WO2013156747A2

WO2013156747A2 - Improvements in or relating to packaging

Info

Publication number: WO2013156747A2
Application number: PCT/GB2013/000174
Authority: WO
Inventors: Hamed AL-NAQEEB; Marcus Donald KIRK
Original assignee: Lirage Investments Ltd
Priority date: 2012-04-20
Filing date: 2013-04-18
Publication date: 2013-10-24
Also published as: WO2013156747A3; GB201418464D0; GB2515237A

Abstract

Packaging (80) is provided and comprises a base shell (10) and a lid shell (50) which are heat seaiable together. One of the shells is more rigid than the other to facilitate opening of the packaging in use.

Description

IMPROVEMENTS IN OR RELATING TO PACKAGING

The present invention relates generally to packaging and particularly to packaging with two or more parts which are sealed together and at least partly separable to access the contents thereof.

Packaged goods, for example foodstuffs and electrical items, have become commonplace. Depending on the nature of the goods to be packaged there are always a variety of requirements, some of which are conflicting.

The present invention seeks to provide improvements in or relating to packaging.

According to an aspect of the present invention there is provided packaging comprising or including two or more parts which are sealable together by a peelable seal.

There are a number of approaches for incorporating "peelability" to a packaging material. Heat seal coatings are traditionally solution applied. Resins and additives are dissolved into a solvent (an organic solvent or water) to create the coating, the coating is applied to a web, and then the coated web passes through an oven to evaporate the solvent and in some cases cure the coating. Incorporating peelable sealants into extruded films is an effective way of achieving a peelable sealant. Generally, films are coextrusions with a bulk layer of relatively inexpensive resin(s) and a thinner peelable sealant layer. The bulk layer provides a cushioning effect when sealing, gives the film body, and depending upon the choice of resins, can enhance durability and barrier.

If the coextruded film can be used without further processing (e.g. a high density polyerhy!ene/polybutylene blend coextrusion), it will generally be the most cost effective approach to providing a peelable film sealant. However, the peelable film may need to be laminated (either adhesive laminated or extrusion laminated) to provide additional functionality (e.g. thermal stability, dimensional stability, and/or barrier). In an extrusion coating process, resin(s) are cast directly onto a web (e.g. paper, aluminium foil, films). As with films, extrusion coatings can be coextruded to maximize economics and/or to provide additional functionality. Peeiable seals formed according to aspects and embodiments of the present invention may open in one of three ways: i) Interfacial Separation - the seal opens at the seal interface and sealing temperature is a key determinant of the seal strength of a given material; ii) Deiamination - the structure separates at an internal interface, i.e. between the seal layer and an inside layer or between inside layers. Layer thickness and adhesion between internal layers determines peel strength; and iii) Cohesive Failure - the structure separates within the seal layer. The material's inherent strength determines the force required for separation.

The peeiable seal formed according to the present invention may, for example, be openable with a deliberate deiamination.

Acceptable peel strength for packages formed according to the present invention may range from about ) 00 to 5000 g/in for example from about 500 to about 1500 g/in.

The parts may be formed as a clam shell and joined by a hinge.

The parts may be formed discretely such that the package is openable by separating the parts.

At least one of the parts may be formed as a shell. Other possibilities for parts include, for example, flat or curved panels, laminar sheets, boards and the like.

The parts may include corresponding sealing flanges.

At least one of the parts may be substantially rigid.

One or more of the parts may be thermoformed. One or more of the parts may be formed from a thermoplastics material. One or more of the parts may be formed from a non-thermoplastics material, for example cardboard or paperboard. A parting line between the parts may be substantially linear.

A parting line between the parts may be substantially horizontal.

The packaging may be hermetically sealable. Therefore a balance must be struck between a seal which can provide a hermetic seal but yet still be peelable.

The packaging may have a modified atmosphere.

The packaging may be provided as food packaging, for example a sandwich pack which comprises or includes packaging as described herein.

In some embodiments the packaging may be provided as beverage container which comprises or includes packaging as described herein. According to a further aspect of the present invention there is provided packaging comprising a base shell and a lid shell which are heat sealable together, in which one of the shells is more rigid than the other.

This aspect of the present invention seeks to provide a pack which is comprised of two (or more) shell sections with differential rigidity /stiffness. This may have particular benefits for the subsequent opening of the package, because the more rigid shell could therefore be held more tightly without risk of collapse whilst the less rigid shell is separated from it. The pack may be formed as a body with two or more shell parts. In some embodiments the shell parts may be referred to as shell "halves"; it is to be understood that the term "half" does not necessarily imply that the shells are identical and/or the same size. Whilst this is possible, the term may merely imply that there are two shells. According to a further aspect of the present invention there is provided packaging comprising a base shell and a lid shell the shells being hermetically sealed together by a peelable seal. This aspect of the present invention addresses two conflicting requirements for many packs; that is a seal which is strong enough to provide a hermetic interior and yet easily opened when required. Packaging formed according to these aspects may be formed as a clamshell and joined by a hinge; alternatively the shells may be formed discretely and completely separable upon opening.

According to a further aspect of the present invention there is provided packaging comprising a base shell and a lid shell which are formed discretely and heat sealable together by a peelable seal such that the package is openable by separating the shells.

In aspects of the present invention one of the shells may be deeper than the other. For example the lid may be deeper than the base. The relative sizes of the lid and base may be important for certain products, especially products in which the join between the shells does not obscure particular parts.

For example, in the presentation of ready-to-eat foods such as sandwiches the sandwich filling may preferably be highly visible so that the relative sizes of the lid and base can be selected such that this can clearly be viewed without interruption by the interface.

The shells may be substantially identical. For example, the shells may be substantially the same shape and/or formed from the same materials and/or have the same thickness of materials.

Alternatively, differences between the shell sections may be used to provide particular advantages,

In some embodiments the material from which one of the shells is formed is thicker than the other. Alternatively or additionally the material from which at least part of one shell is formed may be denser than the other. At least one of the shells may include one or more strengthening ribs. The strengthening rib/s may be used to provide increased rigidity in a particular direction to assist with opening. In embodiments in which two shell halves are used the container may be elongate. For example the packaging may be a generally parallelepiped shape. This may be particularly useful for packaging so-called submarine sandwiches, also known as subs which are sandwiches which consist of a long roll of bread split lengthwise usually either into two pieces or opened into a "V" on one side and filled, for example with meats, cheeses, vegetables, seasonings and sauces.

The shells may include corresponding sealing flanges, rim or the like. In some embodiments the flanges are substantially the same shape but include one or more overhangs, tabs or the like to help separate the shells when required.

The shells may be substantially rigid or semi-rigid. In some embodiments the shells are thermoformed, for example from thermoplastics materials. The material from which at least part of the packaging is made may comprise multiple layers. This allows for multiple properties to be included e.g. gas barrier and peelable ^' seal.

In some embodiments the material from which either or both or all of the shell halves, sections/regions is formed (depending on the configuration) may comprise: a layer of PET; a layer of EVOH; and a layer of PE.

In other embodiments the material from which either, both or all of the shell halves/sections/regions is formed (depending on the configuration) may comprise PET and PE.

Polyethylene terephthalate (PET) is a thermoplastic polymer resin of the polyester family. PET consists of polymerized units of the monomer ethylene terephthalate, with repeating CtaHeC units. Depending on its processing and thermal history, polyethylene terephthalate may exist both as an amorphous (transparent) and as a semi-crystalline polymer. In some embodiments amorphous PET (or APET) may be used. Alternatively or additionally recycled PET (or RPET) may be used.

Ethylene Vinyl Alcohol (EVOH) is a formal copolymer of ethylene and vinyl alcohol. The plastic resin is commonly used in food applications and its primary purpose is to provide barrier properties, primarily as an oxygen barrier for improved food packaging shelf life. EVOH is typically coextruded or laminated as a thin layer between cardboard, foil, or other plastics. Polyethylene (PE) is a thermoplastic polymer consisting of long hydrocarbon chains. PE is classified into several different categories based mostly on its density and branching. The mechanical properties of PE depend significantly on variables such as the extent and type of branching, the crystal structure and the molecular weight. With regard to sold volumes, the most widely used polyethylene grades are high-density polyethylene (HOPE) and low-density polyethylene (LOPE).

The parts of the packaging may be adapted to be sealed together by a peelable seal. The two parts of the pack may have different optical properties. For example the "clarity" of two halves of a pack may be the same or different. In some embodiments one half (for example a half which provides higher visibility of product) is clearer than the other. Different light transmission properties may be achieved by varying the nature and proportion of light transmitted, which may be influence by selection of the materials from which the shells are made.

The parting line between the shells may be substantially linear. In some embodiments the parting line between the shells is substantially horizontal, although inclined parting lines/sealing planes are not beyond the scope of the invention.

The packaging may be formed as a hermetically sealable unit. In some embodiments the packaging is formed with a modified atmosphere, for example in order to improve shelf life of foodstuffs. The present invention may be formed as two rigid or semi-rigid parts which are heat sealed together and can be easily opened manually and without requiring any tools.

The present invention may also provide methods for producing packaging. For example, in one embodiment a base is formed and loaded with product before a top is formed. The base and top are placed in a sealed chamber and a vacuum is applied to remove the air. A modified atmosphere is back-filled into the chamber and then the two package parts are brought together for heat sealing before release from the chamber. Modified atmosphere gas may be used to help with the shelf life of a product. In some embodiments the gas is a mixture of carbon dioxide and nitrogen e.g. 60% CO2 : 40% 2 which may be pre-mixed. The material from which at least part of the pack (for example one shell) is made may be a combination PET/PE structure, with a PE adhesive layer on the underside of each edge (where the seal areas will touch). The present invention may provide a standalone automatic heat sealer machine, with a top and bottom tool set profiled to the shape of the shells.

The machine may be formed as a tabletop heat sealer. The machine may be configured to seal corresponding flange of shells together.

The functions may include vacuum and gas flush, through the tool itself - vacuum chamber in top tool, prior to sealing the two layers together. The seal temperature may be in the region of 1 0 to 160 degrees C.

The tooling may comprise one or more cavities; for example a single cavity (one clamshell per cycle). The tooling may be configured as a first cavity section for receiving one shell and a second cavity section for receiving the other shell. One of the cavities may be movable and the other may be static; so that one shell can be moved to fit against the other prior to sealing; the shells could thereby be "pressed" together. Product may be ^' positioned in one of the shells, for example the shell in the static cavity, then the other shell is brought down or up to meet it ready for heat sealing.

The machine may use the concept of the top and bottom clamshell being heat sealed.

The present invention may be formed as food packaging, for example ready-to-eat foods such as sandwiches and salads to protect it from contamination during distribution and/or vending thereof.

Other specific uses may comprise, for example, packaging of electrical appliances. Aspects and embodiments described herein may be used together and/or separately.

Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combination other than those explicitly set out in the claims.

The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a base shell formed according to an embodiment of the present invention; Figure 2 shows the shell of Figure 1 filled with a product- Figure 3 is a perspective view of a top shell for use with the shell of Figures 1 and 2; Figure 4 is a perspective view of the two shells being brought together;

Figure 5 is a perspective view of the shells of Figures 1 and 2 sealed to the shell of Figure 3;

Figure 6^"is a schematic diagram of a manufacturing method suitable for producing packaging of the type shown in Figure I to 5;

Figure 7^"is a section of two shell halves formed according to an embodiment of the present invention; Figure 8A is a bottom perspective view of a base shell formed according to an alternative embodiment;

Figure 8B is a top perspective view of the shell of Figure 8A; Figure 9 is a side elevation of the shell of Figures 8A and 8B; Figure 10 is a plan view of the shell of Figures 8 and 9;

Figure 1 1 A is a top perspective view of a top/lid shell formed according to an alternative embodiment;

Figure 1 I B is a bottom perspective view of the shell of Figure 1 1 A; Figure 12 is a side elevation of the shell of Figures 1 1 A and 1 1 B;

Figure 13 is a plan view of the shell of Figures 1 1 and 12; Figure 14 is a perspective view of the base and top shells of Figure 1 1 to 13 offered up to each other for sealing; and

Figure 15 is a side elevation of a formed, sealed pack with the shells of Figures 1 1 to 14.

Referring first to Figure 1 there is shown a base shell or skillet generally indicated 10. The shell 10 is a generally parallelepiped shape tray with two opposing side walls 15, 20, two opposing end walls 25, 30 and q bottom wall 35. The side walls 15, 20 each have longitudinal sealing rims 16, 21 projecting orthogonally along their free edges.

The shell can receive an item, which in Figure 2 is shown as a "sub" sandwich 40.

In Figure 3 a fop shell or skillet 50 is shown. The shell 50 is similar to the shell 10 and accordingly has side 55, 60, end 65, 70 and bottom 75 walls. The side walls 55, 60 have sealing rims 56, 61.

The shells are brought together as shown in Figure 4.

The shells 10, 50 are formed from materials which allow them to be heat sealed together along the corresponding rims as shown in Figure 5 to form a final package 80.

In some embodiments (not shown) one or both of the shells may have strengthening ribs. In other embodiments finger grips may be moulded into one half, for example the base. One or both of the shells may have finger tabs to help separation, for example at a corner.

Referring now to Figure 6 there is illustrated a method of forming a package 80 of the type described in relation to Figure 1 to 5. The basic steps of the method are as follows. 1.) The base material will be loaded onto a driven carrier roller which is located at the left side of the machine near to ground level. This material will pass through a series of rollers and a breaking system until it reaches a set of pulling gripper chains which are located horizontally to this bed of the machine which will pass through the total length of the equipment.

Once the material enters the chains it will pass through a pre-heat film station which will make it pliable and ready to be formed.

2. ) Material exits the pre heat and enters the forming chamber where the material will be formed into the desired shape of tray. To do this quickly and successfully the machine may also need air plug assist. This allows for cleaner and quicker forming.

3. ) Once the tray is formed the product will be loaded into the cavity cell and index along the bed in an automatic manner.

4. ) After this point the top film/tray is introduced to the application gain, top flat web material is fed through a series of rollers then into a set of top gripper chains to form the top tray/lid in the same manner as previously mentioned. Top film feeding by chains is a very unusual application but giving the nature of what we need to achieve is paramount to this application. 5.) Once the top lid is formed the whole package (top and base tray) then enters a chamber system which is where the atmosphere is exchanged and modified to the required percentage.

6. ) Atmosphere modified then the sealing takes place while the product is still inside the chamber under M.A Sealing specifications which is paramount to achieve the

"peel seal" which is needed.

7. ) Once the product exits the chamber as one hermetic sealed unit it passes through two sets of knives to make individual packs, and then exits the machine at the assembly station.

Referring to Figure 7 there is shown a section of films used to form a base and lid. The base is formed from material which is thicker in gauge than the lid. Possible materials for the multi-layer films are shown together with potential thickness ranges.

Referring now to Figures 8 to 10 there is shown a base shell or skillet generally indicated 1 10. The shell 1 10 is a generally parallelepiped shape tray with two opposing side walls 1 15, 120, two opposing end walls 125, 130 and a bottom wall 135. The side walls 1 15, 120 and end walls 125, 130 have a continuous sealing flange 1 16 projecting orthogonally along their free edges with a sealing area 1 17 shown.

At the two corners defined by walls 120, 125 and 130 there are finger recesses 123, 124 in the flange 1 1ό shown best in Figures 8B and 10. It will be noted that the recess are outside of the sealing area 1 17.

A plurality of lateral strengthening ribs 136 are provided and pass along the bottom wall 135 and up the two side walls 1 15, 120.

In Figures 1 1 to 13 a top shell or skillet 150 is shown. The shell 150 is similar to the shell 1 10 and accordingly has side 155, 1 0, end 1 5, 170 and bottom 175 walls. The side and end walls have a sealing flange 156 providing a sealing area 157. The flange includes two unsealed areas 156, 157 at the corners of walls 155, 165 and 1 .

The shells are brought together as shown in Figure 1 . The shells 1 10, 150 are formed from materials which allow them to be heat sealed together along the corresponding sealing areas 1 17, 157 of the flanges as shown in Figure 15 to form a final package 180. With the. shells sealed together along the respective flange sealing areas 1 1 , 157 the finger recesses 123, 124 allow access to the unsealed areas 156, 157 so that the shells can be peeled apart and separated.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

CIAI S

Packaging comprising a base shell and a lid shell which are heat sealable together, in which one of the shells is more rigid than the other to facilitate opening of the packaging in use.

2. Packaging comprising a base shell and a lid shell, the shells being hermetically sealed together by a peelable seal. 3. Packaging as claimed in Claim 1 or Claim 2, in which the shells are formed as a clam shell configuration and are joined by a hinge.

4. Packaging as claimed in Claim 1 of Claim 2, in which the shells are formed discretely and are completely separable upon opening.

5. Packaging comprising a base shell and a lid shell which are formed discretely and heat sealable together by a peelable seal such that the package is openable by separating the shells. 6. Packaging as claimed in any preceding claim, in which one of the shells is deeper than the other.

Packaging as claimed in any preceding claim, in which the lid is deeper than the base.

Packaging as claimed in any preceding claim, in which the shells are substantially identical.

Packaging as claimed in any preceding claim, in which the shells are substantially the same shape.

10. Packaging as claimed in any preceding claim, in which the shells are elongate.

U . Packaging as claimed in any preceding claim, in which the packaging is a generally parallelepiped shape.

12. Packaging as claimed in any preceding claim, in which the shells include corresponding sealing flanges.

13. Packaging as claimed in any preceding claim, in which at least one of the shells includes strengthening ribs.

1 . Packaging as claimed in any preceding claim, in which the material from which one of the shells is formed is thicker than the other.

15. Packaging as claimed in any preceding claim, in which the material from which at least part of one shell is formed is more dense than the other.

16. Packaging as claimed in any preceding claim, in which at least one of the shells is substantially rigid.

17. Packaging as claimed in any preceding claim, in which the shells are thermoformed.

18. Packaging as claimed in any preceding claim, in which the shells are formed from thermoplastics material.

19. Packaging as claimed in any preceding claim, in which the parting line between the shells is substantially linear.

20. Packaging as claimed in any preceding claim, in which the parting line between the shells is substantially horizontal.

21. Packaging as claimed in any preceding claim, in which the packaging is hermetically sealable.

22. Packaging as claimed in any preceding claim, in which the packaging has a modified atmosphere.

23. Packaging comprising or including two or more parts which are sealable together by a peelable seal.

24. Packaging as claimed in Claim 23, in which the peelable seal is openable with a deliberate delamination.

25. Packaging as claimed in Claim 23, in which the parts are formed as a clam shell and joined by a hinge.

26. Packaging as claimed in Claim 23, in which fhe parts are formed discretely such that the package is openable by separating the parts.

27. Packaging as claimed in any preceding claim, in which at least one of the parts is formed as a shell.

28. Packaging as claimed in any preceding claim, in which the parts include corresponding sealing flanges.

29. Packaging as claimed in any preceding claim, in which at least one of the parts is substantially rigid.

30. Packaging as claimed in any preceding claim, in which one or more of the parts is thermoformed.

31. Packaging as claimed in any preceding claim, in which one or more of the parts is formed from a thermoplastics material.

32. Packaging as claimed in any preceding claim, in which one of the parts is formed from a non-thermoplastics material.

33. Packaging as claimed in any preceding claim, in which a parting line between the parts is substantially linear.

34. Packaging as claimed in any preceding claim, in which a parting line between the parts is substantially horizontal.

35. Packaging as claimed in any preceding claim, in which the packaging is hermetically sealable.

36. Packaging as claimed in any preceding claim, in which the packaging has a modified atmosphere.

37. Food packaging comprising packaging as claimed in any preceding claim.

38. Packaging substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

39. A sandwich pack comprising or including packaging as claimed in any preceding claim.

40. A submarine sandwich pack comprising or including packaging as claimed in any preceding claim.

41. A method of forming a packaging article substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings. 42. A fabletop heat sealer machine for heat sealing a sandwich pack of the type comprising a base shell and a lid shell, the machine comprising a cavity for receiving the shells and means for heating the shells to seal them together.

43. A beverage container comprising or including packaging as claimed in any preceding claim.