PVC (Polyvinyl Chloride) Chemical and Physical Properties Rigid PVC is one of the most widely used plastic materials.PVC material is a non-crystalline material. Stabilizers, lubricants, processing aids, colorants, impact agents and other additives are often added to PVC materials in practice.
PVC material has non-flammable, high strength, weather resistance and excellent geometric stability. PVC is highly resistant to oxidizing agents, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid, and is also not suitable for contact with aromatic hydrocarbons and chlorinated hydrocarbons.
The melting temperature of PVC is a very important process parameter during processing, and if this parameter is not correct, it will lead to problems of material decomposition. The flow characteristics of PVC are quite poor and its process range is very narrow. Especially large molecular weight PVC material is more difficult to process (this material usually need to add lubricants to improve the flow characteristics), so usually use small molecular weight PVC material. The shrinkage of PVC is quite low, typically 0.2 to 0.6%.
Injection Molding Process Conditions
Drying Treatment: Drying treatment is usually not required.
Melting temperature: 185~205C Mold temperature: 20~50C
Injection pressure: up to 1500 bar Holding pressure: up to 1000 bar Injection speed: In order to avoid degradation of the material, the injection speed should be quite high.
Runners and gates: All conventional gates can be used. For smaller parts, it is best to use a pin-tip or dive-in gate; for thicker parts, it is best to use a fan gate. The minimum diameter of a pin-tip or submerged gate should be 1mm; a fan gate should not be less than 1mm thick.
Typical applications Water supply lines, household plumbing, house wall panels, commercial machine housings, electronics packaging, medical devices, food packaging, etc.