Claims
- 1. A plywood glue comprising in aqueous admixture with each other and in parts by weight, dry solids basis:
- Urea-Formaldehyde Resin--30-90
- Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70
- the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor,
- the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH.sub.3) on a spent liquor solids basis,
- the spent liquor component of the mixture prior to mixing having a pH of from 3-9,
- the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2.
- 2. The plywood glue of claim 1 wherein the urea formaldehyde resin is used in an amount of from 50-75 parts, the spent liquor in an amount of from 25-50 parts, and the filler in an amount of from 75-150 parts.
- 3. The plywood glue of claim 1 wherein the amylaceous filler comprises a cereal flour type plywood glue filler and not more than 75% by weight, based on the total weight of the filler, of a non-amylaceous plywood glue filler.
- 4. The plywood glue of claim 1 wherein the amylaceous filler comprises a cereal type plywood glue flour filler.
- 5. The plywood glue of claim 1 wherein the amylaceous filler comprises a wheat flour filler.
- 6. The plywood glue of claim 1 wherein the amylaceous filler comprises a sorghum flour filler.
- 7. The plywood glue of claim 1 wherein the amylaceous filler comprises a root starch type plywood glue filler.
- 8. The plywood glue of claim 1 wherein the amylaceous filler comprises a potato starch filler.
- 9. The plywood glue of claim 1 wherein the amylaceous filler comprises a tapioca starch filler.
- 10. The method of making plywood which comprises applying to the surfaces of wood veneers a bonding quantity of an aqueous plywood glue comprising in admixture with each other and in parts by weight, dry solids basis:
- Urea-Formaldehyde Resin--30-90
- Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70
- the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor,
- the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH.sub.3) on a spent liquor solids basis.
- the spent liquor component of the mixture prior to mixing having a pH of from 3-9,
- the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2,
- assembling the resulting glue-coated wood veneers and pressing the veneers to form the finished plywood product.
- 11. The plywood product produced by the method of claim 10.
BACKGROUND AND SUMMARY OF THE INVENTION
This application is a continuation-in-part of the patent application of Folke J. Edler Ser. No. 899,237, filed Apr. 24, 1978; now U.S. Pat. No. 4,194,997 the same being a continuation-in-part of the abandoned patent application of Folke J. Edler, Ser. No. 738,370, filed Nov. 3, 1976; the same being a continuation of abandoned patent application Ser. No. 574,515, filed May 5, 1975.
US Referenced Citations (7)
Continuations (1)
|
Number |
Date |
Country |
Parent |
574515 |
May 1975 |
|
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
899237 |
Apr 1978 |
|
Parent |
738370 |
Nov 1976 |
|