What are the functions of release agents in fiberglass production

In order to prevent the molded fiberglass products from sticking to the mold, a layer of release agent must be applied between the product and the mold, so that the product can easily detach from the mold, thereby ensuring the surface quality of the product and the integrity of the mold. 

All substances have surface free energy, and the magnitude of surface free energy varies depending on the substance. Generally speaking, the free energy of metal surfaces is relatively high, while release agents have extremely low surface free energy and can evenly penetrate the surface of the mold, forming a thin coating to achieve easy demolding.

After polishing the mold, it is necessary to apply fiberglass release agent first. Even if the coating is thin, it should be brushed clean immediately without leaving any water marks. It's difficult to clean it thoroughly after it dries. In addition to being more user-friendly, the key factor in polishing fiberglass mold release agents is the quality of the water sandpaper used in the water polishing process, which should start with 600-800 #. If the mold is too rough, it is recommended to use 400 # first, because using too coarse water sandpaper at the beginning will also cause coarse sand marks, which will eventually prolong the water sandblasting time. This is a very patient and meticulous process, and polishing can only be carried out after the process meets the technical requirements.

In addition to having good demolding effect, release agents should also have the performance of reducing the emission of low molecular weight substances and the advantage of not damaging the gloss of the mold. But the prerequisite is that the mold must be fully cured and clean. If the mold is very dirty, relying solely on high gloss release agents cannot produce a mirror effect product.