Production Process of PVC plastic packaging film

 PVC (polyvinyl chloride) chemical and physical properties of rigid PVC is one of the most widely used plastic materials. PVC material is a non-crystalline material. PVC material in actual use, often by adding stabilizers, lubricants, auxiliary processing agents, pigments, impact agents and other additives. PVC material is not easily flammable, high strength, resistance to climate variability and excellent geometric stability. PVC oxidant, reductant and acid has a very strong resistance. However, it can be concentrated oxidizing acids such as concentrated sulfuric acid, concentrated nitric acid corrosion and does not apply to contact with aromatic hydrocarbons, chlorinated hydrocarbons occasions. PVC melting temperature in the processing is a very important process parameters, if this parameter incorrectly will cause the material to decompose problems. Very poor flow characteristics of PVC, very narrow scope of the process. Especially high molecular weight PVC material more difficult to process (this material is usually added to improve the flow characteristics lubricant), it is often used are low molecular weight PVC material. PVC contraction rate is very low, typically 0.2 to 0.6%.

    Injection molding conditions:
    1, drying: usually do not require drying.
    2, melting temperature: 185 ~ 205C mold temperature: 20 ~ 50C, injection pressure: can be as large 1500bar holding pressure: can be as large 1000bar injection speed: To avoid material degradation, the general use of injection speed considerably.
    3. Runners and Gates: All conventional gate can be used. If the processing of smaller components, it is preferable to use needle-type gate or sneak into the gate; for thicker parts, it is best to use the fan gate. Tip gate or sneak into the gate of the minimum diameter should be 1mm; fan gate thickness can not be less than 1mm.