PVDC film blowing shrinkage rate control method

The invention relates to a PVDC (Polyvinyl Dichloride) blown film shrinkage rate control method which comprises the following steps: melt extrusion: setting the extrusion amount of PVDC blown films with different specifications to be unchanged; different widths of the PVDC blown film are controlled by controlling the water temperature of the cold water tank, and the blowing temperature of the PVDC blown film is controlled to be consistent by controlling the water temperature of the hot water tank; the thickness of the PVDC blown film is controlled to be consistent by controlling the rotating speed of a front traction roller; and the shrinking percentage levels of PVDC blown films with different specifications are controlled to be equivalent by controlling the working temperature of the drying oven and the traction tension of the rear traction roller. According to the method, a set of shrinkage rate mathematical relationship close to reality is summarized through tests, exploration and conclusion, complicated