PTFE mainly has the most common molding technologies such as molding, hydraulic pressure, pressing, extrusion, spraying, bonding, welding and winding. The first five are directly processed into products using PTFE resin, and the last three are processed into various products using PTFE plastic plates or thin strips. In addition, there are molding methods such as rolling and thermoforming. Now briefly introduce the various molding methods.

01 Molding method

Most of the compression molding uses suspension resin. When manufacturing thin plates with a thickness of less than 1.5mm, dispersing resin is used. Its process: resin-sieving (suspended resin is crushed, loosened, and sieved through a 20 mesh sieve)-press (the PTFE powder loaded into the mold is compacted by the press under the pressure of 20-235Mpa) -Sintering (sintering in a sintering furnace at a temperature of 370 ° C to 380 ° C)-Molded product (after cooling and setting in the mold or in a free state, it becomes the required plate, rod, tube, gasket and filler product, etc.).

02 Hydraulic method

The hydraulic method, also known as the isostatic method or the rubber bag method, is a special method for making PTFE products. It is to apply hydraulic pressure to the rubber bag to expand the PTFE resin toward the mold, sinter it into a product after compaction, and perform basic operations. The process is: put the rubber bag in the outer mold-connect the water pump, fill the tap water to make the rubber bag swell into a cylindrical shape-the resin is evenly added between the bag and the outer mold-close the mold-continue to fill the water and gradually increase the water pressure, When the pressure reaches 12-13Mpa, hold the water for 30 minutes, then release the water-reduce the pressure, remove the mold, sinter, and cool down to make the appearance of smooth and clean.

03 Push method

Pressing is also called pasty extrusion molding. A 20-30 mesh sieved dispersion resin and organic liquid (toluene, petroleum ether, solvent oil, etc.) are formulated into a 1: 5 pasty mixture, which is pre-pressed into a thick-walled cylinder. The blank is put into the barrel of the press, heated, pressed with a plunger, dried, sintered at a temperature of 360-380 ° C, and cooled to obtain a strong push tube, rod and other products.

04 extrusion method

Extrusion molding can be divided into screw extrusion and plunger extrusion. The pre-sintered resin after sieving and sieving is added to the barrel, and the raw material is compacted and conveyed to the extrusion through the rotation of the screw or the reciprocating push of the plunger. In the machine, it is continuously extruded, sintered and cooled at 360-400 ℃ to form various tube and rod products.

05 spray method

The spraying method includes two processes: sintering and filming after PTFE emulsion spraying and direct spraying and filming with PTFE resin powder plasma.