The slit beam projecting technique combined with the image processing is used, and three-dimensional image of the wrinkle of fabrics is obtained by the method, in which there is no influence on the results from the colors and the patterns of fabrics, and the fabric wrinkles can be evaluated and analyzed objectively. The parameters, such as standard deviation of height values of surface profiles, increasing ratio of surface area, one of surface length, and fractal dimension of surface, are defined and suggested to evaluate and characterize the fabric wrinkles. There are logarithm relationships between the parameters and the wrinkle grades of standard replicas, and their correlations are high, too. There is a good agreement between the subjective appraisal and the objective evaluation results for the fabrics.

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This paper investigates about the simulation of warp tension variation in a weaving machine, based on mathematical and mechanical equations. To perform simulation, a differential equation system was formed and solved by numerical method. The results shown as the curves of warp tension variations and back rail oscillation of the loom were compared with the experimental results obtained from warp tension measurement. The result of comparison showed a good agreement between the theoretical and experimental results.

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Weld-lines degrade the mechanical and optical properties of products. This is because the polymer molecules near the weld-line highly orient owing to the elongational flow and the molecular orientation is fixed by solidification of the polymer melts before it returns to a random condition. Birefringence experiments were, therefore, carried out for welding flows of a low density polyethylene (LDPE) past a spider supporting a mandrel. The die used in the present study has a glass window to observe the birefringence pattern. The birefringence in the polymer melts was measured by the photoelastic method. The purpose of the present study is to elucidate the effect of the die temperature, spider shapes and a viscoelastic property of polymer melts on the anisotropy of the molecular orientation in the stress relaxation process downstream of the spider. The birefringence pattern in the welding flow of LDPE was measured at the die temperature T_d=190, 205°C and the polymer melts temperature T_p=19O°C for flow rates of 0.7, 1.0, 2.2, 2.9, 4.6cm³/s. The results showed that complete relaxation of birefringence depended on the flow rate. For high die temperature (205°C), the distance necessary for the relaxation of molecular orientation was short. Moreover, the birefringence pattern in the welding flow was numerically calculated using the single-mode Giesekus model as a constitutive equation, and the results were compared with the experimental data. The numerical predictions agreed with the experimental results.

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