Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
  • A23B2/00—Preservation of foods or foodstuffs, in general
  • A23B2/20—Preservation of foods or foodstuffs, in general by heating materials in packages which are progressively transported, continuously or stepwise, through the apparatus
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23B—PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
  • A23B2/00—Preservation of foods or foodstuffs, in general
  • A23B2/30—Preservation of foods or foodstuffs, in general by heating materials in packages which are not progressively transported through the apparatus
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/24—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2323/00—Polyalkenes
  • B32B2323/04—Polyethylene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging

Definitions

• the present invention relates to a method for treating a container for foods as well as to the container itself. More specifically the invention relates to a method for heat preservation of a container filled with a material, the heat preservation being accomplished by means of heating and a pressure which is maintained during the holding time of the preservation process.
• Completed containers for consumers or for individual portions of the non-disposable type have existed for a long time within the packaging technology. After their first use these containers are intended to be returned and prepared for a new use. Foods are nowadays often filled and transported in containers of a through-away type, i.e. containers intended to be used only once and then discarded or recycled.
• a good product protection implies among other things that the container should be sufficiently mechanically strong and dimensionally stable in order to withstand the outer influences which it is exposed to during normal handling without being deformed or destroyed. Furthermore, the container should be sufficiently physically and chemically impermeable in order to prevent a transport of liquid and/or gases through the walls of the container.
• the container is constructed in such a way that it allows aseptic filling of a product which is sterilized and filled under sterile conditions in a likewise sterilized container which after filling is sealed in such a way that while stored before being consumed the filled product is not reinfected by harmful micro-organisms.
• the foodstuff should be heat preserved in its container.
• a laminate means a material which is constructed of more than two layers joined together. By combining materials with different properties the laminate can obtain such a state which would not be achieved with one material only.
• a known package material consists of a base layer of paper or cardboard, which gives the container mechanical strength and dimensional stability, and of outer layers of polyethylene which make the container liquid impermeable.
• the package material is provided with at least one additional layer of a material with desired properties, e.g. aluminium or a barrier polymer.
• a package material of the laminated type described becomes more complicated in its construction the higher and more well- balanced the demands on the completed container are for the purpose of achieving optimal protection of the product to be filled.
• known containers of a packaging laminate with a liquid absorbing fibre layer cannot be used for heat treatment with moist heat without the desired mechanical rigidity of the packaging laminate and thus the dimensional stability of the container being impaired or lost.
• a container which is manufactured from a laminated material, the container being intended for heat treatment with moist heat.
• the purpose of the invention is thus to provide a method for heat preserving, preferably by means of moist heat, a container filled with goods which is manufactured from a packaging laminate without the above mentioned drawbacks.
• the invention also relates to a container for exercising the method according to claim 3, the container being intended for containing a filling material which is to be heat preserved.
• FIG. 1 schematically shows a cross section through a packaging laminate according to the invention in the form of a sheet or a web.
• a packaging laminate shown in Fig. 1 can be used.
• the laminate comprises a relatively thick strengthening base layer 1 and an inner coating 3.
• the packaging laminate also includes an outer coating 2.
• the container to be preserved includes a laminate containing a plastic with memory.
• a plastic with memory means a polymer material which is deformed at a suitable temperature and when chilled retains its deformed shape.
• Such a plastic with memory is preferably included in one of the layers in the packaging laminate according to Fig. 1, but it can also be included in the other layers which are indicated below.
• polyolefins polyesters, polyamids, polyvinyl alcohols, polycarbonates or acrylic polymers can be used as a plastic with memory.
• Examples of usable polyolefins are low density polyethylene, medium density polyethylene, high density polyethylene, metalized high density polyethylene, polypropylene, oriented polypropylene, metalized (usually with aluminium) oriented polypropylene, a polypropylene copolymer and ethylene/vinyl alcohol, i.e. a copolymer of ethylene and vinyl alcohol (EVOH) .
• polyesters examples include polyethylene naphtalate, polybutene terephtalate, polyester, oriented polyester, metalized (usually with aluminium) oriented polyester and amorphous polyester, the polyester for example being polyethylene terephtalate.
• Examples of usable polyamides are PA 6, PA 66 and Nylon MXD6.
• An example of a usable acrylic polymer is polyacrylonitrile.
• the heat treatment can be accomplished by means of dry air, water or steam as heat transfer medium.
• a heat treatment is used with moist heat at a pressure above the atmospheric in autoclaves which are filled with water or steam. In this way the treatment can take place at such a high temperature as more than 100 °C.
• the process can be divided into a rise time, a holding time and a cooling time.
• the rise time is the time from the beginning of the heating until the desired temperature has been obtained.
• the steam has a temperature of about 110 °C and at a pressure above the atmospheric of 1.1 bar the temperature is about 121 °C.
• the pressure above the atmospheric in the autoclave is lowered to the normal atmospheric pressure, and during the cooling time the temperature is lowered by means of cooling of the autoclave.
• a supporting pressure means a pressure within the autoclaving vessel, which during the cooling time is of the magnitude of up to 1 bar more than that in the closed container with filling material. The supporting pressure is maintained until the plastic with memory has set, which usually takes place at about 100 °C.
• the container can thus be filled at room temperature or lower and can obtain a concave surface without having a negative pressure after the preservation procedure.
• Cans according to the state of the art are often filled with its contents at 60 °C, after which they are closed and heat preserved. After a cooling to room temperature the lid forms a concavity which indicates that a negative pressure still exists in the can.
• the can is expanded (a so called bombage) and this results in that the lid first becomes straight and then bulgingly curved.
• bombage a so called bombage
• the base layer 1 in a container according to the invention preferably consists of a material which can be cardboard, paper, polypropylene, foamed polypropylene, filled polypropylene (e.g. with chalk) , polyester, amorphous polyester, filled polyester or filled amorphous polyester, the polyester for example being polyethylene terephtalate.
• the coatings 2 and 3 are according to the invention designed to be heat resistant and to have good vapour barriers.
• the outer coating 2 consists of a polymer which can be polypropylene, oriented polypropylene, metalized (usually with aluminium) oriented polypropylene, high density polyethylene, metalized high density polyethylene, linear low density polyethylene, polyester, metalized (usually with aluminium) oriented polyester or amorphous polyester, the polyester for example being polyethylene terephtalate.
• the outer coating 2 is not necessary when the base layer consists of another material than paper and cardboard.
• the inner coating 3 consists of a polymer which can be polypropylene, high density polyethylene, linear low density polyethylene, polyester or amorphous polyester, the polyester for example being polyethylene terephtalate.
• the packaging laminate according to the invention also has a barrier layer 4 arranged between the base layer 1 and the inner coating 3, which barrier layer 4 is intended to be facing the filling material of the packaging container.
• the barrier layer can consist of aluminium, a silica coating, ethylene/vinyl alcohol, polyvinyl alcohol, metalized (usually with aluminium) oriented polypropylene, an aluminium oxide coating or metalized (usually with aluminium) oriented polyester, the polyester for example being polyethylene terephtalate.
• the packaging laminate according to the invention can have a layer 5 arranged between the base layer and the outer coating 2, which layer 5 can consist of polypropylene, low density polyethylene, medium density polyethylene, high density polyethylene or amorphous polyester, the polyester for example being polyethylene terephtalate.
• An additional similar layer can be arranged on the other side of the base layer 1.
• the packaging laminate according to the invention can have a coating 6 adjacent one or both sides of the barrier layer 4, which coating 6 can consist of an adhesive plastic, a heat sealable plastic, e.g. polyethylene, a primer or a lacquer.
• An additional layer can be incorporated between the base layer 1 and the adjacent coating 6, which layer then preferably consists of one of the above mentioned components for the layer 5.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Food Science & Technology (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Chemical & Material Sciences (AREA)
• Polymers & Plastics (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)
• Packages (AREA)
• Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
• General Preparation And Processing Of Foods (AREA)
• Auxiliary Devices For And Details Of Packaging Control (AREA)
• Supplying Of Containers To The Packaging Station (AREA)
• Wrappers (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Containers And Plastic Fillers For Packaging (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20398813

Family Applications (1)

Country Status (12)

Cited By (12)

Families Citing this family (17)

Citations (3)

Family Cites Families (8)

• 1995
  • 1995-07-03 SE SE9502391A patent/SE515816C2/sv not_active IP Right Cessation
• 1996
  • 1996-05-29 JP JP50504897A patent/JP3884074B2/ja not_active Expired - Lifetime
  • 1996-05-29 PT PT96922313T patent/PT836573E/pt unknown
  • 1996-05-29 DE DE69622869T patent/DE69622869T2/de not_active Expired - Lifetime
  • 1996-05-29 BR BR9609511A patent/BR9609511A/pt not_active IP Right Cessation
  • 1996-05-29 CA CA002225907A patent/CA2225907C/en not_active Expired - Fee Related
  • 1996-05-29 EP EP96922313A patent/EP0836573B1/en not_active Expired - Lifetime
  • 1996-05-29 WO PCT/SE1996/000689 patent/WO1997002181A1/en not_active Ceased
  • 1996-05-29 ES ES96922313T patent/ES2181898T3/es not_active Expired - Lifetime
  • 1996-05-29 AU AU63223/96A patent/AU710954B2/en not_active Ceased
  • 1996-05-29 US US08/981,389 patent/US5958486A/en not_active Expired - Lifetime
  • 1996-05-29 AT AT96922313T patent/ATE221835T1/de not_active IP Right Cessation

Patent Citations (3)

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