| 摘要 |
PURPOSE:To enable to continuously coat wire rod with a tetrafluoroethylene resin (PTFE) on an industrial scale, by a method wherein a preform consisting of PTFE and a lubricant is loaded in a cylinder of a ram-type extruder, and pressure is exerted on the preform while drawing out a wire rod through a die of the extruder. CONSTITUTION:The preform 7 is formed in a cylindrical shape with a penetrating hole from a mixture of particulate PTFE and a lubricant for imparting moldability to PTFE. In the extruder 3 in which the preform 7 is loaded, the preform 7 is pressed by a plunger 6 while drawing out a wire form conductor 2 introduced through a hole part 6b of the plunger 6 to the die 5 side at a constant velocity, whereby the mixture is extruded with an outside diameter restricted by the diameter of the die 5. Accordingly, the conductor 2 is coated with the mixture of PTFE and the lubricant. The coated wire 11 thus produced is passed through three drying furnaces 13 to remove by heating the lubricant contained in the coating, and is introduced into a firing furnace 14 to fire PTFE. |
