METHOD OF MAKING A DUNNAGE PLATFORM
A dunnage platform is in the general shape of a rectangular slab with legs extending form one side. The dunnage platform is made from an expanded polystyrene core. A chemical combination process is used to chemically combine portion of the core proximal to its surface with high impact polystyrene. In a first of two parts of the combination process, the core is placed in a forming mold with one of its two sides and two thirds of its thickness extending therefrom. A heated sheet of high impact polystyrene is brought into contact with the portion of the core extending from the mold. In a similar manner, the other of the two sides of the core is made to extend from the forming mold for contact with a heated sheet of high impact polystyrene.
Latest AIRDEX INTERNATIONAL, INC. Patents:
- Light weight, strong, fire retardant dunnage platform bag and system of loading, dispensing and using bag
- CARGO CONTAINER FOR STORING AND TRANSPORTING CARGO
- Modular, knock down, light weight, thermally insulating, tamper proof cargo container
- LIGHT WEIGHT, STRONG, FIRE RETARDANT DUNNAGE PLATFORM BAG AND SYSTEM OF LOADING, DISPENSING AND USING BAG
- LOAD BEARING STRUCTURE HAVING ANTIMICROBIAL PROPERTIES
This application is a continuation of and claims priority to pending U.S. patent application Ser. No. 13/240,839, filed Sep. 22, 2011, which is a continuation of U.S. patent application Ser. No. 12/464,283, filed May 12, 2009 which issued as U.S. Pat. No. 8,142,589 on Mar. 27, 2012, which application is a continuation of U.S. patent application Ser. No. 11/617,578, filed Dec. 28, 2006 which issued as U.S. Pat. No. 7,544,262 on Jun. 9, 2009, which application is a continuation of U.S. patent application Ser. No. 11/490,372, filed Jul. 20, 2006 which issued as U.S. Pat. No. 7,611,596 on Nov. 3, 2009, which application is a continuation of U.S. patent application Ser. No. 10/921,903, filed Aug. 20, 2004 which issued as U.S. Pat. No. 7,128,797 on Oct. 31, 2006, which application is a divisional of U.S. patent application Ser. No. 10/166,988, filed Jun. 11, 2002, and which issued as U.S. Pat. No. 6,786,992 on Sep. 7, 2004. The above applications and patents are herein expressly incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention is in the general field of load-bearing structures and, more particularly, is a load bearing structure made from an expanded polystyrene core that is chemically combined with high impact polystyrene.
2. Description of the Prior Art
A shipping pallet is a well known load-bearing, moveable platform whereon articles are placed for shipment. The pallet usually is loaded with a multiplicity of items, such as cartons or boxes. The loaded pallet is movable with either a pallet truck or a forklift
There is a nine billion dollar market for pallets in the United States. There is a thirty billion dollar world wide market. Approximately ninety percent of these markets is for pallets made from wood.
The weight of the wood pallet is in a range of forty to seventy pounds. Therefore, the weight of a cargo shipped on the wood pallet is reduced by from forty to seventy pounds to provide for the weight of the wood pallet.
It should be understood that injuries caused by wood splinters and nails are frequent occurrences among people who handle the wood pallet. Additionally, disposal of the wood pallet at the end of its useful life is a threat to the environment.
There has been concern among nations about the use of the wood pallet causing an import of wood-boring insects, including the Asian Longhorned Beetle, the Asian Cerambycid Beetle, the Pine Wood Nematode, the Pine Wilt Nematode and the Anoplophora Glapripwnnis. Exemplary of damage caused by imported insects is the fate of the Chestnut Tree in the United States. There was a time when it was said that a squirrel could cross the United States on Chestnut Tree limbs without ever touching the ground. Insect infestation has caused the extinction of the Chestnut Tree in the United States.
Therefore, the wood pallet's weight, the injuries that it causes, its threat to the environment and the possibility of it causing an importation of wood-boring insects militates against the use of the wood pallet. As explained hereinafter, there is an attractive alternative to the wood pallet.
SUMMARY OF THE INVENTIONAn object of the invention is an easily movable load bearing structure that is not likely to carry wood-boring insects.
Another object of the invention is a movable load bearing structure that does not have splinters and nails that may cause injury.
According to the present invention, a dunnage platform has an expanded polystyrene core with a region proximal to its surface that is chemically combined with a high impact polystyrene.
Because of a chemical combination of components, comparing the core before the chemical combination to the dunnage platform that is formed, there is an increase in strength to weight ratio of as much as 1000:1 that allows the dunnage platform to carry loads comparable to loads carried by a wooden pallet. The dunnage platform does not support insect life and does not have splinters and nails that cause injury.
Other objects, features and advantages of the invention should be apparent from the following description of a preferred embodiment thereof as illustrated in the accompanying drawing.
As shown in
The edge 12 is proximal to ma spaces 42, 44, 46, 48 on the bottom side 18. The marginal spaces 42, 44, 46, 48 separate the legs 26-28, the legs 20, 2326, the legs 20-22 and the legs 22, 25, 28, respectively, from the edge 12.
Because the core 10 is made from expanded polystyrene, it does not have sufficient structural strength to be useable as a load bearing platform. A dunnage platform with sufficient strength is formed by chemically combining a region of the core 10, proximal to its surface, with a high impact polystyrene. Expanded polystyrene and high impact polystyrene are well known. The dunnage platform described hereinafter has substantially the same dimensions as the core 10.
A first of two parts of a chemical combination process causes portions of the expanded polystyrene proximal to the bottom side 18 to be chemically combined with the high impact polystyrene to form strengthened polystyrene. Additionally, a portion of the expanded polystyrene that is proximal to the edge 12 and in a proximal relationship to the bottom side 18 is chemically combined with the high impact polystyrene to form the strengthened polystyrene.
As shown in
An interior of the walls 52-55 form a shelf 60 that extends around the interior 56. The shelf 60 has a surface 62 that is parallel to the surface 58. For reason's explained hereinafter, a displacement between the surfaces 58, 62 is less than one half of the width 14 (
As shown in
A fixedly positioned clamping frame 64 has a first high impact polystyrene sheet 67 clamped therein. A heater 68 is positioned proximal to the frame 64.
As shown in
As shown in
As shown in
It should be understood that when the sheet 67 is heated, it becomes fragile. Because the frame 64 is fixedly positioned, a risk of damage to the sheet 67 is minimized.
As shown in
It should be understood that the core 10 is porous. When the vacuum pump 84 operates, air may pass through the core 10, from the top side 16, to the pump 84. The heated sheet 67 is not porous, thereby causing one atmosphere of air pressure that draws the heated sheet 67 onto the bottom side 18 and the two thirds of the edge 12 that extends from the mold 50.
The expanded polystyrene proximal to the bottom side 18 and proximal to the two thirds of the edge 12 that extend above the mold 50 chemically combine with the high impact polystyrene of the sheet 67 to form the strengthened polystyrene. The strengthened polystyrene is not porous. The side 18 and the legs 20-28 with the strengthened polystyrene proximal to their surface are hereinafter referred to as a side 18C with legs 20C-28C, respectively.
As shown in
As shown in
The frame 64 frames a second high impact polystyrene sheet 94, similar to the sheet 67. The frame 64 with the sheet 94 is fixedly positioned above the mold 50. The heater 68 is positioned proximal to the fame 64.
As shown in
As shown in
In accordance with the second part of the process, the expanded polystyrene proximal to the portions of the surface of core 10 that extends from the mold 50 chemically combines with the high impact polystyrene of the sheet 94 to form the strengthened polystyrene. Moreover, because the displacement between the surfaces 58, 62 is less than one half of the width 14, the strengthened polystyrene is formed proximal to the entire edge 12.
The dunnage platform formed by the process weighs approximately eight pounds and can carry an approximately 3500 pound load.
As shown in
Similarly, the legs 20C, 23C, 26C, and the legs 21C, 24C, 27C and the legs 22C, 25C, 28C are arranged in parallel rows 98-100, respectively, that are orthogonal to the columns 95-97. The rows 98-100 are spaced so that tines of a fork lift can fit between the rows 98, 99 and between the rows 99, 100. Accordingly, with the tines parallel to the columns 98-100, the fork lift can lift the dunnage platform from either of two sides.
While the invention has been particularly shown and described with reference to a preferred embodiment, it should be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims
1. A method of making a dunnage platform comprising:
- providing a core made from an expanded polymer for defining the shape of the platform, said core having a dimension, a first side and a second side separated by an edge, and a plurality of legs extending from said first side;
- heating a first thermoplastic sheet having a dimension larger than the dimension of the core, said thermoplastic sheet being held tautly prior to heating;
- placing said first heated thermoplastic sheet on said first side of said core; and
- combining said heated first thermoplastic sheet with a region of said first side and at least a part of said edge of said core proximal to a surface of said side and a portion of said edge to form a dunnage platform with sufficient load bearing strength.
2. The method of claim 1 wherein said first thermoplastic sheet is heated until it sags prior to being placed on said first side of said core.
3. The method of claim 1 wherein said combining comprises applying a vacuum to draw said first heated thermoplastic sheet onto said first side of said core.
4. The method of claim 1 wherein said core is retained in a forming mold to expose said first side, a plurality of legs extending from said first side, and at least part of said edge.
5. The method of claim 1 wherein said thermoplastic sheet is held in a clamping frame.
6. The method of claim 1 further comprising:
- retaining said core combined with said first thermoplastic sheet in a forming mold having an interior that is complementary to a shape of said core to expose the second side and at least a portion of said edge of said core;
- heating a second thermoplastic sheet; and
- combining said heated second thermoplastic sheet with a region of said second side of said core proximal to a surface of said second side.
7. The method of claim 6 where said second thermoplastic sheet covers said second side of the core and at least a portion of said edge.
8. A method of making a dunnage platform comprising:
- providing a core made from an expanded polymer for defining the shape of the platform, said core having a dimension, a first side and a second side separated by an edge, and a plurality of legs extending from said first side;
- heating a first thermoplastic sheet having a dimension larger than the dimension of the core, a portion of said first thermoplastic sheet being held by a clamping frame; and
- combining said heated first thermoplastic sheet with a region of said first side and a part of said edge proximal to a surface of said first side and of said part of said edge.
9. The method of claim 8 wherein said clamping frame comprises an upper frame attached to a lower frame.
10. The method of claim 8 wherein said first thermoplastic sheet is heated until it sags prior to combining with said core.
11. The method of claim 9 wherein said first thermoplastic sheet is clamped between said upper and said lower frame about its edges.
12. The method of claim 8 wherein said combining is effected by heating said thermoplastic sheet at a temperature range of 293° F. to 375° F.
13. The method of claim 8 further comprising:
- retaining said core combined with said first thermoplastic sheet in a forming mold having an interior that is complementary to a shape of said core to expose the second side and at least a portion of said edge of said core;
- heating a second thermoplastic sheet; and
- combining said heated second thermoplastic sheet with a region of said second side and a part of said edge of said core proximal to a surface of said second side and said edge.
14. A method of making a dunnage platform comprising:
- providing a core made from an expanded polymer for defining the shape of the platform, said core having a dimension, a first side and a second side separated by an edge, and a plurality of legs extending therefrom said first side;
- heating a first high impact polystyrene sheet having a dimension larger than the dimension of the core, said high impact polystyrene sheet being held tautly prior to heating;
- placing said first heated high impact polystyrene sheet on said first side of said core; and
- combining said heated first high impact polystyrene sheet with a region of said first side and a part of said edge of said core proximal to a surface of said side and said edge.
15. The method of claim 14 wherein said high impact polystyrene sheet is being held by at least a portion of its edge.
16. The method of claim 14 wherein said first high impact polystyrene is heated at a temperature range of 293° F. to 375° F.
17. The method of claim 14 wherein said combining comprises applying a vacuum to draw said heated first high impact polystyrene sheet onto said first side of said core.
18. The method of claim 14 wherein said first high impact polystyrene sheet is held in a clamping frame about at least a portion of its edges.
19. The method of claim 14 wherein said first side of said expanded core and more than half of said edge is covered by said first high impact polystyrene sheet.
20. The method of claim 14 further comprising:
- retaining said core combined with said first high impact polystyrene sheet in a forming mold having an interior that is complementary to a shape of said core to expose the second side and at least a portion of said edge of said core;
- heating a second high impact polystyrene sheet; and
- combining said heated second high impact polystyrene sheet with a region of said second side of said core proximal to a surface of said second side and said edge.
Type: Application
Filed: Apr 6, 2013
Publication Date: Aug 29, 2013
Applicant: AIRDEX INTERNATIONAL, INC. (Henderson, NV)
Inventor: AIRDEX INTERNATIONAL, INC.
Application Number: 13/858,019
International Classification: B32B 37/18 (20060101);