疏解工艺对簕竹重组材力学性能及尺寸稳定性的影响

Effect of crushing technology on mechanical properties and dimensional stability of bamboo scrimber from Bambusa blumeana

本文以簕竹为原料制备重组材,研究了不同疏解工艺对簕竹重组材力学性能和尺寸稳定性的影响,并通过与毛竹重组材对比,探讨其利用价值。结果表明:随着疏解程度的增加,竹束的载胶量增大,竹青竹黄的存在使竹束对胶黏剂的吸附能力下降;相同条件下,簕竹重组材与毛竹重组材水平剪切强度相当,弹性模量及静曲强度约为毛竹的2倍左右,经28 h循环水处理吸水厚度膨胀率约为毛竹的1/2;带青带黄疏解有利于提高簕竹重组材的抗弯性能,制备的重组竹静曲强度达215 MPa,弹性模量达28 GPa,分别高于常规疏解的8.64%和12.92%,但其水平剪切强度略有下降。竹青的存在可以提高簕竹表面的耐水性,簕竹青黄宽疏解在60 s时接触角仍能达到60°,较其余条件耐水性高。以簕竹开发制备重组材在工程应用上具有较大潜力。

A bamboo scrimber from Bambusa blumeana was prepared in this paper.The effects of different crushing technology on the mechanical properties and dimensional stability of the bamboo scrimber from B.blumeana were studied,and its utilization value was discussed by comparing with that of the bamboo scrimber from Phyllostachys edulis.The results showed that,the resin loading capacity of bamboo bundles increased with the increase of crushing degree,and the adsorption capacity of bamboo bundles decreased with the presence of the outer and inner of bamboo.Under the same conditions,the horizontal shear strength of the bamboo scrimber from B.blumeana and the bamboo scrimber from Ph.edulis were similar,the elastic modulus and static bending strength of the bamboo scrimber from B.blumeana were about 2 times of the Ph.edulis,and the water absorption thickness expansion rate after 28 h circulating water treatment was about 1/2 of the Ph.edulis.The crushing of B.blumeana with the outer and inner of bamboo is beneficial to improve the bending resistance of the bamboo scrimber.The static bending strength reaches 215 MPa and the elastic modulus reaches 28 MPa of the prepared bamboo scrimber,which is 8.64%and 12.92%higher than the conventional crushing.Respectively,the horizontal shear strength of the reconstituted bamboo is slightly decreased.The presence of the outer of bamboo can enhance the water resistance of the surface of the bamboo scrimber from B.blumeana.The contact angle of bamboo scrimber by B.blumeana bundles with the outer and inner of bamboo treated by wide crushing can still reach 60°at 60 s,which is higher than the others.The development and preparation of recombinant wood from B.blumeana has great potential in engineering applications.