What are Differences between Plastic Round Table Blow Molding Machine and Injection Molding Machine?

The process difference between plastic round table blow molding machine and injection molding machine originates from the essential difference of molding dynamics. Plastic round table blow molding machine realizes hollow structure molding by radial expansion of molten parison by compressed gas. The dynamic balance between gas expansion force and mold cooling rate determines the wall thickness distribution of the product. The injection molding process relies on high-pressure jet to fill the closed mold cavity with thermoplastic melt. The molecular orientation induced by shear stress directly affects the anisotropy of the final product.

The material flow characteristics shape the structural characteristics of the equipment. The parison extruder configured by the plastic round table blow molding machine needs to maintain uniform melt vertical extension, while the screw plasticizing system of the injection molding machine must overcome the pressure attenuation at the end of the flow channel. For large flat parts such as round tables, the circumferential stretching advantage of the blow molding process can avoid the common weld line defects of injection molding, but sacrifices the surface microstructure reproduction accuracy.

The energy consumption distribution pattern reflects the essence of the process. The gas compression system of the plastic round table blow molding machine and the hydraulic power unit of the injection molding machine form different energy conversion paths. The constraints in the demoulding stage are completely different. Blow molding relies on the release of air pressure to achieve product shrinkage and separation, while injection molding requires an ejector mechanism to resist the vacuum adsorption force.