Reasons and countermeasures for mold scale after injection molding of engineering plastics

When we can't eliminate mold scale by using various measures, we must strengthen the maintenance and upkeep of the mold.
At the beginning of mold formation, the mold surface is relatively easy to remove, so it is necessary to clean and maintain the cavities and exhaust channels regularly (such as after each batch of molding). If the mold is not maintained and serviced for a long time, it is very difficult and time consuming to remove the mold after a thick layer of mold is formed.
The sprays used for injection mold maintenance and upkeep mainly include: mold release agent, rust inhibitor, ejector oil, gum remover, mold cleaner, etc.
The chemical composition of mold scale is very complex and must be removed and tried using new methods, such as general and various special solvents, oven sprays, lemonade containing caffeine, etc. Another exotic method is to use rubber to clean model tracks.
When using hot runner molding and heat sensitive materials, the melt dwell time is extended, increasing the risk of material breakdown to form mold scale. Clean the screw of the injection molding machine.
Larger runners and gates are used to mold shear-sensitive materials. Multi-point gates reduce flow distances, lower injection speeds, and reduce the risk of mold formation.
Efficient mold venting reduces the likelihood of mold formation and provides proper mold venting during the mold design phase. Automatic removal of the venting system, or a venting method that allows easy removal of mold deposits, is the best option, and improvements in the venting system often result in less mold scale on the mold.
A special non-stick coating is applied to the cavity surface to prevent mold scale formation, and the effectiveness of the coating should be evaluated by testing. Titanium nitride treatment on the inner surface of the mold can prevent mold scale formation on the mold.