When the product has a complex pattern, has undercuts, and is large on the front and small on the back, and other molds cannot smoothly take out the product, we can only use silicone molds for production. Silicone molds are further divided into the following two types:
A. Resin soft mold. This is a type with a soft interior and a hard exterior. Inside the mold is a silicone inner mold. The outside is the same as a resin mold. Channel steel plus resin. Insert the silicone mold into the resin outer mold to form a soft interior and a hard exterior. The upper cover of the mold is also a resin mold.
B. Gypsum soft mold. Steel plate plus silicone. First make the silicone mold. Surround it with channel steel as a frame. Then pour in gypsum. Smooth the back. Use two steel plates to make the bottom and cover of the mold respectively. Weld adjustable hinges between the steel plates. Weld lock catches on the other three sides. Turn the silicone mold over and place it flat between the two steel plates. Adjust the hinges and lock catches.

When producing with this kind of soft mold, the following points should be noted:
A. When the mold is in production, there is little deformation. The waste edge at the joint with the upper mold is small, and there is not much material leakage. However, the cost will be relatively higher.
B. The upper and lower molds are both steel plates. The hinges are adjustable. The lower mold can be shared. Only the inner mold needs to be replaced. Inner molds of different sizes can be used. But the disadvantage is that both the upper and lower molds are steel plates. The sealing is poor. When the hinges are not adjusted properly, there will be material leakage. And the waste edge at the joint with the upper mold is thicker. The back of the product is not flat and needs to be processed such as grinding and planing the bottom.