Hot air welding is a process used to join thermoplastic materials by applying heat. A hot air welder blows heated air onto the surfaces of the materials, softening them until they can be fused together. This technique is commonly used in industries such as construction, automotive, and textiles. The process requires careful control of temperature and speed to ensure a strong bond without damaging the materials. Hot air welding is often used for creating seams in products like tarpaulins, inflatable structures, and plastic films, making it a versatile method for various applications.