Why do we need special injection molding machines for processing PVC parts?
A PVC injection molding machine is a type of injection molding machine that is specifically designed for processing polyvinyl chloride(PVC) materials. Compared with general injection molding machines, PVC-specific molding machines have the following characteristics:
1. Screws and barrels are made of corrosion-resistant materials. PVC materials decompose into hydrogen chloride gas at high temperate, which can corrode ordinary steel screws and barrels. Therefore, the screws and barrels of PVC-specific injection molding machines need to be made of corrosion-resistant materials, such as chrome-plated steel and nitrided steel.
2. Higher injection pressure and speed. PVC is a material with high melt viscosity and poor fluidity. Therefore, when processing PVC products, it is necessary to use an injection molding machine with higher injection pressure and speed to smoothly inject the PVC material into the mold.
3. Longer cooling time. PVC has poor fluidity, and it takes a longer cooling time to solidify.
Features of PVC-specific injection molding machines:
1. Screw design. The screws of PVC-specific injection molding machines usually have a large diameter and longer length to improve the plasticization effect. In addition, the screws also have a higher compression ratio to improve the injection pressure.
2. Barrel design. The barrels of PVC-specific injection molding machines usually adopt a bimetallic structure, with the inner layer made of corrosion-resistant material and the outer layer made of ordinary steel. At the same time. The barrels also have a large heating power to improve the melting temperature.
The design features of PVC-specific injection molding machines are mainly determined by the material properties of PVC materials.
