Process for the production of OSB wood-based boards with reduced emission of volatile organic compounds (VOCs)

Patent metadata

Field	Value
Publication number	US-11007668-B2
Application number	US-201816497535-A
Country	US
Kind code	B2
Filing date	Mar 12, 2018
Priority date	Apr 25, 2017
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

Disclosed is a process for the treatment of wood strands suitable for the manufacture of OSB boards, in which the wood strands are treated with steam without drying after extraction, the steam being passed over the wood strands at a temperature between 80° C. and 120° C. and a pressure between 0.5 bar and 2 bar. Also disclosed is a process for the production of OSB wood-based boards including the steps of a) producing wood strands from suitable wood logs; b) treating at least part of the wood strands with steam; c) drying the steam-treated wood strands; d) gluing the steam-treated and dried wood strands and gluing the non-steam-treated wood strands with at least one binder; e) scattering the glued wood strands onto a conveyor belt; and f) pressing the glued wood strands into an OSB wood-based board.

First claim

The invention claimed is:

1. A process for the treatment of wood strands with steam to reduce emission of volatile organic compounds from such wood strands, comprising:
providing wood strands extracted from suitable wood logs;
treating the wood strands with steam for a period of 5 to 20 minutes, the steam being passed over and through the wood strands at a temperature of between 80° C. and 120° C. and a pressure of 0.5 bar to 2 bar,
wherein the extracted wood strands are not dried before treating, and
wherein the steam treated wood strands are used to produce oriented strand boards (OSB) with reduced emission of volatile organic compounds.

2. The process according to claim 1 , wherein the steam is passed over the wood strands at a temperature between 90° C. and 110° C. and at a pressure between 0.7 bar and 1.5 bar.

3. The process according to claim 1 , wherein the wood strands are treated with steam for a period of 10 to 20 minutes.

4. The process according to claim 1 , wherein the steam treatment of the wood strands takes place in an atmosphere low in oxygen.

5. The process according to claim 1 , wherein the wood strands are continuously guided through the steam.

6. The process according to claim 1 , wherein the steam is collected as a condensate after passing over and through the wood strands.

7. The process according to claim 1 , wherein the steam is passed over and through the wood strands at a temperature of 100° C. at atmospheric pressure.

8. The process according to claim 1 , wherein the steam treatment of the wood strands takes place for 15 minutes.

9. The process of claim 1 , wherein the wood strands have a length of 50-200 mm, a width of 5-50 mm, and a thickness of 0.1-2 mm.

10. A process for the production of oriented strand board (OSB) wood-based panels with reduced emission of volatile organic compounds (VOCs) comprising the steps of:
a) extracting wood strands from suitable wood logs;
b) treating at least part of the wood strands with steam by a process comprising:
treating the wood strands with steam for a period of 5 to 20 minutes, the steam being passed over the wood strands at a temperature of between 80° C. and 120° C. and a pressure of 0.5 bar to 2 bar,
wherein the extracted wood strands are not dried before treatment;
c) drying the steam-treated wood strands;
d) gluing the steam-treated and dried wood strands and optionally non-steam-treated wood strands with at least one binder;
e) spreading the glued wood strands on a conveyor belt; and
f) pressing the glued wood strands into an OSB wood-based panel.

11. The process according to claim 10 , wherein the steam-treated wood strands, or a mixture of steam-treated wood strands and non-steam-treated wood strands, are used as a middle layer and/or top layer of the OSB wood-based panel.

12. The process according to claim 11 , wherein the steam-treated and non-steam-treated wood strands are glued with a binder in an amount of 1.0 to 5.0% by weight, based on the total amount of the wood strands.

13. The process according to claim 11 , wherein the steam-treated and non-steam-treated wood strands are glued with a binder in an amount of 2 to 4% by weight based on the total amount of the wood strands.

14. The process according to claim 11 , wherein the steam-treated wood strands or the mixture of steam-treated and non-steam-treated wood strands are glued with a binder in an amount of 3% by weight, based on the total amount of the wood strands.

15. The process according to claim 10 , wherein the glued wood strands are pressed at a temperature between 200° C. and 250° C. to form an OSB wood-based panel.

16. The process according to claim 10 , wherein the glued wood strands are pressed at a temperature between 220° C. and 230° C.

17. The process of claim 10 , wherein the wood strands have a length of 50-200 mm, a width of 5-50 mm, and a thickness of 0.1-2 mm.

Assignees

• SWISS KRONO Tec AG

Inventors

• Kalwa Norbert

Classifications

• B27N3/143

  Orienting the particles or fibres · CPC title

• B27N3/08

  Moulding or pressing (presses in general B30B) · CPC title

• B27N1/00 Primary

  Pretreatment of moulding material · CPC title

• B27K2200/15

  Pretreated particles or fibres · CPC title

• B27K5/04

  Combined bleaching or impregnating and drying of wood · CPC title