Cushioning device with improved flexible barrier membrane

• US 6,521,305 B1
• Filed: 09/14/1999
• Issued: 02/18/2003
• Est. Priority Date: 08/31/1994
• Status: Expired due to Term

• Current Assignee: Henry W. Bonk, James C. Sell Jr, Paul H. Mitchell
• Original Assignee: Henry W. Bonk, James C. Sell Jr, Paul H. Mitchell
• Inventors: Mitchell, Paul H., Bonk, Henry W., Sell, James C. Jr.
• Primary Examiner(s): Dye, Rena
• Application Number:
  US09/395,896
• Time in Patent Office: 1,253 Days
• Field of Search: 428/35.7, 428/35.4, 428/36.6, 428/36.7, 428/36.8, 428/422.8, 428/423.1, 428/424.2, 428/76, 428/215, 428/220, 428/339, 156/244.11, 156/244.14, 156/244.24, 36/28, 36/29, 36/30.R, 36/35.R, 36/44
• US Class Current: 428/35.4
• CPC Class Codes: A43B 13/203 provided with a pump or valve
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 3/08 characterised by added members at particular parts layer formed of separate pieces of material which are juxtaposed side-by-side B32B3/14, B32B3/18
• CPC Class Codes: B32B 3/26 characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205; characterised by an apertured layer
• CPC Class Codes: B32B 33/00 Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• CPC Class Codes: C08J 5/12 Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives
• CPC Class Codes: F16F 2224/00 Materials; Material properties
• CPC Class Codes: F16F 2230/10 Enclosure elements, e.g. for protection
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1379 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1383 Vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit is sandwiched between layers [continuous layer]
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing
• CPC Class Codes: Y10T 428/231 Filled with gas other than air; or under vacuum
• CPC Class Codes: Y10T 428/239 Complete cover or casing
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component
• CPC Class Codes: Y10T 428/31547 Of polyisocyanurate
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31573 Next to addition polymer of ethylenically unsaturated monomer

Abstract

Products in the form of cushioning devices made from flexible membranes employing at least one layer including thermoplastic urethane and at least one layer of a copolymer of ethylene and vinyl alcohol are inflatable to a relatively high pressure. The cushioning devices maintain the internal inflatant pressure for extended periods of time by employing a phenomenon referred to in the industry as diffusion pumping. Ideally, the cushioning devices of the present invention can be permanently inflated with gases such as nitrogen or air.

Claims

1. A permanently sealed and permanently inflated membrane, comprising

a first layer including thermoplastic polyurethane;

and

a second layer including a copolymer of ethylene and vinyl alcohol;

wherein reactive contact consisting essentially of hydrogen bonding occurs along substantially the entire surface area of contact between the thermoplastic polyurethane and copolymer of ethylene and vinyl alcohol layers

and further wherein said membrane controls the rate of outward diffusion of an internal gas of said membrane and allows diffusion pumping of an external mobile gas into the membrane.

2. The membrane according to claim 1 further comprising a third layer including a thermoplastic polyurethane.

3. The membrane according to claim 1 wherein said thermoplastic polyurethane is selected from the group consisting of polyester, polyether, polycaprolactone, polyoxypropylene and polycarbonate macroglycol based materials and mixtures thereof.

4. The membrane according to claim 1 wherein said copolymer of ethylene and vinyl alcohol is selected from the group consisting of copolymers including an ethylene content of between about 27 mol. % to about 48 mol. %.

5. The membrane according to claim 2 wherein said third layer of thermoplastic polyurethane is selected from the group consisting of polyester, polyether, polycaprolactone, polyoxypropylene and polycarbonate macroglycol based materials and mixtures thereof.

6. The membrane according to claim 1 wherein said first layer including thermoplastic polyurethane has an average thickness of between about 0.0010 inches to about 0.100 inches.

7. The membrane according to claim 1 wherein said second layer including a copolymer of ethylene and vinyl alcohol has an average thickness of between about 0.0010 inches to about 0.010 inches.

8. The membrane according to claim 1 wherein said first layer including thermoplastic polyurethane has an average thickness of between about 0.005 inches to about 0.050 inches and said second layer including a copolymer of ethylene and vinyl alcohol has an average thickness of between about 0.0025 inches to about 0.0050 inches.

9. A gas-filled membrane according to claim 1, wherein said gas filling said membrane comprises a member selected from the group consisting of nitrogen, super gases, and combinations thereof.

10. A gas-filled membrane according to claim 1, wherein said external mobile gas comprises a member selected from the group consisting of argon, oxygen, carbon dioxide, air, and combinations thereof.

11. A gas-filled membrane according to claim 1, wherein said gas filling said membrane comprises nitrogen and further wherein said external mobile gas comprises oxygen.

12. A gas-filled membrane according to claim 1, wherein said membrane retains at least 80% of its initial gas pressure after two years.

13. A bladder, comprising a membrane according to claim 1 having been sealed to define an interior compartment, said interior compartment being gas-filled.

14. A permanently sealed and permanently inflated membrane, comprising

a first layer including a thermoplastic polyurethane;

a second layer including a copolymer of ethylene and vinyl alcohol; and

a third layer including a thermoplastic polyurethane;

wherein reactive contact consisting essentially of hydrogen bonding occurs along substantially the entire surface area of contact between the copolymer of ethylene and vinyl alcohol and the thermoplastic polyurethane layers;

and further wherein said membrane controls the rate of outward diffusion of an internal gas of said membrane and allows diffusion pumping of an external mobile gas into the membrane.

15. The membrane according to claim 14 wherein at least one of said layers including thermoplastic polyurethane is selected from the group consisting of polyester, polyether, polycaprolactone, polyoxypropylene and polycarbonate macroglycol based materials and mixtures thereof.

16. The membrane according to claim 14 wherein said copolymer of ethylene and vinyl alcohol is selected from the group consisting of copolymers including an ethylene content of between about 27 mol. % to about 48 mol. %.

17. The membrane according to claim 15 wherein one of said layers including thermoplastic polyurethane has an average thickness of between about 0.001 inches to about 0.100 inches.

18. The membrane according to claim 15 wherein said second layer including a copolymer of ethylene and vinyl alcohol has an average thickness of between about 0.0010 inches to about 0.010 inches.

19. The membrane according to claim 15 wherein said first layer including a thermoplastic polyurethane has an average thickness of between about 0.005 inches to about 0.050 inches, said second intermediate layer including a copolymer of ethylene and vinyl alcohol has an average Thickness of between 0.0025 inches to about 0.0050 inches and said third layer including a thermoplastic urethane has an average thickness of between about 0.005 inches to about 0.050 inches.

20. A method for producing a permanently sealed and permanently inflated bladder, comprising the steps of:

simultaneously extruding a first layer including thermoplastic polyurethane and a second layer including a copolymer of ethylene and vinyl alcohol together to form a membrane wherein reactive contact consisting essentially of hydrogen bonding occurs along substantially the entire surface area of contact between the first and second layers

forming the membrane into a bladder having an interior compartment and a port,

filling the interior compartment through the port with a gas, and

sealing the port; and

further wherein said bladder controls the rate of outward diffusion of an internal gas of said membrane and allows diffusion pumping of an external mobile gas into the membrane.

21. The method according to claim 22 wherein said copolymer of ethylene and vinyl alcohol is selected from the group consisting of copolymers including an ethylene content of between about 27 mol. % to about 48 mol. %.

22. The method according to claim 20 wherein the extrusion is carried out at a temperature of between about 300°

F. to about 450°

F.

23. A method for producing a permanently sealed and permanently inflated bladder, comprising the steps of:

simultaneously extruding a first layer including thermoplastic polyurethane, a second intermediate layer including a copolymer of ethylene and vinyl alcohol, and a third layer including a thermoplastic polyurethane wherein reactive contact consisting essentially of hydrogen bonding occurs along substantially the entire surface area of contact between at least one layer including the thermoplastic polyurethane and said layer including the copolymer of ethylene and vinyl alcohol,

forming the membrane into a bladder having an interior compartment and a port,

filling the interior compartment through the port with a gas, and

sealing the port; and

further wherein said bladder controls the rate of outward diffusion of an internal gas of said membrane and allows diffusion pumping of an external mobile gas into the membrane.

24. The method according to claim 23 wherein said copolymer of ethylene and vinyl alcohol is selected from the group consisting of copolymers including an ethylene content of between about 27 mol. % to about 48 mol. %.

25. The method according to claim 23 wherein the extrusion step is carried out at a temperature of between about 300°

F. to about 450°

F.

26. A bladder, formed from a tubular membrane that is permanently sealed and inflated to an initial pressure of up to about 100 psi,

wherein said tubular membrane has a first layer including thermoplastic polyurethane and a second layer including a copolymer of ethylene and vinyl alcohol;

and further wherein reactive contact occurs along substantially the entire surface area of contact between the thermoplastic polyurethane and copolymer of ethylene and vinyl alcohol layers, said reactive contact consisting essentially of hydrogen bonding; and

wherein said bladder controls the rate of outward diffusion of an internal gas of said membrane external mobile gas into the membrane.