Wood material board with reduced emission of volatile organic compounds (VOCs) and method for the production thereof

Patent metadata

Field	Value
Publication number	US-10399245-B2
Application number	US-201615778882-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Dec 7, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A method for producing wood material boards with reduced emission of volatile organic compounds (VOCs), including: a) producing woodchips from suitable timbers; b) heat-treating at least one portion of the woodchips at a temperature between 150° C. and 300° C. for a period of 1 to 5 hours; c) crushing the wood chips that are not heat-treated and at least one portion of the heat-treated woodchips by machining in order to obtain wood shavings or by solubilizing in order to obtain wood fibers; d) gluing the wood shavings or wood fibers with at least one binding agent; e) applying the glued wood shavings onto a transport belt while forming a multi-layered shavings cake or applying the glued wood fibers onto a transport belt while forming a single-layer fiber cake; and f) compressing the shavings cake or the fiber cake to form a wood material board.

First claim

The invention claimed is:

1. A process for producing woodbase panels with reduced emission of volatile organic compounds (VOCs), comprising:
a) producing wood chips from suitable lumbers,
b) heat-treating at least a part of the wood chips by heating in an oxygen-depleted or oxygen-free environment at a temperature between 150° C. and 300° C. over a period of 1 h to 5 h;
c) comminuting the non-heat-treated wood chips and at least a part of the heat-treated wood chips by shaving to give wood shavings or by digesting to give wood fibers;
d) resinating the wood shavings or wood fibers with at least one binder, wherein the wood shavings or wood fibers have been produced from the heat-treated and the non-heat-treated wood chips according to step (c);
e) applying the resinated wood shavings to a conveyor belt, to form a multilayer shaving cake, or applying the resinated wood fibers to a conveyor belt, to form a single-layer fiber cake; and
f) compressing the shaving cake or the fiber cake to form a woodbase panel.

2. The process as claimed in claim 1 , wherein the step of heat-treating the wood chips is integrated into the operation of producing the woodbase panel.

3. The process as claimed in claim 1 , wherein the step of heat-treating the wood chips is carried out separately from the operation of producing the woodbase panel.

4. The process as claimed in claim 1 , wherein the wood chips are heat-treated at temperatures between 200° C. and 280° C.

5. The process as claimed in claim 1 , wherein the wood chips are heat-treated over a period between 2 h and 3 h.

6. The process as claimed in claim 1 , wherein the wood chips are heat-treated by heating in an oxygen-depleted or oxygen-free atmosphere.

7. The process as claimed in claim 1 , wherein at least a part of the wood chips with a moisture content of 20-50 wt % are heat-treated.

8. The process as claimed in claim 1 , wherein the heat-treated wood chips are cooled in a water bath, the water being admixed with at least one wetting agent.

9. The process as claimed in claim 1 , wherein the moisture content of the heat-treated chips is adjusted to 5% to 20%.

10. The process as claimed in claim 6 , wherein the wood chips are heat-treated by heating in a saturated steam atmosphere.

11. The process as claimed in claim 9 , wherein the moisture content of the heat-treated chips is adjusted to 10% to 15%.

12. The process as claimed in claim 4 , wherein the wood chips are heat-treated at temperatures between 220° C. and 260° C.

13. The process as claimed in claim 1 , wherein the woodbase panels are wood chipboard or wood fiberboard panels.

14. The process as claimed in claim 2 , wherein the wood chips are heat-treated at temperatures between 200° C. and 280° C.

Assignees

• SWISS KRONO Tec AG

Inventors

• Kalwa Norbert

Classifications

• B27N1/00

  Pretreatment of moulding material · CPC title

• B27K5/0085

  Thermal treatments, i.e. involving chemical modification of wood at temperatures well over 100°C · CPC title

• B27N3/02

  from particles · CPC title

• B27N1/003 Primary

  for reducing formaldehyde gas emission · CPC title

• B27K2240/10

  Extraction of components naturally occurring in wood, cork, straw, cane or reed · CPC title