Plastic Molding Manufacturer | China Custom Plastic Parts Services Contact@china-plasticparts.com
Author: MULAN -Plastic Molding Manufacturer
How to deal with the dents of the plastic mold, the following Xiaobian of Guangdong Plastic Mold Factory Xingye will teach you how to remove the dents of the plastic mold: 1. The reasons for the dents. 1. The thickness of each part of the product is different. 2. The internal pressure of the plastic mold is insufficient.
3. The cooling of the plastic mold is insufficient. 4. Deformation caused by insufficient cooling time. 2. Relevant knowledge.
1. In the process of product production, dents occur frequently in discomfort. Plastic injected into a plastic mold shrinks as it cools. Some surfaces harden first, and air bubbles develop inside.
The so-called dent means that the part that cools slowly produces an obvious concave surface in the direction of bubble shrinkage. 2. High shrinkage materials are also prone to dents. The setting condition should be set to shrink small direction.
That is, the temperature of the plastic mold and the cylinder body are lowered, and the injection pressure is increased, but attention should be paid to the possibility of residual internal stress. 3. Because the dent is not conspicuous, if it does not affect the appearance, it will be deliberately processed into a corrosive appearance on the plastic mold, such as striations, grains, etc. In addition, if the molding material is HIPS, it is also useful to reduce the plastic mold temperature and finish.
But once these methods dent, it is very difficult to restore polished products. Three, the solution. 1. Immediately: Increase the injection pressure, prolong the injection holding time, reduce the temperature of the cylinder and the plastic mold, and force cooling at the place where the dent occurs.
2. Short-term: Make up where the dent occurs (Figure A). When there is a narrow place in the edge of the material where the dent is produced, this part of the edge is thickened (Fig. B). 3. Long-term: The difference in the thickness of the design product should be avoided.
Ribs are prone to dents, and the shape should be as short as possible. 4. Material differences. The molding material has large shrinkage and large dents.
For example, PE and PP, even with a little reinforcement, will produce dents. V. Reference items: 1. When the temperature is reduced to no dents, if the material in the cavity is still under pressure, it should be considered that no dents will be produced. The pressure of the material around the plastic mold is static pressure, not necessarily anywhere.
The pressure near the gate is high. If the edge of the material is wide, due to the pressure transfer at each corner, the difference between the pressure difference near the gate and the place far from the gate is smaller than that of all pressure differences, and no dents will be generated, so it is possible to obtain a material that does not leave internal stress product. When some material flows into a difficult place, the pressure is high in this place, and the pressure is reduced in other places, causing dents.
This part of the high pressure residue is also the internal stress of the product. In an ideal state, as the material temperature and plastic mold temperature rise, the material fluidity will be better, and the radiation under static pressure will also be reduced. 2. When the molding conditions change, a table for the combination of temperature, pressure and time should be made in advance, and carried out in order, so as to know the results in advance.
First, it's easy to know small changes in pressure long after the time has changed. It should be noted that the results when the temperature changes should be produced after waiting for the temperature to drop after injecting the material. For more information about plastic molds, please visit Xingye's official website: http://www.dgxingyesj.com.