Inflation molding is a processing method that melts thermoplastic resin, extrudes a parison (molten tube) from an annular die, and then inflates it with air pressure from the inside to continuously form a thin-walled tubular film. This process allows for the efficient production of wide films and sheets, or bag-like products by cutting and welding these. Its main applications are diverse, including food packaging films, agricultural mulch films, garbage bags, shopping bags, and liquid containers (bottles). It is characterized by its ability for continuous production and suitability for mass production with relatively simple equipment. Particularly, general-purpose resins such as polyethylene and polypropylene are frequently used.