Impact strength, chopped integral strands

Impact Strength. Figure 6, notched Izod impact strength, shows one of the main reasons for the interest in chopped integral strands (c/s) as RRIM urethane reinforcement. The nonreinforced urethane polymer used in this study had an impact value of approximately 12 ft-lb/in. Reinforcement with 20% milled glass fibers lowers this value to about 5 ft-lb/in. (Column B). 

Urethane RIM panels reinforced with chopped integral strands have better impact strength, less heat sag, and less anisotropy than those reinforced with milled fiber, at the same loading level or higher. 

Tensile strength, elongation, and Impact properties of chopped strand RRIM urethane panels increased with increased integral strand aspect ratios flex modulus was not affected. 

Hybrid reinforcement of Integral chopped strand and milled fiber Improved flex properties but hurt Impact strength and heat sag. This could be due to the amount of milled fiber In the mixture. The hybrid contained about 70% by weight of milled fiber. The overriding properties were that of milled fiber composites. 

Four types of Si-PAA s were evaluated in 30% GR Valox-type PBT polyester. Aside from producing chopped strand with outstanding bundle integrity, the polyazamides generally outperformed A-llOO aminosilane in strength and thermal properties. Also, except for Y-5987, the polyazamides clearly outdistance the monomeric coupler in Izod impact strength. 

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