How to solve the problem of hard rubber indentation encountered by injection molding manufacturers in the process of injection molding?

In the process of injection molding, some problems are often encountered, such as the top height, the side of the nozzle of the shell bottom, line clamping, deformation, strain, burnt, etc., among which hard rubber indentation is one of the problems. The following editor will share the problem of hard rubber indentation.





Hard rubber indentation refers to the indentation on the rubber surface of the communication product volume key during the production process.
The reason for the indentation problem of hard rubber is that the product mold is designed as double injection molding of hard rubber and soft rubber (that is, a set of molds first injects hard rubber products, and then the special hard rubber penetrates into the soft rubber and touches the injection molded soft rubber). When the soft rubber is injected, due to the small space of the steel parts, there are indentations on the surface of the hard rubber product






When encountering the problem of hard rubber indentation, our solution is:
(1) Product characteristics

Material: TPU 85 degrees Color: Black Product weight (single piece). 5g Nozzle weight: 1.2g

(2) Analysis of the causes of defective injection molding products

①The product mold is designed as secondary injection molding of hard rubber and soft rubber, which affects the product structure. The back mold design of the soft rubber mold uses a probe sealant. When soft rubber is injected, the surface of hard rubber products is silent due to the small space.

②Due to the looseness of the insert during injection molding, the thickness of the hard rubber product mold is different.

(3) Countermeasures

①Clean the surface of the soft rubber mold and keep the surface of the hard rubber free of dirt.



②Elevate and level the tail of the hard rubber contact tool to avoid backing up during injection molding.