Shrinkage rate of liquid silicone rubber
Although LSRs do not shrink inside the mold, they often shrink by 2.5% -3% after demolding and cooling. As for the exact amount of shrinkage, it depends to some extent on the formula of the adhesive material. However, from the perspective of the mold, the shrinkage rate may be affected by several factors, including the temperature of the mold, the temperature of the rubber material during demolding, as well as the pressure inside the mold cavity and the subsequent compression of the rubber material.
The location of the injection point is also worth considering, as the shrinkage rate in the direction of the adhesive flow is usually greater than that in the direction perpendicular to the adhesive flow. The external dimensions of the product also have an impact on its shrinkage rate, and thicker products generally have a smaller shrinkage rate than thinner ones. If secondary vulcanization is required, additional shrinkage may occur.