Application of silane coupling agent in casting molds

Application of silane coupling agent in casting molds

Silane coupling agent can improve the surface properties of organic and inorganic materials and enhance the bonding force between fillers and resins. Resin usually refers to an organic polymer that has a softening or melting range after heating, tends to flow under external force when softened, and is solid, semi-solid, or sometimes liquid at room temperature. The three most commonly used resins in the casting industry are furan resin, phenolic resin, and urethane resin.

Resin sand formula: In the production of furan resin, phenolic resin, urea-formaldehyde resin and other resin sands, silane coupling agents (such as SF-S550) connect inorganic silica sand with organic resin through chemical bonding, significantly improving sand mold strength, water resistance and demolding performance. ‌

‌Coated sand process‌: It is used to improve the interfacial bonding force between thermoplastic resin film and silica sand, prevent agglomeration, improve fluidity, and at the same time enhance the surface density of the core and reduce gas emission.

Silane can produce condensation with the surface of sand particles under certain conditions through the silane molecular group, releasing methanol and forming silicon-oxygen bonds, so that silane is "connected" to the sand particles. When the epoxy group at the other end meets acid, the ring is opened and it is connected with the active gene of the resin molecule. In this way, the inorganic sand particles and the organic resin are connected by the bridging effect of silane. Therefore, the adhesion strength of the resin to the surface of silica sand (sand particles) is greatly improved, so the mechanical strength of the resin self-hardening sand is also improved.