The reason why mold silicone is dry on the surface and not on the inside is mainly due to its special chemical structure and properties. Silicone is an inorganic polymer compound with excellent high temperature resistance, corrosion resistance, and flexibility, which is widely used in mold making.
Firstly, silicone has extremely strong hygroscopicity, which can absorb moisture from the air, leading to rapid drying of the surface, but internal moisture still exists. This hygroscopicity makes silicone easily affected by environmental humidity during the mold making process. Although the surface appears dry, there is still a certain amount of moisture inside, resulting in a dry surface and non dry interior state of silicone.
Secondly, silicone gel releases moisture during the curing process, which is also one of the reasons why the surface does not dry inside. During the curing process of silicone, water is released due to changes in the molecular structure of the reactants. However, due to the sealing and hygroscopicity of silicone itself, the internal water cannot evaporate quickly, resulting in a dry surface while still containing water inside.
In addition, the curing time and temperature of silicone can also affect its surface dry and non dry state. If the curing time of silicone is not long enough or the curing temperature is not high enough, the reaction is incomplete, and the internal moisture cannot be completely evaporated, resulting in a dry state of silicone on the surface but not on the inside.
Overall, the non drying of silicone surfaces is the result of a combination of factors such as its special moisture absorption, release of moisture during curing, and insufficient curing time and temperature. In the process of mold making, it is necessary to pay attention to controlling the humidity, curing time, and temperature of the environment to ensure that the silicone gel solidifies uniformly and avoid situations where the surface is dry and the inside is not dry, thereby ensuring the quality and service life of the mold.
