A new method for obtaining high strength phenol formaldehyde resin-impregnated wood composites at low pressing pressure

Shams M. I., . and Yano H., . A new method for obtaining high strength phenol formaldehyde resin-impregnated wood composites at low pressing pressure. pp. 175-180. ISSN 0128-1283

To obtain high strength phenol formaldehyde (PF) resin-impregnated compressed wood at low pressure we investigated the effects of sodium chlorite treatment followed by sodium hydroxide treatment prior to low molecular weight PF resin impregnation. Sawn veneers of Japanese cedar (Cryptomeria japonica) were first treated with 2 aqueous solution of NaClO2 followed by 0.5 aqueous solution of NaOH. A total weight loss of 12 was obtained by the combination of these two treatments. It was found that the treatments showed potential for the marked deformation of PF resinimpregnated wood at low pressure. The result suggests that depolymerization or partial removal of lignin can be effective for the removal of hemicellulose which softens the cell wall swollen by PF resin and makes it possible to compress wood remarkably at low pressing pressure. Pressure holding during compression caused creep deformation of resin-impregnated wood and resulted in density Youngs modulus (MOE) and bending strength (MOR) of 1.16 g cm-3 29 GPa and 307 MPa respectively at a pressing pressure of 1 MPa. This technique imparts high strength and attractive surface to plywood and other wood composite materials with conventional hot press equipment.

Full text available from: Official URL: http://www.frim.gov.my/v1/JTFSOnline/jtfs/v21n2/17...

Abstract

To obtain high strength phenol formaldehyde (PF) resin-impregnated compressed wood at low pressure we investigated the effects of sodium chlorite treatment followed by sodium hydroxide treatment prior to low molecular weight PF resin impregnation. Sawn veneers of Japanese cedar (Cryptomeria japonica) were first treated with 2 aqueous solution of NaClO2 followed by 0.5 aqueous solution of NaOH. A total weight loss of 12 was obtained by the combination of these two treatments. It was found that the treatments showed potential for the marked deformation of PF resinimpregnated wood at low pressure. The result suggests that depolymerization or partial removal of lignin can be effective for the removal of hemicellulose which softens the cell wall swollen by PF resin and makes it possible to compress wood remarkably at low pressing pressure. Pressure holding during compression caused creep deformation of resin-impregnated wood and resulted in density Youngs modulus (MOE) and bending strength (MOR) of 1.16 g cm-3 29 GPa and 307 MPa respectively at a pressing pressure of 1 MPa. This technique imparts high strength and attractive surface to plywood and other wood composite materials with conventional hot press equipment.

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Item Type:	Article
AGROVOC Term:	Phenols
AGROVOC Term:	Formaldehyde
AGROVOC Term:	Resins
AGROVOC Term:	Pressing
AGROVOC Term:	Cryptomeria japonica
AGROVOC Term:	Resins
AGROVOC Term:	Pressure
AGROVOC Term:	Lignins
AGROVOC Term:	Hemicellulose
AGROVOC Term:	Compression wood
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	24 Apr 2025 06:27
URI:	http://webagris.upm.edu.my/id/eprint/21671

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