PVC resin SG8 with the K Value of 55-59 is mainly used for bottles, sheets, calendaring, rigid injection and moulding pipes. This model of PVC resin has high apparent density, goof oil absorption and excellent plasticizing properties.
The average degree of polymerization of SG8 PVC resin is between 650 and 750. It has the characteristics of low melting and gelation temperature, short plasticizing time and good fluidity. It can be processed with little or no plasticizer. The plastic products produced by PVC resin k57 have high transparency and are widely used in the fields of records, profiles, home appliance shells, food packaging, and substitute plexiglass products, and have good application prospects.
About the Production Process of PVC Resin SG8
The production of SG8 PVC resin generally adopts two processes, high temperature process without chain transfer agent and process with chain transfer agent. The SG-8 PVC resin produced by the process without transfer agent has relatively good particle size. However, the polymerization temperature of SG-8 PVC resin produced by high temperature method is 67 °C. Generally, the dispersant can’t be used normally when the temperature is too high, that is, when the temperature exceeds the cloud point.
Although the process if adding chain transfer agent will improve the thermal stability of the resin product, the chain transfer agent has an impact on the dispersion system and is prone to produce coarse materials. Therefore, after comparison, our company decided to optimize the selection of dispersant, and use a suitable quaternary dispersion system to produce PVC resin SG8 by high temperature process without adding chain transfer agent. Our technological innovation and transformation are mainly carried out through three aspects. One it to increase the production capacity of PVC resin K57, which is achieved by shortening the polymerization batch and auxiliary time. The second is ti improve product quality and strive to achieve sanitary standards. The third is to extend the cleaning cycle and transform the original 108m³ polymerization reactor production process. Through continuous technological transformation, sanitary grade SG8 polyvinyl chloride has been produced, and the rate of high-quality products has been significantly improved.