Effect of speed: The advantages of low-speed filling are smooth flow, stable size of parts, less fluctuations, low internal stress of parts, and good uniformity of internal and external isotropic stress.

The disadvantage is that the parts are susceptible to layering and poor melting point. Traces, water lines, etc., high-speed filling can be used to lower the injection pressure, improve product gloss and smoothness, eliminating the phenomenon of seam lines and delamination phenomenon, shrinking depression is small, more uniform color.

Disadvantages are easy to generate "free spray", ie, stagnation or turbulence. Excessive temperature rise, yellow color, poor exhaust and sometimes difficult to remove the mold. High viscosity plastics may cause melt fracture, the surface of the workpiece to produce fog Spots, at the same time, also increase the tendency of the warp caused by internal stresses and the cracking of thick parts along the seam line.