据统计杂草在全球造成的经济损失高达一千多亿美元[1]。为了有 效控制由杂草造成的经济损失,合成土工布早已被用来抑制杂草,但 是它们是髙分子材料,是不可生物降解的,并且其生产过程会造成空 气和水污染。为了解决这个问题,可生物降解的天然纤维便被研究制 成抑草材料。本文探讨了国内外学者鲜有研究的天然亚麻和大麻纤维 制作针刺抑草土工布可行性的研宄。通过对所制亚麻和大麻抑草土工 布与商用聚丙烯和木纤维抑草土工材料进行单位面积克重、厚度、机 械性能、透水性、吸水性以及阻光性各方面的测试比对,以确定其是 否适合这个特殊的用途。本报告的研究结果可为天然纤维抑草土工布 的加工和制备提供新的思路并奠定良好的理论基础。 本课题的研究结果如下: 1.比较亚麻、大麻抑草土工布和商用聚丙烯和木纤维抑草土工 布平方米克重和厚度等性能。实验结果表明,亚麻和大麻纤维具有成 网性,其制成的针刺抑草土工布厚度为2. 44mm-4. 33mm,平方米克重 为237-318g/m2。其比商用聚丙烯和木纤维抑草材料更厚更重,但是 东华大学硕士学位报告 有研究表明厚度和平方米克重与土工布的抑草能力没有显著相关性, 所以亚麻、大麻纤维具有制成抑草土工材料的潜力。 2.亚麻纤维和大麻纤维相对于聚丙烯纤维具有优良的回潮率, 所以其所制成抑草土工布吸水性强,其吸水量为9. 8g-26. 3g,从而 能够加快杂草的分解。通过对比亚麻、大麻纤维抑草材料与商用聚丙 烯和木纤维材料的透水性,结果表明其透水性类似,这一性能保证了 目标植物的正常生长。 3.阻光性是判断抑草土工布的一项最重要的标准,通过阻碍光 透过材料照射到杂草而破坏杂草的光合作用,从而达到抑制杂草的目 的。本报告所制备的亚麻和大麻土工布阻光率为96. 5%-99. 5%远高于 商用聚丙烯材料79. 4%的阻光率,可实现杂草抑制。 4.亚麻、大麻纤维抑草土工布拉伸断裂强力为 0.26-1. 18kgf/cm2,拉伸断裂韧性为4.0-31.7kgf/cm2,初始模量为 1. 1-5. 3kgf/cm2。其机械性能虽然不及商用聚丙烯和木质纤维材料, 但是通过进一步改进制作工艺,增加其机械性能,其仍具有制备抑草 土工布的潜力。 5.对比亚麻和大麻所制备土工布抑草性能,结果表明本报告所 用大麻材料中所含杂质少,吸水和阻光性能更优越,这表明大麻材料 更适合用来做抑草土工布。 东华大学硕士学位报告 总之,经过适当改善,如增加强度以便于安装,大麻和亚麻土工 布具有杂草抑制的性能。这项研究还提供了另一种处置亚麻和大麻纤 维初加工产品的方法,既有生态效益又具经济效益。 关键词:亚麻,大麻,抑草,针刺,土工布 东华大学硕士学位报告 UTILIZATION OF FLAX AND HEMP FIBERS IN NONWOVEN WEED SUPPRESSION GEOTEXTILES ABSTRACT It is claimed that global economic loss due to weeds is more than one hundred billion dollars⑴. Synthetic geotextiles have long been used to suppress weeds, but they are manmade high molecular materials, not biodegradable, and it will cause air and water pollution during production. To solve this problem, natural fibers have been utilized to produce weed suppression geotextiles, but few studies have been conducted to make weed suppression geotextiles using natural fibers such as flax and hemp fibers. This research is focused on utilization of flax and help fibers in nonwoven weed suppression geotextiles. These fabrics have been compared with currently available weed control fabrics (made from polypropylene and wood fiber) to determine their suitability for this particular purpose. The resulting fabrics were evaluated for basis weight, thickness, tensile properties, light, and water transmission. The main results are listed as follows: 1. The basis weight, thickness properties have been tested in this research to compare the properties of flax and hemp nonwoven geotextiles and that of the commercial polypropylene and wood fiber weed suppression materials. The results show that the flax and hemp geotextiles are with thickness of 2.44mm-4.33mm, 237-318 g/m2. They are thicker and heavier than polypropylene and wood fiber weed suppression materials. But studies showed that fabric basis weight and thickness are not well correlated with ability to suppress weeds, so flax and hemp fibers have the potential to make weed suppression geotextiles. 2. Flax and hemp fibers have superior moisture regain values than that of polypropylene fibers, which will lead to great moisture absorbency (9.8g-26.3g) to speed up degradation of the weeds. Flax and hemp fiber geotextiles have similar water penetration property as that of polypropylene and wood fiber weed suppression textiles, which can make sure the growth of the desired plants. 3. Light blockage is a key factor for weed suppression. Good weed suppression geotextiles will block the sunlight from going through the material to avoid photosynthesis so that weed cannot grow. The flax and hemp geotextiles have very high light blockage rate: 96.5%-99.5%, far better than that of polyethylene weed suppression materials (79.4%), which proved that they can suppress weed. 4. The tensile strength of flax and hem fiber geotextiles is 0.26-1.18 kgf^cm2, tensile toughness is 4.0-31.7 kgf/cm2 while the initial modulus is 1.1-5.3 kgf/cm2. Even though flax and hem fiber geogextiles have lower tensile properties than that of polypropylene and wood fiber 东华大学硕士学位报告 weed suppression materials, it still has the potential of producing as weed suppression geogextiles with proper tensile improvement. 5. Between the flax and hemp fibers, the hemp fibers that were utilized in this research have less . unties, better moisture absorbency and light blockage, which indicates better suital y for weed suppression application. Overall, the flax and hemp geotextile fabrics have the potential to be used as weed suppression fabric with suitable modifications like increasing the strength to achieve easier installation. This research also provides an alternative disposal method for pre-processing flax and hemp fibers, which has both ecological and economic benefits. Ying Wen (Textile Materials and Design) Supervised by Prof. Yiping Oiu KEY WORDS: flax, hem, weed suppression, needlepunching, geotextiles 东华大学硕士学位报告 1.1抑草土工布的研宄背景及概况 1.1.1杂草抑制 1. 1.2杂草抑制的方法 1.2天然纤维 1. 2. 1亚麻纤维 1. 2. 2大麻纤维 1.3非织造技术 1. 3.1气流成网 1. 3. 2针剌法 1. 3. 3生物可降解非织造材料 1.4本课题的研宄内容及意义 1.4. 1本文研宄内容 1. 4. 2本文研究意义 第2章天然纤维土工布的制作 2.1实验材料 2.2制样过程 2. 3实验样品制备参数及列表 第3聿天然纤维土工布物理性能测试结果及分析..... 3. 1表面形态 3.2厚度测试 3. 3厚度测试结果及分析 3.4平方米克重测试 3.5平方米克重测试结果及分析 第4章天然纤维土工布机械性能测试结果及分析..... 4.1机械性能测试 4. 2机械性能测试结果分析 第5章夭然纤维土工布透水、吸水性能测试结果及分析 5.1透水、吸水性能测试 5. 2透水性能结果及分析 5. 3吸水性能结果及分析 第6章天然纤维土工布透光性能測试结果及分析..... 6.1透光性测试 6.2透光性能结果及分析 第7聿结论与展望 7.1结论 7. 2后续研宄展望 辦文献 附录所有抑草土工布的应力-应变曲线 目录 i 笛1 i @ 论 1 录 m m ii 21 22 22 24 24 27 27 28 36 36 37 39 41 41 42 45 45 46 47 50 东华大学硕士学位报告 攻读硕士学位期耐发表报告 58 gC It 59 东华大学硕士学位报告 图目录 图1-1.天然纤维的分类[27] 11 图1-2.气流成网原理[42] 14 图1-3.简单针刺机的运动原理图[42] 15 图2—1.亚麻和大麻纤维 17 图2-2.两种商用抑草土工布 18 图2-3.本报告实验流程示意图 19 图2-4.麻纤维土工布制备(a)气流成网(b)针刺加固 19 图3-1.最终样品(a)亚麻(b)大麻(c)亚麻、大麻重量百分比50%土工布21 图3-2.非织造材料表面由于针刺造成的孔隙 22 图3-3.厚度测试结果正态概率图 23 图3-4.亚麻和大麻土工布与商用聚丙烯和木浆纤维土工布的厚度对比.....23 图3-5.亚麻大麻土工布与商用聚丙烯和木浆纤维土工布的平方米克重对比.25 图4—1.由Instron 5500R测试拉伸强力 27 图4-2.拉伸试验的样品 27 图4-3.F-2X应力应变曲线(a)纵向(b)横向 28 图4-4.F-3X应力应变曲线(a)纵向(b)横向 29 图4-5. FH-2X应力应变曲线(a)纵向(b)横向 29 图4-6.FH-3X应力应变曲线(a)纵向(b)横向 30 图4-7.H-2X应力应变曲线(a)纵向(b)横向 30 图4-8.H-3X应力应变曲线(a)纵向(b)横向 30 图4-9. PP横向应力应变曲线(a)纵向(b)横向 31 图4-10. Wood应力应变曲线(a)纵向(b)横向 31 图4-11.亚麻大麻土工布与商用聚丙烯和木浆纤维土工布拉伸断裂强力对比32 图4-12.亚麻大麻土工布与商用聚丙烯和木浆纤维土工布断裂韧性对比....33 图4-13.亚麻大麻土工布与商用聚丙烯和木浆纤维土工布初始模量对比 34 图5-1.吸水纸 36 图5-2.透水性和吸水性测试 37 图5-3.透水量结果正态概率图 38 图5-4.亚麻大麻土工布与商用聚丙烯和木浆纤维土工布的透水性对比38 图5-5.聚丙稀土工布表面孔隙 39 图5-6.亚麻和大麻土工布与商用聚丙烯和木浆纤维土工布的吸水性对比...40 图6-1.阻光性实验示意图(MTCC 148-1