PVC Molding Characteristics:
Material Form: As an amorphous material, it has low hygroscopicity but poor flowability.
Drying and Mold Selection: To improve flowability, the plastic needs to be pre-dried, and a short, thick mold with a large gate cross-section should be selected to avoid dead corners. The mold needs to be cooled and chrome-plated.
Equipment and Additives: Specialized equipment and molds are recommended, and additives should be added as needed.
Molding Temperature: The molding temperature range is 160-190℃, which is relatively narrow because PVC is prone to decomposition when in contact with metal at high temperatures, producing corrosive gases.
Injection Molding Machine Nozzle and Inserts: The injection molding machine nozzle orifice should have a large diameter to prevent dead corners and material stagnation. Inserts, if used, need to be preheated.
Physical Properties: It has excellent mechanical and electrical properties, high strength, high rigidity, and high hardness.
Chemical Stability: It has extremely strong resistance to acids and alkalis, strong corrosion resistance, and excellent chemical stability, making it an ideal choice for corrosion-resistant equipment in the chemical industry. However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid, and is not suitable for contact with aromatic hydrocarbons or chlorinated hydrocarbons. Thermal properties: Low softening point, wide operating temperature range from -15°C to 60°C. Flame retardancy: Flame retardant and self-extinguishing. Other properties: Low water absorption, easy to bond, easy to paint, easy to process (e.g., simple cutting, welding, and bending), and relatively inexpensive.
