Production of plastic-like moldings from fast growing tree's barks

威利碾磨的马占相思外皮样品根据其树皮颗粒大小，使用一系列筛子进行分级。无论溶剂比和提取时间如何，树皮粉的粒度都会影响萃取率，当馏分低于45[]时，甲醇萃取率可达50%以上。萃取物的平均调整Stiasny值为94.5%，表明单宁丰富且集中在小颗粒级分中。用甲醇、提取的福尔马林和水混合，在pH从4增加到8的情况下，胶凝时间。旋转车床单板和胶粘剂由粒度为Lee Than 63[]的树皮粉、多聚甲醛和水制成。在沸腾中浸泡72小时，剪切强度达到11.7kgf/cm2，符合JIS K6802对外级胶合板的要求。将树皮粉加入固形物质量分数为20%的酚醛树脂中，可降低热压温度，获得外级胶合板。用树皮粉和纸浆按7：3的比例混合制成的模塑制品的弯曲强度可达80兆帕。冷水浸泡24小时后，抗弯强度降至70 Mpa。

Wiley-milled Acacia mangium outer bark samples were fractionated using a series of sieves according to their bark particle size. The extractive yields were affected by bark powder particle sizes regardless of the solvent ratio and extracting time, and at fractions under 45[], more than 50% methanol extractive yields were obtained. The average adjusted Stiasny value for the extractives was 94.5%, indicating that the tannin rich and is concentrated in the the small particle fractions. The gelation time of the mixture of methanol extractive formalin and water fenwith increasing pH from 4 to 8. Plywood was produced using lauan (Shorea spp.) rotary lathe veneers and adhesives prepared from bark powder with a particle size of lee than 63 [], paraformaldehyde and water. A shear strength of 11.7.kgf/cm2 after 72 hrs immersion in boiling, which complies with the requirement of the JIS K6802 for exterior-grade plywood, was attained. When the bark powder was added to a phenolic resin with 20% by weight of solid content of resin, the hot pressing temperature to obtain exterior-grade plywood could be reduced. Moulding products using a mixture of the bark powder and pulp in the ratio of 7:3 attained a bending strength of 80 MPa. After cold water immersion for 24 hrs, the bending strenght reduced to 70MPa.