1) high accuracy (reproducibility) requirement for injection molding parameters. Multi stage injection feedback control should be adopted.

a.多级位置控制；

A. multilevel position control;

b.多级速度控制；

B. multistage speed control;

c.多级保压控制；

C. multistage pressure protection control;

d.多级背压控制；

D. multistage back pressure control;

e.多级螺杆转速控制。

E. multistage screw speed control.

位移传感器的精度要求达到0.1mm，这样可以严格控制计量行程、注射行程以及余料垫的厚度(射出监控点)，保证每次注射量准确，提高制品成型精度。料筒及喷嘴温度控制要精确，升温时超调量要小，温度的波动要小。精密注塑应采用PID控制，使温度精确度在±0.5℃之间为宜。    

The precision of the displacement sensor is required to reach 0.1mm, which can strictly control the metering stroke, the injection stroke and the thickness of the residual cushion (shooting out the monitoring point), so as to ensure the accuracy of each injection and improve the molding precision of the products. The temperature control of the barrel and nozzle should be precise. When the temperature rises, the overshoot is small and the temperature fluctuation is small. Precision injection molding should be controlled by PID, so that the accuracy of temperature should be between 0.5 and C. Such

2) 塑化质量要求，塑料塑化的均匀性不仅影响到注塑件的成型质量，还会影响到熔融塑料通过浇口时所受阻力的大小，为了得到均匀的塑化，设计专用的螺杆使用专用的增塑技术必不可少。另外，机筒的温度也应精确控制，现在螺杆、机筒温度多采用PID控制(比例、微分、积分)，精度可控制在±l℃内，基本可满足精密注塑的要求，如果采用FUZZY控制方法，就更适合于精密注塑了。