Production of high added value products from resin-bonded waste composite wood products

• US 6,841,101 B2
• Filed: 12/04/2000
• Issued: 01/11/2005
• Est. Priority Date: 12/02/1999
• Status: Expired due to Fees

• Current Assignee: Chimar Hellas S.A.
• Original Assignee: Chitnar Hellas SA
• Inventors: Athanassiadou, Eleftheria, Nakos, Panagiotis, Coutinho, Joao Manuel Aires
• Primary Examiner(s): Colaianni, Michael P.
• Assistant Examiner(s): Poe, Michael I.
• Application Number:
  US10/130,732
• Publication Number:
  US 20030056873A1
• Time in Patent Office: 1,499 Days
• Field of Search: 156/94, 156/327, 156/256, 264/36.1, 264/37.28, 264/37.3, 264/82, 264/322, 264/914, 162/234
• US Class Current: 264/36.1
• CPC Class Codes: B27N 1/00 Pretreatment of moulding material
• CPC Class Codes: B27N 3/00 Manufacture of substantially flat articles, e.g. boards, from particles or fibres
• CPC Class Codes: B27N 3/007 and at least partly composed of recycled material
• CPC Class Codes: Y10S 264/914 From cellulose containing articles, e.g. paper
• CPC Class Codes: Y10T 156/1062 Prior to assembly

Abstract

A method of producing dry processed fiberboards from resin-bonded waste composite wood products, wherein said wood products are chemically treated in a pre-heater unit of a refiner system under super-atmospheric pressure in the presence of steam to disrupt adhesive polymer bonds, formed into fibers in a subsequent disc refiner unit of the refiner system and further processed by a dry process to form fiberboards.

Claims

1. A method of producing dry processed fibreboards from resin-bonded waste composite wood products, wherein said wood products are chemically treated in a pre-heater unit of a refiner system under super-atmospheric pressure in the presence of steam to disrupt adhesive polymer bonds, formed into fibres in a subsequent disc refiner unit of the refiner system and further processed by a dry process to form fibreboards with a reduction of resin consumption by the reactivation of resin in said wood products.

2. A method according to claim 1, wherein the waste composite wood products used for recycling comprise particleboard, fibreboard, oriented strand board (OSB), plywood, hardboard as well as their production residues.

3. A method according to claim 1, wherein said fibres are hot-pressed into medium density fibreboards.

4. A method according to claim 1, wherein the waste composite wood products used for recycling constitute over 5% by weight of a feed of fresh wood material.

5. A method according to claim 1, which provides dry processed fibreboards prepared exclusively from recycled wood-containing material.

6. A method according to claim 1, wherein dry processed fibreboards are produced under continuous operation by recycling waste composite wood products.

7. A method according to claim 1, wherein the treatment in the pre-heater is in the presence of weak or strong acids, weak or strong bases, their respective salts, formaldehyde inhibiting chemicals, surfactants or wetting agents.

8. A method according to claim 7, wherein the introduction of chemicals in the pre-heater step is in an amount of from 0.01 to 10% by weight based on dry fibre weight.

9. A method of producing a dry processed fibreboard comprising

(a) providing a resin-bonded waste composite wood product;

(b) soaking the waste composite wood product in water to form a water-soaked waste composite wood product;

(c) feeding the water-soaked waste composite wood product into a pre-heater unit of a refiner system and chemically treating the water-soaked waste composite wood product in the pre-heater unit under super-atmospheric pressure in the presence of steam to disrupt adhesive polymer bonds;

(d) refining the treated waste composite wood product into recycled fibres in a subsequent disc refiner unit of the refiner system; and

(e) processing the recycled fibres into a fibreboard by a dry process with a reduction in resin consumption by the reactivation of resin in said wood product comprising mixing the recycled fibres with a bonding resin, drying the recycled fibres, forming the dried fibers into mats; and

hot pressing the mats to form the dry processed fibreboard.

10. The method according to claim 9, wherein the resin-bonded waste composite wood product is bonded with a resin selected from the group consisting of a urea-formaldehyde resin, a phenol-formaldehyde resin, a melamine-formaldehyde resin, an isocyanate and a mixture thereof.

11. The method according to claim 10, wherein the chemical treating in the pre-heater unit is in the presence of a weak or strong acid or a salt of the weak or strong acid, a weak or strong base or a salt of the weak or strong base, a formaldehyde inhibiting chemical, a surfactant or a wetting agent.

12. The method according to claim 10, wherein the water-soaked waste composite wood product is fed into the pre-heater with fresh wood material, the recycled fibres comprising at least 20% by weight of a fibre content of the dry processed fibreboard.

13. The method according to claim 12, wherein the bonding resin is used in the dry process at a level of at least 7% w/w.

14. The method according to claim 12, wherein the method comprises a step of reducing the size of the resin-bonded waste composite wood product prior to step (b).

15. The method according to claim 14, wherein the process consists essentially of steps (a) to (e) and the step of reducing the size of the resin-bonded waste composite wood product.

16. The method according to claim 15, wherein the bonding resin is a urea-formaldehyde resin.

17. The method according to claim 15, wherein the treatment of step (c) is conducted at a temperature of about 170°

C.