COMPOSITE MATERIAL FOR THE INSULATION OF CONTAINERS AND CONTAINERS FORMED THEREFROM

Abstract: A composite material with qualities of insulation suitable for creating an insulative lining within cartons containing perishable products or encapsulating packages in which specified thermal stability is necessary is formed into one or more panels comprising a thermal property material core on at least one side of which is disposed a stiffening material such as card, both materials being encased within a plastics film such as polyester which may be metallized and the whole sealed to provide a waterproof insulative panel.

Description: COMPOSITE MATERIAL FOR THE INSULATION OF CONTAINERS AND CONTAINERS FORMED THEREFROM The invention relates to a composite material for use in the insulation of containers and to insulated containers which incorporate such composite material. The composite material has insulating properties for the storage of hot or cold items and the invention is particularly useful in forming packaging containers for the transport of products which are perishable or which are required to remain frozen, chilled or heated whilst in transit. Preferably, composite material according to the invention should be resilient to impact and rough handling during the packing and freighting, yet not be overlarge in size when placed in or around a packaging container; not excessively heavy in weight nor unduly expensive to manufacture. In addition, such composite material should have storage characteristics which permit its stockpiling without occupying excessive space and be capable of placement into, upon or over a container and upon termination of use be capable of disposal without causing pollution or with an inability to be absorbed into recycling processes or reclamation. For containers which are required to transport perishable items like fish or certain agricultural products which may require the inclusion of refrigerants, it is desirable that the composite material which will form the insulation of such containers be formed from material of which at least part is waterproof. The present invention seeks to satisfy all these requirements in whole or in part whilst having none of the adverse properties of many materials currently used in the formation of such packaging, such as expanded polystyrene, which is a material virtually impossible to recycle or destroy without creating potentially harmful side effects. According to the present invention, a composite material is formed into one or more panels for use as an insulator, said composite material comprising a core of thermal-property material, a sheet of stiffening material adjacent at least one side of said core and an outer flexible plastics film material disposed such that said thermal and stiffening materials are enclosed within the flexible plastics film. Embodiments of the invention will now be described by way of example. The differing materials which comprise the composite material have individual properties which contribute to the desired final characteristics of the insulation. The core of the material may be a slab of man-made mineral fibre such as rock wool - this material is extensively used in varying applications for its thermal properties, which are well proven. Usually the rock wool will incorporate a binder such as cured urea extended phenol formaldehyde resin, or starch and mineral oil. To this core, which can be of any manageable size and any desired thickness suitable for the required degree of insulation, a stiffening material such as card, is applied and preferably laminated to at least one of two main surfaces of the core. The stiffening material may be solid or corrugated to any manageable size and thickness not necessarily to the same dimensions as the core. The stiffening material may be metallized, printed, foil-stamped, embossed or lacquered and for any of these operations card is a suitable medium. If card is used and is manufactured in corrugated format, then additional thermal enhancement may be obtaine . Furthermore, such corrugation will provide additional stiffening in those instances where the composite material is used as a container per se without the addition of external packaging, or where the composite material is used as an outer cladding to create a thermal barrier around a package. In those instances where the composite material is external to the product to be insulated and any additional inner wrapping, the stiffening material may be used to display graphics and information in such manner as to be visible when the outer covering of plastic film is transparent or translucent and if coated with a reflective surface, to contribute as a thermal barrier to solar rays or other sources of heat. To contain the core and stiffening material as a single unit and to provide additional protection against impact whilst also contributing, in certain specific aspects i.e. when metallized, to insulation, plastics film of a size which exceeds both core and stiffening material is positioned in such manner that the core and stiffening material are contained and enclosed within the plastic film. Such containment may be achieved by using the film in single sheet format so that it is folded around the core and stiffening material whereafter three edges of the film are then sealed and the sheet then encloses the other materials so that the whole forms a panel which may be used as an insulating barrier within any form of packaging. By placing more than one such combination of core and stiffening material within a plastics film material and then sealing between the combination of core and stiffening material as well as around the three outer edges a series of panels connected one to the next may be obtained. If at least one of the outer edges of the film initially is left unsealed, the plastics film may first be prepared to receive the core and stiffening materials. The plastics film sheet can of course be folded upon itself to create, together with the core, an insulated pocket to which a refrigerant may be added without making contact with the materials other than the plastics film. According to one method of manufacture of the composite material it is possible to obtain similar enclosure of the core and stiffening material by using two or more separate sheets of plastics film which may not necessarily be of the same composition but which should be inert to the content of the package, non-toxic and compatible to the joining of one sheet to the other. If a pocket is required it may included in one or both sheets of the plastics film and positioned on whichever side of the core and stiffening material is best suited to the purpose of enclosure, i.e. if to contain instructions on the stiffening material side, if to contain refrigerant on the core side. If two different types of plastics film are used, additional protection and thermal resistance may be obtained, such as combining a metallized film and an encapsulated air bubble film. Combination films can add strength and impact resistance and, in certain instances, a combination of non-permeable and permeable films may provide a waterproof barrier on one side of a composite material panel whilst allowing moisture to pass through the other side which may be advantageous where the composite material is used as a container for plants or other horticultural or agricultural applications which require retention of heat allied to moisture encapsulation. In addition the plastics film enclosing the core and stiffening material may have a perforate line at preselected locations along its length so that if manufactured in multiple panel format, one or more panels of the composite material may be detached or if manufactured without the addition of the core and stiffening material, may be detached and then the other materials added thereafter. As examples of the versatility of the composite material, three specific applications are given below, but whilst these relate to use of the composite material within the packaging art it must be recognised that various other applications related e.g. to home insulation, particularly roof/loft cladding, seed and plant packaging and growing, thermal bags and other packs which may incorporate regrigerants, insulated clothing and accessories, thermal carpet underlay, table and furniture surface insulation and protection and numerous other uses are within the scope of the invention as defined bythe appended claims. Example 1 A triple panel section comprising three composite material panels with sealed spaces between each panel and further including a separate composite material panel are made from the composite material in a manner previously described. The single panel is placed at the bottom of an open-topped container which is then filled with perishable product and refrigerant and the triple panel is placed over the content with the centre panel across the top of the open container top and one panel descending upon each of the respective sides of the container. A separate lid which includes side and end walls is then placed over the whole, thus creating an enclosed package which is insulated over the inner top, bottom and side walls thereof. Example 2 A four sided panel section comprising four main composite material panels with sealed spaces between each panel foldable into a sleeve and additional 'end' panels comprising sections attached to one or more of the main panels is made from the composite material and the whole assembled to form an outer enclosure into which enclosure is inserted a package comprising product. The end panels of the enclosure covering are folded and sealed to the main panels so as to encapsulate and create a thermal barrier around the internal package. The enclosure may be inserted into a two-part outermost box comprising base and lid. Example 3 A double panel section comprising two composite material panels with sealed spaces between each panel both of which panels include a pocket. The pockets accommodate refrigerants and, in use, one panel is laid upon the base of a container so that the sealed space between the panels is disposed adjacent to one side wall of the container. Product is inserted into the container and received on top of the said one panel whereafter the other panel is laid over the product thus forming a thermal wrap inclusive of refrigerant around the content of the container. If the composite material is attached to pre-formed and cut packaging material from which e.g. and outer box like container can be formed, it is possible for the composite material and packaging material to be stored as one entity and when required, to be assembled in one operation. According to the size and thickness of the core material, the composite material may be used in widely varying sizes of packaging, from confectionery boxes to outsize cartons, as well as thermal wrap within airfreight and other containers, thereby reducing the requirement of specialised cartons used for the containment of perishable products transported within such containers.

Claims: CLAIMS 1. A composite material for forming one or more insulated panels, said composite material comprising a core of thermal-property material on at least one side of which is disposed a sheet of stiffening material and wherein a plastics film material covers said thermal and stiffening materials in such manner that thermal and stiffening materials are enclosed within the flexible plastics film. 2. A composite material as claimed in Claim 1 wherein the said thermal-property material is inert vitreous silicate wool. 3. A composite material as claimed in Claim 1 wherein the said thermal property material is inert rockwool. 4. A composite material as claimed in Claim 1 wherein the said thermal-property material is cellulose fibres. 5. A composite material as claimed in Claim 1 wherein the said thermal-property material is borosilicate glass. 6. A composite material as claimed in Claim 1 wherein the said thermal-property material is cotton linter. 7. A composite material as claimed in Claim 1 wherein the said thermal-property material is rigid. 8. A composite material as claimed in Claim 1 wherein the said thermal-property material is flexible. 9. A composite material as claimed in any of the preceding claims wherein the said stiffening material is fibreboard. 10. A composite material as claimed in any of claims 1 to 8 wherein the said stiffening material is corrugated board. 11. A composite material as claimed in any of claims 1 to 8 wherein the said stiffening material is card. 12. A composite material as claimed in any of claims 1 to 8 wherein the said stiffening material is a plastics material. 13. A composite material as claimed in any of the preceding claims wherein the said stiffening material is rigid. 14. A composite material as claimed in any of claims 1 to 12 wherein the said stiffening material is flexible. 15. A composite material as claimed in any of the preceding claims wherein said stiffening material is metal1ized. 16. A composite material as claimed in any of the preceding claims wherein said stiffening material is printed. 17. A composite material as claimed in any of the preceding claims wherein said stiffening material is foiled. 18. A composite material as claimed in any of the preceding claims wherein said stiffening material is embossed. 19. A composite material as claimed in any of the preceding claims wherein said stiffening material is lacquered. 20. A composite material as claimed in any of the preceding claims wherein the said plastics film is polyester. 21. A composite material as claimed in any of claims 1 to 19 wherein the said plastics film is polypropylene. 22. A composite material as claimed in any of the preceding claims wherein the said plastics film comprises encapsulated air bubbles. 23. A composite material as claimed in any of the preceding claims wherein the said plastics film is a laminate of two or more plastics. 24. A composite material as claimed in any of the preceding claims wherein the said plastics film is transparent. 25. A composite material as claimed in any of claims 1 to 23 wherein the said plastics film is translucent. 26. A composite material as claimed in any of claims 1 to 23 wherein the said plastics film is opaque. 27. A composite material as claimed in any of the preceding claims wherein the said plastic film is metallized. 28. A composite material as claimed in any of the preceding claims wherein the said plastics film is printed. 29. A composite material as claimed in any of the preceding claims wherein the said plastics film is foiled. 30. A composite material as claimed in any of the preceding claims wherein the said plastics film is embossed. 31. A composite material as claimed in any of the preceding claims wherein the said plastic film is lacquered. 32. A composite material as claimed in any of the preceding claims wherein the said plastics film has at least two edges joined together by heat-sealing. 33. A composite material as claimed in any of claims 1 to 32 wherein the said plastics film has at least two edges joined together by adhesive. 34. An insulated container substantially formed from or comprising a composite material according to any of the preceding claims. 35. A multiple panel composite material substantially as hereinbefore described with reference to Example I, Example II or Example III.

Inventors: PAYNE STANLEY BRIAN, PAYNE, STANLEY, BRIAN
Applicants: PAYNE STANLEY BRIAN, PAYNE, STANLEY, BRIAN
Application year: 1990
Main classification: F16L59
IPC codes: B32B7, B32B27, B65D81, F16L59