For PTFE products with complex shapes and special purposes, it is difficult to manufacture by cold pressing. Simple products such as rods, tubes, plates, etc. can only be stretched, heated and expanded, heated and calendered, hot vacuum formed, hot blow molded, and machined with PTFE. In addition to the one-time processing described above, there are many secondary processing methods. The secondary processing of PTFE refers to the semi-finished products of PTFE: PTFE sheet, film, tube, rod, etc., are made of various specifications and shapes of PTFE products by thermal deformation, welding, turning, compounding and other processing techniques.

(1) PTFE thermal vacuum forming

Thermal vacuum forming of PTFE is a processing process developed in recent years to process a heated PTFE film into a desired shape under vacuum. The vacuum forming temperature of PTFE is 350 ° C. In this way, thin-walled, complex-shaped PTFE products can be produced. The resulting article had good dimensional stability with a shrinkage of 2% at 260 °C. The surface of the product is smooth and does not require processing. It is especially suitable for making composite parts with other materials.

(2) PTFE hot press forming

The technology is that the PTFE semi-finished product is deformed under heat and pressure and cooled to form a desired shape product. The technology was developed to make a 5 to 10 mm PTFE sheet (or Teflon and aluminum-plastic composite panel) into a cup-shaped product under a pressure of 103 KPa.

(3) PTFE hot blow molding

The hot blow molded PTFE container is dimensionally stable at 250 ° C, the wall thickness is relatively uniform, light weight and good transparency. This technology can also process complex shaped cylinders such as Teflon bellows.

(4) PTFE winding forming

Winding forming is a method for preparing PTFE tubes and equipment linings. Due to the flexible processing method, it is easy to adapt to the requirements of use, and is suitable for chemical anti-corrosion linings and special structural parts. The molding method is that the clean PTFE tape is evenly wound on the mold, and then sintered under a certain pressure for a certain period of time, so that the PTFE macromolecules between the bands are mutually diffused and integrated. It is characterized by integral one-time sintering molding, no local weak points of welding, saving raw materials, ensuring strength, not only uniform, but also thickness.