a scraper bar for use with conveyor belting and the like to clean such belting of material adhering to its surface . the scraper bar consists of a layer of hard abrasion - resistant pellets embedded in an elastomer to form an elastomer / pellet matrix . an additional layer of elastomer is cast to the matrixed layer to provide a surface for attaching the scraper to its support when in service . embedded in the layer of unmatrixed elastomer is an insert of particle board , chipboard , plywood or fibreglass reinforced plastic sheeting . the insert prevents bowing of the scraper bar due to differential shrinkage between the layer of matrixed elastomer and pellets and the supporting layer of elastomer .