Study On Alkali Treatment Process And Performance Of Hemp Fabric

With the improvement of living standard, natural fibers become popular again in our society. Because of the all kinds of unique properties of hemp fibers, it becomes a hotpot in market. More recently, products made of hemp fibers have been used in military, industry and our ordinary life. However, hemp fibers have some drawbacks, such as short, thick and stiff. So, effective methods are necessary to improve the softening property and elasticity. The topic focused research on the technology of alkali treatment and impacts on wear behavior and fabric style to hemp fabrics.Firstly, hemp fabrics were used to perform the single-factor experiment and orthogonal experiment. In the single-factor experiment, temperature, time and alkali concentration were been set up to measure the four typical properties, that is rigidness and softness, wrinkle recovery property, ability of water management and air permeability. Before the orthogonal experiment, three better factors were acquired. The better design is:temperature, time and alkali concentration respectively are 60℃, 20 min and 120g/L and 90℃,20min and 60g/LSecondly, the structure of fibers was analyzed with scanning electron microscope, computer system of biological image and technology of infrared spectroscopy. The results show that the surface of hemp fibers became smooth after treatment, cracks in the fibers reduced obviously and the cross sections became more round due to swelling. After the treatment of the two designs, the average diameter reduced to a large extent and the uneven yarns were improved. The location of absorption peak maintained unchanged, but the intensity reduced after treatment. Specially, the effect from design I was stronger than the design II.Then, the wear behavior of hemp fabrics after alkali treatment were studied, basic structural properties, appearance and comfortable capacity were included. Major conclusions were as follows. Breaking forces were reduced more or less after treatment, while elongation at break increased obviously. The properties of rigidness and softness, wrinkle recovery and drape performance were improved. The air permeability was declined, but this property was still better than the ordinary cotton fabrics. The factors about the properties of water management were improved except the one-way transmission index(R). Wicking height of the warp and weft direction increased to a great degree. Improve effect of the design Ⅰ to hemp fabrics was better than the design Ⅱ.Finally, some conclusions were acquired about fabric style with KES-F system. Elasticity and limpness of the fabrics improved, the fabrics became more plump and smooth, while the formability of fabrics reduced to a small quantity.In a word, the wear behavior and fabric style became better after alkali treatment, this is helpful to the development of hemp fabric in the future.