Abstract: A glass fiber duct board has longitudinally extending, spaced-apart grooves in a major surface that facilitate the folding of the duct board into an air duct. The major surface, including the grooves, is coated with a polymeric latex coating to encapsulate glass fibers and dust within the surface of the duct board. The polymeric latex coating is applied to the surfaces of the grooves as a foam by application nozzles located downstream of groove cutting tools. The polymeric latex coating applied by the nozzles is distributed over the surfaces of the grooves and set to a predetermined thickness by wiper blades, located downstream of the nozzles, which have edge configurations complementary to the transverse configurations of the grooves being coated.

Abstract: Molded fibrous workpieces of various cross sectional configurations are coated with a polymeric latex foam coating material to encapsulate fibers and dust within the exterior surfaces of the workpieces. The foam coating is applied by passing the workpieces through a coating chamber filled with the polymeric foam so that the workpieces are totally immersed in the foam coating as the workpieces pass through the chamber. Openings for introducing the workpieces into and discharging the workpieces from the chamber have a configuration complementary to the transverse configuration of the workpieces. The foam coating is introduced into the chamber both above and below the path of the workpieces through the coating chamber to assure that the coating chamber remains fully charged with the foam coating. Brushes or wiper blades spread the foam coating over the exterior surfaces of the workpieces.

Abstract: Molded fibrous workpieces of various cross sectional configurations are coated with a polymeric latex foam coating material to encapsulate fibers and dust within the exterior surfaces of the workpieces. The foam coating is applied by passing the workpieces through a coating chamber filled with the polymeric foam so that the workpieces are totally immersed in the foam coating as the workpieces pass through the chamber. Openings for introducing the workpieces into and discharging the workpieces from the chamber have a configuration complementary to the transverse configuration of the workpieces. The foam coating is introduced into the chamber both above and below the path of the workpieces through the coating chamber to assure that the coating chamber remains fully charged with the foam coating. Brushes or wiper blades spread the foam coating over the exterior surfaces of the workpieces.

Abstract: An air/liquid polymeric latex foam coating generator includes a static splash plate mixer for forming a coarse foam coating and a conventional static refining mixer which further refines and homogenizes the coarse foam produced by the static splash plate mixer before delivering a refined foam to application heads or nozzles for application to a workpiece. The static splash plate mixer comprises a housing which is divided into two chambers by a splash plate. A stream of pressurized air and a stream of pressurized polymeric latex coating material are introduced into the upstream chamber where the streams intersect each other, impinge upon the splash plate and are mixed into a coarse foam in the upstream chamber. The foam passes through openings in the splash plate to the downstream chamber where the foam is further refine before being discharged from the static splash plate mixer.