A new drape elevator is developed to analyze the drape generation mechanism. The drape elevator can measure drape shape, including node generation at various stages during drape formation. The drape elevator method indicates better reproducibility of the drape coefficient of the fabrics than the conventional method. The drape formation process is experimentally found to consist of three stages, seeds generation, their development, and the final stabilizing stages. A new parameter R, evaluating the shape of the drape, is defined in terms of the drape projection. Both the R parameter and the drape coefficient are expected to be useful parameters for the quantitative analysis of fabric drape formation.

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A new calorimeter is constructed to precisely measure the heat of wetting of cotton, regular viscose rayon, high wet strength viscose rayon, and Tencel®. Our purpose is to investigate the relationship between the heat of wetting and structural characteristics of fibers such as crystal and fiber structure, degree of crystallinity, and water absorbency properties (water regain, moisture regain, and bound water content of fibers). Despite its relatively high water regain, cotton has the lowest heat of wetting among the fibers studied so far. The heat of wetting of cellulosic fibers depends slightly on fiber and crystal structure but decreases proportionally with the increasing degree of crystallinity of the fibers. The heat of wetting is closely related to the amount of bound water estimated by differential scanning calorimetry. These results are discussed from the viewpoint of designing high performance cellulose materials.

Silk is usually dyed at the fabric or yarn stage. It is difficult to dye silk fibers at the cocoon stage because (1) cocoon loses its original shape and (2) dye cannot penetrate easily into the cocoon shell. This study is the first attempt at dyeing cocoons adequately while retaining their shapes. Cocoons were dyed with a reactive dye under various conditions. When the dyeing process was carried out for several hours without a surfactant, the cocoon shells were not dyed adequately from 293 K to 333 K, furthermore at 333 K the silk filaments on the surfaces of the cocoons came loose and were entangled. In contrast, the cocoon shells were almost completely dyed when a surfactant, namely, sodium dodecyl sulfate, was used; in this case, the concentration of the surfactant was greater than the critical micelle concentration. The results suggest that the use of a surfactant and an appropriate temperature are useful for dyeing cocoons.