Research On Gluing Of Outdoor Glued Structural Laminated Bamboo

According to the glue characteristic of outdoor glued structural laminated bamboo, the paper studies the surface characteristics of bamboo strips flattened,and the relation among surface status of bamboo stripsprocess status of bamboo strips and the performance of glued laminated bamboo.This paper is based on the study of surface properties of bamboo strips flattened as the breakthrough point, using different heat treatment processing to deal with bamboo strips flattened, then research the surface wettability, surface chemical composition and structure of bamboo strips flattened, explore different heat treatment methods and heat treatment processes put an influence on the recovery property of bamboo strips flattened, studying different surface's veneer process of bamboo strips flattened, in order to research the characteristics of the bamboo strips flattened, thereby solve the problem in glue processand using bamboo strips flattened as layer board to manufacture glued structural laminated bamboo which using for outdoor.The paper studies the surface wettability of glued structural laminated bamboo because the bonding property mainly depends on the surface wettability. In different heat treatment processes, surface contact angle of glued structural laminated bamboo is becoming larger as processing temperature rising and extension of processing time, the surface wettability property reduce, the influence of time tothe surface wettability property is not in evidence.The paper studies surface chemical composition and structure of bamboo strips flattened. Glue layer penetrate deeper on bamboo yellow surface whose texture is loose, after high temperature treatment, the surface does not have clear fibrous structures, surface fiber are softened, burning and become more smooth, pore are blocked and become denser, then glue is not easy to penetrate into. Strength of bamboo surface absorption peaks drops obviously after high temperature treatment, explain surface carbonized, but there is still a large carbonized of hydroxyl groups. By heat treatment, bamboo cellulose and hemicellulose reduce, then oxygen functional group(such as carboxylic, acetyl groups, etc.) have severe losses, but lignin content increases, this can foresee bamboo surface wettability would decline, while dimensional stability has a certain degree of improvement.The paper studies the resilience property of Bamboo strips flattened. In different heat treatment processes, the Bamboo strips flattened recovery property is different, as hot-pressing temperature and time increase, resilience modulus reduces, and with the heat treatment process corresponding, the range of resilience modulus is constant, and there is less change with different heat treatments. In different heat treatment processes, bamboo strips flattened weightlessness rate is different, with hot-pressing temperature and time increase, weight lost rate of bamboo strips increase, the changes of heat treatment method have some influence on it, and the weight lost rate is less in hot steam treatment method.The paper studies two kinds of adhesive which is used for outdoor glued structural laminated bamboo, the glue process of glued structural laminated bamboo, using EPI and PF.The paper investigates pressure, gelatinize quantity and time factors to influence integrated timber shear strength,WFP and water soak delamination, and make sure the best technical parameters by using EPI; The paper investigates temperature, pressure and time factors to influence integrated timber shear strength,WFP and water soak delamination, and make sure the best technical parameters by using PF.