Three basic types of household washing machines were compared one another with respect to the soil removal, the rinsing effectiveness, the tangle-free action, the gentleness of action, the energy consumption in order to establish the standards which meet the consumer satisfaction. A constant amount of a low-foaming detergent was used, providing a constant ratio of detergent to washing load. In this study, drum-type washers exhibited the greatest soil removal, tangle-free action, gentleness of action, and stain removal. In addition, drum-type washers used the least amount of water. Pulsator washers, on the other hand, showed excellent rinsing effectiveness and stain removal. Agitator types rated highest in electricity consumption in case of wash with cold water. Drum type washers, however, consumed the greatest amount of electricity when the heater was in operation.

View full abstract

Oily substances with ester bonds and fatty acids in n-hexane solution were determined by an attenuated total reflection (ATR) /FT-IR. In this experiment, the solution was dropped on an internal reflection element (IRE) and the residue on IRE was analyzed after n-hexane was evaporated. When the amount of the residue on IRE was from 0.5 to 5μg, triolein and oleic acid could be determined from the absorbance data of peaks close to 1745 cm^-1and 1710 cm^-1, respectively. Though various fatty acids exist in the soil from the human body, they could be determined using the calibration curve for oleic acid. When the amount of interfering substances was small, the influence on the determination of triolein and oleic acid could be neglected.
ATR/FT-IR analysis was compared with gravimetric analysis on the determination of oily substances extracted from an undershirt used for 6 months. As a result, when oily substances with ester bonds were determined using the calibration curve for a mixture of 65% triolein and 35% palmitic acid n-hexadecyl ester, the ATR/FT-IR analysis was nearly equal to the gravimetric analysis. This method enables a speedy and simple determination of oily substances with ester bonds and fatty acids from the human body on fabrics.

View full abstract