A comparison of two techniques for wood fibre isolation evaluation by tensile tests on single fibres with different microfibril angle
A comparison of two techniques for wood fibre isolation evaluation by tensile tests on single fibres with different microfibril angle
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DOI：
10.1055/s-2002-20430
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发表时间：
2002-01-01
期刊：
影响因子：
3.9
通讯作者：
Tschegg, SE
中科院分区：
文献类型：
--
作者：
Burgert, I;Keckes, J;Tschegg, SE
云杉（Picea abies [L.]喀斯特。）通过两种分离技术分离。一方面，使用Jeffrey溶液进行软化学处理。以减少的处理时间（2小时）进行分离，只是为了达到纤维可以容易地用镊子分离的状态。另一方面，利用纤维之间的低剪切强度，用镊子直接剥离纤维。采用这种方法，可以完全避免化学处理。为了比较分离技术，在干燥状态下测试来自具有不同微纤丝角的组织类型（早材、晚材、幼龄材、对生材、压缩材）的单个管胞。用X射线衍射法测定了微纤丝角。处理与两种隔离技术的单管胞应变在微拉伸试验和负载应变图。化学处理的纤维被发现具有低得多的强度和刚度相比，机械隔离的纤维，即使微纤丝角的影响仍然是明显的两种治疗。结果清楚地表明了单纤维提取的重要性，以保持尽可能多的原始性能。
Fibres (tracheids) of spruce (Picea abies [L.] Karst.) were isolated by means of two isolation techniques. On the one hand, a soft chemical treatment with Jeffrey solution was used. The isolation was carried out with a reduced time of treatment (2 h), just to achieve the state where the fibres could be separated easily with tweezers. On the other hand, fibres were directly peeled out with tweezers, taking advantage of the low shear strength between them. Following this approach, a chemical treatment could be avoided completely. In order to compare the isolation techniques, single tracheids from tissue types with different microfibril angle (earlywood, latewood, juvenile wood, opposite wood, compression wood) were tested in the dry state. The microfibril angles were determined by X-ray diffraction. Single tracheids handled with both isolation techniques were strained in microtensile tests and load-strain diagrams were obtained. The chemically treated fibres were found to have much lower strength and stiffness compared to the mechanically isolated fibres, even though the influence of microfibril angle was still obvious for both kinds of treatment. The results clearly show the importance of single fibre extraction to preserve as much as possible the original properties.