Classifications

• • 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
  • B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
  • B65D1/34—Trays or like shallow containers

Definitions

• This invention relates to moulded containers suitable for supporting for display and containing food and other products.
• the invention finds application in a wide range of containers, including moulded trays for food products such as meats, cakes and various forms of so-called fast-foods, and lidded containers suitable for food products such as hamburgers, pizzas and all other forms of fast-foods.
• Food products such as meats, cakes etc. are usually displayed in supermarkets on shallow trays covered by a plastic film.
• the most widely used tray is the moulded polystyrene foam tray which is durable and may be manufactured at relatively low cost.
• containers having integrally hinged or separate lids are also moulded from polystyrene foam and are widely used to package fast-foods such as hamburgers.
• Single-face corrugated board is widely used in the packaging industry as a cushioning material. It is not traditionally used to form cartons or boxes, although proposals have been made in AU-B-30298/63 (277947) to use modified single-face corrugated board for this purpose, and in AU-B-44160/64 (284298) to use multi-ply wound single-face board to form tubular containers. Neither of these proposals has found commercial acceptance due to the greater strength and more widely accepted use of standard (double-face) corrugated board in the packaging industry. It has never been proposed to make moulded containers or trays from single-face corrugated board, the expectation being that it would not be possible to form moulded containers and trays from such material.
• the invention provides a moulded container or tray suitable for food products, comprising a blank of single-face corrugated board having a liner element and a corrugated element moulded to define a base, an upstanding side wall and a rim, characterized by smoothly radiussed regions between the base and said side wall said corrugated element substantially retaining its integrity in said radiussed regions to provide a moulded container or tray of the required rigidity.
• the container or tray is preferably moulded from single-face corrugated board which has been coated to increase its water and heat resistance and to further increase its rigidity and to retain its moulded shape, although advantage may be gained by coating only the corrugated element.
• Various acrylic or modified cry ⁇ c resins known in the packaging industry may be used for this purpose and have the advantage that they are biodegradable and approved for use in the food industry.
• the invention finds application as a food product tray.
• the invention is equally applicable to other moulded containers, such as hamburger and pizza containers having integrally hinged lids and shaped in the nature of a so-called clam shell container.
• the invention further provides a method of forming a moulded container or tray comprising the steps of forming a shaped blank from single-face corrugated board having a liner element and a corrugated element, moulding the blank under heat and pressure to form a moulded container or tray having a base, an upstanding side wall and rim, said moulding being performed to provide smoothly radiussed regions between the base and the side wall to maintain the integrity of the corrugated element in these regions to thereby form a moulded container or tray having the required rigidity.
• the single face corrugated board is preferably made from paper which has been treated to increase its resistance to moisture and heat and increases the rigidity of the moulded product.
• a suitable coating comprises any one of numerous acrylic or modified acrylic resins used in the packaging industry.
• Figure 1 is a perspective view of a moulded tray embodying the invention
• Figure 2 is a plan view of the moulded tray
• Figure 3 is a side elevation showing a half section through the corrugations.
• a moulded tray embodying the invention is seen to comprise a base portion 1, a side portion 2 and a rim portion 3, with the base and side portions 1 and 2 connected by a smoothly radiussed portion 4 and the side portion and rim portion 2 and 3 connected by a further smoothly radiussed portion 5.
• the tray is moulded from a shaped blank of single- face corrugated board having a liner medium M and a corrugated medium C, with the corrugations directed inwardly of the tray.
• the blank is creased in the regions which will be occupied by the corners of the moulded tray to reduce cracking of the board in these regions and to promote retention of the moulded shape.
• the creases are clearly visible in figures 1 and 3 of the drawings.
• the single face board is preferably coated with an acrylic resin or a modified acrylic resin of the type commonly used in the packaging industry.
• the coating is most conveniently performed on the paper medium which subsequently defines the liner and the corrugated medium in the single face board blank.
• modified acrylic resin is intended acrylic resins to which a cross linking agent known in the art has been added to increase the hardness of the resultant coating, or modified base resins, such as styrenated acrylic resins.
• the moulding process is performed under heat and pressure, and to reduce the likelihood of cracks developing in the corrugated board product, the blank should have a moisture content substantially falling in the range eight to ten per cent.
• Generous clearances are maintained between the male and female platens of the moulding die to further ensure the integrity of the corrugations in the corrugated medium C at all regions of the product except at the corners referred to above where the blank is pre-creased to encourage bunching of the material to define the desired shape of the moulded tray.
• Coating of the single-face board with a suitable acrylic resin or modified acrylic resin is preferably performed before the liners are corrugated and glued together.
• the use of a coated product not only improves the retention of the moulded shape and increases the rigidity of the product but also reduces the likelihood of cracking of the board by providing a seal to the exposed paper surface and allowing the paper and coating to soften and flex under the heat and pressure used in the moulding process. After moulding, the coating cools and hardens to maintain the moulded shape and to increase the rigidity of the product.
• the positioning of the corrugations inside the container reduces food adhesion and increases insulative properties, and may obviate the need for blood absorbing inserts such as are used in the packaging of meat.
• the ability of the corrugated medium to absorb such liquids may be controlled by modifying the coating applied to the corrugated medium.

Landscapes

• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Cartons (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=3776151

Family Applications (1)

Country Status (5)

Families Citing this family (11)

Citations (5)

Family Cites Families (3)

• 1993
  • 1993-05-03 NZ NZ25264593A patent/NZ252645A/en unknown
  • 1993-05-03 WO PCT/AU1993/000194 patent/WO1993023294A1/en not_active Application Discontinuation
  • 1993-05-03 JP JP5519699A patent/JPH08504705A/ja active Pending
  • 1993-05-03 EP EP93911680A patent/EP0639139A4/en not_active Withdrawn
  • 1993-05-03 CA CA 2135280 patent/CA2135280A1/en not_active Abandoned

Patent Citations (5)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events