The advantages of increase and reduce the injection speed
The advantages of increase and reduce the injection speed
The most important process conditions in the injection molding process are the temperature, pressure, speed and corresponding action time that affect the plasticizing flow and cooling. However, these factors influence and restrict each other. For example, if the melt and mold temperature are increased, the injection pressure and speed can be reduced. Otherwise, the injection pressure and speed need to be increased.
The core of the influence of various process conditions is the viscosity change of plastics, which is very important for the reasonable selection of parameters and the influence of each other in the injection process.High speed injection has the following advantages in the injection process:
Improve the plastic process, which is conducive to the forming of thin-walled parts;
Improve the surface gloss of products;
It can improve the strength of the welding line and make the welding lines not obvious;
Prevent cooling deformation, etc.
Low speed injection has the following advantages in the injection process:
Prevent forming products from flash;
Prevent spray and flow lines;
Prevent burning marks;
Prevent plastic melt from air entrainment;
Prevent molecular orientation deformation, etc.
The advantage of high-speed injection is the disadvantage of low-speed injection, and vice versa. Therefore, the combination of high-speed and low-speed in the injection process can make full use of their advantages and avoid their disadvantages, so as to ensure product quality and process economy.
In other words, we usually refer to multi-stage injection technology, which has been widely used in modern injection molding machines. At present, most medium-sized and above injection molding machines have five to six stages of injection pressure, speed change and three to four stages of pressure maintaining pressure change (because at the pressure maintaining stage, the melt has filled the cavity, at this time, the feeding material flowing into the cavity through the pressure maintaining pressure has been limited, so the impact of pressure maintaining speed is not significant).
