How select PTFE tube and FEP tube ptfe tubing suppliers ? Which one to choose for PTFE and FEP depends on the user’s needs. The commonly used color of PTFE is opalescent, followed by translucent and colored, and no transparency has been invented yet. While FEP replaces the drawbacks of PTFE, the commonly used color of FEP is transparent.
In addition to color substitution, they have a slight difference in temperature resistance. PTFE is resistant to high temperatures of 260 degrees and FEP is resistant to high temperatures of 200 degrees. If a transparent tube is required and the high temperature is 260 degrees, PFA can be used instead.
Below, I will introduce the difference between PTFE and FEP.
Polytetrafluoroethylene (abbreviated as PTFE), commonly referred to as “non-stick coating” or “easy to clean materials.” This material is resistant to acids and bases and to various organic solvents and is almost insoluble in all solvents. At the same time, PTFE has the characteristics of high temperature resistance, and its friction coefficient is extremely low, so it can be used as a lubricant and it is also an ideal coating for easy cleaning of the inner layer of water pipes.
High temperature resistance: long-term use temperature of 200~260 degrees;
Low temperature resistance: still soft at -100 degrees;
Corrosion resistance: resistant to aqua regia and all organic solvents;
Weather resistance: the best aging life in plastics;
High lubrication: with the smallest coefficient of friction in plastic (0.04);
Non-tacky: has the smallest surface tension in solid materials without adhering to any substance;
Non-toxic: physiologically inert; excellent electrical properties, ideal for Class C insulation, a thick layer of newspaper can block 1500V high pressure; smoother than ice.
The friction coefficient of PTFE is extremely small, only 1/5 of that of polyethylene, which is an important feature of the perfluorocarbon surface. Moreover, since the intermolecular force of the fluorine-carbon chain is extremely low, the polytetrafluoroethylene has no stickiness. Polytetrafluoroethylene maintains excellent mechanical properties in a wide temperature range of -196 to 260 ° C. One of the characteristics of perfluorocarbon polymers is that they are not brittle at low temperatures. The PTFE has a relatively high density of 2.14-2.20 g/cm, hardly absorbs water, and has an equilibrium water absorption of less than 0.01%. Polytetrafluoroethylene is a typical soft and weak polymer. The mutual attraction between macromolecules is small, and the stiffness, hardness and strength are small, and it will be deformed under the action of long-term stress.
Poly(perchloroethylene) propylene FEP is a copolymer of tetraoxyethylene and hexafluoropropylene. The abbreviation is FEP. Polyfluoroethylene propylene FEP is a linear polymer. The molecular chain can be regarded as the main PTFE. As a result of the substitution of one fluorine atom per four carbon atoms in the chain by the CF3 group, the symmetry and regularity of the FEP molecular chain are broken compared with the polytetrafluoroethylene, and the rigidity of the molecular chain is reduced, and the flexibility is increased. The melting point of the material is reduced, the fluidity is increased, and the heat resistance is also low.
The destruction of FEP tubing regularity affects the crystallinity of the material and the crystallinity decreases. The FEP molecular chain still does not show polarity. Polyfluoroethylene propylene is a milky white translucent to transparent body with a density of 2.14 – 2.179 / cm3, only the second sub-polytetrafluoroethylene, the surface is as clean as wax, the water absorption rate does not exceed 0.01%.