1.PTFE products hardness is low, the general hardness of pure tetrafluoroethylene products is about 55 Shore, which makes tetrafluoroethylene products in pressure deformation resistance, can not withstand too much pressure, such as made of gaskets, if screwed very tight, it is easy to make it plastic deformation or cold flow, which is poor creep resistance, so the need to modify treatment, add some fillers to enhance performance;

2, the wear resistance of PTFE is not ideal, the use of PTFE products friction coefficient is very small characteristics of the application of more widely, but at the same time in the movement of products and dual parts, wear resistance is insufficient, poor mechanical strength, rigidity is not enough, such as made of oil-free lubrication bearings, if the speed is fast, it must often replace the bearing, affecting the normal use, which also needs to be improved by adding wear-resistant materials;

3 PTFE material surface energy is poor, so that it has non-stick characteristics with other substances, although in textile, glue, fluid and other methods have a great help, but also limited its application in industry, then we have to give it surface sodium treatment, so that it can bond with other materials;

4. Polytetrafluoroethylene resin is mainly molded products, the fluidity of resin powder is poor, and many parts are often made into semi-finished products by molding and extrusion, and then finished products are processed by fine car. Polytetrafluoroethylene melt viscosity is high, even if the heating temperature rises to the melting point temperature of the decomposition temperature, or can not flow, and other thermoplastics can not be processed by forming methods. Almost every molded part needs a set of molds, which makes the processing cost rise, and the price of PTFE raw materials is high, and the total cost is more expensive. The processing of tetrafluoride is complicated and its application range is limited.

5. The coefficient of thermal expansion of tetrafluorofluoride is too large, its linear expansion coefficient changes irregularly with the change of temperature, and the cold and hot contraction changes greatly, resulting in its processing dimensional stability is not ideal. Sintered cooling or machine tool processing objects, with the change of ambient temperature will still have a significant change, which is not entirely due to the reason of internal stress but the linear expansion coefficient is too large factors. For example, when applied to anti-corrosion equipment, as a container lining it is inconsistent with the linear expansion coefficient of the metal shell, in the fluid heat and cold changes and negative pressure operating conditions, due to the defects of technical molding, it and the container adhere together, so the PTFE lining is prone to deformation, delamination, internal dented and other phenomena, so at present, Pure PTFE is not suitable for precision parts.

6. Ptfe is usually a safe and non-toxic product, but in the ultra-high temperature state, such as at more than 380 high temperature heating will release highly toxic ions, which requires attention to open flame, welding or high temperature heating ventilation safety and prevention.
7. Although the electrical characteristics of PTFE are very good, there is the smallest dielectric constant in solid materials, dissipation factor, high frequency, volume and surface resistance show the maximum that has the best insulation performance, but polytetrafluoroethylene depends on sintering products, itself with very high static electricity, many occasions are not allowed to use, then we need to add antistatic materials for this situation, Become an antistatic product.
8. Polytetrafluoroethylene parts are molded, with high pressure and good tightness, high density, and small shrinkage of sintering size. If the pressure is light, the size shrinkage during cooling is large, and it is an irregular contraction. Polytetrafluoroethylene parts require a large tolerance range, can not be the same as iron, can be precision machining. The change in thermal expansion is 10 times greater than that of iron. Many people mark tolerances according to the requirements of steel parts, so that after the actual processing, cooling shrinkage or cold and heat changes may go out of the tolerance range. The PTFE plate processed by direct molding and sintering is also relatively large, such as the processing of PTFE plate: the specification is 10mm thick, and the thickness tolerance is (+1.00, -0.50) according to the industry standard;
9. Ptfe products are inert, so they do not stick to any objects. However, we often encounter bonding or welding problems in use, among which bonding methods are: discharge treatment and alkali metal solution treatment, which can make tetrafluoroparts and other materials bond. The discharge method is to put the polytetrafluoroethylene parts in the plasma generator or glow discharge tube by vacuum, through a trace inert gas to activate it, and then react with the surface of the polytetrafluoroethylene parts. There are many kinds of alkaline metal solution treatment processes, the most commonly used is naphthalen-sodium complex liquefaction chemical treatment. However, no matter how the bond, the adhesive used has temperature resistance, bond strength, etc., the firmness between the tetrafluoroethylene parts needs to be improved; The use of thermal welding treatment can also solve a part of the four interconnected, but the electrode material and the PTFE material are generally slightly different, their welding firmness is not enough, but also need to be improved.
10. The thermal conductivity of PTFE is low, the thermal conductivity is poor, and the heat dissipation is slow, just like when the surface of a thick plate feels a little bit warm through the hand, the inside of the plate is relatively high, and the temperature changes, the material will shrink. Due to slow heat dissipation, it affects the use of thermal conductivity materials as thick wall products such as bearings, and of course, the addition of filling materials still has a certain effect.