Oriented fiber reinforced monolithic plastic foam pallet

• US 5,687,652 A
• Filed: 02/27/1995
• Issued: 11/18/1997
• Est. Priority Date: 06/28/1993
• Status: Expired due to Fees

• Current Assignee: Joseph G. Ruma
• Original Assignee: Joseph G. Ruma
• Inventors: Ruma, Joseph G.
• Primary Examiner(s): Chen, Jose V.
• Application Number:
  US08/394,795
• Time in Patent Office: 995 Days
• Field of Search: 108/901, 108/902, 108/51.1, 108/56.1
• US Class Current: 108/57.25
• CPC Class Codes: B65D 19/0012 forming a continuous plane contact surface
• CPC Class Codes: B65D 19/0026 and each contact surface having a stringer-like shape
• CPC Class Codes: B65D 2519/00039 Agglomerates, i.e. different materials mixed together
• CPC Class Codes: B65D 2519/00074 Agglomerates, i.e. different materials mixed together
• CPC Class Codes: B65D 2519/00109 Agglomerates, i.e. different materials mixed together
• CPC Class Codes: B65D 2519/00268 made of one piece
• CPC Class Codes: B65D 2519/00288 made of one piece
• CPC Class Codes: B65D 2519/00308 grid type, e.g. perforated plate
• CPC Class Codes: B65D 2519/00318 made of one piece
• CPC Class Codes: B65D 2519/00333 contact surface having a stringer-like shape
• CPC Class Codes: Y10S 108/901 Synthetic plastic industrial platform, e.g. pallet

Abstract

A new and improved unitary plastic foam four-way entry pallet (10) comprising: a top deck (11), with perforated apertures (12), buttressed by a plurality of elongated support runners (13) which are profiled to receive material handling equipment; the runners are joined to a plurality of bottom members (14), perpendicular to the plane of the support runners. All the components are monolithically cast, in a mold, utilizing rigid plastic foam reinforced with oriented strand fibers to form homogenous matrix (16), which has a seamless, smooth finish (15), provided by the use of self-skinning foams.

Claims

1. A monolithic pallet construction, comprising:

an upper deck,

a plurality of depending legs attached to said upper deck, and

a plurality of bottom supports attached to said depending legs, said bottom supports, said upper deck and said plurality of depending legs being integrally formed of a rigid plastic foam,

and oriented reinforcing fibers incorporated into said rigid plastic foam;

within said upper deck, said oriented reinforcing fibers being oriented substantially parallel to a long axis of said upper deck;

within said bottom supports, said oriented reinforcing fibers being oriented substantially parallel to a long axis of said bottom supports.

2. The pallet construction of claim 1 wherein said rigid plastic foam comprises rigid polyurethane foam.

3. The pallet construction of claim 1 wherein said plurality of depending legs is attached to said upper deck by a plurality of support runners which are attached to said upper deck and to said depending legs, wherein said plurality of bottom supports are perpendicular to said support runners, wherein said upper deck is perforated and wherein, within said support runners, said oriented reinforcing fibers are oriented substantially parallel to a long axis of said support runners.

4. A monolithic pallet construction, comprising:

an upper deck,

a plurality of depending legs attached to said upper deck, and

a plurality of bottom supports attached to said depending legs, said bottom supports, said upper deck and said plurality of depending legs being integrally formed of a rigid plastic foam,

a nonfoamed plastic skin covering all exterior surfaces of said pallet,

and oriented reinforcing fibers incorporated into said nonfoamed plastic skin;

within said upper deck, said oriented reinforcing fibers being oriented substantially parallel to a long axis of said upper deck;

within said bottom supports, said oriented reinforcing fibers being oriented substantially parallel to a long axis of said bottom supports.

5. The pallet construction of claim 4 further comprising oriented reinforcing fibers incorporated into said rigid plastic foam;

within said upper deck, said oriented reinforcing fibers in said rigid plastic foam being oriented substantially parallel to a long axis of said upper deck;

within said bottom supports, said oriented reinforcing fibers in said rigid plastic foam being oriented substantially parallel to a long axis of said bottom supports and wherein said nonfoamed plastic skin is formed of the same plastic material as said rigid plastic foam.

6. The pallet construction of claim 5 wherein said rigid plastic foam comprises a rigid polyurethane foam and said nonfoamed plastic skin comprises a rigid polyurethane.

7. The pallet construction of claim 5 wherein said plurality of depending legs is attached to said upper deck by a plurality of support runners which are attached to said upper deck and to said depending legs, wherein said plurality of bottom support are perpendicular to said support runners, wherein said upper deck is perforated and wherein, within said support runners, said oriented reinforcing fibers in said rigid plastic foam are oriented substantially parallel to a long axis of said support runners.

8. The pallet construction of claim 4 wherein said plurality of depending legs is attached to said upper deck by a plurality of support runners which are attached to said upper deck and to said depending legs, wherein said plurality of bottom supports are perpendicular to said support runners, wherein said upper deck is perforated and wherein, within said support runners, said oriented reinforcing fibers are oriented substantially parallel to a long axis of said support runners.

9. A monolithic pallet construction, comprising:

an upper deck formed by injecting plastic foam containing fiber strands into a mold along a long axis of said upper deck such that said fiber strands are oriented substantially parallel to said long axis of said upper deck,

a plurality of support runners attached to said upper deck, said plurality of support runners formed by injecting plastic foam containing fiber strands into said mold along a long axis of said plurality of support runners such that said fiber strands are oriented substantially parallel to said long axis of said plurality of support runners, and

a plurality of bottom supports attached to said plurality of support runners, said plurality of bottom supports having a long axis perpendicular to said long axis of said support runners, said plurality of bottom supports formed by injecting plastic foam containing fiber strands into said mold along said long axis of said plurality of bottom supports such that said fiber strands are oriented substantially parallel to said long axis of said plurality of bottom supports.

10. The pallet construction of claim 9 further comprising a nonfoamed plastic skin covering all exterior surfaces of said pallet, wherein said nonfoamed plastic skin is formed integrally of the same plastic material as said plastic foam by coalescing said plastic material from said plastic foam onto an inner surface of said mold to form said nonfoamed plastic skin.

11. The pallet construction of claim 10 further comprising oriented fiber strands incorporated into said nonfoamed plastic skin;

within said upper deck, said oriented fiber strands being oriented substantially parallel to said long axis of said upper deck;

within said support runners, said oriented fiber strands being oriented substantially parallel to said long axis of said support runners;

within said bottom supports, said oriented fiber strands being oriented substantially parallel to said long axis of said bottom supports.

12. The pallet construction of claim 9, wherein said upper deck, said plurality of support runners and said plurality of bottom supports are formed simultaneously by simultaneously injecting plastic foam containing fiber strands into said mold along said long axis of said upper deck, said long axis of said plurality of support runners and said long axis of said plurality of bottom supports.

13. The pallet construction of claim 12, wherein, prior to injecting said plastic foam containing fiber strands into said mold, said fiber strands are incorporated into said plastic foam by introducing said fiber strands into a moving airstream to orient said fiber strands longitudinally with respect to said moving airstream, then mixing the oriented fiber strands into said plastic foam.

14. The pallet construction of claim 13, wherein said oriented fiber strands are mixed into said plastic foam simultaneously with forming said plastic foam by mixing at least two components by impingement of said at least two components into one another.

20. The pallet construction of claim 9, wherein said fiber strands comprise chopped fiber strands with a length of approximately 0.10-1.00 inches.

21. The pallet construction of claim 20, wherein said chopped fiber strands are chosen from the group consisting of fiberglass, Kevlar fibers, carbon fibers, polyester fibers, cellulose fibers, ceramic fibers, and metal fibers.

22. The pallet construction of claim 9, wherein said fiber strands comprise short fiber strands with a length of approximately 0.10-0.25 inches.

23. The pallet construction of claim 9, wherein said fiber strands comprise long fiber strands with a length of approximately 0.75-1.00 inches.

24. The pallet construction of claim 9, wherein said plastic foam comprises rigid polyurethane foam.

15. A method of manufacturing a pallet, comprising the steps of:

forming an upper deck by injecting plastic foam containing fiber strands into a mold along a long axis of said upper deck such that said fiber strands are oriented substantially parallel to said long axis of said upper deck;

forming a plurality of support runners attached to said upper deck by injecting plastic foam containing-fiber strands into said mold along a long axis of said plurality of support runners such that said fiber strands are oriented substantially parallel to said long axis of said plurality of support runners; and

forming a plurality of bottom supports attached to said plurality of support runners, said plurality of bottom supports having a long axis perpendicular to said long axis of said support runners, by injecting plastic foam containing fiber strands into said mold along said long axis of said plurality of bottom supports such that said fiber strands are oriented substantially parallel to said long axis of said plurality of bottom supports.

16. The method of claim 15 further comprising:

forming a nonfoamed plastic skin covering all exterior surfaces of said pallet, wherein said nonfoamed plastic skin is formed integrally of the same plastic material as said plastic foam, by coalescing said plastic material from said plastic foam onto an inner surface of said mold to form said nonfoamed plastic skin.

17. The method of claim 15, wherein said upper deck, said plurality of support runners and said plurality of bottom supports are formed simultaneously by simultaneously injecting plastic foam containing fiber strands into said mold along said long axis of said upper deck, said long axis of said plurality of support runners and said long axis of said plurality of bottom supports.

18. The method of claim 17, wherein, prior to injecting said plastic foam containing fiber strands into said mold, said fiber strands are incorporated into said plastic foam by introducing said fiber strands into a moving airstream to orient said fiber strands longitudinally with respect to said moving airstream, then mixing the oriented fiber strands into said plastic foam.

19. The method of claim 18, wherein said oriented fiber strands are mixed into said plastic foam simultaneously with forming said plastic foam by mixing at least two components by impingement of said at least two components into one another.

25. The method of claim 15, wherein, prior to injecting said plastic foam containing fiber strands into said mold, said fiber strands are incorporated into said plastic foam as chopped fiber strands with a length of approximately 0.10-1.00 inches.

26. The method of claim 25, wherein said chopped fiber strands are chosen from the group consisting of fiberglass, Kevlar fibers, carbon fibers, polyester fibers, cellulose fibers, ceramic fibers, and metal fibers.

27. The method of claim 15, wherein, prior to injecting said plastic foam containing fiber strands into said mold, said fiber strands are incorporated into said plastic foam as short fiber strands with a length of approximately 0.10-6.25 inches.

28. The method of claim 15, wherein, prior to injecting said plastic foam containing fiber strands into said mold, said fiber strands are incorporated into said plastic foam as long fiber strands with a length of approximately 0.75-1.00 inches.

29. The method of claim 15, wherein said plastic foam comprises rigid-polyurethane foam.

30. The method of claim 15, wherein said upper deck, said plurality of support runners and said plurality of bottom supports are formed by injecting said plastic foam containing fiber strands into a clam-shell mold having removable cores for maintaining open spaces between said upper deck, said plurality of support runners and said plurality of bottom supports, and subsequently removing said clam-shell mold and removable cores from the molded pallet.