Injection mold ejection mechanism is also called the demoulding mechanism. In each cycle of injection molding, plastic parts must be removed from the mold cavity, and the plastic parts removed the action mechanism for the ejection mechanism.
  1.push out mechanism. Ejection mechanism has three kinds: in the mold plastic parts, ensure no deformation and pouring system of aggregate from the mould successfully. In the plastic parts and coagulation materials after removal from the mould, mold, ensure the ejection mechanism correctly reset. Some die with core pulling mechanism, the ejection mechanism can be used as the power source of the core pulling mechanism.
　2.Push out the designing principles. Although many types of ejection mechanism, but the design principle is basically the same, mainly in the following points. The correct analysis of the size and location of the plastic parts of the cavity adhesion, targeted to select the appropriate ejection mechanism; the ejection mechanism motion is accurate and reliable, and have sufficient strength and stiffness, to overcome the demoulding force; the wrapped core will melt solidification, shrinkage, action points for the introduction of force should be as close as possible to the core; the top output should be applied to the plastic parts on the rigidity and strength of the largest sites, such as flange, reinforcing ribs, surface should be as large as possible, to reduce the deformation or damage of plastic parts; ejector location should be arranged in the plastic parts inside or on plastic appearance has little effect on the site. In the push rod demoulding, more attention should be paid to this problem; and the fit clearance between the mold parts plastic direct contact to the small, guarantee not to overflow, so as not to leave traces of flash; in order to make the mold has the advantages of simple structure, should try to make the plastic parts on the moving die side, so can use the opening force driving the ejection mechanism, in order to complete the release action; if the plastic is not easy on the moving die side, should consider the appropriate modification of the shape of plastic parts, or forced to take measures for mold in the die structure; if the plastic it is difficult on the moving die side, then consider the establishment of stripping mechanism in the fixed mould.