About the manufacturing method of pvc films
(1) Calendering method: one of the main methods for the production of PVC films and sheets. The soft pvc films (sheet) and rigid PVC film (sheet) are produced by the calendering method. The softness is mainly made of soft pvc films, and the hardness is mainly made of PVC sheet.
In recent years, a tenter stretching device is added behind the calender to produce stretched polyvinyl chloride film, which is an important method for producing wide-width polyvinyl chloride film.
(2) Blow molding method: It is an important production method for general packaging film. Early production of flexible pvc films, and later developed rigid food packaging PVC film. The general shrink film is also produced by this method and then biaxially stretched.
(3) Flat film method: It is also one of the methods for producing cast film and stretch film (self-mucosa). Since the price of the equipment is higher than that of ordinary film blowing equipment, it is used less.
In addition, according to its special purpose, it adopts special formula and technology to produce, such as uniaxially stretched film, medical film, cold-resistant film and other manufacturing methods. Polyvinyl chloride composite films manufactured by the composite method are relatively less than polyethylene and polypropylene composite films.