Sound insulation for dishwashers

• US 20040206377A1
• Filed: 04/16/2003
• Published: 10/21/2004
• Est. Priority Date: 04/16/2003
• Status: Abandoned Application

• Current Assignee: Monadnock Non-Wovens LLC
• Original Assignee: Monadnock Non-Wovens LLC
• Inventors: Griffin, Rowland, Field, John P.
• Application Number:
  US10/414,498
• Publication Number:
  US 20040206377A1
• Time in Patent Office: Days
• US Class Current: 134/56D
• CPC Class Codes: A47L 15/4209 Insulation arrangements, e.g. for sound damping or heat insulation
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres vinyl or acrylic copolymers B32B2262/0223 or B32B2262/0246
• CPC Class Codes: B32B 2307/102 Insulating
• CPC Class Codes: B32B 2509/00 Household appliances
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12

Abstract

Sound insulation core material is made by melt-blowing a polypropylene resin having a hydroxystearamide wax additive to produce a fibrous mass having improved loft. The core material is encased between outer layers of spun-bond polyethylene fibers by longitudinal seams and transverse seams to form a product suitable for use in dishwashers.

Claims

1. Sound insulation for dishwashers comprising a core layer of melt-blown polypropylene fibers having a density not greater than 1.5 lb/ft³.

2. The insulation of claim 1, further comprising a pair of outer layers, one on each side of said core layer, each of said outer layers being made of melt-blown polypropylene fibers.

3. The insulation of claim 2, wherein the core and the outer layers are interconnected by seams along their longitudinal edges.

4. The insulation of claim 3, wherein the core and the outer layers are interconnected by transverse seams extending between said longitudinal seams.

5. The insulation of claim 4, wherein said transverse seams are formed at regular intervals of about six inches.

6. The insulation of claim 1, wherein the core layer is made by adding a wax additive to polypropylene resin before producing the fibers by melt blowing.

7. The insulation of claim 6, wherein said wax additive is a hydroxystearamide wax.

8. The insulation of claim 7, wherein the hydroxystearamide wax is N,N′

ethylene-bis-12-hydroxy-stearamide.

9. A method of producing sound insulation having high loft, said method comprising steps of

adding a wax additive to a polypropylene resin to form a mixture, and then

extruding said mixture through nozzles onto a moving surface at a temperature and pressure such that a melt-blown fiber mass results.

10. The method of claim 9, wherein said temperature is about 230°

C.

11. The method of claim 9, wherein said pressure is about 200 psi.

12. The method of claim 9, wherein said wax additive is a hydroxystearamide wax.

13. The method of claim 12, wherein the hydroxystearamide wax is N,N′

ethylene-bis-12-hydroxy-stearamide.

14. The method of claim 13, wherein said temperature is about 230°

C.

15. The method of claim 13, wherein said pressure is about 200 psi.

16. The method of claim 13, wherein the amount of said additive is no greater than 1.0% by weight of the amount of the resin.

17. The method of claim 13, wherein the amount of said additive is 0.4% to 0.6% by weight of the amount of the resin.