Water-soluble moisture addition to enhance molding, stiffness, and surface processing of polymer materials

• US 20080145630A1
• Filed: 12/14/2006
• Published: 06/19/2008
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: Owens Corning Intellectual Capital, LLC (Owens Corning)
• Original Assignee: Owens Corning Intellectual Capital, LLC (Owens Corning)
• Inventors: Rockwell, Anthony L.
• Granted Patent: US 8,017,535 B2
• Time in Patent Office: Days
• US Class Current: 428/218
• CPC Class Codes: B60R 13/08 Insulating elements, e.g. for sound insulation sound insulating linings for trains B61D17/185; drivers' cabs for load-carrying vehicles insulated against vibrations or noise B62D33/0604; thermal or acoustic insulation of engines F02B77/11; damping of sounds using compensation by electro-acoustic methods G10K11/178
• CPC Class Codes: D04H 1/4218 Glass fibres
• CPC Class Codes: D04H 1/5412 sheath-core
• CPC Class Codes: D04H 1/5414 side-by-side
• CPC Class Codes: D04H 1/5416 sea-island
• CPC Class Codes: D04H 1/655 characterised by the apparatus for applying bonding agents
• CPC Class Codes: D04H 1/732 by fluid current, e.g. air-lay
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 442/637 Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
• CPC Class Codes: Y10T 442/697 Containing at least two chemically different strand or fiber materials

Abstract

Densified non-woven materials having acoustic and thermal properties are provided. The non-woven material is formed of a thermoplastic material or fibers and a thermoplastic material. The fibers may be an organic, inorganic, or thermoplastic fiber and are desirably devoid of conventional sizing compositions. The densified portion of the non-woven material is formed by applying a moisture additive and subsequently applying heat. Heating the non-woven material causes the water in the moisture additive to turn to steam, which causes a molecular change in the polymer based thermoplastic material(s) of the non-woven material that was treated with the moisture additive. The moisture additive is preferably water, but may include a dilute alkali, a dilute acid, or additives to enhance surface, fire, or mold release characteristics. The water additive may be utilized to surface treat, partially treat, or completely treat the air-laid mat to achieve desired acoustic or thermal properties and/or stiffness.

Claims

1. A densified non-woven material comprising:

a first portion formed of a plurality of randomly oriented thermoplastic fibers, said first portion having a first density; and

a second portion formed of a plurality of said randomly oriented thermoplastic fibers, said second portion having a second density that is greater than said first density,

wherein said thermoplastic fibers in said second portion are densified by an application of a moisture additive and a subsequent application of heat.

2. The densified non-woven material of claim 1, wherein one or both of said first and second portions further comprise at least one member selected from the group consisting of organic fibers and inorganic fibers.

3. The densified non-woven material of claim 1, wherein said moisture additive includes water.

4. The densified non-woven material of claim 3, wherein said moisture additive further includes at least one member selected from the group consisting of a dilute acid, a dilute alkali, fire retardants, thermoset resins, latex, mold release agents and water soluble adhesives.

5. The densified non-woven material of claim 1, wherein said moisture additive and said application of heat causes a molecular change in said thermoplastic fibers in said second portion.

6. The densified non-woven material of claim 5, wherein said air-laid mat has a first major surface and a second major surface, and

wherein said second portion has a thickness extending from said first major surface dependent upon the amount of said moisture additive applied to said first major surface.

7. An acoustic product comprising:

a densified air-laid mat formed of a plurality of randomly oriented thermoplastic fibers, said thermoplastic fibers in at least a portion of said densified air-laid mat being densified by an application of a moisture additive and a subsequent application of heat.

8. The acoustic product of claim 7, wherein said portion of said densified air-laid mat has a thickness equal to said densified air-laid mat.

9. The acoustic product of claim 7, wherein said moisture additive includes water.

10. The acoustic product of claim 9, wherein said moisture additive further includes at least one member selected from the group consisting of a dilute acid, a dilute alkali, fire retardants, thermoset resins, latex, mold release agents and water soluble adhesives.

11. The acoustic product of claim 7, wherein said densified air-laid mat further comprises at least one member selected from the group consisting of organic and inorganic fibers.

19. The method of claim 11, wherein said heating step occurs in a mold.

20. The method of claim 19, wherein said non-woven material has a first major surface and a second major surface, said moisture additive being applied to said first major surface;

and

wherein a reaction of said thermoplastic fibers with said moisture additive creates a densified portion that extends a distance from said first major surface roughly equivalent to the depth of penetration of said moisture additive into said non-woven material.

12. A method of forming a densified non-woven material comprising:

applying a moisture additive to a major surface of a non-woven material including thermoplastic fibers; and

heating said major surface to a temperature sufficient to cause a molecular change in said thermoplastic fibers in contact with said moisture additive and create a stiffened portion in said non-woven material.

13. The method of claim 12, wherein said non-woven material has a first major surface and a second major surface, said moisture additive being applied to said first major surface;

and

wherein said molecular change extends a distance from said first major surface dependent upon the amount of said moisture additive applied to said first major surface.

14. The method of claim 13, wherein said applying step comprises:

treating said first major surface with said moisture additive in an amount sufficient to penetrate at least a portion of said non-woven material.

15. The method of claim 12, wherein said air-laid mat has a first major surface and a second major surface, said moisture additive being applied to said second major surface;

and

wherein said molecular change extends throughout said non-woven material from said second major surface to said first major surface.

16. The method of claim 12, wherein said moisture additive comprises water.

17. The method of claim 16, wherein said moisture additive further comprises at least one member selected from the group consisting of a dilute acid, a dilute alkali, fire retardants, thermoset resins, latex, mold release agents and water soluble adhesives.

18. The method of claim 12, wherein said non-woven material further includes fibers selected from the group consisting of organic fibers, inorganic fibers and combinations thereof.