The DT type High Frequency Plastic welding machine is made especially for Canvas Welding. This machine has proceed a special treatment to deal with high-frequency interfere with electronic devices such as television broadcasts; it is suitable for Canvas shops which are located in residential area. The principle of the high-frequency plastic welding machine is particular. The heating method is by heated the molecules inside the product, so that the materials are uniformly heated. After welding process, the molecular structure of welding point became stronger, absolutely waterproof and cannot be torn by hand.