The stainless steel thermos cup is double-layered, which is divided into an inner container and an outer container. After it is finished, the inner and outer containers are welded to form a whole, and then the air between the inner and outer tubes is pumped out and the pumped hole is sealed with special materials (equivalent to the sharp part on the glass bottle container).

the general processing flow is as follows: Liner processing is also a common hardware processing: the main processes are as follows: making a long tube (round tube)-cutting a short tube (round tube)-rising water (expanding the shape, sealing the two ends of the tube, filling water in the middle to expand outwards, and deforming the round tube to form close to the mold cavity)-beam mouth (size and shape are further in place)-flat mouth-flat bottom (cutting off the leftover material)-

I hope I can help you.