Thermal decomposition in the initial stage of Nylon 66 carpets and their components was analyzed by thermogravimetry (TG), and TG-Fourier transform infrared spectrometry (TG-FTIR). The Ozawa-Flynn-Wall method was applied in the initial stage of thermal decomposition. It was found that the thermal stability of carpet depends on the characteristics of backing materials. Poly(vinyl chloride) (PVC) backing is easily decomposed and mass residues was high due to the presence of additives. HCl gas was evolved from PVC backing in a temperature ranging from 300 to 400 °C where, in contrast, a-olefin backing showed stable performance.
Color reflectance from the cloth dyed with natural indigo was quantitatively compared with that from the cloth dyed with synthetic indigo by the spectrophotometric method, and the results were analyzed by a CIE-LAB color system. The cause of the color difference between the clothes dyed with natural and synthetic indigo was attributed to the mode of dye dispersion in fiber resulted from the aggregation of dye molecules during the reduction process. The results are summarized as follows: 1) The color produced by natural indigo is bluer and brighter than color produced by synthetic indigo reduced by sodium hydrosulfite. 2) The color produced by syn-thetic indigo using zinc powder is more similar to the color of natural indigo than the color of synthetic indigo prepared with sodium hydrosulfite. 3) The chroma and hue of the cloth dyed with natural indigo are higher than the respective values of the cloth dyed with synthetic indigo reduced by sodium hydrosulfite when the clothes are dyed repeatedly. 4) The diffusion coefficient of synthetic indigo reduced by sodium hydrosulfite is higher than that of natural indigo, where the diffusion coefficient of synthetic indigo reduced by zinc powder is similar to that of natural indigo.
The authors have developed an analytical method for hinokitiol using HPLC to determine its content in various textiles treated with it on the market and reported that hinokitiol was not detected in all of the textiles tested. Aiming to clarify the cause for the absence of hinokitiol, hiba oil, synthetic hinokitiol and hinoki leaf oil were microcapsulated and the sample fabrics were prepared by treating with each microcapsulated preparation. Then, the survival rate of hinokitiol in the treated fabric was determined after a light fastness test using a xenon-ark lamp. The results indicated that hinokitiol was much liable to photolysis. The antimicrobial activity of the treated fabrics with synthetic hinokitiol on S. aureus was higher after the light exposure during the test than before, suggesting the photolysis products of hinokitiol have higher antimicrobial activity than hinokitiol itself.
Continuous shrink-resist process of wool top sliver without use of chlorine agents has been recently developed in order to minimize Adsorbable Organic Halogens (AOX) being discharged from chlorine-based shrink-resisting process. The process consists of two steps of oxidation and subsequent reduction with bisulfite, i.e., (1) the oxidation with potassium hydrogen persulfate by pad/steaming as the first and (2) with ozone bubbled in acidic aqueous solution by a line mixer as the second. The characteristic feature of the proposed process was compared with other existing processes in view of comparison with properties of the treated wool. Washability performance of the treated wool products met with IWS TM 31 requirement. The treated fabric hand and fiber friction μa of the tip to root direction were generally the same as those of similar fabric made from untreated control, while, the friction μw of the root to tip direction increased. The difference of (μa-μw), i.e., D.F.E. was remarkably reduced, probably leading to the high resistance to pilling of the treated fabrics. FT-IR, Allwörden test and SEM observation revealed that the proposed process was a just surface treatment without serious damage to the cuticle, maintaining the yarn strength and the water repellency of untreated wool.
Melt spinning experiments of tetrafluoroethylene copolymers, whose components are hexafluoropropylene (FEP), ethylene (ETFE) and perfluoroalkoxy vinyl ether (PFA), respectively, were carried out. When the conventional melt spinning machine with gear pump was used, desirable filaments were difficult to be obtained probably due to the degradation of polymers. The screw structure was designed to decrease the degraded polymer and to keep constant through-put of the polymer without using the gear pump. By the study of melt fracture, the diameter of the orifice was determined. The thinning of the filament during the spinline was controlled by the equipment of heated sleeve under the spinneret.
The changes of fabric surface caused by moisture were investigated by measuring the coefficient of friction between the fabric and the artificial skin. The dynamic surface wetness of fabric was also detected by changes in the fabric's color when using the cobaltous chloride. For the two layered fabric, the difference of surface wetness was observed by the fabric surface color in the same moisture regain. The effect of moisture on the face and back side of a fabric was reflected in the values of the coefficient of friction.