PVC is Hongyi Chemical’s good friend.

PVC was once the most widely used plastic in the world and is widely used in building materials, industrial products, daily necessities, etc. Polyvinyl chloride (PVC) is a polymer formed by polymerizing vinyl chloride monomer (VCM) with initiators such as peroxides and azo compounds or under the action of light and heat according to a free radical polymerization reaction mechanism. Vinyl chloride homopolymer and vinyl chloride copolymer are collectively called polyvinyl chloride resin.
PVC is a white powder with an amorphous structure. It has a small degree of branching and begins to decompose at about 90°C. It has poor stability to light and heat. When it is above 130°C or exposed to sunlight for a long time, it will decompose to produce hydrogen chloride, which will further automatically Catalytic decomposition causes discoloration and rapid decline in physical and mechanical properties.
At this time, PVC heat stabilizer needs to be added to inhibit the decomposition of hydrogen chloride, and various lubricants need to be added to improve the fluidity and demoulding properties of the solution.

Why does PVC need to add fluorescent whitening agent?
1. Catalytic decomposition causes PVC plastic to turn yellow. After adding various stabilizing additives and lubricating additives, the appearance and color of PVC plastic are also different, and the whiteness value is not high.
2. In order to reduce costs, PVC processing needs to add a large amount of calcium powder for filling. Calcium pink phases vary, and adding too much calcium powder will cause the weather resistance of PVC products to decrease. Therefore, whitening agents must be added to remove yellowing, whiten, and improve weather resistance.
3. In order to reduce costs, PVC processing needs to add a large amount of recycled materials. The recycled materials have different hues, so a whitening agent must be added to whiten and remove yellowing.