JPH01127077A - Apparatus for removing film on inner peripheral surface of end part of drum - Google Patents

Abstract

PURPOSE:To exert no effect on a film, by holding a drum to a drum holding stand so as to bring the peripheral surface thereof to an airtight state to introduce a solvent into the drum. CONSTITUTION:After the opening and closing valve 35 of the solvent recirculation pipe 34 provided to a treatment tank 10 is brought to a closed state, a pump 33 is driven to return the solvent in a solvent tank 31 to the treatment tank 10. The returned solvent is stored in the treatment tank 10 and, when the solvent is further returned to the treatment tank 10, the solvent penetrates the piercing hole 21 of a drum 50 without flowing out to the outside of the drum 50. When the solvent further penetrates the drum 50 to immerse the inner peripheral surface of the lower end part of the drum 50 in the solvent, the driving of the pump 33 is stopped to immerse said inner peripheral surface in the solvent for a predetermined time. By repeating this operation, the deposited film is dissolved and removed from the inner peripheral surface of the drum 50.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used in manufacturing an electrophotographic photoreceptor drum by applying a photosensitive substance to the outer circumferential surface of the drum, for example, by dip coating. The present invention relates to a device for removing a coating film adhering to the inner circumferential surface of an end portion of a drum after coating.

(Prior Art) One of the methods for manufacturing photosensitive drums for electrophotographic copying machines is a dip coating method in which the drum is immersed in a photosensitive material and then pulled up to apply a photosensitive material to the outer circumferential surface of the drum. . In such a dip coating method, for example, the drum is immersed in the coating solution using an air chuck method in which the drum is held approximately vertically by a holder that is airtightly fitted into the drum, and the drum is immersed in the coating solution. It is pulled up from the liquid. In this air chuck method, since there is air inside the drum, there is no risk that the entire inner peripheral surface of the drum will be coated with the coating liquid during dipping, but since the air inside the drum is compressed, the coating liquid may be applied to the bottom end of the drum. Liquid gets in. Therefore, when the drum is lifted out of the coating liquid, the coating liquid adheres to the inner circumferential surface of the lower end portion of the drum. Also.

Until the coating liquid applied to the outer peripheral surface of the drum dries, a liquid pool is formed at the lower end, and this liquid pool flows from the end face of the drum to the inner peripheral surface and adheres to the inner peripheral surface. When the applied coating liquid dries, it hardens to form a coating film.For example, when a flange is attached to the end, there is a possibility that the flange cannot be fitted. In this case, if an attempt is made to forcefully fit the flange into the end of the drum, there is a risk that the drum itself will be deformed, or that the flange and the drum may not be in a predetermined fitted state. In such a state, the drum cannot be used as an electrophotographic photosensitive drum. Furthermore, when fitting the flange to the end of the drum, there is a risk that the coating film on the inner circumferential surface of the end of the drum may be scraped off and fall into the drum.

Therefore, it is necessary to remove the coating film adhering to the inner peripheral surface of the end portion of the drum. Conventionally, the paint film adhering to the inner circumferential surface of the end of the drum was wiped off by one worker with a rag or the like. This work has the disadvantage that the inner circumferential surface of the end of the drum must be cleaned without damaging the photosensitive material applied to the outer circumferential surface of the drum, requiring extreme care and poor work efficiency.

In order to eliminate such drawbacks, Japanese Patent Application Laid-Open No. 60-168
Japanese Patent No. 154 proposes an apparatus for removing a coating film from the inner circumferential surface of a drum end. This device injects a solvent capable of dissolving the coating film into the lower end of the drum held approximately vertically,
The coating film on the inner peripheral surface of the lower end of the drum is removed. The coating film adhering to the inner circumferential surface of the lower end of the drum is dissolved in the solvent and removed from the inner circumferential surface of the drum, and the catch together with the solvent is once collected in a tray and then stored in a solvent tank.

(Problems to be Solved by the Invention) The apparatus disclosed in the above-mentioned publication uses a solvent that can dissolve the coating liquid applied to the outer peripheral surface of the drum. Therefore, since the solvent can also dissolve the coating film of the coating liquid applied to the outer circumferential surface of the drum, it is necessary to prevent the solvent from adhering to the outer circumferential surface of the drum.

However, since the apparatus disclosed in the above-mentioned publication uses a nozzle to inject the solvent onto the inner circumferential surface of the drum, there is a risk that the solvent droplets may adhere to the outer circumferential surface of the drum.

When processing a large number of drums with this device.

There is a high possibility that solvent droplets will adhere to the outer peripheral surface of the adjacent drum. The solvent that has dissolved the paint film attached to the inner circumferential surface of the drum is temporarily stored in a pan located below the drum, so that the vapor of the solvent in the pan can have an adverse effect on the paint film on the outer circumferential surface of the drum. There is also a risk of harm.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to provide a device that can remove the paint film attached to the inner peripheral surface of the drum end without adversely affecting the paint film on the outer peripheral surface of the drum. It is about providing.

(Means for solving problems) The present invention provides an apparatus for removing a coating film on the inner circumferential surface of a drum end.

An apparatus for removing a coating film adhering to the inner peripheral surface of an end of a drum having a coating film formed on the outer peripheral surface thereof, and a processing tank in which a solvent capable of dissolving the coating film is supplied and discharged.

The drum holder is equipped with a drum holder for airtightly holding the drum in the processing tank, and a solvent supply/discharge means for supplying and discharging the solvent to the processing tank, and the drum holder is configured to hold the inside of the held drum. It has a through hole that communicates with the inside of the processing tank, thereby achieving the above object.

(Example) The present invention will be described below with reference to Examples.

The present invention provides an apparatus for removing a coating film on the inner circumferential surface of a drum end.

For example, it is used when manufacturing photoreceptor drums for electrophotography.2 For example, after a coating liquid is applied to the outer peripheral surface of the drum by dip coating to form a coating film that is a photosensitive layer, it adheres to the inner peripheral surface of the drum. Remove paint film.

As shown in FIG. 1, the apparatus of the present invention includes a processing tank 10 in which a drum holder 20 is disposed, on which a drum 50 to be treated to remove the coating film on the inner peripheral surface of the end portion is held in a substantially vertical state. , a solvent capable of dissolving the coating film on the inner peripheral surface of the drum end is added to the treatment tank 1.
The processing tank 10 has a solvent supply/discharge means 30 capable of supplying the solvent into the processing tank 10 and discharging the solvent from the processing tank 10.

A solvent supplied by a solvent supply/discharge means 30 is stored in the processing tank 10 , and the solvent is discharged from the processing tank 10 by the solvent supply/discharge means 30 .

A drum holding stand 20 disposed within the processing tank 10 is made of, for example, fluororesin with excellent chemical resistance, and is airtightly attached to the upper inner peripheral surface of the processing tank 10 .

A truncated conical through hole 21 whose diameter decreases toward the bottom is provided in the center of the drum holder 20. Therefore, the circumferential surface of the through hole 21 is a tapered surface 22 whose diameter decreases toward the bottom.

The outer circumferential surface of the end of the drum 50 held by the drum holder 20 has a tapered surface 51 whose diameter decreases toward the end surface so that it can come into airtight contact with the tapered surface 22 of the drum holder 20. It has become. Further, the inner peripheral surface of the end portion of the drum 50 also has a tapered surface 52 whose diameter increases toward the end surface side.

The solvent supply/discharge means 30 includes a solvent tank 31 in which a solvent capable of dissolving the coating liquid applied to the outer peripheral surface of the drum 50 is stored, and a connecting pipe 32 that connects the solvent tank 31 and the processing tank 10. A solvent circulation pipe 34 is provided in the processing tank 10 and discharges the solvent in the processing tank 10 to the solvent tank 31.

An on-off valve 35 is provided in the solvent circulation pipe 34.

The lower part of the solvent circulation pipe 34 is located in the upper part of the solvent tank 31 . A filter 31 a is disposed in the solvent tank 31 so as to face a drain port at the lower end of the solvent circulation pipe 34 .

The connecting pipe 32 communicates the bottom of the solvent tank 31 and the bottom of the processing tank 10, and the connecting pipe 32 is provided with a pump 33. The pump 33 can circulate the solvent in the solvent tank 31 into the processing tank 10 .

The operation of the apparatus of the present invention having such a configuration is as follows. First, the on-off valve 35 of the solvent circulation pipe 34 disposed in the processing tank 10 is opened to remove the solvent remaining in the processing tank 10. In this condition.

For example, a drum 50 on which a coating liquid is applied to the outer peripheral surface by a dip coating method and a coating film is formed by drying the coating liquid,
The drum is placed on the drum holder 20 so as to be in a substantially vertical state. The outer peripheral surface and the inner peripheral surface of the end of the drum 50 are tapered surfaces 51 and 52, respectively, so when the drum 50 is placed on the tapered surface 22 of the drum holder 20, the outer peripheral surface and the inner peripheral surface are tapered as shown in FIG. To.

A tapered surface 51 on the outer circumferential side at the end of the drum 50 contacts the tapered surface 22 of the drum holder 20 in an airtight manner.

In this state, after closing the on-off valve 35 of the solvent circulation pipe 34 provided in the processing tank 10, the pump 33 installed in the connecting pipe 32 is driven to process the solvent in the solvent tank 31. Return to tank 10. The solvent returned to the processing tank 10 is stored in the processing tank 10, and when the solvent is further returned to the processing tank 10, the solvent flows through the through hole 21 of the drum holding base 20.
penetrate inside. At this time, the tapered surface 22 of the drum holding base 20 has a tapered surface 51 on the outer peripheral side of the end of the drum 50.
Because they are in airtight contact.

The solvent that has entered the through hole 21 enters into the drum 50 without flowing out of the drum 50. And drum 5
When the inner circumferential surface of the lower end of the drum 50 is immersed in the solvent, the drive of the pump 33 is stopped, and the inner circumferential surface of the lower end of the drum 50 is immersed in the solvent for a predetermined period of time (approximately 5 to 10 seconds).

After a predetermined period of time has elapsed, the on-off valve 35 of the solvent circulation pipe 34 is opened, and the solvent in the processing tank 10 is returned to the solvent tank 31 through the solvent circulation pipe 34. The solvent discharged from the solvent circulation pipe 34 to the solvent tank 31 is filtered by the filter 31a, and impurities mixed in the solvent are removed from the solvent.
It is stored in the solvent tank 31.

Such an operation is repeated about 30 to 40 times, and during this time, the coating film adhering to the inner peripheral surface of the end portion of the drum 50 is dissolved in the solvent and removed from the inner peripheral surface of the drum 50.

In this embodiment, the drum 5 from which the coating film on the inner circumferential surface of the end portion is removed is
Since the outer circumferential surface of the end portion of 0 is a tapered surface 51, even if the coating liquid is applied to the outer circumferential surface of the drum by dip coating, the liquid pools on the inner circumference of the drum due to the surface tension on the tapered surface 51. Adhesion to surfaces can be suppressed as much as possible. Since the inner circumferential surface of the end of the drum 50 also has a tapered surface 52, when the drum is immersed in the coating liquid during dip coating, the air between the end of the drum 50 and the coating liquid flows through the tapered surface 51 and the coating liquid. 52, the drum 50 can be immersed without retaining air between the end of the drum 50 and the coating liquid. Therefore, there is no possibility that air bubbles will be generated and adhere to the outer circumferential surface of the drum 50, thereby making the thickness of the coating liquid on the outer circumferential surface of the drum non-uniform. Each tapered surface 51 and 52.

It is preferable to form the drum end face so that the thickness a (see FIG. 1) is approximately b/2 to b/3 relative to the thickness b (see FIG. 1) of the drum 50.

(Effect of the invention) The present invention provides an apparatus for removing a coating film on the inner circumferential surface of a drum end.

In this way, the drum is held on the drum holder so that its circumferential surface is airtight, and the drum is placed inside the drum.

Because we introduce a solvent that can dissolve the paint film,
The solvent does not adhere to the coating film on the outer circumferential surface of the drum, and
The coating film on the inner peripheral surface of the drum end can be removed without the coating film on the outer peripheral surface of the drum being adversely affected by solvent vapor. As a result, the flange on the drum end also without deforming the drum.

It can be easily inserted into a predetermined state.

Figure 1 is a sectional view showing an example of the apparatus of the present invention, and Figure 2 is an explanatory diagram of its operation.

10... Processing tank, 20... Drum holding stand, 21...
・Through hole.

22...Tapered surface, 30...Solvent supply and discharge means, 31
...Solvent tank.

31a...filter, 32...connecting pipe, 33...
Pump, 34...solvent circulation pipe, 35...on/off valve.

that's all

Claims (1)

[Claims] 1. A device for removing a coating film attached to the inner circumferential surface of an end of a drum having a coating film formed on the outer circumferential surface, in which a solvent capable of dissolving the coating film is supplied and discharged. A processing tank, a drum holding stand for airtightly holding the drum in the processing tank, and a solvent supply/discharge means for supplying and discharging the solvent to the processing tank, and the drum holding stand holds the drum. A coating film removal device for an inner circumferential surface of an end of a drum having a through hole that communicates the inside of the drum with the inside of the processing tank. 2. The coating film removal device for the inner circumferential surface of the drum end according to claim 1, wherein the abutting surfaces of the drum holding base and the drum circumferential surface are mutually tapered. 3. The solvent supply/discharge means includes a solvent tank in which the solvent is stored, a connecting pipe connecting the solvent tank and the processing tank, a pump provided on the connecting pipe, and a pump installed at the bottom of the processing tank. The apparatus for removing a coating film from the inner peripheral surface of a drum end according to claim 1, comprising a solvent circulation pipe disposed and communicating with the solvent tank, and an on-off valve provided on the solvent circulation pipe.