The Raw Material
Only emulsion polymers are used for the production of PTFE using paste extrusion. These powders have very good flowing properties. We only use raw materials from Dyneon® and DuPont® (Dyneon TF2071 / TF2073 or TFM2001 (mod.) DuPont® 6cn or T62 (mod.).
When preparing the material, the paste powder is wetted by mixing with organic liquids - the so-called lubricant - in defined percentages and rolled for uniform distribution. The material is prepared in special rooms, using specialized work wear, tools and equipment, which ensure the required cleanliness. The mixture then goes through a ripening process whereby the lubricant completely diffuses into the PTFE grains.
Before extrusion, the prepared paste is compressed in a pre-press at a ratio of about 3:1. In order to expel all air, this compression takes some time. The resultant preform is held under pressure for a defined time and subsequently relieved slowly to prevent cracking.
For paste extrusion, hydraulically operated presses are normally used, with a constant feed rate independent of the extrusion pressure. The constant feed rate is vital for the subsequent sintering process. Depending on its size, the extruder is loaded with one or more preforms. To produce strands, the preform is pressed through a conical nozzle, into its finished shape. In the production of tubes or hoses, a mandrel is fitted in the nozzle. This determines the internal diameter of the tube.
The sintering of PTFE is a two-stage process. In the first step, the so-called drying phase, the lubricant added in the preparation phase is removed from the extrudate in a drying zone. In the second step, the pure, moulded PTFE is sintered.
The Final Product
As an end product, you get PTFE tubing of the highest quality and purity, in various diameters and degrees of transparency. We recommend using a 100% pure virgin PTFE. Only in this way can the outstanding properties of PTFE be guaranteed.
Colours, Colours, Colours
Of course, we supply PTFE hoses in a variety of colours and with different fillers (coal, Printex, etc.). However, we point out that whereas the addition of fillers can improve certain mechanical, chemical and physical properties, it can also adversely affect others.