Effect of Fabric Characteristics and Drum Rotation Speeds on the Movements and Drying Performances of Clothes in a Tumble Dryer

The movements of clothes in a tumble dryer were analyzed according to fabric characteristics and drum rotation speeds, along with their effects on drying performances. Furthermore, regression models of the fabric characteristics in relation to their movements and drying performances were developed. When the drum rotation speed was increased from 35 to 50 rpm, dynamic movements were observed at the center of the drum, and the movement ranges continued to expand. However, at 65 rpm, the rotation of clothes occurred primarily along the drum wall. Based on these observations, clothing movements were categorized into four patterns. In addition, the clothing movements in the dryer were found to be completely different from those in the washer owing to the differences in their internal environment (i.e., the drum and water, respectively). Therefore, seven movement indices were newly introduced for the dryer. Drying rates, shrinkages and grades for the smoothness appearance of the clothes tended to decrease in the order of drum rotation speed (i.e., 50 > 35 > 65 rpm), with the exception of polyester shirts. Typically, the cotton samples exhibited lower drying rates and smoothness appearance grades with higher shrinkage rates than the polyester samples. Moreover, compared to dress shirts, T-shirts showed higher shrinkage rates and smoothness appearance grades. Although the standard moisture regain of the fabric significantly affected the drying rate, shrinkage was highly influenced by the elongation and standard deviation of the moving distance from the center of the sample between frames. The smoothness grade was significantly affected by the number of tumbles.