JP3365853B2 - Method of manufacturing aluminum extruded element tube for photosensitive drum substrate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an aluminum extruded tube of a photosensitive drum incorporated in an electrophotographic type printing apparatus. [0002] In this specification, the term "aluminum" is used to include its alloys. [0003] An OPC photosensitive drum used in an electrophotographic type printing apparatus such as a copying machine, a printer, a facsimile or the like is used by thinly coating a photosensitive layer on an outer peripheral surface of a base made of aluminum. . Such a photosensitive drum substrate forms a uniform photosensitive layer and improves print quality.
High surface smoothness is required. [0004] With the spread of low-cost various printing apparatuses, photosensitive drum substrates are required to be mass-producible and have a low manufacturing cost. Therefore, good surface smoothness is obtained without requiring surface cutting. And a non-cutting aluminum pipe which is advantageous in terms of cost has been used. As a non-cutting aluminum tube, an aluminum tube called an ED tube manufactured by drawing an extruded raw tube or an EI tube manufactured by drawing an extruded raw tube is frequently used. In the manufacture of the above-mentioned non-cutting aluminum tube, not only is the surface finish in final drawing or ironing after extrusion important, but also the surface quality by these processes largely depends on the surface quality of the extruded raw tube. Therefore, the surface quality of the extruded raw tube being manufactured is also extremely important. Conventionally, in manufacturing such an extruded aluminum tube, an extrusion die made of a Fe-Cr-Mo type die steel or an extrusion die obtained by nitriding the die steel has been used. . However, the extruded raw tube extruded by the above-mentioned die has a sufficient surface quality, such as small flakes of aluminum scum adhering to the surface, causing defects such as horns. It was not something. If aluminum slag adheres to the extruded raw tube, it is stretched out by drawing or ironing and becomes scale-like or wire-like,
Occurrence of crenellated convex scratches. Even if a photoreceptor is coated on a substrate having such a surface defect, a uniform photosensitive layer cannot be obtained. Become. [0008] It is considered that the aluminum slag on the surface of the extruded raw tube is separated from the aluminum slag adhered to the bearing portion of the mold during the extrusion and is welded to the surface of the extruded raw tube. Then, based on the presumption that the adhesion of aluminum slag was in the deflection of the bearing portion of the mold, an attempt was made to manufacture an extruded raw tube with a cemented carbide mold having a higher high-temperature strength than the above-mentioned mold material. However, the aluminum slag sometimes adhered, and the surface quality of the extruded raw tube could not be improved. The present invention has been made in view of the above-mentioned technical background, and has as its object to provide and provide an aluminum extruded tube for a photosensitive drum substrate having a good surface quality. The inventors of the present invention have noticed that the amount of aluminum slag adhered to the bearing portion of the mold differs depending on the affinity between the material of the mold and aluminum. It has been found that by forming an extrusion die with a WC-Co-based cemented carbide having a low affinity and a specific composition, it is possible to suppress the amount of aluminum slag deposited on the surface of an extruded raw tube and to improve the surface quality. Was. That is, according to the method for producing an aluminum extruded raw tube for a photosensitive drum substrate of the present invention, the raw tube to be subjected to drawing processing is provided.
In producing an extruded tube for a photosensitive drum substrate by extruding aluminum, the bearing portion has a Co content of 1
The present invention is characterized in that aluminum is extruded using an extrusion die formed of less than 6% of a WC-Co cemented carbide. The amount of aluminum slag deposited on the surface of the extruded raw tube depends on WC-
It changes depending on the composition of the Co-based cemented carbide. FIG. 1 shows the relationship between the Co content in a WC-Co-based cemented carbide and the affinity for aluminum with the WC-Co-based cemented carbide plates having different Co contents. It is the graph shown by the wetting angle ((theta)) at the time of making aluminum contact. As shown in FIG. 2, the higher the affinity with the WC—Co-based cemented carbide (1), the more the molten aluminum (2) spreads and the wetting angle (θ) becomes As the value increases, the correlation between the Co content and the affinity for aluminum is seen as shown in FIG. That is, the WC-Co cemented carbide has a higher affinity for aluminum as the Co content increases, and aluminum slag easily adheres to a mold during extrusion, and the aluminum slag separates from the bearing portion. Thus, the amount of aluminum slag deposited on the surface of the extruded raw tube also increases. WC-Co
If the Co content is 16% or more in the cemented carbide composition,
The amount of aluminum slag deposited on the surface of the extruded tube becomes relatively large, and a large number of crenellated scratches are formed on the surface of the photosensitive drum substrate manufactured through drawing or ironing, thereby deteriorating print quality. Therefore, the Co content needs to be less than 16%, and particularly preferably 12% or less. On the other hand, if the Co content is less than 2%, the transverse rupture strength is undesirably reduced. In the extrusion die, only the bearing portion may be formed of a WC-Co cemented carbide having a Co content of less than 16%, or the entire die may be formed of an outer alloy. Is also good. The composition of aluminum extruded by the method of the present invention is not particularly limited.
Various types of alloys including 003 alloy can be used, and the extrusion conditions and the like may be the same as the conventional conditions. In the extrusion die used in the present invention, the bearing portion is formed of a WC-Co cemented carbide having a Co content of less than 16%, and has a low affinity for aluminum. Even so, aluminum slag does not easily adhere to the bearing portion. For this reason, there is no possibility that the aluminum slag attached to the bearing portion is detached and welded to the extruded tube. Next, specific examples of the method for manufacturing an aluminum extruded raw tube for a photosensitive drum according to the present invention will be described. Eleven porthole dies were manufactured by changing the Co content in the WC-Co cemented carbide composition from 2% to 22% by 2%. And A30 by each mold
03 aluminum was extruded from the tube under the following conditions. (Extrusion conditions) Extruder; 1800 tons, 6-inch container billet; A3003, 6 inches in diameter x 505 m in length
m, heating mold at 440 ° C; heating tube shape at 420 ° C; outer diameter 40.0mm x thickness 1.5mm Extrusion speed; 60m / min (base tube speed) Was evaluated by observing the appearance. Table 1 shows the evaluation results. [Table 1] As is apparent from Table 1, when a die having a Co content of less than 16% in the WC-Co cemented carbide composition is used, an extruded raw tube having a smooth surface state is obtained.
The surface condition of the extruded tube using a mold of 2% or less was good. As described above, the method for manufacturing an aluminum extruded raw tube for a photosensitive drum substrate according to the present invention comprises a drawing process.
A mother tube is subjected to, when the aluminum extruded to produce an extruded raw pipe for photoconductor drum substrate, extrusion base bearings portion is formed by a WC-Co cemented carbide under the Co content 16% Since a mold is used, the affinity between the bearing portion of the mold and aluminum is low, and aluminum slag is less likely to adhere to the bearing portion even when aluminum is extruded. As a result, there is no danger that the aluminum slag separates during the extrusion and is welded to the extruded tube, and an aluminum extruded tube for a photosensitive drum substrate having a good surface quality can be manufactured. Hence, it stresses before from such extruded raw pipe
To improve the surface smoothness of the photoconductor drum substrate is manufactured through pressurized Engineering, thereby improving the print quality to form a uniform photosensitive layer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between the Co content in a WC-Co-based cemented carbide and the affinity for aluminum. FIG. 2 is a cross-sectional view showing a wetting angle (θ) of molten aluminum with a WC-Co-based cemented carbide. [Description of Signs] 1: WC-Co cemented carbide 2: molten aluminum

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masatoshi Enomoto 224 Kaiyamacho, Sakai City Showa Aluminum Co., Ltd. (56) References JP-A-64-71519 (JP, A) JP-A-60-125348 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21C 25/02

Claims (1)

(1) Claims 1. A raw pipe to be subjected to a drawing process, in which when the aluminum is extruded to produce an extruded raw pipe for a photosensitive drum substrate, the bearing portion has a Co content of 16 % WC
-A method for producing an aluminum extruded tube for a photosensitive drum substrate, comprising extruding aluminum using an extrusion die formed of a Co-based cemented carbide.