Study Of Improving The Strength Loss After Durable Press Finishing

Durable press finishing is widely used in the textile industry impart wrinkle-resistance to cotton fabrics and garments.Significant loss in mechanical strength of the durable press finished fabrics has been the major concern for the industry.The low tensile strength retention of the cross-linked cotton fabrics reduces the wash and wear durability of the fabrics.N-methylol compounds,such as dimethyloldihydroxyethyleneurea(DMDHEU),are the most commonly used durable press finishing agents for cotton fabrics in the industry.Study has been made to that cotton fabrics cross-linked with modified DMDHEU(SDP)in the presence of a mixed catalyst system,consisting of magnesium chloride,glycolic acid,tartaric acid,citric acid or malic acid.It was proved the fabric treated in the presence of the mixed catalyst system of glycolic acid and magnesium chloride(When the proportion of glycolic acid and magnesium chloride is 1:19)exhibited best balance between WRA and breaking strength,the WAR reached to 286.7°and the breaking strength retentions were as high as 66.6%(Warp)and 65.1%(Weft).Satisfied results could also be obtained even if the samples were cured at lower curing temperature or shorter time.The durable press finishing in the presence of swelling agent was also studied.The addition of swelling agents to the finishing bath provided an high breaking strength retention but accompanied a decline of the wrinkle recovery angle.In this research,a new moisture cross-linking process was studied.The state of swelling during cross-linking produced a better distribution of crossing linkages in the fiber,and allowed the fiber to remain more mobility to share the stress,thus increased the tensile strength retention. The experiments have provided that an optimum water content in the fiber was crucial for maximum dry and wet wrinkle recovery.The study showed that satisfied winkle recovery angles, 260.8°and 280.8°for dry and wet respectively,could be achieved when the water content is between 6%and 8%,meanwhile the breaking strength retentions were 63.6%(Warp)and 68.2% (Weft),higher than the normal.Because of higher wet wrinkle recovery property,the moisture finished fabrics presented a higher DP grade 3.7 compared 3.4 for normally finished fabric.In addition,moisture cross-linked fabric proved a higher moisture regain and more adsorption to dyes.