High-frequency welding is a processing technology that applies a high-frequency electric field to thermoplastic resin materials, generating heat from within the material due to dielectric loss, thereby melting and joining them. It is primarily applied to polar polymer materials such as PVC (polyvinyl chloride), PU (polyurethane), and EVA. By using molds and a high-frequency power supply, clamping the materials, applying pressure, and irradiating them with high-frequency waves, strong welded joints are formed in a short time. A key feature is that it does not require adhesives and enables joining with excellent airtightness and watertightness. It is used for joining films, sheets, and tubes in a wide range of fields, including medical infusion bags, automotive interior materials, tents, tarpaulins, packaging materials, and stationery. Uniform heating achieves a beautiful finish and high productivity.