GB356137A - An improved process for uniting wood and other surfaces - Google Patents

Abstract

Plies, one of which is wood, are united by applying to one of the surfaces an adhesive in discrete particle form, i.e. non-dispersed, developing adhesion by applying pressure with or without heat in the presence of moisture sufficient to moisten the particles and controlling the extent of penetration of the adhesive into the plies. The adhesive may be a proteinous material in ground or finely divided condition, for example an isolated protein such as casein or gluten or an oleaginous seed flour such as ground soya bean, peanut, castor, hemp, cottonseed and linseed, and may be dry, moistened or suspended in water. Additional water may be applied to the surface before, during or after the application of the adhesive. Pressures from 40 to 300 pounds per square inch and temperatures up to 365 DEG F. may be employed. The penetration of the adhesive is controlled by incorporating therewith penetration-promoting agents such as caustic soda, a salt of a weak acid and strong base, for example sodium phosphates, or an alkali metal salt together with an alkaline-earth hydroxide such as lime, or lime alone, with or without ammonia or phenol. Alternately, insolubilizing agents such as compounds of the alkaline-earth group, for example calcium salts, or paraformaldehyde, formaldehyde, hexamethylene-tetramine, bichromates, chromates, alums for example chrome alum, tannic or gallic acid, sulphur compounds for example carbon disulphide with or without pulverized charcoal as absorbent, and copper salts, for example copper chloride may be employed. Fungicides, bactericides, and insecticides such as phenols, creosote, creosote oils, cresylic acid, cresylates, naphthols, naphthalene, camphor and oil of cedar and also fire-proofing agents such as ammonium phosphate and borax may be added. Specification 356,138 is referred to.