Thermosetting plastic refers to plastic, such as bakelite, epoxy plastic, which can be cured or insoluble (fused) under heat or other conditions. Thermosetting Plastics are divided into two types of crosslinking type and formaldehyde. The resin molecule is cross-linked into a net structure by the linear structure after the heat-forming process is formed with insoluble solidified material. A further increase in heat will break down the damage. Typical thermosetting plastics are phenolic, epoxy, amino, unsaturated polyester, furan, poly-silicon ether and other materials, as well as the newer poly-phthalic acid propylene ester plastic. They have high heat resistance, not easy to deformation and other advantages. The disadvantage is that the mechanical strength is generally not high, but can be made by adding fillers, laminated materials or molded materials to improve its mechanical strength.