Polyurethane pultrusion products are made of a polyol and a highly reactive isocyanate that are easily and quickly mixed and formed. Isocyanate are selected for optimizing pultrusion properties. These properties are: low viscosity (guarantee good fiber impregnation), long gel time (convenient start-stop), rapid polymerization (enhance molding speed), good surface finish, and it has competitive power in cost. Compared with other materials, polyurethane pultruded products can improve the glass fiber content of the products and greatly increase the strength of the products, especially the flexural strength and tensile strength are far greater than those of traditional unsaturated polyester resins. For example, the window frame is pultruded with glass fiber and urethane resin. The strength of the new window frame is 8 times higher than that of the PVC window frame, and its electrical conductivity is 40 times lower than aluminum. Therefore, the insulation performance is much better.
Polyurethane pultruded profiles can be used for pultrusion production of new polyurethane profiles. The products can completely replace FRP pultruded profiles, including polyurethane window profiles, trays, trunkings, polyurethane channels, polyurethane tubes and other molded parts.