The product is applied in the automobile Mercedes Benz. It is a part of the tank. It works in the high temperature environment. So it is made of the material PA66 with 30% glass fiber. This is a special heat-resistant material. Also it is a high strength engineering material. This composite materials have superiorities in size stability, formability, stretching resistance and impact resistance. This a long product. The length is 495mm. width is 76mm, height is 83mm. it is easy to deflect after injecting. So it is very important to solve deflect issue in the mold.
The mold is a two-cavities design with hot runner system. The valve gate of the hot runner system is directly on the part. We did mold flow analysis before mold design. Through technical analysis, we can estimate the deformation of the part and find some problems of injection molding. So that we saved some steel for late adjustment about deformation.Meanwhile, we did Some preventive measures for possible problems.
In this way, we can optimized the mold after trailing shoot until the molding was good. The structure of the part was a lot complex. There were some bosses and hooks at the side of the product. It needed several sliders to formed them. For cooling system, it was very important too. Good cooling system can decrease the deformation of the product and the cycle time. So we designed several sufficient cooling loops for this mold. Not only cooling loops were design in the core insert and cavity insert, but also cooling loops were designed in the sliders and the mold plate.
In that case, the temperature of the mold can be controlled well. And the product was very stable. The cycle time was about 41 seconds. By controlling the valves of the hot runner system, we can control the volume of each part and the balance of flowing. Because of the plastic material including 30%glass fiber, the steel of forming insert must be harden steel. We choose to use imported steel 1.2344 which hardness was about 52 HRC. The mold ran well. The mold run over 3 hours for testing before delivery to customer. Customer was satisfied the mold.