Coextruded multiple plastic layer slip pallet

• US 4,649,007 A
• Filed: 04/04/1984
• Issued: 03/10/1987
• Est. Priority Date: 04/04/1984
• Status: Expired due to Fees

• Current Assignee: Portage Industries Corp (Spartech LLC)
• Original Assignee: Composite Container Corporation
• Inventors: Bonis, Laszlo J., Opland, Samuel, Courville, George V.
• Primary Examiner(s): Anderson, Philip
• Application Number:
  US06/596,541
• Time in Patent Office: 1,070 Days
• Field of Search: 264/171, 264/148, 264/230, 264/DIG. 71, 108/51.1, 428/339, 428/519, 425/308, 425/462
• US Class Current: 264/148
• CPC Class Codes: B29C 2793/0027 Cutting off
• CPC Class Codes: B29C 48/0022 combined with cutting
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/307 specially adapted for bringing together components, e.g. melts within the die
• CPC Class Codes: B29K 2105/26 Scrap or recycled material
• CPC Class Codes: B29K 2995/0072 Roughness, e.g. anti-slip
• CPC Class Codes: B29L 2031/7178 Pallets
• CPC Class Codes: B32B 2250/04 4 layers
• CPC Class Codes: B32B 2272/00 Resin or rubber layer comprising scrap, waste or recycling material
• CPC Class Codes: B32B 2307/736 Shrinkable
• CPC Class Codes: B32B 2307/744 Non-slip, anti-slip
• CPC Class Codes: B32B 2307/746 Slipping, anti-blocking, low friction
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B65D 19/00 Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered in devices for lifting or lowering bulky or heavy goods for loading or unloading purposes B66F9/12
• CPC Class Codes: Y10S 264/71 Processes of shaping by shrinking
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component
• CPC Class Codes: Y10T 428/31924 Including polyene monomers

Abstract

A slip pallet made of a multiple layer coextruded sheet, one layer having more shrinkage than a layer below it to provide a natural curl to a gripping edge portion of the sheet such that in use the gripping edge portion is accessible by a gripper of a forklift.

Claims

1. A method of making slip pallets comprising

coextruding a sheet comprising a plurality of plastic layers including an upper nonslip layer of a first plastic and a lower slip layer of second plastic, the exposed upper surface of said upper nonslip layer having a coefficient of friction higher than that of an exposed lower surface of said lower slip layer, to cause said lower surface to slide relative to a platen and said upper surface to frictionally engage boxes on it, one layer of said plurality of layers having more shrinkage than a layer below said one layer to provide a natural curl to gripping edge portions of said slip pallets such that in use said gripping edge portions of said slip pallets are accessible by a gripper of a forklift, and

cutting said sheet into individual slip pallets that are larger than the boxes to be supported to provide said gripping edge portions.

2. The method of claim 1 wherein said second plastic comprises polyethylene.

3. The method of claim 2 wherein said first plastic comprises one of the group including ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ionomer, and scrap plastic including polyethylene and acrylonitrile containing polymer.

4. The method of claim 1 wherein said plurality of plastic layers comprises four layers.

5. The method of claim 4 wherein said first plastic in said upper nonslip layer comprises scrap plastic including polyethylene and acrylonitrile containing polymer, said second plastic in said lower slip layer comprises polyethylene, said plurality of plastic layers comprises an intermediate layer of said scrap plastic above said lower nonslip layer of polyethylene, and an intermediate layer of polyethylene above said intermediate layer of scrap plastic and below said upper layer of scrap plastic.

6. The method of claim 1 wherein said plurality of layers comprises a layer comprising one of the group of polyethylene, polypropylene, polyethylene terepthalate, glycol-modified polyethylene terepthalate, nylon, ultrahigh molecular weight polyethylene, and polycarbonate.

7. The method of claim 1 wherein said gripping edge portion has a radius of curvature between four and nine inches.

8. The method of claim 1 wherein said sheet is less than 200 mils thick.