Nihon Parkerizing Co., Ltd.

Nippon Paint Compnay, Ltd.

Onoda Cement Co., Ltd.

Kenzo Yanagida

Masahiro Yamamoto

Koichi Tsutsui

Mituyosi Kumata

Shannon Libke

Tsutomu Itoh

Yutaka Ishikawa

Hideo Nagasaka

Hiroshi Saitoh

Masayuki Kitoh

Mitsuyoshi Kumata

Takao Amasaki

Manabu Shimoizumi

Kazunori Fujita

In an electrostatic powder spray gun, a cylindrical air curtain is formed toward the front side of a gun main body by supplying compressed air to an air chamber formed between the outer peripheral surface of a cover member and an outer cylinder so as to eject the air from an air blowing opening. Owing to the air curtain, powder particles move toward an object to be coated without the risk of scattering to an ion trap electrode.

Electrostatic powder spray gun

A high voltage generated by a high voltage generator is applied to corona electrodes, and powder supplied from a powder flow passage collides against a diffuser main body while being moved in a vortex by air ejected from a vortex air introduction port and is ejected from a nozzle opening. After the powder is charged by ions generated by corona discharge, it is sprayed to an object to be coated. Free ions generated by the corona discharge are trapped by ion trap electrodes. The adhesion of the powder can be prevented by the ejection of compressed air through a diffuser front portion cover and an outer cylinder cover each composed of a porous member and the ejection of compressed air from a nozzle hole.

Electrostatic powder spray coating method

An electrostatic powder coating gun for dispersing aggregate powder onto substrates. The gun includes swirling air passage outlets to form a vortex of air inside the spray gun tip to reduce powder adhesion and assist in pulverizing the powder material. The coating gun employs a powder supply unit having a fluidized bed that includes temperature and humidity controls to adjust the temperature and humidity of the compressed air supplied to the spray gun and a mixer to agitate the powder in the container.

Electrostatic powder coating method and apparatus

An electrostatic powder coating apparatus is provided which includes a spray gun and a powder supply unit. The spray gun includes facilities for dually functioning to both pulverize and disperse the aggregated powder and powder adhesion preventing facilities. Both the pulverizing and dispersing facilities and the powder adhesion prevention facilities are provided in a nozzle lip of the spray gun of the electrostatic powder coating apparatus. The powder supply unit includes a temperature/humidity control facilities for adjusting the temperature and humidity of the compressed air supplied to an air chamber within the powder supply unit.

A powder flow rate is measured based on a simple construction so as to provide method and apparatus for measuring the powder flow rate for example of a powder coating material, requiring less maintenance cost and facilitating change of color of the coating material. In the method for measuring powder flow rate: a density .rho.1 of the powder within a tank is measured; the powder is drawn out from the tank into a conveying tube; a detecting fluid is blown at a flow rate Qf into the conveying tube a density .rho.2 of the powder in the conveying tube is measured; and a powder flow rate Fm is measured based on an equation of Fm=Qf.multidot..rho.1.multidot..rho.2/(.rho.1-.rho.2). The density .rho.1 of the powder in the tank may be measured by providing a pair of pressure measuring devices at different heights within the tank. The density .rho.2 of the powder in the conveying tube may be measured through a measurement of electrostatic capacity, light transmittance or ultrasonic wave transmittance in the conveying tube.

Method and apparatus for measuring powder flow rate

A thermal fixing roller for use in a copying machine and a method for manufacturing the thermal fixing roller are disclosed. An insulator layer is formed on an outer surface of a cylindrical metallic pipe, a masking wire material is wound in a spiral manner on the surface of the insulator layer and a heat-generating resistor is formed by spray coating heat-generating resistor material on the insulator and wire surfaces. Thereafter the wire material is removed to leave a groove at its trace, and thereby the above-mentioned heat-generating resistor can be formed in a spiral shape. By choosing pitches at the opposite end portions of this spiral resistor smaller than that at the central portion thereof, uniform temperature is maintained over the entire length of the thermal fixing roller. Also by forming a cross-section configuration of the masking wire material in a rectangular shape, it is allowed to reduce the width of the above-mentioned groove to minimum.

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Tokyo, Japan

Kenzo Yanagida