In plastic injection molding, cooling time usually takes up at least two-thirds of the entire molding cycle. If the cooling time could be reduced effectively, the overall production efficiency can be greatly enhanced. Traditionally speaking, most of the cooling channels are designed and built by experienced engineers and molders. However, since the design of plastic products are getting more and more complicated, traditional cooling channels can no longer provide the best cooling efficiency for complex molding in order to fulfill the current industry’s needs and standards.
The control of mold temperature is an important consideration in the injection molding process. Not only will it be reflected in the performance and appearance of the product, but the production efficiency of the product will also have a great relationship with the control of mold temperature. In injection molding, about 80% of a product’s time is used to reduce heat in the mold and cool the product. When the mold temperature is too low, it will cause defects such as scratches, cracks, and cold lines. At this time, a heating system is required to control the injection mold to reach a certain temperature, thereby improving the fluidity of the material and the cooling rate of the mold. The control of mold temperature should be adjusted according to the material performance, working environment, plastic injection mold structure, quality requirements, etc.
In every minute of cycle time, cooling consumes the vast majority of clock-ticks. That makes it an important factor in determining the profitability of a part. Mold and part designers understand the implications, relying on some combination of expertise, experience, intuition, prototyping and CAE analysis to develop trusted cooling system designs. This approach helps practicing engineers maximize productivity. In other words, when you create a cooling system that works well and performs reliably for your application, you can spend more time designing high-quality molds as quickly as possible.
The cooling pipe should be close to the shape of the glue level surface. The optimal distance between the cooling pipe and the glue level surface of the product should be 10-15mm to ensure that the injection mold can quickly transfer the temperature. When the height difference of the glue level surface is large or the glue level is thick, it is necessary to drain well to ensure the temperature of each area of the injection mold is consistent. When designing the water channel, the diameter of the head of the water nozzle is larger than the diameter of the water channel to ensure that the excess water circulation inside and outside the injection mold is the same.
The pipes are evenly arranged, the distance between the pipes cannot be too far or too close, and the distance between the pipes and the pipes is 3 to 4 times the diameter of the waterway. Then the cooling effect is the best. When processing the water channel, it is usually processed by a rocker drill, and the processing error is relatively large. It should be noted that the distance of the water channel from the insert, thimble, and screw must be at least 4mm to prevent the water channel from breaking the hole.