Detailed description of PVC additives

Is for hard products, PVC additives can be divided into: stabilizers, impact modifiers, lubricants, processing aids. Requirements of the additives can be summarized as three aspects: - ensure 100% of the plasticized PVC degree nor excessive decomposition. Which is to ensure the mechanical properties of PVC products in achieving optimal plasticizing degrees, does not decompose or less decomposition. - Should ensure a high degree of polymerization of PVC processing, improve the quality and grade of PVC products. PVC polymerization degree is higher, the higher the tensile strength, higher impact strength, Vicat softening point is higher, the higher the hardness.Metal stearate
- Should ensure that the PVC processing technology in a wide range of PVC can get qualified products. Variety of PVC products, PVC processing machinery varied at different temperatures and shear processing, PVC additive should make possible a wide range of processing in a desired degree of plasticization, the product performance and quality .
For stabilizers, naturally, is to ensure that PVC decompose at high processing temperatures are not critical, or in the normal process temperature, the decomposition level as low as possible, or at a low process temperature and high shear conditions without decomposition decomposition or less ( Although it looks unlikely). Aids for the processing, it should be guaranteed in the process PVC extruder torque and a sufficiently high current to ensure that PVC large enough to withstand shear force, thereby to obtain a good plasticization performance products. PVC impact modifier required to ensure adequate plasticizing process conditions, the formation of the desired alloy and PVC state. Such as "core-shell" structure of the impact modifier, PVC should form a uniform "sea one island" like mixture, and CPE, EVA, etc. should be formed in PVC fine mesh structure.PVC plasticizer
Core-shell impact modifier performance reason, because the greater the shear, torsion moment is higher, the higher the temperature, the more uniform favor - sea island structure is formed, and then the performance of the PVC itself Jia. Because a wide range of processing, CPE, PVC and other network structure formed by a thermodynamically metastable state, it can only be formed in a particular condition. In the high shear, high temperature, the mesh structure easily damaged, even if made of PVC plastic and high performance, the material will be reduced overall performance.