Research On Slenderizing Jute Technical Fiber By Stretching

Jute fiber, the second largest natural cellulose fiber, is a new eco-textile material possessing great developing potential with its outstanding characteristics, rich resources, low cost, no-pollution, and so on. However, the single jute fiber is too short to successfully spin, and the technical jute fibers are too coarse and hard to spin high-count yarns, which make them only be used as simple-to-manufacture products at present. So jute fiber must be refine-treated to develop its application as high added value products.On the basis of traditional method to refine jute fiber, including chemical method, biological method, and biochemical-chemical method, this paper aimed to introduced a process of physical slenderization, which could further increasing the fiber fineness, and reducing the degumming cost and pollution.Firstly, jute fiber was pretreated with compound additives, and the pretreating parameters were optimized by analyzing properties of pretreated fiber. Secondly, the slenderizing feasibility of pretreated jute fiber was studied, and the effects of slenderizing parameters on fiber properties were also discussed, on the base of which pretreated jute fiber were also slenderized with pilot plant. Thirdly, the effects of content of hemicelluloses and lignin in fiber on the properties of slenderized fiber were also discussed. The main conclusions achieved from the researches in this paper were summarized as follows.1. Research on pretreating process of jute fiber. An optimized process parameters are obtained by orthogonal test, that is, NaOH concentration is 15 g/L, compound additives concentration is 120 g/L, pretreating time is 1.5 h, pretreating temperature is 40°C, and liquor ratio is 1:20. The main properties of jute fiber pretreated with the optimized process can be expressed as: bulking degree is 24.7%, breaking elongation is 7.0%, breaking strength is 2.8 cN/dtex, and flexible degree is 1.6 twist/dtex·m.2. Research on the slenderizing feasibility of jute fiber. The effects of process parameters on the properties of slenderizing jute fiber were studied. The experimental results show that the breaking elongation of fiber are improved with the increase of drawing gauge, which indicate that relative slippage is produced among the single jute fibers; fiber strength is improved and elongation reduced with the increase of drawing speed. The jute fiber stretched with drawing gauge of 20 mm and drawing speed of 20 mm/min still have good properties at the drawing ratio of 7%. 3. Research on the jute fiber slenderized with pilot plant. The jute fiber were stretched refer to cotton spinning process. The experimental results show that fiber fineness is improved by 13.9% and relative strength by 7.1% with a slight decrease in fiber elongation. Generally speaking, the jute fiber after stretching has a significant increase in fineness with little damage in mechanical properties.4. Effects of contents of fiber components on the properties of jute fiber after stretching. The experimental results show that, the fineness of slenderized fiber is increased by 16.3% when the content of hemicellulose decreases from 17.47% to 12.61% with the constant content of lignin, and by 17.6% when the content of lignin decreases from 15.08% to 8.45% with the constant content of hemicellulose.