Method for producing a glass mat

• US 6,291,552 B1
• Filed: 10/29/1999
• Issued: 09/18/2001
• Est. Priority Date: 10/29/1999
• Status: Expired due to Fees

• Current Assignee: Owens- Corning Fiberglas Technology Incorporated (Owens Corning)
• Original Assignee: Owens- Corning Fiberglas Technology Incorporated (Owens Corning)
• Inventors: Dong, Daojie
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): RAJGURU, UMAKANT K
• Application Number:
  US09/431,340
• Time in Patent Office: 690 Days
• Field of Search: 523/217, 523/222, 524/492, 524/493
• US Class Current: 523/217
• CPC Class Codes: C03C 25/12 General methods of coating; Devices therefor
• CPC Class Codes: C03C 25/26 Macromolecular compounds or prepolymers
• CPC Class Codes: D21H 13/40 vitreous, e.g. mineral wool, glass fibres
• CPC Class Codes: D21H 21/08 Dispersing agents for fibres
• CPC Class Codes: D21H 23/765 Addition of all compounds to the pulp

Abstract

The invention relates to glass mats and their method of manufacture. In particular, the invention relates to a wet-laid method of making a glass mat and the mats formed by this method. The method includes combining a dispersant, water, glass fiber bundles, and a charged viscosity modifier to form a slurry, adding an oppositely charged viscosity modifier to the slurry, and removing the water from the slurry to form a wet glass mat. The present invention enables improved control of fiber dispersion and subsequent bundling of the fibers to form, for example, bundled glass mats with high porosity and a uniform weight. Mats produced by the present invention may be formed into a variety of products, such as in glass fiber paper, roofing shingles, and composite articles.

Claims

1. A method of making a bundled or structured glass mat comprising the steps of:

(a) forming a slurry of glass fibers, a dispersant, water, and at least one charged viscosity modifier;

(b) subsequently adding at least one oppositely charged viscosity modifier to the slurry; and

,

(c) removing the water from the slurry to form a wet glass mat containing glass bundles.

2. The method of claim 1, further comprising the steps of:

(d) applying a binder to the wet glass mat; and

,

(e) curing the binder.

3. The method of claim 1, wherein the charged viscosity modifier in step (a) is a cationic viscosity modifier and the oppositely charged viscosity modifier in step (b) is an anionic viscosity modifier.

4. The method of claim 3, wherein the cationic viscosity modifier is a cationic polyacrylamide and the anionic viscosity modifier is an anionic polyacrylamide.

5. The method of claim 1, wherein the oppositely charged viscosity modifier of step (b) is added to the slurry of step (a) in the form of an aqueous solution.

6. The method of claim 5, wherein the aqueous solution, in addition to the oppositely charged viscosity modifier, further comprises at least one charged viscosity modifier.

7. The method of claim 1, wherein the charged viscosity modifier is present in an amount ranging from about 0.01 to about 0.1 weight percent of the slurry and the oppositely charged viscosity modifier is present in an amount ranging from about 1 to about 35 weight percent by weight of the charged viscosity modifier.

8. The method of claim 1, wherein slurry step (a) comprises the steps of:

(i) forming a white water comprising water, a dispersant, and a charged viscosity modifier and

(ii) adding glass bundles to the white water.

9. The method of claim 1, wherein the slurried glass fibers have an average fiber length of about 3 to about 50 mm.

10. The method of claim 1, wherein the glass fibers added to form the slurry are in the form of glass bundles having from about 1,000 to about 10,000 individual glass filaments.

11. The method of claim 1, wherein the dispersant is a surfactant.

12. The method of claim 11, wherein the surfactant is selected from the group consisting of nonionic, cationic, amphoteric surfactants and mixtures thereof.

13. The method of claim 11, wherein the surfactant is an ethoxylated amine, cocamidopropyl hydroxysultaine or a mixture thereof.

14. A bundled glass mat formed by the method of claim 1.

15. A method of making a fibrous glass mat comprising the steps of:

(a) foig a slurry of glass fibers, a dispersant, water, and at least one charged viscosity modifier;

(b) subsequently adding an oppositely charged viscosity modifier to the slurry; and

(c) removing the water from the slurry to form a wet glass mat.

16. The method of claim 15, further comprising the steps of:

(d) applying a binder to the wet mat; and

,

(e) removing any excess moisture and curing the binder.

17. The method of claim 15, wherein the charged viscosity modifier is present in an amount ranging from about 0.01 to about 0.1 weight percent of the slurry, and the oppositely charged viscosity modifier is present in an amount ranging from about 1 to about 35 weight percent by weight of the charged viscosity modifier.

18. The method of claim 15, wherein the dispersant comprises an ethoxylated amine or a cocoamidopropyl hydroxysultaine.

19. The method of claim 15, wherein the charged viscosity modifier comprises cationic polyacrylamide and the oppositely charged viscosity modifier comprises anionic polyacrylamide.

20. A slurry comprising:

(a) glass fibers having an average fiber length of about 3 to about 50 mm;

(b) a cationic viscosity modifier in an amount ranging from about 0.01 to about 0.1 weight percent of the slurry;

(c) an anionic viscosity modifier in an amount ranging from about 1 to about 35 weight percent by weight of the cationic viscosity modifier;

(d) a surfactant; and

(e) water.

21. The slurry of claim 20, wherein the cationic viscosity modifier is a cationic polyacrylamide and the anionic viscosity modifier is an anionic polyacrylamide.