What is the Core Process of a Teflon Wire Extruder?

The core process for a Teflon wire extruder involves paste/powder extrusion, which consists of mixing the Teflon resin with a lubricant and preforming it into a slug. This preform is then pushed through a die and over a wire, after which the coated wire goes through heating ovens to evaporate the lubricant (drying) and then to sinter (fuse) the Teflon coating, followed by cooling, winding, and take-up.

1. Preparation
· Sieving: Teflon powder is sieved to ensure uniform particle size. 
· Mixing: The powder is mixed with a liquid lubricant, such as naphtha, to form a paste. 
· Preforming: The paste is compressed into a cylindrical preform or slug under light pressure. 

2. Extrusion and Drying
· Extrusion: The preform is placed in the extruder cylinder and pushed through a die with a wire running through the center. This extrudes the Teflon over the wire as it is coated. The newly coated wire is sometimes called "green" and is susceptible to deformation.
· Drying: The "green" wire passes through a low-temperature oven to evaporate the liquid lubricant. 

 3. Sintering and Cooling
· Sintering:
The wire is then heated in a second, high-temperature oven to a temperature between 350 and 750°C. This fuses the polymer particles into a solid, continuous coating. 
· Cooling: After sintering, the wire is cooled, often with a water bath, to solidify the insulation and set its dimensions. 

4. Finishing and Take-up
· Capstan and Tension Control: A capstan is used to control the speed and tension of the wire as it moves through the line. 
· Take-up: The finished, coated wire is wound onto a spool or reel for storage, packaging, and subsequent testing.