| abstract |
PURPOSE: To increase the hardwearing properties and the durability by mixing a specified amount of the burnt PTFE (polytetrafluoroethylene) powder featuring the particle diameter within the specified range with the unburnt PTFE powder and then giving the burning to secure the specific porosity. n CONSTITUTION: Burnt powder (also available with regenerated powder) 1W 30pts.wt. of PTFE featuring the grain size of 0.5W200μ plus liquid lubricant (paraffin, etc.) 30pts.wt. are mixed evenly with unburnt powder 100pts.wt. of PTFE, and then undergoes the extrusion molding after the preform to be formed into the round rod and then the sheet form through the rolling. The sheet thus formed is then soaked into the trichloroethylene to remove the lubricant. Then the orientation is given for the burining under orientation. As a result, the sliding sheet featuring the porosity of 20W85% and suited to the inner wall or the like of the magnetic tape cassette can be obtained. Furthermore, the saving of the resources and the cost reduction can be realized by reusing the burning scrap, the molding scrap of the burnt products and the like. n COPYRIGHT: (C)1980,JPO&Japio |