We all know that the main function of the wire forming machine is to turn the wire material into the shape required by the customer in a certain way. In easy-to-understand terms, that is stereotypes. Ensure that the mold is locked when the melt is injected into the cavity, because the pressure in the cavity is very high at this time, and a considerable clamping force may be required. Generally, the clamping modes of injection molding can be divided into the following categories: hydraulic (or pneumatic) type, hydraulic-mechanical type and mechanical type. Hydraulic, hydraulic (or pneumatic) clamping mechanism is different from the other two forms as follows: hydraulic clamping mechanism is an example, the advantages of this kind of mechanism are mainly simple structure and easy to realize. Typical hydraulic clamping mechanism The hydraulic-mechanical clamping mechanism has the following differences from other types: the clamping path is realized by the movement of the liquid (oil or air) pressing the clamping cylinder. Such hollow plastic products include bottles, cans, drums, storage tanks, pipes, pipes, etc.
The wire forming machine adopts a vertical storage cardboard method, which can be refilled at any time without stopping the machine.
Filling stage. This is when the screw (or plunger) starts to move, and the melt enters the mold cavity until it fills the mold cavity. When starting to fill the mold, there is no pressure in the cavity. After the cavity is filled, the pressure of the material flow rises to the maximum value rapidly. The mold filling time is related to the molding pressure. When the mold is filled at a slow speed, the melt of the ancestor mold will cool and the viscosity will increase. The subsequent melt will enter the cavity under a higher pressure, because the melt is subject to higher The shear stress and the high degree of molecular orientation reduce the quality; and during rapid filling, the melt will generate more frictional heat when passing through the pouring system quickly, which will increase the temperature of the material. Keep the temperature at a higher value, the degree of molecular orientation can be reduced, and the degree of welding of plastic parts is also higher. However, when the mold is filled too fast, the welding of the rear part with the insert is often not good, resulting in poor strength of the plastic part. Pressure holding stage. This means that the melt fills the cavity until the screw (or plunger) retreats. At this time, the melt pressure is basically stable, and the holding pressure is relatively stable.
However, the melt shrinks due to cooling. Because the melt is still under constant pressure, the melt in the barrel will flow into the mold cavity to make up for the gaps caused by shrinkage, which is beneficial to increase the density of the plastic part, reduce the shrinkage rate and overcome Surface defects. In addition, since the melt is still flowing and the temperature is constantly decreasing, the orientation molecules are easily frozen. Therefore, this stage is the main stage of the formation of macromolecular orientation. The longer this period is, the greater the degree of molecular orientation.