Light transmission property of plain woven fabrics was studied in order to perform the fabric design considering the transmission. A light transmission measurement apparatus which could change incidence and receiving direction of light was developed and the change of the transmission factor by light direction was measured for plain woven fabrics. Because structures of the fabrics are anisotropy, the light transmission property showed anisotropy. The anisotropy of transmission factor was remarkable in large incidence angle, and the minimum or maximum values were showed every Pai/4 cycle. An approximation curve of anisotropy was proposed and the anisotropic light transmission factor was estimated from a measurement at front of a fabric and structure of the fabric based on crimp theory of Peirce.

View full abstract

Estimation of thermal sensations at the moment when certain objects are touched is an important concern in material evaluation. Heat conduction phenomena can be modeled with the use of thermal contact resistance, not only in cases where imperfect contact is caused by rough and/or uneven contact surfaces, but also in cases where thin films are formed on contact surfaces under certain conditions. First, it has been made clear how thermal contact resistance affects temperatures and rates of temperature change at contact interfaces or at temperature reception sites in the skin. Temperatures at contact interfaces in the absence of thermal contact resistance are defined as substantial ones on the boundary between the skin and the object. However temperatures at the sites having thermal contact resistance are virtual ones that do not really exist. The maximum of the non-dimensional temperature changing rate at the receptive site decreases when thermal contact resistance becomes larger, and it corresponds exactly to the daily experience that object's temperatures are felt nearer to the body temperatures in the presence of thermal contact resistance. Finally, using the universal interface temperature in the absence of thermal contact resistance, we expressed the contact interface temperature that is felt just after touching an object that has thermal contact resistance. We propose calling this temperature "effective contact temperature". It is defined by the initial temperatures, thermal contact resistance and thermal properties of the skin and the object.

View full abstract

Clothing pressure distribution in tight-fit sportswear was simulated by using numerical computational method. Three sets of tight-fit sportswears were simulated on the basis of their mechanical properties. In addition, a 3D human body was also simulated in order to investigate its interaction with sportswear in the wearing process. Result shows that pressure increases significantly around the waist girth until it passes through body pelvis during the wearing process. Meanwhile, pressure begins to increase for other tested body locations. Based on body contour plot, we found that pressure distribution was not uniformly distributed and high-pressure zone was concentrated around the waist girth at the end of the wearing process. The simulated pressure has no significant difference (p > 0.05) with the experimental pressure measurements. Furthermore, subjective pressure comfort rating was linearly correlated with the simulation, suggesting the simulation method can provide reliable prediction in term of pressure comfort. From the tight-fit sportswear manufacturer's point of view, simulation result would help them to satisfy consumers' physiological and psychological needs in term of pressure comfort at a lower cost.

View full abstract

Wastewater sludge containing cellulose from a paper manufacturing facility was saccharized using Meicelase (cellulase from Trichoderma viride). As a result of process optimization, maximum saccharification was obtained at pH 4.0, 40deg, and 0.1 % enzyme concentration. After neutralization of hydrolysis products by acid, a Corynebacterium glutamicum inoculum and cultivation medium were added to the solution. Lactic acid and succinic acid, as major metabolic products, were synthesized in this reaction under anaerobic conditions by bubbling of carbon dioxide gas. Lactic acid was identified to be of L-form, which is useful as a starting material for the manufacture of biodegradable polymers such as poly lactic acid. Both these organic acids can also be converted to a wide variety of organic products. This production of organic acids was thus accompanied by CO2 fixation. Paper sludge saccharification and organic acid production were done in the same reactor to reduce the reaction time and simplify the overall process by using Celluzyme (cellulase from Humicola microorganism), whose optimum activity is at around pH7. This study illustrates the use of biodegradable wastes in prevention of global warming.

View full abstract

Characteristics of fading of nylon and polyester fabrics dyed with a disperse dyestuff were investigated on a radiant energy basis by exposure to monochromatic light. In this way, the fading characteristics are compiled in the form of action spectrum. Then discussion was made on an energy basis under the comparison of the effects of wavelength on the fading. One of typical disperse dyestuffs, C I Disperse Blue 165, was used in this study. The maximum peaks of fading were observed at 310 nm on polyester and 254 nm on nylon. Especially, the strong fading response on nylon is spread more widely in the wavelength ranging to about 400 nm. It is concluded that substrates greatly gave the influence on the fastness of dyed dyestuff. In this study, nylon caused lesser fastness compared with polyester.

View full abstract