Claims
- 1. In a method for forming a wet-laid glass fiber mat which includes the steps of adding wet-chopped glass fibers to an aqueous mixture containing a surfactant and a viscosity modifier, thereby forming a slurry, agitating the fibers to cause them to disperse, removing water from said fibers to form a web, and applying a binder to said web to form said glass fiber mat, the improvement comprising the step of adding a sufficient amount of a suitable hydrophobic agent, having an HLB value of from about 1 to about 15, to said slurry to cause said chopped fibers to form bundles in said slurry.
- 2. The method of claim 1 in which said hydrophobic agent has an HLB value of from about 1 to about 10.
- 3. The method of claim 1 in which said hydrophobic agent comprises a polyalkoxane defoaming agent.
- 4. The method of claim 3 wherein the polyalkoxane defoaming agent has an HLB value of from about 1 to 10.
- 5. The method of claim 1 in which from about 300 to about 1000 ppm of said hydrophobic agent is added to said slurry.
- 6. The method of claim 3 in which said surfactant comprises from about 30 to about 200 ppm of a cationic surfactant.
- 7. The method of claim 1 in which said viscosity modifier comprises about 2000 ppm hydroxyethyl cellulose.
- 8. The method of claim 1 further comprising the step of adding a complexing agent for said surfactant to said slurry.
- 9. The method of claim 8 in which said complexing agent comprises a polycarboxylate salt.
- 10. The method of claim 8 in which from about 20 to about 100 ppm of said complexing agent is added to said slurry.
- 11. The method of claim 1 including the step of drying said mat after application of said binder.
- 12. The method of claim 1 in which said chopped fibers have a length of from about 3 mm to about 50 mm.
- 13. The method of claim 1 in which said chopped fibers have a length of from about 25 mm to about 50 mm.
- 14. The method of claim 1 in which the bundle size is from about 50 to about 1000 fibers.
- 15. The method of claim 1 including the step of controlling the size of said bundles by controlling the amount of said hydrophobic agent added to said slurry.
- 16. A wet-laid method to produce non-woven glass fiber mats comprised of bundles of glass fibers comprising the steps of:
- providing an aqueous slurry containing a surfactant, a viscosity modifier, and wet-chopped fibers;
- adding a sufficient amount of a suitable hydrophobic agent, having an HLB value value of from about 1 to about 15, to said slurry to cause said fibers to form a plurality of bundles;
- removing water from said fibers to form a web; and
- applying a binder to said web to form said glass fiber mat.
- 17. The method of claim 16 further including the steps of adding a sufficient amount of a surfactant to said slurry to cause said fibers to disperse, removing water from said fibers to form a web, and applying a binder to said web to form a glass fiber mat comprising dispersed fibers.
- 18. The method of claim 17 in which said surfactant is added to said slurry in an amount to reach a level of from about 30 ppm to about 200 ppm.
- 19. The method of claim 16 in which a complexing agent for said surfactant is added to said slurry with said hydrophobic agent.
- 20. The method of claim 19 in which said complexing agent comprises a polycarboxylate salt.
- 21. The method of claim 19 further including the step of adding a sufficient amount of a cationic polyacrylamide to said slurry to cause said fibers to disperse, removing water from said fibers to form a web, and applying a binder to said web to form a glass fiber mat comprising dispersed fibers.
- 22. The method of claim 21 in which about 25 to about 50 ppm of said cationic polyacrylamide is added to said slurry.
- 23. A method of forming a wet-laid glass fiber mat comprising the steps of:
- adding chopped glass fibers to an aqueous mixture, thereby forming a slurry;
- adding a sufficient amount of a suitable hydrophobic agent, having an HLB value of from about 1 to about 15, to said slurry to cause said chopped fibers to form a plurality of bundles;
- removing water from said fibers to form a web; and
- applying a binder to said web to form a mat.
- 24. A method of claim 23 wherein said hydrophobic agent has an HLB value of from about 1 to about 10.
- 25. The method of claim 23 in which said hydrophobic agent comprises a viscosity modifier.
- 26. The method of claim 25 in which said viscosity modifier comprises an anionic polyacrylamide in the form of a water-in-oil emulsion.
- 27. The method of claim 23 in which from about 30 to about 1000 ppm of said hydrophobic agent is added to said slurry.
- 28. The method of claim 23 in which said hydrophobic agent comprises a polyalkoxane defoaming agent.
- 29. The method of claim 28 in which from about 50 to 1000 ppm of said hydrophobic agent is added to said slurry.
- 30. The method of claim 28 in which said slurry further contains from about 30 to about 3000 ppm of a viscosity modifier.
- 31. The method of claim 30 in which said viscosity modifier is selected from the group consisting of hydroxyethyl cellulose, anionic polyacrylamide, and polyethylene oxide.
BACKGROUND OF THE INVENTION
This is a continuation-in-part application of U.S. patent application Ser. No. 08/712,711, filed Sep. 12, 1996, now abandoned, the disclosure of which is hereby incorporated by reference.
US Referenced Citations (19)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
712711 |
Sep 1996 |
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