PTFE welded components

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This post was last edited by goldliyang on 2019-8-10 at 16:48. With the advancement of anti-corrosion technology, new anti-corrosion materials continue to be developed. Among them, polytetrafluoroethylene (PTFE) has gained increasing attention due to its excellent chemical stability, high temperature resistance, and resistance to chemical corrosion; it is thus an ideal choice as an anti-corrosion material and one of the most important materials in use today. As a special corrosion-resistant material, PTFE is mainly used in the form of processed parts in everyday applications. However, due to the extremely high chemical stability and non-stick properties of PTFE material itself, its bonding and welding are rather difficult, which has long been a major challenge in the application of PTFE materials. After resolving the bonding and welding issues associated with PTFE, its use as an anti-corrosion material in industrial production will become even more widespread. Jiangsu Fluorin Fluid Technology Co., Ltd. has contributed to this development. 1. For any solid to be bonded, it must be able to be wetted by the adhesive and possess adhesiveness. PTFE materials have a low surface energy, a large contact angle with liquids, poor wettability, and weak adhesion properties; therefore, their adhesion to other substances is generally poor, and they require special treatment before they can be bonded. 2. Hot air welding: This method is commonly used for PTFE components with complex geometric shapes, and its welding strength is slightly lower than that of hot pressing welding. Depending on the strength requirements of the welded joint and the process needs, there are lap welding, butt welding, and reinforced butt welding. In general, an inert gas is used as a medium to heat the temperature to 420–480°C, thereby melting the PTFE welding surfaces and simultaneously fusing the electrodes or the welded components together. ⑴Before welding, the surfaces to be bonded should be cleaned with acetone or ethanol solution and then dried; (2) If butt welding or enhanced butt welding is to be used, the welding surfaces of the workpieces need to be prepared with grooves, typically in a “V” or “X” shape; (3) A fusible polytetrafluoroethylene electrode should be used, as it possesses fusibility and good melt fluidity, allowing it to effectively wet the PTFE surface; (4) When moving the electrode, it should be kept perpendicular to the welding surface and in contact with it. The welding torch should be positioned at a 45° angle relative to the workpiece, at a distance of 5–10 mm from the welding surface. The speed at which the electrode is moved should be 60–80 mm/min, while the welding air pressure should be between 0.098 and 0.294 MPa; (5) An inert gas is used as a medium to heat the surfaces to 420–480°C, thereby melting the PTFE surfaces and fusing the electrodes together. After cooling, the weld seam is mechanically processed to the desired shape. With the rapid development of modern industry, the issue of material corrosion prevention has attracted widespread attention around the world. In numerous practices related to corrosion prevention, PTFE is widely used by various companies due to its unique properties. It is one of the materials most commonly employed in industrial corrosion protection, offering the best results. With the advancement of research methods and manufacturing processes, new adhesives, bonding techniques, and welding methods suitable for bonding and welding PTFE materials will continue to emerge. Once the problems related to bonding and welding are resolved, PTFE-manufactured components will surely play a greater role in the field of corrosion resistance.