Analysis and solution of common problems in blowing film (8(injection molding products)

8, the heat sealing performance of the film is poor

Reason 1: The frost line is too low, the polymer molecules are oriented, so that the performance of the film is close to the directional film, resulting in reduced heat sealing performance;

Reason 2: The blowing ratio and traction ratio are too large, and the film will have tensile orientation, which affects the heat sealing performance of the film;

solution

(1) Adjust the size of the air volume in the wind ring, make the dew point higher, and blow and pull under the melting point of the plastic as much as possible to reduce the molecular tensile orientation caused by blow and pull;

(2) The blowing ratio and traction ratio should be appropriately small, if the blowing ratio is too large, and the traction speed is too fast, the transverse and longitudinal stretching of the film is excessive, then the performance of the film will tend to be bidirectional stretching, and the heat sealing property of the film will become worse.