Study On Application Of Phenolic Resin Adhesive Cured Under Low Temperature To Container Floors

This paper mainly discussed the feasibility of applying modified phenolic resinunder middle/low temperature as container floors. This paper mainly studied thefollowing contents:(1) Influence of veneer density and moisture content on bonding strength wasinvestigated. Different density could lead to different bonding strength: too high ortoo low density was not beneficial to bonding strength. In addition, density of veneershould be less than0.8g/cm3and appropriate density could improve bonding strength.On the other hand, moisture content of veneer also had effect on bonding strength.Too high moisture content resulted in defects of plywood and prolonging of resincure time, which may lead to decrease of bonding strength. While too low moisturecontent would reduce wetting ability of resin, which may also had bad effect onbonding strength.(2) According to the orthogonal analysis of the influence of three factors (rate ofspreading, hot-pressing temperature and adding amount of flour) on bondingstrength of plywood, optimal factors were chosen. When hot-pressing temperaturewas145℃, spreading ratewas340g/m2of two sides,10%of flour adding amount,bonding strength was the largest,2.21MPa. In this research, spreading rate had thelargest influence on bonding strength, and then did hot-pressing temperature, and thelatter did adding amount of flour. Among the three factors, spreading rate andhot-pressing temperature had significant effect on bonding strength. Whenhot-pressing temperature was125℃, spreading ratewas340g/m2of two sides,10%of flour adding amount, bonding strength was1.78MPa. By adding calciumcarbonate and resorcinol-formaldehyde (RF), bonding strength could be furtherimproved. When adding amount of calcium carbonate was6%and RF was9%,bonding strength reached2.09MPa.(3) Influence of hot-pressing pressure on mechanical properties of container floorsmanufactured with modified phenolic resin adhesive was researched. When pressurewas too high, adhesive was squeezed out of plywood, leading to unfavorable bondingstrength. Meanwhile, it could also cause damage to cell structure, which had badeffect on mechanical properties of container floors. On contrary, too small pressurecould not fully bind veneer together and therefore floors properties were affected. In this research, when hot-pressing pressure was3MPa, mechanical properties were thebest. Moreover, adhesive impregnation amount of bamboo curtain also had influenceon MOR and MOE of bamboo/wood composite container floors. When adhesiveimpregnation amount was8%, performances of bamboo/wood composite containerfloors were the most favorable.(4) ASTM D1037six cycles accelerated aging method of American standards wereapplied. After accelerated aging treatment, lengthwise MOR and MOE retention rateof factory manufactured container floors was26.4%and32.7%, respectively.Lengthwise MOR and MOE retention rate of container floors manufactured withmodified phenolic resin adhesive was36.5%and38.8%. And that of bamboo/woodcomposite container floors manufactured with modified phenolic resin adhesive was54.8%and68.4%. According to the results, aging-resistant performance ofbamboo/wood composite container floors manufactured with modified phenolic resinadhesive was apparently more favorable than that of container floors manufacturedwith modified phenolic resin adhesive and factory manufactured container floors.And aging-resistant performance of container floors manufactured with modifiedphenolic resin adhesive was better than that of factory manufactured containerfloors.