Step 1: Make the preforms

The PTFE powder is stored in pouring containers, from where it is withdrawn by small coned pots. With the help of these coned pots the operator fills the preform press. This press is pricipally a long cylinder which is in the center equipped with a mandrel bar. Correspondent to the mandrel bar a round cavity develops in the middle of the preform. After the PTFE material has carefully and without pressure marks been filled into the cylinder, a piston compresses the material with a pre-defined sequence so that a preform is created. This can be unloaded with the help of a plexiglas tube. Again the operators have to be very careful during this process in order not to break the highly instable preforms.