Computer Controlled Chamber Measurements for Multiple Contacts for Soil-Skin Adherence from Aluminum and Carpet Surfaces

A computer-controlled mechanical chamber was used to perform multiple contacts between human cadaver skin or cotton sheet samples and soil-laden carpet or aluminum foil to measure mass soil transfer. The amount transferred was measured with an analytical balance. The contact parameters of pressure (10 to 50 kPa) and time (10 to 50 s) were varied for 760 separate multiple contact experiments, where two soil types (play sand and lawn soil) and two soil sizes (< 139.7 and >= 139.7 < 381 mu m) were used. Through parametric and non-parametric tests, this article specifically looks at the influence and interaction of these experimental parameters on the transfer of soil or sand to human skin during multiple contacts. The relationships between the amount of soil or sand that transfers for a first contact, for a second contact, and overall are also presented. On average, a second contact added an additional 8% of soil or sand to the adherence material (i.e., cloth, skin). The experimental variables of pressure, time, soil size, and soil type had less influence on the magnitude of transfer for the second contact as compared to the first contact.