The Effects Of Protease Treatment On Tactile Comfort Of Worsted Woven Wool Fabrics

In this paper, tactile comfort of worsted woven wool fabrics which were treated by hydrogen peroxide, protease, and hydrogen peroxide-protease-softener techniques was measured, and the effects of protease treatment on tactile comfort of worsted woven wool fabrics were studied.Firstly, the worsted woven wool fabric was treated by different hydrogen peroxide techniques, and then the prickle and tensile strength of the treated fabrics were measured. The effects of hydrogen peroxide concentration, time and temperature of treatment on the prickle and tensile strength of fabrics were analyzed. It was found that the tensile strength and the prickle of worsted woven wool fabrics reduced after the treatments. The rate of fabric weight reduction increased with the increasing of the hydrogen peroxide concentration, the time and the temperature of the treatment. And the fabric tensile strength decreased with the increasing of the hydrogen peroxide concentration, the time and the temperature of the treatment. When the hydrogen peroxide concentration was 3.5%～5%, temperature of treatment was 45～60℃, time of treatment was 30～60 minutes, the fabric prickle was weakened obviously, and the reduction of fabric tensile strength was not too much.Secondly, the worsted woven wool fabric was treated by protease Nuohe LAN. Based on the analysis of the effects of protease concentration and time of treatment on the fabric prickle and tensile strength, it was found that the fabric prickle and tensile strength reduced after the treatment. When the protease concentration was 1.0%, the time of treatment was 45minutes, the fabric prickle was weakened obviously, and the reduction of fabric tensile strength was not too much.By correlation analysis, it was found that the rate of weight reduction, the prickle and tensile strength of the treated fabrics were closely related to hydrogen peroxide concentration, time and temperature of hydrogen peroxide treatment when keeping other factors the same. The correlation coefficients between the protease concentration and the fabric prickle, between the time of protease treatment and the fabric prickle, between the protease concentration and the fabric tensile strength, and between time of the protease treatment and the fabric tensile strength were low.Thirdly, the worsted woven wool fabric was treated by hydrogen peroxide-protease-softener technique. Based on the measurement results of the prickle, handle and tensile strength of the treated fabrics, it was found that the prickle of the treated fabrics by hydrogen peroxide-protease-softener was weakened obviously, the tensile strength was decreased, the treated fabrics were softer and smoother. But the resilience of the fabrics was decreased.By carrying out analysis of variance on the tests results of fabric prickle, handle and tensile strength of the worsted woven wool fabrics treated with hydrogen peroxide-protease-softener combination treatment, it was found that the hydrogen peroxide concentration and time of hydrogen peroxide treatment had a significant effect on the fabric prickle while the protease concentration and temperature of protease treatment didn't have a significant effect on the fabric prickle. On fabric handle, hydrogen peroxide concentration was the most important factor which influenced the surface roughness of the treated fabrics; the time and temperature of the hydrogen peroxide treatment had significant effects on the fabric flexural properties and the fabric smoothness. The protease concentration also influenced the fabric surface properties. The time of the protease treatment could affect the fabric tensile linearity. The temperature of hydrogen peroxide treatment played the most important role on the fabric tensile strength. The hydrogen peroxide concentration, the time of hydrogen peroxide treatment and protease treatment also influenced the fabric tensile strength, while the protease concentration didn't influenced the fabric tensile strength significantly.Based on the comprehensive consideration about the prickle, handle, tensile strength of the treated worsted woven wool fabrics, the optimal process was obtained as follow:the fabric was firstly immersed in 2% hydrogen peroxide (30%) for 30minutes at 55℃, then kept in 0.5% Nuohe LAN protease for 45minutes at 55℃, and finally dipped in POWERSOFT@ AE 38 CN softener for 30minutes at 45℃and dried.Finally, the diameters of the yarn surface fibers of the worsted woven wool fabrics after hydrogen peroxide-protease-softener treatment were measured and the number and types of the yarn surface fibers were counted and recorded by using a microscope with 400～500 magnification. It was found that the yarn surface fibers were finer, the most diameters of the yarn surface fibers was below 26μm. It was also found that the temperature of hydrogen peroxide treatment played most important role on the reduction of yarn surface fiber diameter.19μm and 23μm were found to be the critical points for the prickle of worsted woven wool fabrics. The time of protease treatment was the most important factor to the percentage of the surface fiber diameters coarser than 19μm. The protease concentration also influenced this percentage. The temperature of hydrogen peroxide treatment influenced the percentage of the surface fiber diameters coarser than 23μm.