How much do you know about thermal contact welding of polyvinyl chloride film

News:

During intermittent thermal contact welding, two films can be clamped with a thermal splint or other thermal disaster tools, the electrically heated welding tool can also be used to press the polyvinyl chloride film, and the heat is transmitted to the welding place through the film, so that the welding surface is softened by heat, and fusion welding occurs between the welding surfaces under pressure, this method has the following two disadvantages:

① heat is transmitted to the welding place through the film. Due to poor thermal conductivity of polyvinyl chloride, it is easy to cause overheating of the film surface, but the weld is not hot enough (Figure 4-14). (2) because the single adding tool is continuously heated, the weld cannot be cooled under pressure. When opening the splint, the film is still soft, so it is easy to attach to the splint, resulting in Weld Deformation and poor combination of appearance.

cover the heating fixture with a non-adhesive isolation film (Such as silicone oil or silicone rubber membrane. Polytetrafluoroethylene film, fabric impregnated with polytetrafluoroethylene or silicone resin) After that, the film can be prevented from attaching to the welding fixture. If the welded surface is coated with thermoplastic paint lower than the melting temperature of the film (Heat sealing paint) Because the heat sealing paint is 90 ~ It can be welded at 110 °c, and the film is not completely softened at this temperature, so that the film can be avoided from being attached to the welder. This kind of film coated with heat sealing paint is called heat sealing film, and the fusion welding effect produced by this film is called Heat Sealing (Figure 4-15).