Claims
- 1. A method of bonding wood or bark to form composite products comprising:
- (a) subdividing plant foliage to a fine particle size;
- (b) uniformly contacting the wood or bark to be bonded with adhesive which consists essentially of one of,
- (i) said subdivided foliage,
- (ii) said subdivided foliage with up to 20% formaldehyde by weight of the adhesive, and
- (iii) said subdivided foliage having its natural acid pH raised to neutral or alkaline pH, said adhesive being present in sufficient amounts to bond the wood or bark,
- (c) subjecting the crude composite to bonding pressure at a selected temperature above the softening temperature of the foliage, the selected temperature being high enough to give the desired bond strength; and
- (d) recovering the hot-pressed composite wood or bark product.
- 2. The method of claim 1 wherein the hot-pressing temperature is selected from within the range of 45.degree. to 250.degree. C.
- 3. The method of claim 1 wherein the hot-pressing pressure is from about 50 to about 600 psi.
- 4. The method of claim 1 wherein the amount of the foliage is within about 15% to about 80% by wt. of the composite.
- 5. The method of claim 1 wherein the amount of the foliage is from about 20% to about 40% of the composite.
- 6. The method of claim 1 wherein the foliage in step (b) is in the form of a dispersion in an aqueous liquid carrier.
- 7. The method of claim 1 wherein the foliage in step (b) is in the form of a free-flowing powder.
- 8. The method of claim 1 wherein the foliage is selected from evergreen foliage, deciduous tree foliage and mixtures thereof.
- 9. The method of claim 1 wherein the foliage or a mixture of foliages is selected for a particular combination of properties.
- 10. The method of claim 1 wherein the foliage is bonded at neutral or alkaline pH.
- 11. The method of claim 1 wherein the formaldehyde cross-linking agent is incorporated before bonding.
- 12. A hot-pressed composite wood or bark product comprising wood or bark and wood adhesive, said wood adhesive consisting essentially of one of
- (i) subdivided foliage,
- (ii) said foliage with up to 20% formaldehyde by wt. of the adhesive, and
- (iii) said foliage having its natural acid ph raised to neutral or alkaline pH said foliage being heat-softened and bonded under pressure.
- 13. The composite wood product of claim 12 wherein the foliage is selected from evergreen foliage, deciduous tree foliage and mixtures thereof.
- 14. The composite wood product of claim 12 wherein the foliage is present in amounts within about 15 to about 80% by wt. of the composite.
- 15. The composite wood product of claim 12 wherein the foliage is present in from 20% to about 40% by wt. of the composite.
- 16. The composite wood product of claim 12 wherein the adhesive wave bonded at alkaline pH.
- 17. The composite wood product of claim 12 wherein the internal bond strength is increased by formaldehyde crosslinking.
RELATED APPLICATION
This application is a continuation-in-part of my application Ser. No. 771,992 filed Feb. 25, 1977 (now U.S. Pat. No. 4,082,903).
US Referenced Citations (4)
Continuation in Parts (1)
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Number |
Date |
Country |
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771992 |
Feb 1977 |
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