High-frequency welding is a technology that utilizes dielectric heating by a high-frequency electric field to generate heat and melt thermoplastic resin materials from within, thereby joining them. It is primarily used for welding sheets and films made of materials such as PVC, PU, and EVA, allowing for the formation of strong, airtight, and watertight joints in a short time without the need for adhesives. The process involves pressurizing, welding, and cooling the material using a mold heated by electric power supplied from a high-frequency oscillator, making it possible to join complex shapes. Its uniform heating and high productivity are utilized in a wide range of fields, including medical infusion bags, tents, automotive interior materials, waterproof sheets, and stationery.