SMC, also known as sheet molding compound, is also an insulating material. In the early 1960s, it was first developed in Europe. Then the United States and other developed countries introduced this technology and developed this kind of process in their own countries. Like laminate, sheet molding compound is also a kind of composite insulator material. China introduced this technology in the late 1980s. It is mainly composed of SMC special yarn, unsaturated resin and various fillers. SMC is widely used in transportation vehicles, construction, electronics or electrical industries with its superior electrical performance and corrosion resistance.
In fact, these two types of insulating materials are different. Its application scope is also certain, and there is no common overlap between them.
GPO-3 is widely used as an insulator in motors and electrical equipment, and can be used in circuit breakers, DC motors and AC contactors. It uses glass fiber felt board as the reinforcing material. It has high elastic modulus, good rigidity and excellent machinability. Even after processing, it is not layered or split. In terms of insulation, its surface resistivity and volume resistivity are relatively high and its insulation performance is good.
The elastic modulus of SMC is not as good as that of GPO-3 laminate, and its effect on unsaturated polyester is poor. Moreover, its elastic modulus is low, it is easy to deform, and its rigidity and machinability are relatively poor. In terms of insulation, the insulation resistance of SMC is very small compared with that of GPO-3. SMC is mainly used in electrical industry, electrical components and motor components. Some electrical enclosures, switch boxes, instrument panel covers and insulators of electrical appliances are made of SMC.
