What are the advantages of polyurethane resin pultrusion compared with unsaturated resin and epoxy resin?

The mechanical and physical properties of polyurethane resin pultrusion products formed by pultrusion by high-pressure injection of polyurethane resin injection machine are compared with unsaturated polyester, vinyl ester, Epoxy resin and other resins, the physical properties of polyurethane have been comprehensively improved. Take, for example, a polyurethane specially formulated for the pultrusion process. Polyurethane resin pultrusions exhibit excellent flexural strength, flexural modulus, and short-beam shear properties. Overall, polyurethane is 2 to 5 times stronger and more rigid than polyol.

The typical physical and mechanical performance of polyurethane resin for pultrusion is as follows:

Comparison of advantages and disadvantages of various resins

It is worth mentioning that the water absorption of polyurethane pultruded products is much lower than that of other resins because of the hard surface and low porosity. Generally speaking, when pultruded products absorb water or other solutions, the exuded liquid may cause degradation, especially those resins that are easily hydrolyzed. In order to improve water resistance and UV protection, it can be applied to the surface of polyurethane pultruded products.