Baybond PU 403 is an anionic/non-ionic crosslinking polyester urethane polymer. It is used as the film-forming component in glass fiber sizes. Properties / Applications: Baybond PU 403 was developed for the sizing of glass fibers used to reinforce thermoplastics, particularly polyamide. Glass fiber sizes based on Baybond PU 403 are characterized by their outstanding film-forming properties and very good adhesion. They have high colorfastness, even at elevated temperatures. The mechanical film properties of Baybond PU 403 are enhanced by post-crosslinking at temperatures from 170°C for a duration of 30 minutes. Baybond PU 403 is also very stable against shear forces. As with any product, use of Baybond PU 403 in a given application must be tested (including but not limited to field testing) in advance by the user to determine suitability. Information provided by Covestro |