SOLID POLYPROPYLENE INSULATION FOR WIRE AND CABLE APPLICATIONS,

Although polypropylene is not subject to environmental stress cracking, several compounds commonly used in the wire and cable industry were found that have a deleterious affect on polypropylene. For example, polypropylene will embrittle rapidly when in contact with polybutenes at elevated temperatures. Several basic applications were found where polypropylene can be used to advantage. Because of its excellent resistance to high temperature deformation and its excellent electrical properties, polypropylene was used to replace rubber insulation and thus miniaturized some constructions. The superior abrasion resistance of polypropylene over polyethylene permitted miniaturization and manufacturing in longer lengths some cables formerly insulated with polyethylene. The combination of excellent processing and abrasion resistance properties were used to replace nylon insulation with polypropylene and take advantage of the latters superior electrical properties. The addition of stabilizers to resist copper catalyzed oxidation is a major break through. It is anticipated that with the added stabilizer polypropylene will become more widely accepted as an insulating material and that a market for polypropylene in the wire and cable industry will develop in the next few years. Author