Design and Fabrication of PTFE Tubes

PTFE is Poly Tetra Fluoro Ethylene a polymer that was discovered by Mr.Plunkett at Dupont.

PTFE exists in powdered form and do not melt and flow. When heated to temperatures above 350-degree Celsius PTFE it transforms from solid to the gas phase. Because PTFE does not melt flow it is not possible to injection mold it. PTFE tube can, however, be changed into a molded, ram extruded or paste extruded. PTFE Tubing is manufactured with the help of paste extrusion. It is flexible. It is possible to manufacture PTFE tubing which is as small as 0.3 mm to max 100 mm and wall thickness as small as 0.1 mm to 2 mm. PTFE tubing service temperature varies from -60 to + 260-degree Celsius.

PTFE tubing is popular because of its flexibility because it offers chemical resistance in commercially available polymers and also because of its non-stick quality (in fact it is one of the most slippery substances known.

 Some standard metric sizes of PTFE tubes are as follows  2×4, 4×6, 6×8 & 8×10 while some of the standard metric sizes are as follows 1/16×1/8, 1/8×3/16, 3/16×1/4, 1/4×5/16, 3/8×1/2″.

Small sizes of PTFE tubing are used for Chromatography, spectrometer & Titrators while larges sizes are utilized for sampling lines, pneumatic supply and as electrical, heat or chemical insulation. The pressure rating of PTFE tubing depends a lot on the IDxOD of the tubing.

PTFE tubing is fitted to equipment and machines that use compression fittings such as connector and adapters. It is important that the dimension of ID & OD of the PTFE tubing be very tight so there is no leakage at the end fitting. The fittings are manufactured in various materials such as stainless steel grades SS304 or SS316 and also using PTFE material. PTFE fitting is used in conjunction with PTFE tubing in applications where metal fittings are not allowed. 

 It’s important to note that leakages happen because of incorrect cutting of the PTFE tubing before it is inserted in the fitting by PTFE tubing manufacturers. One needs special cutters for a straight cut.

PTFE tubing is manufactured in continuous lengths, which ranges from 25-250 meters or more depending on the IDxOD of the PTFE tubing. PTFE tubing is also a part of coils or wound on plastic or wooden spools.

PTFE tubing has a milky opaque or milky translucent appearance and this appearance depends on the type of PTFE raw material that is used for the manufacturing use. PTFE tubing can also be manufactured in varied colors such as red, black, blue, green, yellow. In addition, PTFE tubing comes with a color stripe for identification.

PTFE tubing is flexible and you can easily bend it.  Care should be taken however to ensure the bend radius is not in any way less than the bend radius kept separately for the IDxOD of the PTFE tubing.