Apparatus for the coating of glass containers has a series of vertical slots for applying coating chemicals to a hot glass jar with a minimal neck and shoulder area. An opposing horizontal slot exhausts spent coating material and reactants in a laminar flow. A center section provides a current of gas without chemicals parallel to the coating stream, and flowing with low velocity relative to the coating stream, but with high velocity relative to the extraneous turbulent and convection currents.
Apparatus and method for coating hot glass bottles are improved by providing a controlled non-turbulent air supply directed downward across the coating material stream. The apparatus has a relocated blower for delivering process fluid (e.g. air) into an end of a plenum upper chamber, passing the air first through an permeable attenuator, then into a lower plenum chamber and finally through a diffuser plate to provide a uniform stream of process air directed downward across the coating-material stream into the finish region of the bottle. In the method, process air is blown to a plenum, through an angled attenuator plate with small holes to distribute the process air evenly and to avoid standing waves and regions of high or low air velocity. Several attenuator plates can be juxtaposed to permit removal of particulates by movement of the plates relative to each other. An iris or throttle valve after the blower can be used as an additional method of controlling the force and velocity of process air. A clean out is provided in the plenum through which the attenuator plates can be removed or cleaned. The method is improved by passing the air through an attenuator plate mounted at an angle to the flow of process fluid to provide a controlled non-turbulent air supply.
