Introduction of PTFE welding process

Write By: sukoptfe Published In: PTFE Polymer Created Date: 2019-02-20 Hits: 4469

Steel-lined PTFE equipment usually has a discharge port, a mirror, etc. in the production, but how to successfully apply this type of nozzle to the complicated head intersection line, of course, our answer is welding So how do you weld it? How to control the temperature of PTFE welding? Let us tell you one by one.

 

1. Production of Teflon head nozzle

      To weld the Teflon nozzle to the head, we should first make a PTFE head nozzle, according to the inner diameter of the steel head nozzle and use a powder molding process to make the nozzle at a certain ratio, at 380 plus or minus Sintering is carried out at 5 degrees Celsius for 8 hours. After the completion, the sintered nozzle is turned to the appropriate size with a lathe. At this point, congratulations on the production of the Teflon nozzle are complete.

2, the opening of the PTFE head

      Put the drawn head into the steel head, and use the principle of light transmission to accurately open it. Note that the Teflon head must be matched with the steel head when it is placed, otherwise the drum will be easy to appear when finalizing the equipment. Potential hazards such as rupture.

3. Welding of Teflon nozzle

      We can carry out the welding of PTFE through the first two steps. Here we know that there are two ways of welding (hot pressure welding, hot air welding).

(1) Hot pressure welding

      Before the hot pressure welding is carried out, we need to know the necessary theoretical knowledge. Thermal pressure welding is a kind of hot-melt welding that provides sufficient heat and sufficient pressure. Here we must ensure that the welding interface temperature must reach 673.15K, the pressure reaches 1-2MPa, so in order to ensure the welding progress, we need to do the corresponding mold to ensure the successful completion of the hot pressure welding. After all is completed, the FEP film can be welded by pressurizing and heating the interface between the nozzle and the head.

(2) hot air welding

      The same hot-air welding of PTFE is also a kind of hot-melt welding. It is much simpler than hot-pressure welding. It does not need so many molds. After the nozzle is placed, the PFA electrode and the hot air welding gun higher than 713K are used first. Preheating is then carried out on the weld for continuous welding.

Note: Whether the temperature of hot-pressure welding or hot-air welding is higher than the melting point of polytetrafluoroethylene, PTFE may be cracked at this temperature, and highly toxic gases such as perfluoroisobutylene may be generated during the cracking process. Therefore, the welding should be carried out in a ventilated environment. When the conditions are not allowed, such as lining the PTFE tank, the wind must be blown by the fan to ensure the air flow and at the same time wear a gas mask to ensure safety.