Gas Auxiliary Injection Molding Parts

In June, Meike undertook the mold development and injection molding business of one-gas auxiliary injection molding parts for a famous enterprise in Chongqing. Both parts are nitrogen assisted molding.These two parts are supposed to be installed on energy storage products, and the products are manufactured for the American market.

The biggest challenge we have met is from the the side handles.The product has two side handles on both left and right side. The product has symmetry and the side handles can be assembled on both sides of the product at the same time. As the customer requires that the surface of the product shall not be provided with rubber inlet, we have adopted two-point hot runner to inject from the back of the product in the mold structure, and the mold is installed upside down. The surface of the product has successfully avoided the plastic entry marks, which brings difficulties to the injection molding and gas-assisted molding technology. The problem is that the wall thickness of the product is too thick, and most of the main thickness has reached more than 20mm. In the injection molding stage, the amount of plastic ejected repeatedly fills the mold cavity back and forth in an irregular manner in the super large space. When the plastic lands on the surface of the mold cavity, several welding marks have been formed. After nitrogen pressurization, the welding marks formed on the surface of the mold cavity cannot be eliminated any more, and the strength of injection molding and pressure maintaining cannot be achieved. Therefore, there are many welding marks on the surface of the product after molding.

In order to eliminate these weld marks, Meike and our client have repeatedly reviewed to get the improvement plan. The mold has been adjusted for several times, and finally the samples got some improvement, but there is still a long journey to go for achieving the desired result. As our client requested, it’s needed to add the texture on the surface of the side handle.Meike is considering if this texture could be helpful to eliminate the welding marks. If this plan can not meet the customer's surface requirements for this part yet, it may be necessary to go back to the previous proposal to inject the plastic from the side of the part.

Back to the moment when we were making the DFM report, Meike has already offered this suggestion, and the mould was also reserved in structure and verified. We knows this suggestion works, but whether it is finally accepted or not needs to be notified by our client. We always take the thoughts and requirements of our clients into first consideration.

Also we wish to receive your valuable suggestion if you have similar products and experience. Thank you!