木材界面液化的自胶合工艺参数对胶合性能的影响

Technics of Wood Self-adhesion by Interfacial Liquefaction

针对木材的自胶合,引入溶剂催化液化法,以杨木和桉木单板为原料,进行了界面液化自胶合试验。分析了液化剂种类(苯酚、丙三醇)、涂布量(150、300、450 g/m2)、热压温度(125、150、175℃)、热压时间(10、15、20min)和树种(杨木、桉木)5个因子对胶合剪切强度的影响。结果表明:利用液化方法在木材表面构造黏稠过渡层以取代木材界面,实现木材的自胶合在技术上完全可行;单板树种对液化胶合性能有明显影响,在试验的工艺条件下,桉木的胶合性能优于杨木;丙三醇液化胶合性能高于苯酚;热压温度和时间对苯酚液化胶合性能的影响不明显,而对丙三醇影响明显。建议就木材界面液化自胶合的机理开展进一步深入研究。

Acid-catalyzed liquefaction of poplar and eucalyptus wood veneers was conducted for self-adhesion experiment. Effects of 5 processing factors, i.e. liquefaction agents （ phenol and glycerol）, content （ 150,300 and 450 g · m-2 ）, hot-pressing temperature（ 125, 150 and 175 degrees C）, time （10, 15 and 20min）, and wood species（ poplar and eucalyptus）, on bonding strength of veneer samples were specifically analyzed. Liquefaction of two wood veneers produced between a sticky transient interracial layer, which was demonstrated to be technically feasible to bond the two adherent veneers. Wood species had an obvious effect on bonding performance of two surface-liquefied veneers, and the eucalyptus veneers showed higher bonding strengths than the poplar ones. Glycerol-liquefied veneers presented higher bonding strengths than veneers liquefied by phenol. Both hot-pressing temperature and time had signlfieant effects on the self-adhesion of glycerol-liquefied veneers, while had no evident influence on veneers liquefied by phenol. Suggestions on the mechanism of wood selfadhesion by interfaeial liquefaction were also given.