In case of serious shrinkage of Air Cooler Mould, injection moulding technology should be adopted to solve the problem.
First of all, on the premise of ensuring that the injection-moulded parts are not deformed, the cooling time should be shortened as much as possible so that the injection-moulded parts can be produced at high temperature as soon as possible. At this time, the temperature of the outer layer of the injection moulding part is still very high, the skin is not too hard, and the temperature difference between the inner and outer layers is not too large, which is beneficial to the overall shrinkage, thus reducing the centralized shrinkage of the injection moulding part. The inside of the spraying part. As the total shrinkage of the injection moulded parts remains unchanged, the larger the overall shrinkage, the smaller the concentrated shrinkage, and the smaller the shrinkage of the inner shrinkage cavity and the surface.
Secondly, it is different to solve the problem of concave shrinkage after high temperature injection moulding in improving surface concave shrinkage. The surface of the air cooler die is heated, the cooling capacity is reduced, and the concave shrinkage problem occurs. The surface of the newly solidified injection moulded part is still relatively soft. Due to the formation of vacuum, the incompletely eliminated internal shrinkage cavity is compressed inward at atmospheric pressure. At the same time, under the action of contraction force, concave shrinkage problem occurs. Born. In addition, the slower the surface hardening speed is, the more easily shrinkage cavities are generated, such as polypropylene materials, whereas shrinkage cavities are more easily generated.
Third, after the air cooler mould takes out the injection part in advance, it should be properly cooled so that the surface energy of the injection part can maintain a certain hardness and a concave die is not easily generated. However, if the problem of indentation is serious and moderate cooling cannot be eliminated, a rapid cooling method must be adopted, which is why we sometimes see products being cleaned when they come out of the mould. Of course, this situation will not damage the appearance of the product surface. Concave shrinkage can only be prevented by rapidly hardening the surface of the injection moulded part.
At the same time, if the cooling time is replaced by an extended injection moulding time, the surface concavity can be improved and even the internal shrinkage cavity can be improved. The above is the long-term practice summary and analysis of how to solve the air cooler mould shrinkage method.
