Laser welding fluoroplastics PFA, FEP laser welding pipe fittings plastic

In the field of plastic laser welding, many people pay attention to some thermoplastic materials, which are traditional and widely used in the market, but few relevant practitioners have developed the relatively difficult fluorine material welding. This article briefly introduces the laser welding of fluoroplastics. (Fluoroplastie) refers to plastics made of fluorine resin. Polytetrafluoroethylene (PTFE), tetrafluoroethylene is an ethylene copolymer (F), tetrafluoroethylene-hexafluoropropylene copolymer (F46, ethylene copolymer trifluorochloroethylene (F30), etc. The molecular structure of fluoroplastics has excellent electrical insulation properties because it contains fluorine atoms. High heat resistance. Outstanding oil resistance. Solvent resistance. Abrasion resistance. Moisture resistance and low temperature performance are good. Therefore, the superior performance makes the welding of fluorine materials particularly difficult. Due to the less development of domestic technology in this field, 80% of the fluoroplastic pipes or plates in the domestic market are currently hot press welding or hot air welding. Fluoroplastic laser welding was realized many years ago in foreign countries and has been mass-produced (PFA, FEP pipes and plates).

Current status of fluoroplastic welding technology: Traditional welding methods (hot pressing welding) PFA, FEP also have certain requirements for the welding environment, the single-head welding time cycle is about 45 minutes, the welding efficiency is low, and the power consumption is high.

We developed a fluoroplastic laser welding equipment plan in view of the current situation. At present, the plan has achieved large-scale production. The single-head welding time cycle is about 2 minutes, and the welding strength is high. The ordinary indoor environment can meet the welding requirements. In the early stages of research on PFA and FEP, major problems were encountered in welding, including blasting points, white spots, cold welds, and burns. Laser welding is divided into materials, forming, structure, and welding process parameters, rather than a welding equipment that can solve all problems. From the perspective of laser technology, the short wave we use is 10,000, which requires comprehensive process analysis capabilities and cognition of material properties. The nm laser welding product is around the band. This band has a strong laser penetration ability, which can effectively penetrate thick fluorine joints, so that the laser can play a role in light energy on the fitting surface of the pipe and the joint &The purpose of welding between the joint and the pipe body is to instantly convert heat energy into the welding melting temperature of the fluorine material. The material properties of PFA and FEP are analyzed in many aspects. Although PFA propylene and perfluoroethylene (FEP) are very similar, it can show better mechanical properties at higher temperatures. At the same time, PFA's better high temperature resistance is very similar to polytetrafluoroethylene (PTFE). Therefore, welding temperature is one of the essential control factors in welding.

The following is the material of PFA electrolytic cell pipe fittings after laser welding.

Performance indicators: 8Mpa welding appearance has no white spots, bubbles, discoloration, burns, and the pulse test under air pressure lasts for 5 minutes.