a region free of adhesive where the second flow channel is formed; and an adhesive where the second flow channel is not formed.
15. A laminate according to claim 14 wherein the second adhesive layer comprises one of: a permanent adhesive and a resealable adhesive.
16. A laminate according to any one of the preceding claims wherein one of the layers is a foil layer or a metallised polymer layer.
17. A package comprising a laminate wrapper according to any one of the preceding claims.
18. A package according to claim 17 and further comprising a container for containing a quantity of a product, wherein the wrapper is an outer wrapper located around the container.
19. A package according to claim 17 wherein the wrapper is located around a quantity of a product, the package further comprising a container with an openable portion, wherein the quantity of the wrapper-enclosed product is within the container and wherein the openable portion of the wrapper is located beneath the openable portion of the container.
20. A package according to claim 18 or 19 wherein the product is a tobacco industry product.
21. A method of manufacturing a laminate for forming a package comprising: providing a first layer of sheet material; providing a second layer of sheet material; applying a first adhesive layer between the first layer and the second layer; forming a first opening in the first layer; forming a second opening in the second layer at a position laterally offset from the first opening; wherein the step of applying a first adhesive layer forms a flow channel between the openings which is openable and closable in response to a pressure differential.
22. A method according to claim 21 wherein the first adhesive layer comprises a resealable adhesive where the flow channel is formed.
23. A method according to claim 22 wherein the first adhesive layer comprises: a resealable adhesive having a first tack strength where the flow channel is formed; and a resealable adhesive having a second tack strength where the flow channel is not formed, wherein the first tack strength is lower than the second tack strength.
24. A method according to claim 22 or 23 wherein the first adhesive layer comprises: a first thickness of adhesive where the flow channel is formed; and a second thickness of adhesive where the flow channel is not formed, wherein the first thickness is less than the second thickness.
25. A method according to claim 21 wherein the first adhesive layer comprises: a resealable adhesive where the flow channel is formed; and a permanent adhesive where the flow channel is not formed.
26. A method according to claim 21 wherein the first adhesive layer comprises: a region free of adhesive where the flow channel is formed; and an adhesive where the flow channel is not formed.
27. A method according to claim 26 wherein the first adhesive layer comprises one of: a permanent adhesive and a resealable adhesive.