1). The production speed of the extrusion cast film production line is higher than that of the blown film method, which can be as high as 300m/min, while the blown film method is generally only 30-60m/min due to the limitation of the cooling speed of the bubble film. The temperature of the middle cooling roller can be 0-5℃, and it is directly attached to the roller, and the cooling effect is good.
2). The transparency of the extrusion cast film is better than that of the blown film method. Whether it is PE or pp, it can produce a film with good transparency by extrusion casting method. However, when the film blowing method is air-cooled, p cannot have good transparency. To obtain good transparency, water cooling method must be used.
3). The thickness uniformity of the extrusion casting method is better than that of the blown film method.
4). The longitudinal and transverse properties of the extrusion cast film are balanced, while the longitudinal and transverse properties of the blown film are different due to the difference in the speed of the traction roller and the inflation ratio. In principle, the film produced by the extrusion casting method is transmitted from one roll to another without the tension of winding or pulling, so the extrusion casting film is not stretched in either the longitudinal or transverse direction, and the performance is balanced.
Post time: Mar-09-2022