Processing properties of polypropylene and its films
DATE：2019/11/12 8:51:49 / READ： / SOURCE：This station
Processing properties of polypropylene and its films
Polypropylene has good molding processability, and a variety of molding processes to produce films. The molding process has a significant effect on the performance of the PP film.
The extrusion blown film method of PP has two kinds of molding methods: 1 upper blowing method, the bubble is inflated upward, and the bubble is cooled by air. The film has poor transparency and large haze, and is only used to produce unidirectionally stretched flat yarn, tying rope, rope and rope and other fiberized film products: 2 down blowing method, bubble inflating, water Quenching produces a tubular or monolithic film with high transparency and low haze, which is commonly used in PP extrusion blown film (IPP).
PP extrusion cast film method (CPP), there are three different process routes: 1 unstretched PP film. After the PP melt is extruded from the T-die, it is rapidly cooled to form a film (such as a packaging film, a matte film) by a plurality of sets of cooling rolls, and the film is uniaxially stretched. The cast cast film was subjected to longitudinal stretching. 3 biaxially stretched film. The extruded cast film was subjected to longitudinal and transverse stretching. Since PP is biaxially stretched, the degree of orientation of the PP film in both the longitudinal and transverse directions can be adjusted within a certain range, and it is further divided into a biaxially oriented film having the same degree of orientation and a biaxially oriented film having a different degree of orientation. The biaxial stretching orientation can significantly improve the mechanical properties, transparency and barrier properties of the PP film. In the biaxial stretching process, if the film is not subjected to a heat setting process, the PP film is biaxially stretched to form a heat shrinkable film.
The printing performance of PP film is better than that of polyethylene film, but it still needs corona treatment before film printing, bonding, dry compounding and so on. In addition to being used for blown film, metallocene polypropylene is used to make extruded cast film with low heat sealing temperature and low heat shrinkage ratio; it is used to make biaxially oriented film (BOPP) with low heat shrinkage rate. High tensile strength and high gloss. When the PP film is used for bag making, a copper hot knife is used to complete the cutting and heat sealing operations at one time.
Polypropylene has good molding processability, and a variety of molding processes to produce films. The molding process has a significant effect on the performance of the PP film.
The extrusion blown film method of PP has two kinds of molding methods: 1 upper blowing method, the bubble is inflated upward, and the bubble is cooled by air. The film has poor transparency and large haze, and is only used to produce unidirectionally stretched flat yarn, tying rope, rope and rope and other fiberized film products: 2 down blowing method, bubble inflating, water Quenching produces a tubular or monolithic film with high transparency and low haze, which is commonly used in PP extrusion blown film (IPP).
PP extrusion cast film method (CPP), there are three different process routes: 1 unstretched PP film. After the PP melt is extruded from the T-die, it is rapidly cooled to form a film (such as a packaging film, a matte film) by a plurality of sets of cooling rolls, and the film is uniaxially stretched. The cast cast film was subjected to longitudinal stretching. 3 biaxially stretched film. The extruded cast film was subjected to longitudinal and transverse stretching. Since PP is biaxially stretched, the degree of orientation of the PP film in both the longitudinal and transverse directions can be adjusted within a certain range, and it is further divided into a biaxially oriented film having the same degree of orientation and a biaxially oriented film having a different degree of orientation. The biaxial stretching orientation can significantly improve the mechanical properties, transparency and barrier properties of the PP film. In the biaxial stretching process, if the film is not subjected to a heat setting process, the PP film is biaxially stretched to form a heat shrinkable film.
The printing performance of PP film is better than that of polyethylene film, but it still needs corona treatment before film printing, bonding, dry compounding and so on. In addition to being used for blown film, metallocene polypropylene is used to make extruded cast film with low heat sealing temperature and low heat shrinkage ratio; it is used to make biaxially oriented film (BOPP) with low heat shrinkage rate. High tensile strength and high gloss. When the PP film is used for bag making, a copper hot knife is used to complete the cutting and heat sealing operations at one time.
Author：admin