IMPROVEMENTS IN OR RELATING TO COMPOSITE BOARDS FROM RICE HUSK AND COMPOSITE BOARD OBTAINED BY SAID PROCESS

摘要

Process for making improved composite boards from rice husk characterized in coating and admixing the raw rice husk with a water dispersible resin wherein the said resin is prepared by the method comprising condensation of phenol : cardanol and/or CNSL with an aldehyde in the presence of an alkaline catalyst wherein the improvement comprises in the one step sondensation of the following ingredients to the proportion as set forth herein :(i) Cardanol and/or cashewnut shell liquid 25 to 60% by weight.(ii) Phenol 34-75% by weight.(iii) Formaldehyde 1-5 to 2 mol (formalin) on cardanol and phenpol used as above and (iv) Alkaline catalyst 5% by weight of cardonol and phenol used above, spreading thus coated and admixed rice husk into a mat of desired thickness and subjecting the same to hot pressing at 160°C-220°C.