1. The external cooling method is the first way to produce a cooling air around the ring by releasing a cooling ring on a circular ring along the extrusion direction and the outer surface of the film bubble. Inside the cooling ring, the upper air is expelled at a faster rate than the lower. This ensures that the shape of the bubble is consistent with the air cooling ring, which increases the average velocity of the air and thus enhances the heat transfer.
2. Internal cooling directly through the film bubble heat to achieve cooling purposes. Because the air velocity in the film bubble is relatively low and has no regularity, the external cooling is dominant. Film Blowing machine blow molding process, to ensure that the quality of membrane products, film formation must consider the stability of film bubble before the effective control of product eligibility rate. Blown film blowing machine film production, in addition to the film bubble constraints, but also to consider the film blowing machine cooling system. A perfect cooling system needs the reasonable configuration and stability of the film blowing machine.