AU2011256139B2

AU2011256139B2 - A package and process

Info

Publication number: AU2011256139B2
Application number: AU2011256139A
Authority: AU
Inventors: Danny Smith
Original assignee: Amcor Pty Ltd
Current assignee: Amcor Pty Ltd
Priority date: 2010-05-19
Filing date: 2011-05-19
Publication date: 2017-01-12
Anticipated expiration: 2031-05-19
Also published as: WO2011143708A1; AU2011256139A1

Abstract

The present invention relates to a process and packaging, wherein the process includes applying adhesive to sections of the surface of a substrate in a non-uniform manner to form regions containing more adhesive than others, and placing the sections of adhesive together to form a sealed seam. One of the advantages of the present invention is that the amount of the adhesive required to form a sealed seam is able to be reduced.

Description

WO 2011/143708 PCT/AU2011/000589 - 1 -

A PACKAGE AND PROCESS

Field Of The Present Invention 5 The present invention relates to a package for a product such as food and a process for making seams of the package.

Background Of The Present Invention ίο A type of package that is widely used for snack bars and other convenience foods is a satchel comprising a polymeric wrapper that is resistant to air and moisture ingress so as to maintain its contents fresh and unspoilt for an extended period. During manufacture of the satchel, the wrapper is folded about the food item so that lengthwise sections of the wrapper are overlaid and sealed together to form a 15 longitudinal seam, and similarly, widthwise sections of the wrapper are overlaid and sealed at opposite ends of the food item to form end seams to totally enclose the item in a sealed satchel. The longitudinal seam and end seams may be sealed by heat and pressure welding or, alternatively, by a glue. In the case where the glue has been employed, a homogeneous coating of glue of uniform thickness and typically width is 20 applied to the surfaces of the wrapper to be sealed together.

The cost of packaging food items is dependent on range of variables including the amount of polymeric wrapper used, and in the case where the seams are formed using a glue, the consumption of glue. However a reduction in the amount of adhesive 25 applied to form a seam may be limited by the need to apply a prescribed amount of glue. In particular, if an insufficient amount of adhesive is applied the resulting glue thickness may be insufficient to form a sufficient bond.

Satchel type packaging is used for many other products besides convenience foods. 30 For example, satchel type packaging made from polymeric materials is used for dried foods and even non-food items such as components and consumer products. When used to form satchels, adjacent surfaces of polymeric package are adhered together by one of two common techniques. The first technique is to ‘weld’ the adjacent surfaces together by the application of heat where the adjacent surfaces are joined. 35 The second technique is to use an adhesive as described in this specification. In addition adhesives are used to join together other types of materials, for example paper based packaging, and even items of steel in some industrial applications such PCT/AU2011/000589 WO 2011 /143708 - 2 - as carmaking. A common feature of these applications is that a seam is formed to join together adjacent surfaces.

It is an object of the present invention to provide an alternative package and a process 5 for making the package that is suitable for food items and other products.

Summary Of The Present Invention

The present invention is based on the realisation that it is possible to reduce the ίο amount of adhesive required to form a sealed seam by applying adhesive non-uniformly to surfaces to be joined together during a manufacturing process.

Accordingly, the present invention relates to a process including the steps of: a) applying an adhesive to sections of the substrate in amounts so that the is sections can be adhered together, wherein the adhesive is applied non-uniformly to at least one of the sections so that there are, • first regions of the at least one section at which the adhesive is applied in a required amount so that the first regions can adhere to another of the sections to form a seal, and 20 · second regions of the at least one section at which the adhesive is applied in an amount that is less than the amount applied to the first regions; and b) placing together the sections of the substrate to which the adhesive has been applied in step a) to form a sealed seam of a package. 25 The sealed seam may form part of the seams of a package for a product.

Step a) may include applying the adhesive non-uniformly to the sections that are adhered together, in which the adhesive is applied to the first regions of each section in an amount so that the first regions of the different sections can adhere together to form 30 a sealed seam, and adhesive is applied to the second regions of each section in an amount that is less than the amount applied to the first regions. In other words, the adhesive may be applied so that the first and second regions are present on each of the sections that are intended to be sealed together. It is also within the scope of the present invention that step a) may include applying the adhesive to a first section of the 35 substrate having the first and second regions, while adhesive is applied uniformly or without the first and sections regions to another section that joined in step b) with the PCT/AU2011/000589 WO 2011/143708 - 3 - first section. For example, the adhesive may be applied at a covering to the other section at a loading that equal or is greater than the loading applied to the first region.

Throughout this specification references are made to an amount or loading of adhesive 5 being applied to the substrate. It is expected that these terms are used interchangeably to describe that the adhesive is applied at a coverage of mass per unit area.

Adhesive applied to the substrate suitably forms a perimeter about an inner area of the ίο substrate that is free of adhesive for contacting a product contained by the substrate. The perimeter of adhesive defining the inner area may be partly or completely formed by the sections of adhesive applied according to step a).

The substrate may include a series of segments for forming separable packages, and is in which case step a) may include applying the sections of adhesive about an inner area of each segment that is free of adhesive for contacting the product.

The sections of adhesive may be applied to peripheral areas and peripheral sections of the segments. Although the sections of adhesive may be applied to only part of the 20 peripheral areas of the segments, suitably, the sections of adhesive applied according to step a) extend about an entire peripheral area of the segments. A package such as a satchel is able to be formed by placing together the sections of adhesive about the peripheral area of the substrate to form a closed satchel. 25 The substrate may be a continuous roll of the substrate and the adhesive is applied to the substrate to form a line of segments on the substrate, each segment includes the sections of adhesive having the first and second regions applied according to step a) which can be placed together to form a sealed seam. Suitably, the adhesive is applied to the substrate after the substrate has been unwound from the roll. 30

The process may include a pre-treatment step in which the substrate is exposed to a plasma treatment including a corona treatment prior to the applying the adhesive. The purpose of the pre-treatment step is to increase the surface energy and, in turn, the strength of the bond of the adhesive to the substrate. 35

The process may include severing the segments from the continuous roll of the substrate, and suitably severing the segments consecutively one after the other. The PCT/AU2011/000589 WO 2011/143708 - 4 - segments may be interconnected by preformed frangible lines of the weakness which are severed after the adhesive has been applied according to step a). In another embodiment, the segments may be severed by cutting the substrate. Suitably, the severing step is carried out after the adhesive has been applied to the segments. 5

The amount of adhesive applied to the second regions may be at a loading or any amount that is less than the loading or amount applied to first region. Suitably, step a) involves applying the adhesive to the first regions only, and without applying adhesive to second regions. In other words, adhesive is not applied to the second region during ίο step a). In this example, the first regions may be referred to as applied regions and the second regions may be referred to as blank regions.

Suitably, the first regions cover at least 50% of the area of the section(s), and even more suitably at least 60% or 70% of the area of the section(s), and yet even more 15 suitably at least 75% of the area of the section(s). Suitably the second regions occupy the remaining area of the section(s) of the substrate. It is also possible that the sections may include other regions at which the adhesive is applied in amounts greater or less than the amounts applied to the first or second regions. For example, adhesive may be applied to the first region in a minimum amount to form a sealed seam, 20 adhesive may be applied to the second region in an amount less than the amount applied to the first regions and adhesive may not be applied to a third region of the sections.

In an embodiment, the adhesive is applied to the first sections at an amount as 25 recommended by the supplier of the adhesive to suit the substrate and other manufacturing conditions.

The adhesive may be applied to the first regions at an amount of at least 2.5 gm/m2. Suitably, the adhesive is applied to the first regions at an amount of at least 3.0 gm/m2 30 or suitably in an amount of at least 3.5 gm/m2. The adhesive may be applied to the first regions in an amount from 2.5 to 5.0 gm/m2 and suitably from 3.0 to 4.0 gm/m2. It will be appreciated that the amount of the adhesive applied to the first regions will depend on factors such as the types of the adhesive and the properties of the substrate including the strength of adhesion to the substrates. It therefore follows that 35 other amounts of the adhesive may be sufficient to achieve an adequate seal. PCT/AU2011/000589 WO 2011/143708 - 5 -

It will be appreciated by those skilled in the art that once the sections of the flexible substrate have been placed together, it is possible that the adhesive may be spread to the second regions. 5 For instance in an embodiment, step b) may include applying pressure to the sections of the substrate that have been placed together, and while applying pressure, it is possible that the adhesive may spread from the first regions to the second regions. In another situation the adhesive may, prior to setting, having a relative low viscosity, which allows the adhesive to spread or run prior to, or after, the sections of the ίο substrate have been placed together.

Step b) may include aligning the first regions of the sections so that the first regions register in an overlaid relationship so as to form a seal therebetween. However in some cases, and probably in the majority of cases, packaging machinery will be unable 15 to function at the tolerances necessary to align the first regions of different sections.

Accordingly the adhesive may be applied in step a) so that the first and second regions form patterns of adhesive applied to the substrate. In one example, the second region may be areas that define a pattern that is adhesive free, and the first region may be 20 defined by areas in which the adhesive is applied in a pattern.

Step a) may include applying the adhesive in the first regions of the sections to be joined together in the same pattern. Although the patterns of adhesive of the first regions of each section may be the same, ideally, the relative positions of the patterns 25 in the sections that are joined together in step b) may be different.

In one example, adhesive is applied to the first regions of two longitudinal sections of the same configuration of the substrate and are intended to be adhered together such that the first regions of one longitudinal section is at least partially offset relative to the 30 location of the first regions of the other longitudinal section. When the sections are placed together, the first regions of the sections at least partially overlap such that first region of one section overlays the first region and second region of the another section and vice versa. 35 When the sections of the substrate are placed together in accordance with step b), a majority of each of the first regions of one section contact with, or adhere to, at least two of the first regions of another section. In other words, the first regions of the PCT/AU2011/000589 WO 2011/143708 - 6 - different sections interconnect with each other when the sections are placed together. In other words, the first regions of the different sections interconnect or contact to some extent to form a sealed seam. 5 Step a) may include applying the adhesive in the first regions in a pattern that is asymmetric about an axis of the substrate.

The section(s) of the flexible substrate to which the adhesive is applied may be a peripheral section(s) that include, for example,: i) a peripheral lengthwise section that ίο extends along the length of the substrate and ii) peripheral width section(s) that extend along the width of the substrate.

The first region may include a pattern of adhesive applied in strips. 15 Suitably, the adhesive strips may be arranged so as to form ring formations that are arranged in layers. The ring formations may extend about the peripheral sections of the substrate. The ring formations may include closed loop formations or in another variant, the ring formations may be a spiral formation. 20 The second regions may include a pattern of adhesive or a pattern free of the adhesive in strips.

The patterns of adhesive of the second region may also include ring formations. The ring formations may extend about peripheral sections of the substrate. The ring 25 formations may also include closed loop formations or in a variant in a spiral formation.

The strips of the first and second regions may include linear segments of adhesive.

The adhesive pattern of the first and second region may have a non-linear profile. The 30 adhesive pattern of the first and second region may also have linear profile.

The pattern of adhesive of the first regions may include the adhesive being applied in dot formations. The dot formations may be isolated from another dot formation by the second region, i.e., the second regions surround each dot formation of adhesive of the 35 first regions. The dot formations may have any geometric shape including circular, quadrangular, rectangular, square, triangular, figure 8, bean or hour glass shapes. PCT/AU2011/000589 WO 2011/143708 - 7 -

The adhesive pattern of the first region may include a semi-continuous or discontinuous coating of the adhesive that extends across the sections and includes a series of isolated second regions that are distributed over the first region. Suitably, the second regions do not include adhesive. Suitably, the isolated blank regions include 5 dot formations of any geometric shape including cross formations.

In an embodiment, the process includes wrapping or folding the substrate about the item being packaged before placing together the sections of the flexible substrate in according with step b). 10

The adhesive may be applied by a variety of padding, inkjet or spraying techniques. However, according to an embodiment, the adhesive is applied using one or more rollers in which the adhesive applied transfers from a roller onto the flexible substrate. For instance, the roller may be a lithographic, flexographic or gravure roller. 15

The substrate may be a flexible substrate that can be folded.

The flexible substrate used in some embodiments of this invention may be any polymeric film including metallised and non-metallised polymeric films, or paper pulp 20 substrates including paper, cardboard, corrugated board. The flexible substrate may also have a laminated structure including both polymeric and paper based materials laminated together.

The substrate may also be a roll of continuous web, for instance a web that is fed 25 continuously between a roller applying adhesive to the substrate and a backing roll.

The flexible substrate may also be in the form of separate sheets that are fed sheet-bysheet.

The adhesive may be any form of adhesive including cold glue, hot glue, and two part 30 glues such as epoxy glues.

The adhesive may be applied so that the first and second regions are present on each of the sections that form longitudinal seams of the package. The adhesive may also be applied so that the first and second regions are present on each of the sections that 35 form non-longitudinal seams or end seams of the package. PCT/AU2011/000589 WO 2011/143708 - 8 -

Accordingly, the present invention may relate to a process for packaging an item such as food and other perishable items, the process including the steps of: a) applying an adhesive to sections of the flexible substrate, wherein the adhesive 5 is non-unifomnly distributed so that there are applied regions within the sections to which the adhesive is applied, and blank regions within the sections without the adhesive; and b) placing together the sections of the substrate to which the adhesive has been ίο applied in step a) to form a sealed seam.

The present invention also relates to a package for food and other perishable items, the package including a flexible substrate and an adhesive applied to two or more sections of the substrate which, when the substrate is wrapped about the item, adhere 15 together to form a closed seam, wherein the adhesive is applied to at least one of the sections so that there are: • first regions at which the adhesive is applied in a required amount so that two of the first regions can adhere together to form a seal, and • second regions at which the adhesive is applied in an amount that is less than 20 the amount applied to the first regions.

Suitably, the first and second regions as described in the paragraph immediately above may be present when adhesive is initially applied to the substrate, and thereafter merged together. However, the first and second regions may also exist when the 25 adhesive has set.

The present invention also relates to a package for food and other perishable items, the package including a flexible substrate and an adhesive applied to two or more sections of the substrate which, when the substrate is wrapped about the item, adhere 30 together to form a closed seam, wherein the adhesive is distributed over the sections so that there are adhesive regions (that include the applied adhesive) and blank regions within the sections without the adhesive.

The package may also include any one or a combination of the features of the process 35 of the present invention described herein. WO 2011/143708 PCT/AU2011/000589 - 9 -

Brief Description Of The Drawings A series of embodiments of the present invention will now be described with reference to the accompanying drawings, of which Figures 1 to 9 are plan views of nine separate 5 embodiments of flexible substrates for packaging perishable items. Each figure illustrates a different pattern over which an adhesive has been applied to peripheral sections of the substrates so that the peripheral sections can be placed together to form a satchel having sealed seams. ίο Figure 10 is a block diagram of process steps according to an embodiment of the present invention.

Figure 11 is schematic illustration of the steps of applying adhesive to a continuous roll of substrate, the adhesive being applied to peripheral areas of segments and severing 15 the segments.

Figures 12 and 13 schematically illustrate perspective and end views of a package according to an embodiment of the present invention. 20 Detailed Description

As a matter of convenience, the same reference numerals have been used in the Figures to identify the same features or substantially the same features on the different embodiments. 25

The embodiments of the invention depicted in Figures 1 to 9 each comprise a rectangular flexible polymeric substrate 40. The Figures show individual patterns in which an adhesive is applied to the inner surface of the substrate in a non-uniform or non-homogeneous coating. The adhesive is applied in the sections having first regions 30 at which the adhesive is applied in a required amount so that two of the first regions can adhere together to form a seal, and second regions at which the adhesive is applied in an amount that is less than the amount applied at the first regions. In the case of embodiments shown in Figures 1 to 9 the first regions comprise patterns of adhesive shown in the lines and dots, and the second regions comprise blank regions 35 without adhesive. The adhesive is applied along peripheral sections, and specifically to lengthwise peripheral sections, identified by reference numeral 10 in Figure 1, and widthwise peripheral sections at the ends of the substrate identified by reference PCT/AU2011/000589 WO 2011/143708 - 10 - numeral 20 in Figure 2. An inner edge of the widthwise sections 20 include inwardly facing peaks and troughs along their length.

The adhesive may be any type of adhesive including cold adhesives, hot adhesives 5 and two part or epoxy adhesives. An example of a suitable cold adhesive is sold under the trade name Fullaseal 22/121 ™. Suitably, the Fullaseal 22/121 ™ adhesive is applied at an amount of 3.5mg/m2 in regions of the outer peripheral area where the coating is applied. A range of other cold suitable cold adhesives are also available under the trade name Bostik. 10

In the case of the embodiment shown in Figure 1, the pattern of adhesive of the first regions includes dots and a grid or lattice structure 21. In particular, the adhesive is applied in a grid structure comprising sets of linear strips that are arranged perpendicular to one another. The grid structure 21 is also angled to the length of the 15 substrate which includes a series of diamond shaped cells. A diamond shaped dot 22 of adhesive is applied inside each cell so as to from an annular blank region free of adhesive between the dot of adhesive and the blank region. Moreover, the dots 22 and grid structure 21 suitably comprise an adhesive that has been applied in an amount so that when the substrate is folded and the dots 22 and grid structure 21 20 contact the adhesive forms a seal. Spaces between the grid structure 21 and the dots 22 are free of adhesive i.e., in this instance form the second regions.

The embodiment shown in Figure 2 is essentially the same as the embodiment of Figure 1, save for two rings of cells 20 being substantially free of the adhesive. The 25 rings of cells extend along lengthwise and widthwise peripheral sections of the substrate.

The embodiment shown in Figure 3 comprises a pattern of adhesive in which the first regions are in the form of non-linear strips 23 extending widthwise at the end sections 30 of the substrate. In addition, the non-linear strips 23 of adhesive also extend in a widthwise direction along the length of the substrate. The non-linear strips of adhesive are separated by non-linear blank regions 24, i.e., the second regions that are narrower than the adhesive sections. 35 The embodiment shown in Figure 4 comprises an adhesive applied across lengthwise and widthwise peripheral sections 10 and 20 of the substrate. The adhesive is applied as a semi-continuous or discontinuous coating or layer that extends across the PCT/AU2011/000589 WO 2011/143708 - 11 - sections 10 and 20, and includes a series of isolated blank regions 25 that are distributed over the adhesive material. As can be seen, the isolated blank regions include cross formations 25 from which the adhesive is absent. 5 The embodiment shown in Figure 5 comprises an array of small dot formations 25 of adhesive applied across the lengthwise and widthwise peripheral sections 10 and 20 of the substrate. Each of the dot formations 25 are separated by blank regions that are free of adhesive. As can be seen, the dot formations 25 are evenly and consistently distributed over the sections 10 and 20 of the substrate. 10

The embodiment shown in Figure 6 is similar in concept to the embodiment shown in Figure 5. However, in contrast the embodiment in Figure 6 comprises an array of larger sized dot formations 25 of adhesive applied across the lengthwise and widthwise peripheral sections of the substrate. Each of the dot formations 25 are separated by 15 blank regions that are free of adhesive. As can be seen, the dot formations 25 are evenly and consistently distributed over the sections of the substrate.

The embodiment shown in Figure 7 comprises linear strips 26 of adhesive and the linear blank strips 27 without an adhesive that extend lengthwise and widthwise of the 20 peripheral sections. The linear adhesive strips 26 and the blank strips 27 are arranged in consecutive ring formations that form alternating layers of rings of adhesive and rings without adhesive. In addition as can be seen, two or more continuous or discontinuous adhesive strips and blank strips extend along inner portions of the widthwise sections. 25

The embodiment shown in Figure 8 is similar in concept to the embodiment shown in Figure 7 in the sense that both comprise strip of adhesive 26 and blank strips 27 free of adhesive that are arranged in ring formations. However, the embodiment shown in Figure 8 differs from the embodiment of Figure 7 in the sense that width of the 30 adhesive and blanks strips 26 and 27 is significantly narrower than the adhesive and blank strips 26 and 27 shown in Figure 8.

The embodiment shown in Figure 9 includes elongated dot formations 21 having a bean or hourglass shape. The dot formations 21 are aligned in the widthwise direction 35 of the substrate 40. PCT/AU2011/000589 WO 2011/143708 - 12 -

The embodiments shown in Figures 1 to 9 are examples in which the adhesive is applied to at least 60% of the area of the peripheral sections 10 and 20, and suitably at least 70% of the area of the peripheral sections 10 and 20. The adhesive is also suitably a cold glue sold under the trade name Fullaseal 22/121 and is applied at an 5 amount of at least 3.5 mg/m2. The adhesive applied in this amount enables the regions of adhesive to be adequately adhered together to form regions that are substantially resistant to the ingress of moisture and air.

In the case of the embodiments shown in Figures 1,2, 3, 4, 6 and 9, the adhesive is ίο applied in first regions and absent from second regions in the patterns described above. In addition, we have circled isolated sectors labelled by reference numeral 30 that identifies corresponding sectors on opposed sections of the substrate 40 that are intended to be placed together. Although the overall geometrical pattern of adhesive is the same, the layout of the pattern of adhesive and non-adhesive regions is offset for is the corresponding sectors. In this regard, the embodiments shown in Figures 1 and 2 are examples in which the pattern is offset by approximately half the width of the dot 22 or cell. The embodiment shown in Figure 3 is an example in which the patterns are offset by approximately half the width of the non-linear strips 23 for corresponding sector 30. The embodiment shown in Figure 4 is an example in which the patterns are 20 offset by approximately the half the width of each cross formation 25 for corresponding segments. The embodiments shown in Figures 6 and 9 are examples in which the dot and bean formations 21 are again offset in corresponding sections by approximately half the width of the formations 21. 25 One of the benefits of offsetting the regions of adhesive of sections is that when the sections are placed together a majority of the first regions of adhesive of the separate sections overlap, or at least partially overlap so as to form an array of interconnected regions of adhesive. We have found that can increase impermeability and/or strength of the seal formed. 30

Figure 10 is a block diagram of process steps according to a preferred embodiment of the present invention. The initial step includes applying the adhesive to a sheet of the substrate 40 to define multiple segments, each for forming a package on the sheet. Each segment may have peripheral sections including adhesive applied in a 35 quadrangular shapes according to the patterns of adhesive shown in Figures 1 to 9. The peripheral sections define a centralised portion free of adhesive for wrapping the product. According to an embodiment the substrate may be in the form of individual PCT/AU2011/000589 WO 2011/143708 - 13 - sheets on which the adhesive may be applied to define a multiple segments.

According to another embodiment, the substrate may be a continuous web wound into a roll and the substrate that passes through an adhesive application station including a roller that applies the adhesive. The segments may then be cut from the sheet to form 5 individual packages onto which a product may be loaded centrally onto the segments. The segment may then be closed to the form a sealed satchel about the product. In addition, the substrate may be exposed to a corona or plasma treatment to enhance the strength of the bond between the substrate and the adhesive. ίο Figures 1 to 9 and Figure 11 illustrate individual segments for forming packages.

Although the patters of the adhesive may be applied lengthwise and widthwise to peripheral sections, the peripheral sections may be i) applied up to the edge of the substrate, ii) spaced from the edge of the substrate, or iii) a combination of both. 15

Figure 11 illustrates a continuous web 41 of the substrate being unwound and passing through an adhesive application station 42 in which adhesive is applied in peripheral sections about a central blank region 43 for receiving a product. Following the adhesive application station 42, the continuous web 41 of material is then conveyed to 20 a cutting station 44 at which the web 41 is cut into individual segments for forming satchels for a product.

Figures 12 and 13 are schematic perspective and end views respectively of a stachel package 50 in which the peripheral sections of adhesive have been applied. 25

The segments 40 are wrapped about the product so that the opposed lengthwise peripheral sections 10 are placed together to form a longitudinal seam 51. The widthwise sections 20 are then closed to form ends of the satchel 50. In particular, the widthwise sections 20 are folded to form a centralised sub-section 52, two flanking 30 sub-sections 53 either side of the centralised sub-section 52 and two end sub-sections 54. The flanking sub-sections 53 may be longer than the centralised sub-section, but are preferably equal to, or smaller than the centralised sub-section 52. Substantially equal sized parts of the flanking sub-sections 53 adjacent to the centralised subsection 52 are folded over and bonded to the centralised sub-sections 52. The end 35 sub-sections 42 may then be placed and bonded together such that the end seam has, as shown in Figure 12 and 13, an inverted T-shape in which the centralised sub- PCT/AU2011/000589 WO 2011/143708 - 14 - section 52 and adjacent flanking sub-sections 53 form the top of the T-shape, and the leg of the T-shape includes the end sub-sections 54 bonded together.

Trials 5

We have also conducted a series of trials of the embodiments shown in Figures 1, 3, 4, 6, 7, and 9. The trials involved applying Fullaseal 2/121 ™, Fullaseal 22/121 ™, and Bostik™ cold glues using a gravure roller to polymeric substrates. The substrates to which Fullaseal 2/121 ™ was applied was subjected to a corona pre-treatment. The ίο substrates to which Fullaseal 22/121 ™ and Bostik™ adhesive were applied were not subject to a corona pretreatment. The respective glues were applied in an amount of equal to or greater than 3.5mg/m2 in the patterns of adhesive described above. Glue was not applied in the regions between the patterns of adhesive. 15 In addition, a control sample in which the glue was applied uniformly according to the standard and conventional technique over the sections to be bonded together was prepared for comparative purposes.

The glue was applied in sections having a width of 25mm and a length of at least 20 50mm. The sections were placed together and a pressure of approximately 2 bar was applied to the sections at ambient temperature to bond the sections together to form the test samples. After an appropriate period of time has lapsed to allow the glue to set, the samples were then delaminated over a length of 50mm. Table 1 below sets out the results of the peal tests. 25

The test results were measured in terms of grams-force per 25mm width of the sample. WO 2011/143708 PCT/AU2011/000589 - 15 - TABLE 1

Cold seal trials bond test (2 bar 0.5S) TYPE CONTROL Fig 1 Fig 4 Fig 7 Fig 3 Fig 6 Fig 9 Fullaseal 2/121 with corona treatment Test 1 483 286 391 217 440 296 399 Test 2 521 218 403 307 420 329 425 Fullaseal 22/121 without corona treatment Test 1 456 241 337 304 354 294 337 Test 2 500 216 370 227 361 305 363 BOSTIK without corona treatment Test 1 550 299 384 360 514 366 355 Test 2 552 272 417 398 441 359 424

Generally speaking, the test results having a measurement of greater than or equal to 5 250g/25mm are regarded as confirming that the seam formed would adequately prevent the ingress of moisture and air into the package.

Those skilled in the art of the present invention will appreciate that many variations and modifications may be made to the embodiments of the invention described above ίο without departing from the spirit and scope of the present invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A process for forming a sealed seam of a sealed package made from a substrate including the steps of: a) applying an adhesive to at least two sections of the substrate in amounts so that the sections can be adhered together, wherein the adhesive is applied non-uniformly to at least one of the sections so that there are, • first regions of the at least one section at which the adhesive is applied in a required amount so that the first regions can adhere to another of the sections to form a seal, and • second regions of the at least one section at which either no adhesive is applied, or the adhesive is applied in an amount that is less than the amount applied to the first regions; and b) placing together the sections of the substrate to which the adhesive has been applied in step a) to form the sealed seam of the package.
2. The process according to claim 1, wherein step a) includes applying the adhesive non-uniformly to all sections of the substrate that are adhered together so as to have the first and second regions.
3. The process according to claim 2, wherein a majority of each of the first regions of one section contact with, or adhere to, at least two of the first regions of another section.
4. The process according to any one of claims 1 to 3, wherein the sections of adhesive applied to the substrate according to step a) are located outwardly of an inner area of the substrate that is free of adhesive for contacting a product contained by the package.
5. The process according to any one of claims 1 to 4, wherein the substrate includes a series of segments for forming multiple packages from the substrate, and step a) includes applying the sections of adhesive outwardly of, and about, an inner area of each segment that is free of adhesive for contacting the product.
6. The process according to claim 5, wherein the sections of adhesive applied according to step a) are applied to peripheral areas of the segments.
7. The process according to any one of claims 1 to 6, wherein the substrate is a continuous roll of flexible substrate and the adhesive is applied to the substrate to form a line of segments on the substrate, in which each segment includes the sections of adhesive having the first and second regions applied according to step a) which can be placed together to form the sealed seam.
8. The process according to claim 7, wherein the process includes severing the segments from the continuous roll of the substrate.
9. The process according to claim any one claims 1 to 8, wherein step a) involves applying the adhesive to the first regions, and the second regions are free of the adhesive.
10. The process according to any one of claim 1 to 9, wherein the first regions cover at least 50% of the area of the section(s).
11. The process according to any one of claims 1 to 9, wherein the first regions cover at least 75% of the area of the section(s).
12. The process according to any one of claim 1 to 11, wherein the adhesive is applied to the first regions at an amount of at least 2.5 gm/m2.
13. The process according to any one of claims 1 to 11, wherein the adhesive is applied to the first regions at an amount range from 2.5 to 5.0 gm/m2.
14. The process according to any one of claims 1 to 13, wherein the adhesive applied in step a) is applied to the first region in a first pattern, and the adhesive is applied to the second region in a second pattern or the second region is free of adhesive.
15. The process according to claim 14, wherein step a) includes applying the adhesive in the first regions of different sections to be joined together in the same pattern.
16. The process according to claim 14, wherein the positions of the first patterns of adhesive of the first regions of different sections are out of alignment such that when the substrate is folded the first regions of the different sections partially overlap.
17. The process according to claim 14, wherein the first and second patterns of adhesive include strips of adhesive, and wherein the adhesive strips are arranged in ring formations in the shape of closed loops and/or spirals.
18. The process according to claim 14 or 17, wherein the first pattern of the adhesive of the first regions includes the adhesive applied in dot formations.
19. The process according to claim 14, wherein the first pattern of the adhesive of the first regions includes a discontinuous coating of the adhesive and the second regions include a series of isolated blank regions free of adhesive distributed over the first region.
20. The process according to any one of claims 1 to 19, wherein the adhesive is applied using one or more rollers in which the adhesive applied transfers from a roller onto the substrate.
21. The process according to any one of claims 1 to 20, wherein the process includes wrapping or folding the substrate about the item being packaged before placing together the sections of the flexible substrate in according with step b).
22. The process according to any one of claims 1 to 21, wherein the substrate includes any one or a combination of a polymeric film including metallised and non-metallised polymeric films, or paper pulp substrates including paper, cardboard, corrugated board or a laminated substrate including both polymeric and paper based materials laminated together.
23. The process according to any one of claims 1 to 22, wherein the adhesive is cold glue.
24. A sealed package having a sealed seam made according to the process of any one of the preceding claims.
25. A sealed package for a product, the sealed package including a substrate and an adhesive applied to two or more sections of the substrate, in which the substrate is wrapped about the product and the sections adhered together to form a sealed seam, wherein the adhesive is applied to at least one of the sections so that there are: • first regions at which the adhesive is applied in a required amount so that two of the first regions can adhere together to form a seal, and • second regions at which either no adhesive is applied, or the adhesive is applied in an amount that is less than the amount applied to the first regions.
26. The sealed package according to claim 25, wherein the first and second regions of the package are present when the adhesive is set.
27. The sealed package according to claim 25 or 26, wherein the first region includes a pattern of adhesive and the second region is free of adhesive.
28. The sealed package according to any one of claims 25 to 27, wherein the sections form a longitudinal seam of the package and two end seams at opposite ends of the package to from a close satchel.
29. The sealed package according to claim 28, wherein the ends seams have a T-shape formation.