| 摘要 |
<p>1,199,452. Forms of wood. VEDEX DANSK SKOVINDUSTRI A/S. 10 Oct., 1967 [24 Oct., 1966], No. 46332/67. Heading B5L. [Also in Division C3] A method of producing wooden boards from pieces of wood such as veneer sheets or shavings comprises first vacuum impregnating the pieces with one component of a two-component plastic adhesive prior to a bonding process, applying to the pieces an adhesive formed from an admixture of the other plastic component and then bonding the pieces together by heat and pressure. In an example beechwood veneer sheets are placed in a vacuum chamber into which is introduced a solution of 20% diammonium phosphate, 2% copper sulphate, 8% urea, and 70% water. After a certain time the sheets are removed and every second sheet coated with a film of a phenolic formaldehyde adhesive consisting of 100 parts of a pre-mix of phenolic formaldehyde, 15 parts of formalin. 10 parts of diammonium-phosphate, 25 parts of kaolin and 15 parts of paraformaldehyde. The sheets are then placed in a press and heat and pressure applied.</p> |
