Process for Spraying a Band of Foam and Dispensing Nozzle Therefore

A process for spraying a band of foam of a desired width on a surface, comprising

• a) providing a pressurized source of foamable material having a dispensing nozzle for spraying a fan spray, or attaching a dispensing nozzle for spraying a fan spray to a pressurized source of foamable material,
• wherein said pressurized source is in fluid connection with the dispensing nozzle, the dispensing nozzle comprising an exit orifice for discharging the pressurized material, the exit orifice in fluid connection with a fan spray tip for forming the fan spray, the fan spray tip forming an exit face of the dispensing nozzle,
• wherein the fan spray tip provides a transverse slot in the exit face of the dispensing nozzle,
• the transverse slot formed by first and second spray-limiting walls, the walls having facing surfaces set apart from each other at the exit face of the dispensing nozzle,
• the transverse slot having a curved vertex end and an exit face end,
• wherein the curved vertex end is in fluid connection with the exit orifice, and the exit face end is in fluid connection with the exit face of the dispensing nozzle,
• wherein the first spray-limiting wall has an interior surface facing the second spray-limiting wall, and the second spray-limiting wall has an interior surface facing the first spray-limiting wall, and
• wherein between the exit face end and the curved vertex end of the transverse slot, the interior surface of the first spray-limiting wall has curvature towards the interior surface of the second spray-limiting wall, and the interior surface of the second spray-limiting wall has curvature towards the interior surface of the first spray-limiting wall, the two interior surfaces joining to form the curved vertex end of the traverse slot at the exit orifice, the curved vertex end having a vertex, and
• wherein
• i) the exit orifice has a dimension L parallel to the transverse slot at the connection to the fan spray tip,
• ii) the facing surfaces of the first and second spray-limiting walls are set apart a dimension W at the exit face of the dispensing nozzle,
• iii) the transverse slot has an overall depth D measured from the exit face of the dispensing nozzle to the vertex of the transverse slot, and
• iv) the ratio of D:W is 0.30 to 2.40;
• b) dispensing onto a surface a fan spray of the foamable material from the dispensing nozzle,
• the fan spray having a centerline plane that is parallel with the slot in the dispensing nozzle, and
• c) moving the dispensing nozzle perpendicular to the centerline plane of the fan spray to form a band of foam of the desired width on the surface.