Basic Composition and Structure of Injection Mold Maker

1. Injection device

The injection device is the core part of the injection mold maker. Its function is to ensure that the materials are heated, plasticized and melted quantitatively on time; and then the molten plastic of  one injection volume should be injected into the mold cavity at a certain pressure and as soon as possible. A certain dwell time should be ensured after the injection to replenish a part of the molten material that shrinks due to cooling into the cavity so as to make sure the density and to prevent countercurrent inside the cavity. Therefore, the injection device must ensure that the plastic is evenly plasticized and has sufficient injection pressure and dwell pressure. The injection device that can meet these requirements mainly includes plunger type, plunger-screw type, screw type and so on. The injection device is mainly composed of plasticizing device (screw or plunger, cylinder, nozzle and heater, etc.), hopper, metering device, screw transmission device, injection cylinder and integral moving cylinder of injection seat.

The injection device is to heat the resin and melt it into the mold. At this point, the screw should be rotated, and the resin put into the hopper should stay at the front end of the screw (called metering), and then be ejected after the stroke storage equivalent to the required amount of resin. When the resin flows in the mold, the screw speed (ejection speed) should be controlled, and the pressure (dwell pressure) is used to control the resin after filling. When a certain screw position or a certain ejection pressure is reached, the controlling is switched from speed control to pressure control.

2. Clamping unit

The main function of clamping unit is to fix the mold and realize the opening and closing of mold. To ensure the mold is tight enough during injection and pressure maintaining, and perform demolding operation. The clamping unit of injection mold maker is mainly composed of the front template of the fixed device, rear template of installing the transfer-mould cylinder or the tonal template device, moving template, pull rod, mold clamping cylinder,transfer-mould cylinder, connecting rod mechanism,tonal template mechanism, the ejector mechanism and the safety protection mechanism.

3. Hydraulic transmission and electrical control system

The function of hydraulic transmission and electrical control system is to ensure that the injection mold maker works accurately and effectively according to the predetermined requirements (pressure, temperature, speed and time, etc.) and action procedures of the process. Hydraulic transmission is mainly composed of various hydraulic components, hydraulic basic circuits and other accessories. Electrical control system is mainly composed of various electrical components, instruments, electronic control system (heating, measurement), microcomputer control system and so on. Hydraulic transmission and electrical control system are combined organically to provide power and action control for injection mold maker.