Method of making wood composites treated with soluble boron compounds

Abstract

A novel method of producing a wood composite treated with a soluble boron compound is disclosed. Either a phenol-formaldehyde resole or novolac type resin can be used as the binder for a wood furnish. The wood furnish is surface treated with either the resole type resin or novolac resin together with a water soluble boron compound whereafter the surface treated wood furnish is formed into a mat and then consolidated in a press. When novolac is used as the resin, the consolidation takes place under sufficient pressure, heat and time in order to cure the novolac type resin and to form the wood composite. Optionally, the curing of the novolac resin can be promoted by injecting the compressed mat with steam, rather than by means of heated press platens. However, if a resole type resin is employed as the binder, while in its consolidated condition, pressurized steam is injected into the consolidated mat for a time sufficient to cure the binder and form the composite. The wood composite so produced and which contains the soluble boron compound, exhibits acceptable internal bond strength, and due to the inclusion of the boron compound, renders the composite less susceptible to biological attack and more fire retardant than conventional composites employing phenol-formaldehyde alone as the thermosetting adhesive.