A simple apparatus and technique are described for measuring contact angles of liquids on small-denier fibers. This technique is based on the level-surface method and can be used to obtain either advancing or receding contact angles. Contact angles determined by this method are accurate and precise and the apparatus is inexpensive, rugged, easy to operate, and suitable for routine work.

A study was made of the desorption of carbon-14 labeled fatty acid, fatty alcohol, hydrocarbon, triglyeeride, and hydrophobic and hydrophilic particulate carbon from cellulose, Nylon, and polyethylene terephthalate films into aqueous solutions of cationic, anionic, and nonionic detergents. Use of the polymers in film form as endwindows of a Geiger counter and labeling of the soils with radioactive carbon-14 allowed continuous monitoring of the amount of sorbed material and normalized the usual complication of fiber and fabric geometry so that results obtained with different polymers could be directly compared.An excellent correlation was established between fatty soil removal from polyethylene terephthalate film and fabric surfaces; thus results obtained with film substrates have practical significance. Wash variables were carefully controlled and were altered one at a time to learn their effect on the soil-removal process. Results are discussed in terms of the possible mechanisms of soil removal.

Princen's modification of Vonnegut's rotating drop procedure for measuring inter‐facial tension between low viscosity liquids has been adapted for use with pairs of liquid polymers with viscosities up to 5000 poise. Extrapolation to infinite time of results obtained with 10–20 min of rotation provided steady state data as indicated by its corre‐spondence with results reported from other techniques. An adaptation of this procedure was also found useful for determining surface tension values of molten polymers at temperatures up to 290°C. Reductions of 60–70% in interfacial tension between viscous samples of a polydimethylsiloxane and a copolyether were accomplished by addition of 1–2% of amphi‐pathic or polar compounds such as polydimethylsiloxane‐polyoxyethylene copolymers and carboxyl‐substituted polydimethylsiloxanes. A linear reduction in interfacial tension with a logarithmic increase of additive concentration was noted.

A computer model is described that yielded results consistent with Instron stress- strain curves for both the machine and cross directions of various polyester, thermally point-bonded, nonwoven fabrics. Fiber and bond tensile properties, bond layout, fabric density, and fiber curl and orientation were entered into the computer, and the program followed the evolution of the fabric system as it was distorted under stress.

A study was made of the transfer of compounds, similar to those found in human sebum, from cellulose to polyethylene terephthalate films and the deposition of these soils on polymer films from surfactant and aqueous solutions. The polymer films were used as end windows of a Geiger tube. The soils were labeled with radioactive 14 carbon so that the amount of sorbed material could be continuously monitored. The effect of variables such as detergent type, detergent concentration, temperature, sorption time, addition of sodium carboxymethylcellulose, and soil concentration on deposition have been investigated. Results are discussed in terms of possible mechanisms for soil deposition and changes in wash conditions that should reduce deposition on man-made polymers.