SMC Light Duty Manhole Cover

Resin manhole cover (also called polymer glass fiber reinforced plastic manhole cover/composite manhole cover) is a kind of glass fiber and its products (glass cloth, tape, felt, yarn, etc.) as reinforcing materials, and synthetic resin as matrix material, it is mainly composed of unsaturated polyester resin, fillers, initiators, thickeners, low shrinkage additives, film mold agents, pigments and reinforcing materials, etc., and then high-temperature compression molding is a new type of manhole cover product.    The main addition materials are fiber reinforced materials (glass cloth, tape, felt, yarn, etc.), which are characterized by small specific gravity, large specific strength and specific modulus. For example, carbon fiber and epoxy resin composite materials have specific strength and specific modulus several times larger than steel and aluminum alloys. They also have excellent chemical stability, friction reduction, wear resistance, self-lubrication, heat resistance, fatigue resistance, and Creep, noise reduction, electrical insulation and other properties. The composite of graphite fiber and resin can obtain a material whose expansion coefficient is almost equal to zero. Another feature of fiber reinforced materials is anisotropy, so the fiber arrangement can be designed according to the strength requirements of different parts of the product. . The aluminum-based composite material reinforced with carbon fiber and silicon carbide fiber can still maintain sufficient strength and modulus at 500°C. The composite manhole cover can be divided into two types: BMC and SMC according to market demand, production process and materials.   The characteristics of resin manhole covers play a great role in life, so they are widely used.