Nordson Corporation

Harry J Lader

William R Rehman

Jeffrey R Shutic

Thomas E Hollstein

John F Carlson

Ernest J Fena

Keith E Williams

James W Messerly

Joseph G Schroeder

Gerald W Crum

Jeffrey A Perkins

Walter H Cobbs, Jr

Herman E Turner, Jr

Michael R Sanner

Jeffrey S Noss

James L Kennon

Jan L Shanaberger

Robert L Wacker

Dale R Juhn

Kevin C Becker

Richard C Morgan

Merle N Hirsh

David H Chow

James R Hollstein

An apparatus for applying powder coating material onto large objects such as automotive, truck or other vehicle bodies includes a powder spray booth defining a controlled area within which to apply powder coating material onto the vehicle bodies, a powder kitchen located at a remote position from the powder spray booth, and, a number of feed hoppers located proximate the booth which receive powder coating material from the powder kitchen and supply it to automatically or manually manipulated powder spray guns associated with the booth. Oversprayed powder coating material is removed from the booth interior by a powder collection and recovery system which transmits the oversprayed powder back to the powder kitchen for recirculation to the powder spray guns.

Vehicle powder coating system

A plurality of unconventional negative tribo-charging materials are described for use as the powder contact surfaces in tribocharging and corona powder spray guns, gun components, and powder delivery system components. The invention also provides a short barrel tribo-charging powder spray gun having an interchangeable powder contact insert and nozzle, with turbulence inducing air jets. The invention further provides novel tribocharging and corona gun designs. Improved powder coating systems are made possible wherein, for example, negative tribo guns can be utilized with negative corona guns to coat different parts of the same workpiece in a powder coating system.

Unipolarity powder coating systems including improved tribocharging and corona guns

Powder charge sleeve

A powder spray coating system includes a power source and an electrical supply line connected to the power source. A spray gun sprays powder in a spray pattern onto a part. The spray gun includes an electrode which charges powder as the powder is dispensed from the gun toward the part. The electrode is connected to the electrical supply line. A first current sensing device is located in the electrical supply line measuring gun current between the power source and the electrode. An ion collector or ABI probe is mounted with the gun for collecting free ions produced by the electrode. The collector has a forward portion positioned near the spray pattern and is spaced from the electrode. The collector is connected to a ground line. A second current sensing device is located in the ground line measuring back current between the ion collector and ground. A controller is connected between the power source and the electrode to control the gun current. The controller is also connected to the first and second current sensing devices for controlling the gun current in accordance with the difference between the measured gun current and the back current. By automatically controlling the current between the gun and the part, the present invention controls the field strength and the current between the tip of the gun and the ABI probe, making unnecessary adjustment of the position of the ABI probe in order to maximize the benefits of the probe in situations where the distance between the gun and the part changes.

Spray gun having a current monitored anti-back-ionization probe

In a triboelectric powder spray gun in which a charge is imparted to the powder triboelectrically by repeated impacts of the powder with contact surfaces, the charging effectiveness of the gun is enhanced by using an electrode to produce corona treatment of the contact surfaces. The corona treatments discharge the contact surfaces and eliminate the need for adjacent grounds with the powder flow path.

Triboelectric powder spray gun with internal discharge electrode and

An apparatus and method for utilizing and controlling finer particles in a powder coating system returns the finer particles to the spraying apparatus to be sprayed on parts by the system. Finer particles are continuously removed from the system by application onto parts, and the accumulation of fines is thereby prevented. The finer particles may be sprayed through specially adapted spray guns, which also permits the utilization of the special advantages of spraying fine powder materials. By removing fine powder particles from the system before they build up, the present invention improves the powder coating operation in various respects.

System for controlling and utilizing finer powder particles in a powder

A diaphragm assembly includes a pair of superposed flexible diaphragms adhesively secured to an annular spacer ring. The space between the diaphragms and the interior of the rings is filled preferably with de-ionized water. The resistivity of the water is monitored to detect conductivity changes upon leakage or diaphragm rupture when pumped materials or pump lubricant mix with the water. Diaphragm assembly and rupture detection methods are disclosed.

Dual diaphragm apparatus with diaphragm assembly and rupture detection

In an apparatus and method for measuring the strength of an adhesive bond, a dispenser applies adhesive to a substrate for a prescribed period of time, a conveyor moves the substrate to a compressing station within a preselected open time, after which time a compressor compresses the substrate against another substrate to form an adhesive bond therebetween, the bond being formed under a substantially constant compression force and for a preselected compression time. During the latter portion of the compression time, the bonded substrates are moved together at a substantially constant rate of speed through a transition distance, one of the substrates contacting a stop plate at the end of the compression time to prevent further movement while the other of the substrates continues at the substantially costant rate of speed to break the bond. A load cell measures the maximum pull force required to break the bond and also provides a real time analog signal for the pull force of the bond during tension, thereby to obtain an indication of the total energy expended in breaking the bond.

Method and apparatus for bond testing

Method and apparatus for charging powdered particles and delivering only these charged particles to a workpiece. A high voltage electric field is created between upper and lower surfaces. Powder is continuously delivered to the lower surface. The lower surface is vibrated to bounce the particles so that each repeatedly contacts the lower surface and picks up an electrostatic charge with each contact. When the charge from the particle is great enough to overcome gravity, the particle levitates and is thereafter transported to a workpiece, where it adheres by electrostatic attraction. Three important features of this method are: (1) No uncharged particles are levitated to the workpiece, thereby eliminating the need for recirculating uncharged powder. (2) The method is capable of producing high throughput of charged particles. (3) The method is capable of producing powder with a controlled charge level.

Method and apparatus for induction charging of powder by contact

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Lakewood, OH, United States of America

Harry J Lader