JPS58109166A - Electrostatic drum coating method - Google Patents

Abstract

PURPOSE:To form a dielectric layer with a uniform ruggedness distribution easily by scattering powder particles over the injection passage of a spray gun for liquid coating agent injection and applying its mixture to an electrostatic drum surface. CONSTITUTION:A liquid sprya gun 2 is equipped on a guide rail 3 and powder spray guns 4 are fixed on both sides of the liquid spray gun 2 in such a manner that the both reciprocate along the guide rail 3. A liquid coating agent 10 is spouted from the liquid spray gun 2 and at the same time, powder particles 11 for forming a rugged sirface such as alumina particles of about 8-16 particle size are spouted from the powder spray guns 4 on both sides; and they are allowed to reciprocate on the guide rail 3, thus coating the surface of a cylindrical electrostatic drum. Consequently, the alumina powder particles 11 are dispersed uniformly in the liquid coating agent 10 to laminate a dielectric layer which has a uniform rugged surface.

Description

Detailed Description of the Invention (1) Technical Field of the Invention Jl-Invention [Phase] on the surface of an electrostatic drum in which a dielectric layer is formed by spraying on the surface of the electrostatic drum of an electrostatic printer
This relates to the mounting method.

(2) Background of the Technology The electrostatic drum of an electrostatic printer is a cylindrical drum made of aluminum or the like, with a dielectric layer formed on the surface of the drum via a resistance layer made of carbon or the like.

In an electrostatic printer, electric charges are removed from this dielectric layer using a uniform electrode made by Teiden in accordance with the image to form a complete image, and this latent image is transferred to recording paper using fAW with toner. The desired image gIt- is obtained.

The dielectric layer of such an electrostatic drum has conventionally been formed as a mirror-like surface with a uniform thickness in order to make the charge distribution uniform. In order to form a high-resolution skin image on such a mirror-like dielectric layer, the pin electrode must be brought close to the drum surface. The problem arises that In view of this point.

In recent years, the surface of the electrotropic material layer has been formed as an uneven surface, and even if the distance between the pin electrode and the drum surface is increased, a good discharge effect can be obtained, and the uneven surface can also be prevented from clogging by floating toner. Electrostatic drums have been developed.

(3) Discrepancies between the conventional technology and the conventional technology: When forming a dielectric layer on an electrostatic drum by painting, 0.3 μM4! i1 degree dielectric particles such as alumina t
A liquid coating agent mixed in a solvent with a binder such as acrylic or melamine resin is sprayed onto the surface of a drum that rotates at high speed by spraying it to a thickness of approximately 20 to 3 mm.
A uniform dielectric layer of 0.011 m is formed. In order to form the electrostatic drum with the uneven surface described in #, it is necessary to mix powder particles with a large particle size (8 to 16 μm) to this liquid coating agent for forming a dielectric layer. When spraying onto the entire drum surface of a liquid coating agent containing powder particles with such a large particle size and therefore a large weight, the powder particles in the coating agent are uniformly dispersed.9 VC Because of this, the powder particles are not uniformly dispersed and coated on the drum surface, and the unevenness of the drum surface varies greatly depending on the location.As a result, the discharge characteristics of the bottle electrode change in a JaPfr manner, making it impossible to form a stable latent image.

(4) Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a method for coating an electrostatic drum that can easily provide a uniform uneven surface using a simple mechanism. .

(5) 411th Accomplishment of the Invention In order to achieve this object, the present invention comprises scattering powder particles for forming irregularities on the drum surface onto the injection path of a spray gun for injecting a liquid coating agent. The particles and the liquid coating agent are mixed on the injection path, and the mixture is coated on the surface of the electrostatic drum.

(6) Example of invention #! FIG. 1 is a block diagram of a coating apparatus for carrying out the method of the present invention. A cylindrical electrostatic drum 1 rotates at high speed around a shaft 7. As shown in FIG. A liquid spray gun 2 for spraying a liquid coating agent is mounted on a guide rail 3 so as to be able to slide back and forth as shown by arrow A. Powder spray guns 4 for spraying powder particles for forming an uneven surface are fixed to both sides of the liquid sagging gaff 20 and reciprocate together with the liquid spray guns 2 along guide rails 3. 5 is a powder container.

A liquid coating agent 10 (which may contain fine particles made of a dielectric material such as aluminum with a particle size of about 0.3 μm) is sprayed from the liquid spray gun 2, and at the same time the powder on both sides is sprayed. Powder particles 11t for forming unevenness of Narumina particles having a particle size of about 8 to 16 μm are sprayed from the body spray gun 4. The spraying direction of the double-wheeled spray gun 4 and the spraying direction of the liquid spray gun 2 are made such that they intersect somewhat in front of each other due to the electrostatic charge and the surface of the 2mm 1, and the spraying pattern of each souffle gun is If the shape is flJ, a! As shown in Figure 2, liquid spray gun 2 is represented by a, powder spray gun 4 is represented by b and C, and the area a on the drum surface is about 80 to 100% of the combined area of b and C. Determine the spray direction of each spray gun so that The air pressure to obtain the injection pressure of liquid spray gun 2 is 1-1.511
4/ctl, 9 atm to obtain the injection pressure of the powder spray gun 4 is 0.5 to 1 Kg/ls? Liquid coating agent 10 and unevenness forming powder particles 111I'i
The powder particles 11 are well mixed on the injection path and are uniformly dispersed and attached to the surface of the electrostatic drum, and are applied during liquid application 4310 onto the carbon resistance layer 13 on the aluminum drum body 12 as shown in FIG. A dielectric layer 14 having an uneven surface formed by uniformly dispersing alumina powder particles 11 is laminated.

FIG. 4 is a block diagram showing another embodiment of the invention. This 5J! In the embodiment, a container 6 containing powder particles of the unevenness forming layer is provided above the injection path of the liquid coating agent 10 injected from the body spray gun 2, and a mesh member provided at the outlet of the powder container 6. (not shown) through which powder particles 11 are injected with liquid coating agent lO! ◇8 is a liquid coating agent supply pipe; 1
2 is a compressed air supply pipe. The powder axle 11 is uniformly mixed with the liquid coating agent 16 in the spraying passage, and the spraying pressure causes the powder axle 11 to be deposited on the surface of the electrostatic drum 1 rotating in the direction of arrow B, as shown in FIG. Forming the dielectric layer 14 with a uniform distribution of unevenness 〇 (7J J7A Effect of Light□) As explained above, in the electrostatic drum coating method according to the invention, Fi, in the liquid coating agent sprayed by the liquid spray gun. without mixing powder particles for forming irregularities in advance.
Powder particles are mixed by supplying the powder particles onto a liquid jet passage close to the coating surface from a system different from that of the liquid spray gun. Therefore, the powder particles are uniformly dispersed and mixed into the coating agent and adhered to the surface of the drum in a uniform manner, thereby easily forming a #stop layer with a uniform unevenness distribution.

[Brief explanation of the drawing]

Figure 1 shows a coating apparatus O'M4 for carrying out the method of the present invention.
Fig. 2 is a plan view showing the spray pattern shape of the coating device shown in Fig. 1, Fig. 3 is a cross-sectional view of the surface of the nine electrostatic drum formed by the method of the present invention, and Fig. 84 is a plan view showing the spray pattern shape of the coating device of Fig. 1. It is a WII diagram of another example of a coating device for coating. l... Electrostatic drum, 2... Liquid spray gun. 4...Powder spray gun, 5,6...Powder container. 10...Liquid coating agent, 11...Powder particles. Patent applicant Fujitsu Ltd. Patent application agent Minoru Masuji: Ro Masuji Kazuyuki Nishidate Masuji Yukio Uchida Masuji Akiyuki Yamaguchi Figure 1 C Figure 2 Figure 3] 2 Figure 4

Claims (1)

[Claims] 1. In an electrostatic drum surface mounting method in which a dielectric layer is formed by spraying on the surface of an electrostatic drum of an electrostatic printer, 2. There are irregularities on the drum surface like the injection passage of a spray gun for ejecting a liquid coating material. The powder particles and the upper B liquid coating agent are mixed on the above-mentioned injection passage by scattering the powder particles to form the upper B pipe, and the mixture is transferred to the electrostatic dome! ! An electrostatic drum coating method characterized by coating the surface.