Mixed PTFE Powder and a High Density Multi Expanded (HDME) PTFE Yarn with Excellent Tensile Strength Using the PTFE Powder, and Methods of Preparing the Same

摘要

A mixed PTFE powder according to the present invention is prepared by the steps of preparing a PTFE mixed dispersion by dispersing MoS2, Al2O3, and Al(OH)3 in a PTFE emulsion; dehydrating the PTFE mixed dispersion by adding Na2CO3 into the PTFE mixed dispersion to form a cake type compound; preparing an ingot by drying the cake type compound for about 16 to 24 hours at the temperature of about 120 to 190° C.; and pulverizing the ingot in a 30-35 mesh vibrating net. An HDME PTFE yarn according to the present invention is prepared by the steps of preparing the mixed PTFE powder; adding kerosene of about 18 to 25 wt. % as solvent to the mixed PTFE powder and maintaining the resultant for about 40 to 50 hours at the temperature of about 30 to 50° C.; extruding the resulting mixed PTFE into the form of rod at about 70 to 90° C.; calendering the rod into the form of sheet at about 100 to 150° C., the width of the sheet being about 100 to 300 mm and the thickness about 0.3 to 0.7 mm; folding the sheet to become a three layered sheet and passing through the three layered sheet in an oven of about 250 to 270° C. at a speed of about 10 to 40 cm per second; and drawing the three-layered sheet at the temperature of about 450 to 500° C. at the speed of about 30 to 100 cm/s and the drawing ratio of about 200 to 600%.

主权项

1. A method of preparing mixed polytetrafluoroethylene (PTFE) powder for preparing a high density multi expanded (HDME) PTFE yarn with a high tensile strength, which comprises the steps of:
preparing a PTFE mixed dispersion by dispersing MoS2, Al2O3, and Al(OH)3 in PTFE emulsion having 10 to 25% by weight of solid PTFE; dehydrating the PTFE mixed dispersion by adding Na2CO3 into the PTFE mixed dispersion in order to remove the solid PTFE, MoS2, Al2O3, and Al(OH)3 from the PTFE mixed dispersion to form a cake type compound; preparing an ingot by drying the cake type compound for about 16 to 24 hours at the temperature of about 120 to 190° C.; and pulverizing the ingot in a 30-35 mesh vibrating net.