EP4747169A1

EP4747169A1 - A 2-ply seal for packaging and packaging therewith

Info

Publication number: EP4747169A1
Application number: EP24740846.1A
Authority: EP
Inventors: Richard John ANDREWS
Original assignee: Koninklijke Douwe Egberts BV
Current assignee: Koninklijke Douwe Egberts BV
Priority date: 2023-07-18
Filing date: 2024-07-05
Publication date: 2026-05-27
Also published as: GB202310976D0; WO2025016749A1; GB2631947A

Abstract

A 2-ply seal for packaging, the 2-ply seal comprising two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion and packaging comprising at least one 2-ply seal defining at least a portion of a perimeter seal to contain one or more items.

Description

A 2-PLY SEAL FOR PACKAGING AND PACKAGING THEREWITH

Technical Field of the Invention

The present invention relates generally to the field of seals in flexible packaging materials and more particularly to a 2-ply seal formed from a layer of flat material flush with a second layer of flat material with no 3-ply or 4-ply seals in the primary seal area of packaging.

Background to the Invention

Conventional packaging formed of flexible packaging materials such as paper, utilises 3-ply or 4-ply seals.

Figure lb shows a 3-ply lap seal. Figure 1c shows a 4-ply fin seal. Figure Id shows a 4-ply fin seal and gussets. In these Figures, the plys are illustrated spaced apart for clarity but the plys would normally abut one another.

The designation/characterisation of the seal (as a 2-ply seal, a 3-ply seal or a 4- ply seal) is determined by the number of layers between the seal jaws during the sealing step.

As can clearly be seen in these Figures, these seals have varying/uneven material thickness in seal jaws. Figures 1c and Id for example which illustrate 4-ply sealing used in fin seals and gussets, or inside-to-inside sealing, shows that the seal thickness in the seal jaws transitions from 4 material thickness (4-ply) to 2-ply outside the seal jaws. The 4-ply areas receive most seal pressure, with less pressure applied to the 2-ply area. To make an air/moisture tight, the seal material must melt and be squeezed into the transition region as shown in the detail view.

Figures lb and l id illustrate 3-ply sealing used in lap seals, or inside to outside sealing. Lap seals have a similar challenge to fin seals with uneven seal pressure and sealing the transition region, but to a lesser extent with a 3-ply to 2-ply transition.

A bigger challenge with lap seals is creating a good seal between the outside and the inside of a material. Outside material is typically heat resistant so as not to stick to sealing jaws. Seal lacquers can be used in the areas where sealing is needed, but brings its own challenges and limitations. It would therefore be an advance in the art to provide a 2-ply seal formed from a layer of flat material flush with a second layer of flat material in the primary seal area which solves any one or more of the abovementioned problems.

Summary of the Invention

According to one aspect of the invention, there is provided a 2-ply seal for packaging, the 2-ply seal comprising two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion.

According to another aspect of the invention, there is provided packaging comprising at least one 2-ply seal defining at least a portion of a perimeter seal to contain one or more items, the 2-ply seal comprising two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion.

Providing a 2-ply seal as defined above focuses on simplifying the sealing by containing product within simple 2-ply seals formed by flat material flush with flat material, no 3-ply or 4 ply areas (gussets or fin seals); enabling even pressure and temperature distribution, and faster sealing. It also enables a wider range of more sensitive materials to be used for example seal coating replacing laminate seal layers. Residual benefits can include enabling faster sealing times and alternative sealing technologies e.g. ultrasonic sealing.

The 2-ply seal of the invention is directed at having only 2 plies of packaging material in the sealing jaws.

The 2-ply seal may be formed from a single ply of material folded back upon itself. This configuration may be referred to as a 3-sided or 3-edge seal (if the package is rectangular). In a 3-sided or 3-edge seal, one ply of packaging material may be folded back on itself, and the 2 plies may then preferably be sealed to one another on 3 sides or 3 edges with the fold on the other side or edge.

In this configuration, a ‘fake’ 4-sided or 4-edge seal can be formed by sealing the fold side or edge as well. In a 3-sided or 3-edge seal, the two lateral side edge seals may be formed initially to form an open pouch or similar into which one or more items or products can be dispensed before the formation of the final seal to close the pouch.

Alternatively, one or more items or products may be placed onto an inside surface of a ply and another portion of the ply may be folded over the one or more items or products and all 3 sides or edges may be sealed at the same time.

The 2-ply seal may be formed from two separate plies of material. This configuration may be referred to as a 4-sided or 4-edge seal (if the package is rectangular). In this configuration, the two separate plies may preferably be stacked and then sealed to one another. Any number of side seals can be formed at the same time. For example, seals may be formed on 3 sides or edges initially to form an open pouch or similar into which one or more items or products can be dispensed before the formation of the final seal to close the pouch.

Alternatively, one or more items or products may be placed onto an inside surface of a ply and another ply may be located over the one or more items or products and all 4 sides or edges may be sealed at the same time.

The 2-ply seal may preferably be a primary seal to contain one or more items or products within the packaging. A primary seal may be hermetic. A primary seal may preferably be a 2-ply seal in which the respective plies are sealed inside to inside.

The 2-ply seal may be non-hermetic. Many packaging applications don’t require oxygen or moisture protection (e.g. chocolate). When non-hermetic, the 2-ply seal may utilise a pressure sensitive, cold seal adhesive.

In a primary seal, sealing pressure and/or heat may preferably be applied to the packaging outside the product area. This means that any sealing pressure and/or heat will not affect the one or more items or products contained by the packaging.

The one or more primary seals may be formed using any mechanism. For example, heat, and/or pressure may be preferred. Adhesive may be used for a hermetic seal but may be less preferred given the difficulties in forming a hermetic 2-ply seal using adhesive only. Flat material to flat material flush seals are the simplest seal types, the most forgiving on material selection, and on the sealing process (time, temperature, pressure).

One or more secondary seals may be formed on or in the packaging. Any secondary seals may be formed after the primary seal(s) have been formed. Formation of the primary seal(s) may preferably locate the one or more items or products within the packaging. The primary seal(s) may define the containing area of the packaging. One or more secondary seals may then be formed after the primary seal(s) have been formed, outside the area defined by the primary seal(s).

The packaging may be folded before one or more secondary seals are formed to provide a desired or required form to the packaging.

The one or more secondary seals may preferably be outside to outside seals.

Sealing pressure and/or heat may be used in the formation of the one or more secondary seals. However, any sealing pressure and/or heat used in the formation of the one or more secondary seals within or over the containment area may be less than that required to form the one or more primary seals.

The one or more secondary seals may preferably not be hermetic seals. The one or more secondary seals may be cosmetic or aesthetic seals, not required to seal the containment area but used to define a final package shape and/or size and/or configuration.

The one or more secondary seals may be formed using any mechanism. As with the primary seals, sealing pressure and/or heat may be used, but adhesive may be preferred for secondary seals as using adhesive obviates the use of secondary seals pressure and/or heat, particularly if the secondary seal is formed within or over the containment area of the packaging.

Heat may be used to activate a heat seal layer or portion applied to an outer side of one or both plies. It is preferred that any adhesive used may be used outside the sealing jaws used to form the primary seals to prevent pollution of the sealing jaws used for the primary seals.

One or more of the plies may be folded, at any stage, before or after the formation of the one or more primary seals and/or the one or more secondary seals. The folds may be dead folds, with or without subsequent sealing. Dead fold characteristics rely on material properties to retain their shape after folding. Materials such as flexible plastics exhibit dead fold characteristics whereas more rigid packaging materials do not exhibit dead fold characteristics. Dead folded packaging is stable and does not bounce back to its original shape.

In other materials, a fold or hinge line may be provided to prevent the folded material bouncing back to its original shape.

The ply or plies used may be shaped. Preferably, the shape of the ply or plies used may be determined by the final shape of the packaging, taking into account the primary and/or secondary seals required to arrive at the final shape of the packaging.

For example, external gussets may be provided to allow the final shape of the packaging to achieve a 3D form using 2-ply seals only. External gussets may require a flared portion to be provided in the ply or plies used.

In one form, one or more plies used may be axiniform or shaped like the head of an axe. If a 3 -sided seal is used, the ply may be axiniform when folded. A primary seal may be provided on at least one lateral side. A first cross seal may be provided at a lower edge. Once the primary seals are formed, a portion of a lateral side seal may be folded against the containing area. A lower portion may be folded to overlie against a portion of the containing area to form a base wall. The gussets so formed may be folded toward the sidewalls of the package or toward and underneath the base. One or more secondary seals may be formed to seal the folded portions in position. The package can be filled. A final primary seal may be formed to close the containment area.

A shaped forming part may be used to form the package. The forming part may provide a device for providing counter pressure for forming the folds and/or secondary seals. A longitudinal primary seal may be offset to one side of the package. This offset may be required to align the longitudinal seal plies flush in the cross seal jaw to avoid 4 plies of material in the seal area. The longitudinal primary seal may be formed at the same time as a primary cross seal, or before.

The material flare of the plies may be larger on the seal side, if the packaging is constructed using 3 side seal. As mentioned above, a symmetrical pack for visual appeal may be possible with a fake 4 side seal, creating a seal mirrored on the opposite side.

After forming a simple 3 or 4 side sealed containment area with primary 2-ply seals, other features may be included in the packaging using secondary seal(s) and cutting, excess material and subsequent process steps.

For example, one or more secondary side seals may be formed. One or more exterior gussets may be formed. Excess material may be provided outside an initial containment area formed by primary seals which can subsequently be folded over to create a wallet closure.

As a further example, after the base a 3D, flat-based package has been formed, the top may be sealed in a shape and cut in a shape, removing excess waste material to form box- shaped top, a triangular shaped top, or pack feature such as a pouring spout.

A ‘stick’ package may be formed from flat material from a reel (e.g. paper, film etc) with product contain using only 2-ply seals. First, one or more long primary seal may be formed, then a first primary cross seal may be formed to close a lower side of the containing area. The package may then be filled. A second primary cross seal may then be formed to close the package. One or more of the primary seals may be folded back on itself and sealed to the outside of the pack (secondary seal step). The secondary seal may preferably be formed by applying seal pressure in the already flat areas of the overlapping primary seals (top and bottom of the stick package) for sufficient counter pressure and to avoid exerting seal pressure in the containment area.

Gussets in packs can enable 3D forms from a 2 D material, which can be beneficial e.g. to enable the pack to be freestanding, such as in pouches.

A package may be formed from flat material from a reel (e.g. paper, film etc) with product contain using only 2-ply seals. Two or more adjacent chambers may be formed using primary seals and then the chambers may be folded together to create a pack depth, that can enable the package to free stand. The chambers may be 3 or 4-side sealed.

The chambers may be sealed/ bonded to each other in a secondary seal step, after being folded together.

The package may be merchandised vertically or horizontally. For example, the package could stand on either the joining fold portion, or the lateral (side edges) of the chambers.

The chambers may be different sizes to enable independent opening (e.g. one protrudes from the other enabling it to be ripped open without opening the other chamber).

Alternatively, the pouch chambers may be peeled open if primary seals are peelable. An unsealed area or excess material above the top primary seal may allow an easy grip area for this.

According to another aspect of the invention, there is provided a method of forming packaging comprising at least one 2-ply seal defining at least a portion of a perimeter seal to contain one or more items, comprising the step of sealing two portions of packaging material with an inside surface of one packaging portion flush to an inside surface of a second packaging portion.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure la is an end view of a 2-ply inside to inside seal according to an embodiment.

Figure lb is an end view of a 3-ply inside to outside lap seal.

Figure 1c is an end view of a 4-ply inside to inside fin seal. Figure Id is an end view of a 4-ply inside to inside fin seal and gussets.

Figure 2 is a top view of a package with a 4 sided, 2-ply inside to inside seal according to an embodiment.

Figure 3 is a top view of a package with a 3 sided, 2-ply inside to inside seal according to an embodiment.

Figure 4 is a top view of a package with a 2-ply inside to inside seal about three sides according to an embodiment.

Figure 5 is a front view of a package for a pourable product with a 2-ply inside to inside seal about three sides and exterior gussets according to an embodiment.

Figure 6 is an axonometric view of the package illustrated in Figure 5.

Figure 7 is an axonometric view of the package illustrated in Figure 5 with spout.

Figure 8 is a flow diagram of a process to form a package as illustrated in Figure

5.

Figure 9 is a front view of two stick packages with a 3 sided, 2-ply inside to inside seal according to an embodiment, one package including a secondary seal.

Figure 10 is a front view of two stick packages with a 3 sided, 2-ply inside to inside primary seal and a secondary seal according to an embodiment.

Figure 11 shows a stick package as illustrated in Figure 9 prior to folding and secondary seal formation.

Figure 12 show the stick package illustrated in Figure 11 after folding and secondary seal formation.

Figure 13 is an axonometric view of a stand up pouch package with two containing portions each formed of 4 sided, 2-ply inside to inside seal according to an embodiment.

Figure 14 is a side view of the pouch package illustrated in Figure 15 showing the folds. Figure 15 is an axonometric top view of the pouch package illustrated in Figure 15 prior to folding.

Packaging 10 illustrated in Figures 2 and 3 comprises at least one 2-ply seal 11 defining at least a portion of a perimeter seal to contain one or more items and an example method to make such packaging is illustrated in Figures 8 to 15.

The 2-ply seal 11 comprises two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion as illustrated in Figure la. In Figure la, the plys are illustrated spaced apart for clarity but the plys would normally abut one another.

The 2-ply seal 11 of the invention is directed at having only 2 plies (a thickness or layer) of packaging material in the sealing jaws.

A package utilising a 2-ply seal 11 may be formed from a single ply of material folded back upon itself. This configuration may be referred to as a 3 -sided or 3 -edge seal (if the package is rectangular) as shown in Figure 3. In a 3-sided or 3-edge seal, one ply of packaging material is folded back on itself to form a fold edge 12 and the 2 plies are then preferably sealed to one another on 3 sides or 3 edges with the fold on the other side or edge.

In this configuration, a ‘fake’ 4-sided or 4-edge seal can be formed by sealing the fold side or edge as well.

In a 3-sided or 3-edge seal, the two lateral side edge seals 11’ may be formed initially to form an open pouch or similar into which one or more items or products can be dispensed before the formation of the final cross seal 11” to close the pouch.

Alternatively, one or more items or products can be placed onto an inside surface of a ply and another portion of the ply can be folded over the one or more items or products and all 3 sides or edges can be sealed at the same time.

The 2-ply seal of the embodiments illustrated in Figures 2 and 3 is formed from two separate plies of material. This configuration may be referred to as a 4-sided or 4- edge seal (if the package is rectangular) as shown in Figure 2. In this configuration, the two separate plies are preferably stacked and then sealed to one another. Any number of side seals can be formed at the same time. In the examples illustrated in Figures 2 and 3, 2-ply seals are formed on the two lateral side edge seals 11’ and the lower cross seal 11” initially to form an open pouch or similar into which one or more items or products can be dispensed before the formation of the final cross seal 11” to close the pouch.

Alternatively, one or more items or products can be placed onto an inside surface of a ply and another ply can be located over the one or more items or products and all 4 sides or edges can be sealed at the same time.

The 2-ply seal of the illustrated embodiments is a primary seal to contain one or more items or products within the packaging which is formed. A primary seal is preferably hermetic. A primary seal is a 2-ply seal in which the respective plies are sealed inside to inside.

In a primary seal, sealing pressure and/or heat is applied to the packaging outside the product containment area 13. This means that any sealing pressure and/or heat will not affect the one or more items or products contained by the packaging.

Figure 4 shows a 3D package formed using a former or guide to create a package containing a 3D rectangular product (or having that shape) and shows the primary 2- play seals along on one longitudinal side and a pair of cross seals, one at either end.

The one or more primary seals may be formed using any mechanism. For example, heat, and/or pressure may be preferred. Adhesive may be used but may be less preferred given the difficulties in forming a hermetic 2-ply seal using adhesive only.

One or more secondary seals 24 can be formed on or in the packaging. Any secondary seals may be formed after the primary seal(s) have been formed. Formation of the primary seal(s) will preferably locate the one or more items or products within the packaging. The primary seal(s) may define the containing area of the packaging. One or more secondary seals may then be formed after the primary seal(s) have been formed, outside the area defined by the primary seal(s). The packaging may be folded before one or more secondary seals are formed to provide a desired or required form to the packaging.

The one or more secondary seals may not be hermetic seals. The one or more secondary seals may be cosmetic or aesthetic seals, not required to seal the containment area but used to define a final package shape and/or size and/or configuration.

Heat may be used to activate a heat seal layer or portion applied to an outer side of one or both plies.

It is preferred that any adhesive used is used outside the sealing jaws used to form the primary seals to prevent pollution of the sealing jaws used for the primary seals.

The one or more secondary seals are preferably outside to outside seals to form flat based packaging such as that illustrated in Figures 5 to 7 for example. The process shown in Figure 8 could be used.

As shown in Figure 8, a length of packaging material which may be provided in a roll 14, can be dispensed and wrapped about a shaped former 15 to form the package. The shaped former 15 in Figure 8 is a hollow rectangular cross section former providing counter pressure for forming the folds and/or secondary seals.

The ply or plies used in Figure 8 are shaped, determined by the final shape of the packaging, taking into account the primary and/or secondary seals required to arrive at the final shape of the packaging. For example, the packaging formed in Figure 8 has external gussets to allow the final shape of the packaging to achieve the rectangular 3D shape using 2-ply seals only. External gussets 16 require a flared portion as shown, to be provided in the ply or plies used.

In the form shown in Figure 8, thee one or more plies is axiniform or shaped like the head of an axe. If a 3 -sided seal is used, the ply may be axiniform when folded. A primary seal is formed on at least one lateral side 17. A first, lower cross seal 18 may be provided at a lower edge. Once the primary seals (17, 18) have been formed, a portion of the lateral side seal 17 may be folded against the containing area to form the rectangular 3D shape which is open at the top. A lower portion may be folded to overlie against a portion of the containing area to form a base wall. The gussets 16 so formed may be folded toward the sidewalls of the package or toward and underneath the base. One or more secondary seals may be formed to seal the folded portions in position. The package can be filled. A final, upper primary seal 19 can be formed to close the containment area.

As shown in Figure 8, the sealing pressure is provided (in the direction shown by the arrows) outside the containing area of the package.

The longitudinal primary seal may be offset to one side of the package. This offset may be required to align the longitudinal seal plies flush in the cross-seal jaw to avoid 4 plies of material in the seal area. The longitudinal primary seal may be formed at the same time as a primary cross seal, or before.

The material flare of the plies may be larger on the seal side, if the packaging is constructed using 3 -side seal such as is shown in the package in Figure 5.

After forming a simple 3 or 4-side sealed containment area with primary 2-ply seals, other features can be included in the packaging using secondary seal(s) and cutting, excess material and subsequent process steps.

For example, one or more secondary side seals may be formed. One or more exterior gussets may be formed. As shown in Figures 5 to 7, after a 3D, flat-based package has been formed, the top can be sealed in a shape and/or cut in a shape, removing excess waste material to form box-shaped top as shown in Figure 5, a triangular shaped top as shown in Figure 6, or pack feature such as a pouring spout as illustrated in Figure 7.

A ‘stick’ package may be formed from flat material from a reel (e.g. paper, film etc) with product contain using only 2-ply seals. Examples of such a stick pack are illustrated in Figure 9. First, one or more longitudinal primary seals 21 are formed, then a first primary cross seal (lower seal 22) is formed to close a lower side of the containing area. The package can then be filled. A second primary cross seal 22 is then formed to close the package at an upper end. The right-hand image in Figure 9 shows the 3 seals. The left-hand image shows the same package as in the right-hand image but with the longitudinal primary seal 21 folded back on itself and sealed to the outside of the pack (secondary seal step).

Figure 10 shows additional secondary seals 24 provided to reduce the overall size of the stick package by sealing the secondary seals 24 to the adjacent primary seal 22.

Figure 11 shows the folding of the longitudinal primary seal 21 back on itself and sealed to the outside of the pack (secondary seal step). In Figure 12, the secondary seal is formed by applying seal pressure in the already flat areas 25 where the longitudinal primary seal 21 overlaps with the primary cross seals 22 (top and bottom of the stick package) for sufficient counter pressure and to avoid exerting seal pressure in the containment area.

Gussets in packs can enable 3D forms from a 2 D material, which can be beneficial e.g. to enable the pack to be freestanding pouches such as that illustrated in Figures 13 and 14.

In the embodiment illustrated in Figures 13 to 15, two adjacent chambers 30 are formed using 4-sided primary seals to form the package shown in Figure 15. The chambers 30 are then folded together to create a pack depth, that can enable the package to free stand.

The chambers are sealed/ bonded to each other in a secondary seal step, after being folded together. The package can be merchandised vertically or horizontally. For example, the package can stand on either the joining fold portion 31 as shown in Figure 13, or the lateral (side edges) of the chambers 30.

The chambers 30 in Figures 13 and 14 are different sizes/volumes to enable independent opening (e.g. one protrudes from the other enabling it to be ripped open without opening the other chamber).

Alternatively, the pouch chambers could be peeled open if primary seals are peelable. An unsealed area or excess material above the top primary seal may allow an easy grip area for this. The one or more embodiments are described above by way of example only.

Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

1. A 2-ply seal for packaging, the 2-ply seal comprising two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion.

2. A 2-ply seal for packaging as claimed in claim 1 formed from a single ply of material folded back upon itself and at least one seal formed between overlapping portions thereof.

3. A 2-ply seal for packaging as claimed in claim 1 formed from two separate plies of material and at least one seal formed between adjacent portions of the two separate plies.

4. Packaging comprising at least one 2-ply seal defining at least a portion of a perimeter seal to contain one or more items, the 2-ply seal comprising two portions of packaging material with an inside surface of one packaging portion sealed flush to an inside surface of a second packaging portion.

5. Packaging as claimed in claim 4 comprising one ply of packaging material folded back on itself, and the 2 plies sealed to one another on three side edges with a fold on a fourth side edge.

6. Packaging as claimed in claim 5 wherein a material flare of the plies is larger on a seal side.

7. Packaging as claimed in claim 5 or claim 6 comprising an artificial side edge seal formed by sealing the fold on the fourth side edge.

8. Packaging as claimed in claim 4 wherein the 2-ply seal is formed from two separate plies of material stacked and sealed to one another.

9. Packaging as claimed in any one of claims 4 to 8 wherein the 2-ply seal is a primary, hermetic seal, sealing an inside of a first ply to an inside of a second ply or a second portion of the first ply.

10. Packaging as claimed in claim 9 comprising one or more secondary seals formed on or in the packaging by folding the packaging before the one or more secondary seals are formed.

11. Packaging as claimed in claim 10 wherein the one or more secondary seals are outside to outside seals.

12. Packaging as claimed in claim 10 or claim 11 wherein the one or more secondary seals are cosmetic or aesthetic seals to define a final package shape and/or size and/or configuration.

13. Packaging as claimed in any one of claims 9 to 12 comprising two or more adjacent chambers formed by primary seals and folded to create a pack depth, the chambers sealed/ bonded relative to each other in a secondary seal step.

14. Packaging as claimed in claims 13 wherein the chambers are different sizes to enable independent opening.

15. Packaging as claimed in any one of claims 4 to 14 wherein the ply or plies used are shaped determined by the final shape of the packaging for folding after formation of the at least one 2-ply seal.

16. Packaging as claimed in claim 15 wherein a material flare of the plies is larger on a seal side.

17. A method of forming packaging as claimed in any one of claims 4 to 7 wherein two primary lateral side edge seals are formed initially to form an open pouch into which one or more items or products are dispensed before formation of the third primary seal to close the open pouch.

18. A method of forming packaging as claimed in any one of claims 4 to 7 wherein one or more items or products are placed onto an inside surface of a ply and another portion of the ply is folded over the one or more items or products and sealed using a primary 2-ply seal on three side edges.

19. A method of forming packaging as claimed in claim 8 wherein a primary seal is formed on three side edges initially to form an open pouch into which one or more items or products are dispensed before formation of the fourth primary seal to close the open pouch.

20. A method of forming packaging as claimed in claim 19 wherein one or more items or products are placed onto an inside surface of a ply and a second ply is placed over the one or more items or products and sealed using a primary 2-ply seal on four side edges.

21. A method of forming packaging as claimed in any one of claims 17 to 20 wherein a shaped forming part is used between the plies or parts of a ply to form the packaging.

22. A method of forming packaging as claimed in any one of claims 17 to 21 wherein one or more secondary side seals are formed by folding the packaging and then forming one or more secondary seals.

23. A method of forming packaging as claimed in claim 22 wherein one or more of the primary seals is folded back on itself and sealed to the outside of the pack to form a secondary seal.

24. A method of forming packaging as claimed in claim 22 or claim 23 wherein the secondary seal is formed by applying seal pressure in already flat areas of the overlapping primary seals.

25. A method of forming packaging as claimed in any one of claims 17 to 24 wherein a portion of the packaging is sealed and/or cut in a shape, to form a packaging feature such as a pouring spout.