Nordson Corporation

Wataru Kakuta

Masafumi Matsunaga

Laurence B Saidman

Gerald W Crum

Timothy E Wilson

Ronald E Niemiec

William L Palmer

Raymond J Merk

Donald A Chicatelli

Hikaru Saito

Methods and apparatus are disclosed for spraying powder into the interior of welded hollow can bodies from a spray gun mounted to the welding arm of a can forming machine. The spray gun can either apply a stripe of highly charged powder on the welded seam areas of hollow can bodies, or can simultaneously apply a coating of powder having a first thickness on the longitudinally welded seam areas and a second thickness less than the first thickness on the remainder of the interior surface. Air is vented off from the powder flow being transported through the welding arm so that the powder to air ratio is increased. Air is introduced at the downstream end of the welding arm to provide a suction force to help draw the powder flow through the welding arm and to increase the velocity of the powder flow for better tribo charging of the powder in the gun and to improve spray pattern stability. A flow of cleaning air through the powder spray gun prevents powder from collecting on the front surface of an offset nozzle secured to the spray gun. The gun assembly is affectively grounded to prevent arcing, and has an exterior shape which has been geometrically configured to improve powder coating of the can. A collector hood surrounds an input conveyor on which cans are transported while being spray coated and an output conveyor which removes the cans at a higher speed than at which they traveled on the input conveyor. The collector hood has two operating conditions for collecting oversprayed powder from between the cans during the spraying operation or directly from the gun when the cans are not being sent down the line.

Densifier for powder coating welded cans

Apparatus for powder coating welding cans

Methods and apparatus are disclosed for spraying powder into the interior of welded hollow can bodies from a spray gun mounted to the welding arm of a can forming machine. The spray gun can either apply a stripe of highly charged powder on the welded seam areas of hollow can bodies, or can simultaneously apply a coating of powder having a first thickness on the longitudinally welded seam areas and a second thickness less than the first thickness on the remainder of the interior surface. Air is vented off from the powder flow being transported through the welding arm so that the powder to air ratio is increased. Air is introduced at the downstream end of the welding arm to provide a suction force to help draw the powder flow through the welding arm and to increase the velocity of the powder flow for better tribo charging of the powder in the gun and to improve spray pattern stability. A flow of cleaning air through the powder spray gun prevents powder from collecting on the front surface of an offset nozzle secured to the spray gun. The gun assembly is affectively grounded to prevent arcing, and has an exterior shape which has been geometrically configured to improve powder coating of the can.

Apparatus for powder coating welded cans

An improved powder particle supply and transport apparatus and method include a hopper filled with powder particles, an ejection chamber spaced from the hopper and a movable conveying member with a plurality of cavities formed therein. During operation, the conveying member moves the cavities between the hopper and the chamber, and the cavities are filled with powder particles at the hopper and emptied of powder particles at the chamber. An ejector nozzle sprays pressurized air into the chamber toward an aligned outlet, thereby to: 1) create negative pressure in the chamber to draw powder particles from the cavities as the cavities are moved therethrough; and 2) transport powder particles through the outlet to a spray gun. Additional structure may be used to assure complete powder filling of the cavities at the hopper and/or complete powder emptying of the cavities in the chamber. The invention achieves supply and transport of uniform and stable quantities of powder particles to a spray gun, even over very small units of time, regardless of powder particle size and/or cohesive properties.

Apparatus and method for supply and transport of powder particles

An apparatus for applying coating material to inner surfaces of cans includes a coating material spray gun and a cleaning material spray gun which are mounted in a side-by-side relationship on a manifold block. The coating material spray gun is connected in fluid communication with a coating material supply conduit through the manifold block. The cleaning material spray gun is connected in fluid communication with a cleaning material supply conduit through the manifold block. The cleaning material spray gun is operable to direct a flow of cleaning material toward a nozzle on the coating material spray gun to clean the nozzle. Three point mounting systems are utilized to accurately mount the spray guns on the manifold block. A heater is provided to maintain body of coating material in the coating material spray gun at a desired temperature. A transducer is provided to sense changes in the pressure of the coating material during operation of the coating material spray gun from a closed condition to an open condition. Cleaning material is conducted through the coating material spray gun to clean an interior portion of the coating material spray gun. The operating stroke of valve assemblies in the coating material spray gun and the cleaning spray gun are set by utilizing shims having thicknesses corresponding to the desired operating strokes of the valve assemblies.

Apparatus and method for applying coating material

Growing community of inventors

Kanagawa, Japan

Wataru Kakuta