Sonoko Ishimaru

Prediction method for clothing pressure distribution by the numerical approach: attention to deformation by the extension of knitted fabric

In general, clothing pressure is measured using a sensor set on the surface of a human body or dummy, and it is not possible to measure clothing pressure without the sewing process. We have developed a numerical-analysis-based technique to simulate clothing pressure without having to sew the cloth into clothes. We presupposed that clothing made of knitted fabric was applied to a mannequin in close contact with its surface. Based on this simulation, this paper proposes a model for fabric deformation, by extension applicable to large deformation, with anisotropy and non-linearity taken into account. In this model, the fabric is separated into isotropic and anisotropic elements, and non-linearity is assigned to both the isotropic and anisotropic elements. Furthermore, to use this model, we propose a method for fitting the knitted fabric tightly to a human body model while sewing the knitted fabric model reflecting the paper pattern. To prevent excessive extension of the knitted fabric model reflecting the paper pattern during the process of fitting, we adopted the two-step fitting method involving application of the fabric to a temporary human body model (intermediary) followed by its application to a formal human body model. The clothing pressure values calculated with this method were very close to the actually measured values using a rigid mannequin.

Heat-Controllable Man-Made Fibers

Thermal-retaining properties of clothing materials are indispensable for a comfortable life in the winter season. In general, thermal retention of clothes is enhanced by the amount of stationary air stored in space among the constituent fibers. Specifically, thinning the fibers, crimping the fibers, and increasing the number of fluffs are effective methods to enhance the thermal retention ability.

Moisture and Water Control Man-Made Fibers

Moisture and water absorption properties of clothes are very important for the excellent wearing comfortability. Moisture-absorbing materials absorb gas-phase water and suppress humidity rise within clothing. Water-absorbing materials absorb and diffuse liquid-phase perspiration, increase the amount of evaporation heat transfer, and expedite the heat dissipation. At one time, many research projects were conducted to provide man-made fibers, which are hydrophobic innately, with moisture and water absorption ability as well as natural fibers. At the present, however, moisture and water absorption abilities of some man-made fibers exceed those of natural fibers. And also, according to the development of assessment technologies of consumption science for wearing comfortability, man-made fibers with excellent moisture and water absorption abilities, which cannot be attained by natural fibers, have been developed and used for sports and inner wears. Specifically, perspiration-absorbent and quick-drying materials, polyacrylate fibers which have 3.5 times larger moisture absorption ability than that of cotton, man-made fibers with improved moisture-absorbing and moisture-releasing abilities, materials with self-controlling functions, and yarn and knitted or woven fabric composite structural materials, are examples. In this chapter, basic scientific knowledge and the evaluation methods of moisture and water absorption, current moisture- and water-absorbing materials, imparting method of these abilities, etc., are presented.