摘要 |
<p>A method for extruding, stretching and sintering polytetrafluoroethylene in a single pass operation to form tubular articles of low density, low matrix tensile strength, sintered polytetrafluoroethylene and articles such as electric cable having low density, low matrix tensile strength sintered polytetrafluoroethylene insulation applied about a conductor by such method. A high reduction ratio rating polytetrafluoroethylene powder with a lubricant is extruded by an extruder (14) having a low reduction ratio, and the extrudate is heated (16) to remove the lubricant and is stretched (17) prior to sintering (18) of the polytetrafluoroethylene tube (T) which is held in its previously stretched state during sintering.</p> |