PTFE is known as the "Plastic King" and has a very high chemical stability. The lining equipment used to process it is resistant to almost all strong acids, strong oxidants, reducing agents and various organic solvents, and is also suitable for a wide temperature range. Through certain processing improvements, the use of ≤2.5 MPa at higher pressures can be achieved. PTFE lining equipment has been widely used in chemical production enterprises with high corrosion resistance requirements.

    In order to adapt to complex conditions such as pressure and temperature, the PTFE lining structure is usually improved in a targeted manner. For example, adding a metal mesh to the PTFE layer can reduce the thermal expansion and cooling of the PTFE lining. Shrinkage, improve the ability to withstand negative pressure; add perfluoroethylene propylene to the tetrafluoro layer, improve temperature resistance and deformation resistance, and so on.

    PTFE lining can be divided into two types: loose lining and tight lining. The loose lining is generally wrapped around the corresponding abrasive tool, sintered on the abrasive tool, and then put into the equipment after demoulding, and completed after the burring; the characteristic is between the steel body of the equipment and the lining of the PTFE sheet. There is a gap; it is suitable for conveying pipes and reaction cylinders with small temperature variation and positive pressure; the advantages are simple process, low investment and fast forming; the disadvantage is that in the environment with large negative pressure and temperature change, it is easy to cause aggregation. Problems such as ruthenium, bubbling, and cracking of the flange of the PTFE sheet; in the spark detection, the vacuum on some PTFE sheets may not be detected.

    The tight lining is a surface treated PTFE sheet, which is bonded to the inner wall of the equipment steel by a special adhesive; the characteristic is that the steel body of the equipment is tightly bonded to the lining PTFE sheet without gap; It is suitable for environments with frequent changes in temperature and pressure and large variations; the advantages are: 1. There is no leakage point in EDM detection; 2. It can be used to lining the larger equipment and reduce the sealing point; 3. Not subject to The shape of the device can be limited to a variety of devices, such as squares. The disadvantage is that the surface treatment of the inner wall of the equipment steel and the quality of the binder determine the stability of the lining.

    Due to the inherent defects of the loose lining process, many problems have arisen after application to production. The tight lining equipment can be spliced by the lining of the slab, and the spliced gap is welded into a whole, so that it is no longer constrained by the shape of the equipment. As early as in the 1980s, foreign countries replaced the loose lining with a tight lining process. In recent years, many domestic manufacturers have developed their own tight lining equipment technology by absorbing foreign tight lining technology. At present, China's PTFE lining process technology has basically reached the international advanced level.