Marlex 50 polyethylene is a new plastic recently developed by Phillips Petroleum Company, Bartlesville, Okla. It is significantly different in a number of important respects from the familiar "squeeze-bottle" polyethylene. The new plastic is produced from ethylene gas in a carrier solution by catalytic action at relatively low pressures. After separation from catalyst and solvent, the resulting solid product has the same appearance as conventional polyethylene. However, the new plastic has a highly crystalline molecular structure, affording an unusually high softening temperature and high tensile strength as compared with conventional material. By hot-melt extrusion at 400 to 600 F through an orifice, Marlex 50 polyethylene is readily made into monofilament. Cloth made from this fiber is impervious to water and possesses outstanding chemical resistance. It has a softening temperature of 260 F, allowing it to be sterilized in an autoclave with no damage. The tensile strength of Marlex monofilament is