MOLD MASKING APPARATUS AND METHOD

摘要

A method and apparatus is disclosed for powder coating the interior surface of a heated mold cavity. Electrostatically charged powder is sprayed upwardly onto the interior surface of a mold surrounded by a mask. The mask includes a shield located adjacent to but spaced from the shear edge of the mold. Additionally, the mask includes a vacuum duct located beneath the shield. While air is drawn into the vacuum duct air is either blown through the slot defined between the shield and the mold shear edge or air is pulled into the slot so as to prevent oversprayed powder from coming into contact with and adhering to the shear edge of the mold. There is no enclosure surrounding the mold cavity other than the mask because rising heated air currents entrap and maintain the cloud of sprayed powder interiorly of the mold cavity and the surrounding mask. Any oversprayed material escaping from the cavity is caught in the vacuum duct and carried to a powder collector.