Extrusion blowing film refers to the process of continuously extruding plastic melt through a die under specific temperatures and shearing forces, then inflated by compressed air, cooled by a wind ring, and stretched by a variable-frequency traction to obtain a double-fold plastic film. This machine is mainly used for testing the feasibility of blowing film for polymer materials, as well as the gel condition within the material, the dispersion of colored pigments, controlled mixed materials, and the dispersibility of the extrudate.