Development of green composites using thermoplastics and bamboo fiber

采用三种方法从毛竹和日本毛竹中提取竹纤维。(1)用常规的纤维松解机进行机械加工。它有一个旋转的钉鼓，在那里使用薄竹条。这种方法适合于一年生以下的竹子。(2)碱(NaOH)处理：首先，将竹条在热碱浴中浸泡几个小时，然后进行机械加工。(3)蒸汽爆破法：将生竹条放在蒸汽室中，蒸汽室中注入高压过热的蒸汽。然后，蒸汽突然释放出来。微细胞爆炸发生在细胞内。然后，用脱毛机从蒸汽爆竹中提取纤维。碱处理和蒸汽爆破法可获得较长的纤维，而机械加工竹子则可提取短纤维。然而，可以获得足够长的纤维来制造无纺布FA…更多的金砖国家通过混合热塑性塑料(TP)纤维，只要竹子很年轻。利用较短的竹纤维和PP、PE等TP纤维成功地开发出非织造布。可作为绿色复合材料，用于汽车天花板、后托盘等汽车内件的成型。玉米制成的PIA(聚乳酸)纤维也可以用来代替PP纤维。用双螺杆挤出机将短于50 mm的纤维与茶多酚混合，制得绿色复合材料颗粒。为了提高注塑件的拉伸/弯曲强度，竹纤维直径和长径比是关键。竹纤维的公称直径应小于0.1 mm，长径比应大于20。通过双挤出机路径，复合材料中竹纤维的长径比降低。竹纤维(质量分数为50%)/PP复合材料的最大拉伸强度约为50 Mpa。采用马来酸改性来提高竹纤维绿色复合材料的力学性能。测试了无规竹纤维毡/聚酯复合材料的力学性能。采用树脂传递模塑(RTM)法制备了BFRP，并通过碱处理从毛竹中提取了长纤维。竹席是用梳理机和针刺机相结合的方式制作的。垫子很厚，生成的BFRP强度低，不足以制造小船(5米长)。然后，为了增加竹纤维的含量，对竹席进行了预压缩和使用。据观察，改进后的BFRP强度足够大，可以用于船只。然而，对吸水率的研究告诉我们，对水的关注很多。研究表明，微纤化竹纤维的加入不仅提高了PIA的力学性能，而且提高了PIA的高温耐热性。竹短纤维可以提高复合材料的拉伸强度和耐热性，但冲击强度因竹纤维的存在而降低。另一方面，如果竹纤维稍微原纤化，冲击强度就会得到很好的提高。最后，以聚乳酸为基的复合材料的力学性能和热性能有时高于20wt%玻璃纤维/ABS复合材料。原纤化竹纤维也被用于制作半导体验证盘。较少

Bamboo fibers were extracted from raw bamboo such as Moso (Chinese) and Madake (a typical Japanese bamboo) by following three methods. (1) Mechanical processing by using the conventional fiber loosening machine. It has a rotating nail drum where thin bamboo strips are used. Younger bamboo than one year old is suitable for this method. (2) Alkali (NaOH) treatment: First, bamboo strips are immersed in a hot alkali bath for a couple hours, then, they are machined(3) Steam explosion method: Raw bamboo is set in a steam chamber which will be filled with super heated steam at high pressure. Then, the steam is abruptly released. Micro-cell explosion occurs in cells. Then, fibers are extracted by using the loosing machine from steam exploded bamboo. Relatively long fibers are obtained by the alkali treatment and the steam explosion method while short fibers are extracted when bamboo is mechanically processed. However, long fibers can be obtained enough to be used for fabricating non-woven fa … More brics by mixing thermoplastic (TP) fibers as long as the bamboo is very young. Non-woven fabrics using relatively short bamboo fibers as well as TP fibers such as PP and PE were successfully developed. It can be used as a green composite material to form inner components of automobiles such as ceiling and rear trays. PIA (Poly Lactic Acid) fibers made from corns can also be used instead of PP fibers. Fibers shorter than 50 mm are mixed with TP using a twin screw extruder to fabricate green composites pellets. In order to increase the tensile/bending strengths of the injection molded parts, the bamboo fiber diameter is a key as well as the aspect ratio. Thinner than 0.1 mm is desirable for the nominal diameter of bamboo fibers as well as a high aspect ratio greater than 20. Through the twin extruder path, the aspect ratio of bamboo fibers in a composite decreases. The maximum tensile strength of a bamboo fiber (50%wt content) /PP composite is about 50 Mpa. The maleic acid modification is obliged to increase the mechanical properties of bamboo fiber green composites.The mechanical properties of random bamboo fiber mats/Polyester composites (BFRP) were measured. The BFRP was fabricated by RTM (Resin Transfer Molding) while long bamboo fibers were extracted from MOSO bamboo by the alkali treatment. The bamboo mats were fabricated by using a carding machine in conjunction with a needle punching machine. The mats was very thick and the resultant BFRP had a low strength not enough to use for fabricating small boats (5 m long). Then, in order to increase the bamboo fiber fraction, bamboo mats were compressed in advance and used. The observed strength of the improved BFRP is strong enough to use for the boats. However, the study on water absorption tells us to pay a lot of attention on water. An appropriate treatment to prevent the water absorption during service is strongly suggested.The present study shows that not only the mechanical properties of PIA but also the heat resistance at elevated temperature are well improved due to inclusion of micro-fibrillated bamboo fibers. Short bamboo fibers can enhance the tensile strength and heat resistance, but the impact strength becomes low due to bamboo fibers. On the other hand, if the bamboo fibers are slightly fibrillated, the impact strength is well improved. Finally, the mechanical and thermal properties of the composite materials based on PLA are sometimes higher than those of 20 wt% glass fiber/ABS composite. The fibrillated bamboo fibers are also applied to fabricate the proving disks for semi-conductors. Less