The mechanical and physical properties of polyurethane resin pultruded products formed by high-pressure injection using a polyurethane resin injection machine are compared to those of unsaturated polyester, vinyl ester, The physical properties of resins such as epoxy resin and polyurethane have been comprehensively improved. Take, for example, a certain polyurethane specially formulated for the pultrusion process. Polyurethane resin pultruded products exhibit excellent flexural strength, flexural modulus and short beam shear properties. Overall, polyurethane is 2 to 5 times stronger and stiffer than polyurethane.
Typical physical and mechanical properties of polyurethane resin for pultrusion are as follows:
Bending strength/MPa |
1200 |
D790 |
Flexural modulus/GPa |
48 |
D790 |
Bending strain/% |
3.0 |
D790 |
Pendulum impact strength/Jk ·m-2 |
>189 |
(ISO 179) |
Short shear strength/MPa |
62 |
D2344 |
Heat distortion temperature (1820KPa) |
/℃ 240 |
D648 |
Comparison of the 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 the surface is hard and the porosity is also very low. Generally speaking, when pultruded products absorb moisture or other solutions, the exuded liquid may cause degradation, especially those resins that are prone to hydrolysis. In order to improve the water resistance and UV protection, it can be applied on the surface of polyurethane pultruded products.