The performance of commercial wrinkle-free garments

Abstract

This thesis concerns the following aspects: 1) the effect of wrinkle-free treatment on fabric physical and mechanical properties, 2) comparison of the performance of different wrinkle-free garments 3) investigation on the relationship between subjective comfort perception and objectively measured fabric properties, and 4) the effect of repeated launderings on physical and mechanical properties of wrinkle-free treated fabrics. Water retention (Swelling index method) is commonly used by the industrial partner for indicating wrinkle-free treatment level. A study has been carried out to investigate the relationship between the swelling index and the Nitrogen Content, which is a theoretical measure of the level of wrinkle-free treatment. It was found that the swelling index might not be appropriate as an indicator of wrinkle-free treatment level. The effect of wrinkle-free treatment level, as measured by the Nitrogen Content, on fabric physical and mechanical properties also has been investigated. After wrinkle-free treatment, fabric strength and water absorption rate decrease. Since there is no clear relationship between the reduction in fabric strength and the increase in Nitrogen Content, the reduction of fabric strength may not be mainly due to the in-take of DMDHEU but due to other parameters during the wrinkle-free process. The performance of wrinkle-free garments in terms of durability, appearance retention and comfort has also been studied. In order to achieve a balanced performance in durability and appearance as well as maximize the comfort, the industrial partner has developed novel finish formulae and procedures based on hydrophilic softener. In this work, a comparison has been made between the newly developed wrinkle-free treatment and the conventional wrinkle-free treatment. They have been tested and compared with fabrics without wrinkle-free treatment, and with different garment finishing processes. Based on this work, it was found that the newly developed wrinkle-free treatment has much better water absorption rate than the conventional one, but slightly poorer performance in shape retention, appearance retention and resilience to bending or wrinkling. The newly developed treatment also tends to be stiffer in handle than the fabric with the conventional wrinkle-free treatment. This significant difference in the water absorption rate is however difficult to perceive in the subjective wearer trial unless under strenuous exercises. The wearer trial also showed that surface tactile sensations are important for governing the overall discomfort sensation before sweating, while moisture related sensations are important after sweating. The newly developed wrinkle-free treatment was slightly more comfortable when sweating but probably a bit less comfortable before sweating due to slightly more stiff and pricky sensation. Wrinkle-free treatment can reduce the adverse effect of washing on many low stress mechanical properties. Washing has only small effect on the wrinkle-free treated fabrics in terms of water absorption rate, air penetration, fabric density and resilience. Wrinkle-free treated fabrics can achieve better shrinkage control and resilience than the non-treated fabrics even after repeated launderings. Fabrics with the newly developed treatment has better water absorption rate than the conventional one even after repeated launderings, however, it is not as good in terms of softness handle.