Marble injection molding machine plastic products production technology is actually a kind of injection molding technology at the same time, at the same time, co-injection molding technology is through a number of injection molding systems, the different marble colors or different marble materials or different marble colors and marble materials of the plastic injection molding method at the same time or in order. The method generally used for multi-color injection plastic products is to directly use the marble injection molding machine, and the plastic of a variety of marble colors or marble materials mixed with the two-color injection molding machine is injected into the same injection molding machine.

The open and closed loop control methods of injection molding machine automatic control are divided into two categories: the first type of sequence control, that is, open loop control; The second type of feedback.

Passive loop control system. The speed and pressure of the injection molding machine in our factory are controlled by open loop, and the displacement and temperature are controlled by closed cycle. (1) In open-loop control, if the system output is not compared with the specified input, and there is no feedback channel between the system output and input, this situation is called open-loop control, as shown in Figure 19. This control system has the advantages of simple structure, few components, low cost and stable system. Because the controlled quantity cannot be detected, when the system is disturbed, the offset cannot be eliminated once the controlled deviates from the original equilibrium state, thus limiting the application of the system.

In the open loop control system, when the set value of the object amount is given, the ten brands of injection molding machine system can make the control amount (pressure, speed, speed, displacement) get the real value, and can be displayed by the instrument. However, due to the interference of various environmental factors, there is a deviation between the given value and the actual value of the system, but it is not necessary to re-correct this deviation, that is, the system itself can not adjust this deviation.