Michelman (Cincinnati, Ohio) is introducing two polyurethane dispersions designed as fiber sizing for reinforced composites in automotive underhood applications. Hydrosize Link dispersions react directly with the matrix resin, delivering what is said to be exceptional composite performance under extreme exposure to water, ethylene glycol and high temperatures. Michelman says Hydrosize Link technology eliminates the fiber producer’s step of adding secondary crosslinkers such as blocked isocyanates to the sizing bath. This reportedly not only simplifies the fiber manufacturing process, but also allows better control over the desired degree of reactivity, and ultimately, composite performance. The two new grades differ in their level of reactivity.