Precautions for the manufacture of liquid silica gel molds:

1. Shrinkage rate: Although liquid silica does not shrink in the mold, it typically shrinks 2.5 to 3 percent after demitting and cooling. The precise degree of shrinkage depends in part on the formulation of the compound. From a mold perspective, however, shrinkage can be affected by several factors, including mold temperature, the temperature at which the compound is demoulded, pressure in the cavity, and subsequent compression.

The location of the injection point is also worth considering because the contraction in the direction of the compound flow is usually greater than the contraction in the direction perpendicular to the compound. The shape of the product size also has an effect on its shrinkage, thicker products have less general shrinkage.

⒉ Parting line: the first step of silicone rubber injection mold design is to determine the position of the parting line. Venting is achieved mainly through a groove on the parting surface, which must be located in the final area of the injected rubber to avoid the formation of bubbles and reduce the strength loss of the bonded joint.

Due to the low viscosity of liquid silica gel, the parting line must be accurate to avoid overflow. Even so, dividing lines are often seen in the final product. Liquid silicone moulds are influenced by the product's geometry and parting surface position. A slightly chamfered product design helps ensure that the product has a consistent affinity with the desired half of the cavity.