What are the reasons for the difficulty of demolding plastic injection molds?
After the plastic part is injection-molded, the plastic part is released from the mold cavity. Whether it is a single or multi-component ejection mechanism, the demolding work is generally completed at one time. However, sometimes due to the special shape of the plastic part or the need for production automation, after one demolding job is completed, the plastic part is still difficult to remove from the cavity or cannot fall off automatically. Fall off. The difficulty of demolding is mainly due to the tightness of the gate or plastic part in the mold. Reasons:
1. In terms of equipment: the ejection force is not enough.
2. In terms of mold
(1) The mold release structure is unreasonable or improperly located.
(2) The demolding slope is insufficient.
(3) The mold temperature is too high or the ventilation is poor.
(4) The surface of the runner wall or cavity is rough.
(5) The nozzle is inconsistent with the mold inlet or the diameter of the nozzle is larger than the diameter of the inlet.
3. Process aspects
(1) The barrel temperature is too high or the injection volume is too high.
(2) The injection pressure is too high or the holding pressure and cooling time are long.
4. In terms of raw materials: insufficient lubricant.
The traditional demolding methods of plastic molded parts are roughly divided into four types: ejecting, pushing, pumping, and spinning. There is a new demoulding technology that can easily solve the problem of plastic demolding. In the plastic mold industry, in particular, it is necessary to use various resin compounds for highly complex designs. When the appearance is high-gloss finishing, there are many unsolvable problems.