Study On Soft Finish Technology Of Hemp Yarns

The hemp fiber is one of earliest spinning fiber that mankind used. It grows in China earlier, and fiber is one of the oldest natural fibers in China. Historical records as far as Northern and Southern Dynastic (AD500) to about2800BC years ago,"Shen Nong" taught Chinese people growing hemp and use of large linen.The hemp planter is not high to the climate and the soil request, can suppress the weed to grow effectively, does not need to spurt executes the weed killer, has the very good ecology compatibility and the ecological protection function, is very small to the environmental effect. The fabric of hemp fibers have many fine characteristic as follows:good drapability, fastness of moisture absorption and liberation, odor resistant, antiseptic, noise elimination, resistance to ultra-violet-radiation, less scratchiness, biodegradability and so on, so people favor and pay much attention on hemp fiber and its products today.Because of hemp application and its related product research started later, research and development institutions less, development take products (especially the knitting class) is relatively small. And hemp fiber structure and chemical composition is different from cotton, ramie and flex. The fiber is relatively hard, the length and the fineness is very not divide evenly. Hemp yarn for knitting machine production in the existence of difficult woven into rings issue, easy appear yarn breaking, hole and bad needle. The hemp of products is belonged to low and medium-grade goods, almost no have high-grade products. Hemp products can seen on the market are mainly hemp seats and jeans, knitting products knitting with a small amount of the product in the application, high-grade functional products, remains to be developed.The thesis discussed the hemp yarns soft finishing influence by sodium hydroxide, enzyme, cationic softener and ultrasonic; reduce the rigidity of hemp yarn, enhancing their weaving performance, consequently to the level and quality of hemp fabric.The thesis study as followings:1、By orthogonal design experiment and the single-factor experiment of softer treatment with concentration, temperature and treating time, initial modulus, breaking strength and loss rate were tested to evaluate the soft effect, and get the best technological conditions. We compare and discuss the super-soft finish and soft finishing.2、I choose cellulose enzyme and pectinase enzyme to conduct an experiment in the enzyme and softening experiment. By orthogonal design experiment and the single-factor experiment of enzyme treatment with concentration, pH, temperature and treating time, initial modulus, breaking strength and loss rate were tested to evaluate the soft effect, and get the best technological conditions. We compare and discuss the super-soft finish, enzyme finish and soft finishing.3、By orthogonal design experiment and the single-factor experiment of ultrasonic power, treating time and enzyme treatment with concentration, initial modulus, breaking strength and loss rate were tested to evaluate the soft effect, and get the best technological conditions. We compare and discuss the super-soft finish, enzyme finish and soft finishing.