# US 12,005,602 B2 · Method for producing wood fiberboards

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- Number: US 12,005,602 B2
- Document ID: US12005602B2
- Status: Granted
- Kind: B2
- Application number: 16/964,342
- Filed: 2019-02-12
- Published: 2021-02-18
- Granted: 2024-06-11
- Earliest claimed: 2018-02-20
- Assignees: BASF SE
- Applicants: BASF SE
- Inventors: Ferdinand Leifeld; Sabine Both; Achim Fessenbecker
- Web page: https://patentgrep.com/patent/US12005602B2

## CPC

- B27K 5/007: {using pressure (B27K3/08 takes precedence)}
- B27K 5/0085: {Thermal treatments, i.e. involving chemical modification of wood at temperatures well over 100°C}
- B27N 1/00: Pretreatment of moulding material
- B27N 3/04: from fibres
- B27N 3/12: from fibres
- B27N 3/18: Auxiliary operations, e.g. preheating, humidifying, cutting-off
- B27K 2200/10: Articles made of particles or fibres consisting of wood or other lignocellulosic material
- B27K 2200/15: Pretreated particles or fibres
- B27N 7/00: After-treatment, e.g. reducing swelling or shrinkage, surfacing; Protecting the edges of boards against access of humidity
- B27K: PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR (applying liquids or other fluent materials to surfaces in general B05; coating wood or similar material B44D); CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27N: MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL (containing cementitious material B28B; shaping of substances in a plastic state B29C; fibreboards made from fibrous suspensions D21J; drying F26B17/00)

## Abstract

The disclosure relates to a method for the production of wood fiberboards such as MDF boards.

## Claims

### Claim 1

A method for the production of wood fiberboards, comprising the following steps:
a) crushing wood into wood chips,
b) hydrothermally pretreating the wood chips with steam in a pre-steaming bin at a temperature of 100 to 180° C. and a pressure of 1 to 10 bar,
c) grinding the pre-treated wood chips into fine wood particles in a refiner in a presence of steam at a temperature of 150 to 200° C. and a pressure of 4.5 to 16 bar,
d) gluing and drying the fine wood particles, wherein the drying of the fine wood particles can also be carried out prior to gluing,
e) forming mats from bonded fibers and precompacting the mats,
f) pressing the glued and dried fine wood particles at a temperature of 170 to 240° C. into wood fiberboards,
wherein at least one of steps d) to e) is carried out in a presence of one or a plurality of surfactants added in step d) and/or in step e);
wherein the surfactants are selected from alkyl polyglycosides of the general formula (IIa) or (IIb)
R1O(R2O)b(Z)a (IIa)
R1O(Z)a(R2O)bH (IIb)
wherein
R1=linear or branched C4-C30 alkyl,
R2=C2-C4 alkylene,
Z=independently, one sugar radical each with 5 or 6 carbon atoms,
b=0-12, and
a=1-15; and
wherein in step d) at least one surfactant is injected with the glue into the blow line and/or in step e) at least one surfactant is sprayed on or under the precompressed mat.

### Claim 2 (depends on 1)

The method according to claim 1, wherein step d) is carried out in the presence of one or a plurality of surfactants.

### Claim 3 (depends on 1)

The method according to claim 1, wherein step e) is carried out in the presence of one or a plurality of surfactants.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the surfactants are nonionic surfactants.

### Claim 5 (depends on 1)

The method according to claim 1, wherein an amount of surfactants in step c) is 0.05 to 5% by weight based on bone-dry wood.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the fine wood particles are reductively bleached.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the wood fiberboards are medium-density fiberboards.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the surfactants are selected from alkyl polyglycosides of the general formula (IIa) or (IIb)
R1O(R2O)b(Z)a (IIa)
R1O(Z)a(R2O)bH (IIb)
wherein
R1=linear or branched C6-C30 alkyl,
R2=C2-C4 alkylene,
Z=independently, one sugar radical each with 5 or 6 carbon atoms,
b=0-12, and
a=1-10.

### Claim 9 (depends on 8)

The method according to claim 8, wherein R1 is a C8-C16 alkyl chain, b=0 and a=1-4.