JPH06269716A - Coating apparatus - Google Patents

Abstract

PURPOSE:To obtain a coating apparatus preventing coating material from being splashed from a coating roll by constituting the roll end part in the axial center direction in the opposite areas to a coating thickness regulating member for the coating roll so that it may act as a nonrotating part which becomes a nonrotating state at least on coating. CONSTITUTION:In a coating apparatus, magnetic coating material is fed to a coating part 1a of a rotating gravure roll 1 to fill grooves 1b with it by a doctor blade 12 and excess coating material 16b is scraped off. The excess coating material 16b flow in the direction along a center axis line CL of the gravure roll 1 and flows don along the surface of an elastic body 7 at the end of the doctor blade 12 to be returned to a paint pan. The elastic body 7 is crushed to be deformed by the doctor blade 12, ensuring the close adhering of the doctor blade 12 to the gravure roll 1, to accomplish the scraping. Since the elastic body 7 stands still not rotated together with a sleeve 2, centrifugal force is not applied to it and the magnetic coating material 16b flowing out is not splashed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus, for example, a coating apparatus for coating a base film with a magnetic coating material in the manufacture of a magnetic recording medium.

[0002]

2. Description of the Related Art A magnetic recording medium such as a magnetic tape or a floppy disk is manufactured by a process in which a magnetic coating is applied to a wide long base film by gravure coating, dried, and then cut into a predetermined width.

The magnetic paint is supplied by a gravure roll and is applied to the surface of a base film which is conveyed by being sandwiched between a gravure roll and a backup roll. The base film coated with the magnetic paint needs to be discharged from a coating part including a gravure roll and a backup roll, and the magnetic paint needs to be applied to the surface of the base film in a substantially uniform thickness.

In order to apply the magnetic paint substantially uniformly, the magnetic paint supplied to the gravure roll is filled in a pattern engraved in the coating width of the gravure roll, and the excess paint is then removed by a doctor blade. It is wiped off and the coating thickness of the magnetic paint is regulated.

FIG. 10 is a front view of the main part of the coating apparatus.

In this apparatus, the magnetic paint 16 supplied from the magnetic paint supply unit 15 is carried on the surface of the gravure roll 51, the layer thickness is regulated by the doctor blade 12, and the magnetic paint 16 is sandwiched between the gravure roll 51 and the backup roll 14. A magnetic paint 16a having a predetermined thickness is applied to the surface (the lower surface in the figure) of the uncoated base film 31A conveyed and conveyed. The base film is sent from the gravure roll 51 and the backup roll 14 and becomes the coated base film 31B.

Gravure roll 51 supplied with magnetic paint 16
The excess paint 16b is scraped off by the edge of the doctor blade 12, and the layer thickness is regulated. However,
There is a problem that the magnetic paint 16b that is scraped off and flows out is scattered on the end surface of the gravure roll or the end surface of the doctor blade. That is, as shown in FIG. 11, the magnetic paint 16b flowing on the end surface of the doctor blade 12 is
It rotates together with the gravure roll on the surface of the non-application portion 51c of 51 and is scattered by the centrifugal force. When the scattered magnetic paint adheres to the base films 31A and 31B, coating unevenness occurs, which leads to deterioration of the quality of the magnetic recording medium. In the figure, 51a is a coating part and 51b is a groove.

The scattering of the magnetic coating material during the coating operation requires periodic interruption of the coating operation for cleaning, which causes a difficulty in production due to the suspension of the coating operation. Further, the scattering of the magnetic paint causes an increase in consumption of the magnetic paint and a deterioration in quality.

Therefore, as shown in FIG. 12, an L-shaped paint splash preventive tool 59 made of, for example, Teflon is provided to connect the end face of the gravure roll 51 and the end of the doctor blade 12 to prevent the splash of the paint 16b. Attempts have been made to prevent it.

However, in this case, it is difficult to completely eliminate the scattering of the magnetic paint due to poor adhesion of the edge portion, wear of the paint scattering preventive tool 59, etc.
Can be halved, but not quite enough.

As shown in FIG. 13, it has been attempted to use a long doctor blade 52 such that the edge of the doctor blade contacts the end 51d of the roll surface of the gravure roll 51.

Also in this case, the doctor blade 52
The excess magnetic paint 16b wiped off by the sessile adheres to the gravure roll end surface 51d, rotates with the gravure roll 51, and scatters due to centrifugal force.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to prevent the paint from scattering from the coating roll against the paint scattering which is the fate of a high speed roll coater. It is an object of the present invention to provide a coating device that can be used.

[0014]

That is, according to the present invention, in a coating apparatus having a coating roll and a coating thickness regulating member facing the coating roll, in a region where the coating thickness regulating member faces the coating roll. The roll end portion in the axial direction of the roll is configured as a non-rotating portion that is in a non-rotating state at least during coating.

In the present invention, the coating roll is a gravure roll, and non-rotating portions provided at both ends of the gravure roll are sleeve members supported by bearings fixed to the rotating shaft of the coating roll. The coating thickness regulating member is preferably a doctor blade.

In the present invention, it is desirable that an elastic body is provided on the surface of the non-rotating portion at least in a region facing the coating thickness regulating member, and the coating thickness regulating member is pressed against this elastic body.

Further, when the coating thickness regulating member is not in contact with the elastic body, the outer diameter of the non-rotating portion is such that the elastic body projects beyond the surface of the coating roll. It is desirable to be larger than.

Further, in the present invention, it is desirable that a sealing means having an outer peripheral surface substantially the same as the outer peripheral surface of the coating roll is interposed between the coating roll and the non-rotating portion.

[0019]

EXAMPLES Examples of the present invention will be described below.

Example 1 FIG. 2 is a perspective view showing a relationship between a gravure roll and a doctor blade in a coating portion for coating a base film with a magnetic coating material, and FIG. 3 includes a central axis of the gravure roll in FIG. A cross-sectional view, FIG. 1 is a cross-sectional view similar to FIG. 3 showing a state in which a gravure roll and a doctor blade are in contact with each other during coating. It should be noted that the same parts as those in FIGS. 9 to 12 are denoted by the same reference numerals (hereinafter the same).

The gravure roll 1 is rotatable by an end shaft portion 1e. And gravure roll 1
The doctor blade 5 is located so as to face the surface.

The gravure roll 1 is in contact with the coating portion 1a in which a large number of grooves 1b are engraved, a non-coating portion 1c having the same diameter as the coating portion 1a, and a non-coating portion 1c adjacent to the non-coating portion 1c and a small diameter portion smaller than this ( The bearing mounting portion) 1d and the tip shaft portion 1e.

In the small diameter portion 1d, the inner rings 3a of the bearings 3 and 3,
3a is fixed by being sandwiched between the collars 8A, 8B and 8C.
This fixing is performed by tightening the nut 6 that is screwed into the male screw at the end of the small diameter portion 1d. Outer ring 3 of bearing 3, 3
The sleeve 2 is attached to b and 3b. Sleeve 2 is
The sleeve 2 and the gravure roll 1 are relatively rotatable by being fixed by the cover 5 that is in contact with the end surface and the outer ring 3b of the bearing 3. The bearings 3 and 3 have balls 3c and 3c.
It uses a ball bearing with.

The sleeve 2 and the innermost collar 8A come into contact with the non-coating portion 1c of the gravure roll via the annular seal plate 4. The seal plate 4 is made of, for example, Teflon having a low coefficient of friction, is fixed to the non-coating portion by screwing, and is processed at the same time when finishing the outer peripheral surface of the gravure roll to have the same diameter as the coating portion 1a and the non-coating portion 1c. . The seal plate 4 prevents the magnetic paint from laterally squeezing out from the applying portion 1a during the application and creeping into the bearing housing space.

An elastic body 7 such as rubber is coated on the outer peripheral surface of the sleeve 2 by coating. The outer peripheral surface of the elastic body is higher (larger diameter) than the outer peripheral surface of the seal plate 4 in a free state (a state in which the doctor blade 12 is not in contact).
However, a step d of 0.2 mm is formed between them. The gravure roll 1 has the above structure on both end sides.

During coating, the gravure roll 1 rotates,
As shown in FIG. 1, the doctor blade 12 descends from the virtual line position to the solid line position. And doctor blade 12
Touches the seal plate 4, the non-applied portion 1c and the applied portion 1a of the gravure roll so as to crush the elastic body 7.
Thus, the sleeve 2 is stationary without rotating due to the elastic body 7 and the bearings 3 which are crushed by the doctor flade 12. The elastic body 7 also functions as a cushion for the doctor blade 12. When the gravure roll 1 is rotated and the doctor blade 12 is not in contact with the gravure roll 1, the sleeve 2 can be rotated together with the gravure roll 1 without any problem.

In the above state, the magnetic paint 16 is supplied to the coating portion 1a of the rotating gravure roll 1 and the groove 1b of the gravure roll 1 is filled with the doctor blade 12. Then, the excess magnetic paint is scraped off. A part of the excess magnetic paint flows in the direction along the central axis line CL of the gravure roll 1, and as shown in FIG. 2, the magnetic paint 16b that has flowed out flows along the surface of the elastic body 7 at the end of the doctor blade 12. After flowing, it falls and is returned to the paint pan (not shown) below.

If the sleeve 2 is not provided with the elastic body 7, a step is formed at the boundary between the sleeve 2 and the sealing plate 4, and the paint scraping by the doctor blade becomes incomplete. By crushing and deforming the elastic body with the doctor blade as described above, the doctor blade is firmly attached to the gravure roll, and the scraping is completed. If the step d is not provided, the elastic body 7 and the doctor blade
The close contact with 12 becomes uncertain, excess magnetic paint leaks between them, and the rotation stop of the elastic body 7 becomes uncertain, and extra magnetic paint scatters.

Since the elastic body 7 does not rotate and stands still together with the sleeve 2, the centrifugal force does not act, and the magnetic paint 16b that has flowed out does not scatter. Therefore, the paint scattering prevention tool 59 shown in FIG. 10 is unnecessary. Further, the magnetic paint is not consumed more than necessary.

FIG. 4 is a front view of the main part of the coating apparatus.

The magnetic coating material 16 supplied from the magnetic coating material supply hose 15 is temporarily stored on the gravure roll 1 and the coating material supply auxiliary roll 13 that comes into contact with the gravure roll 1 and is carried by the coating portion 1a of the gravure roll 1. . In the gravure roll, as shown in FIG. 2, the magnetic paint 16 is carried on the surface of the coating portion 1a of the gravure roll and filled in the groove 1b.

Then, the doctor blade 12 comes into contact with the gravure roll 1, the magnetic paint 16 is surely filled in the groove 1b by the doctor blade 12, and the excess paint of the magnetic paint is scraped off by the doctor blade 12. Magnetic paint 16a whose layer thickness is regulated by scraping off excess paint
Is applied to the surface (the lower surface in the figure) of the uncoated base film 31A that is conveyed by being sandwiched between the gravure roll 1 and the backup roll 14. The base film is
The base film 31B is delivered from the gravure roll 1 and the backup roll 14 and applied.

Next, steps before and after applying the magnetic paint will be described with reference to FIG. FIG. 8 is a schematic front view of the entire apparatus including a coating apparatus in which a magnetic layer is formed on an uncoated base film to form a wide and long magnetic sheet.

The uncoated base film 31A wound around the hub 42 is conveyed while being guided by the guide roller 40 while being given an appropriate tension, and passes through the backup roll 14,
The magnetic paint is applied by being sandwiched between the backup roll 14 and the gravure roll 1.

The magnetic paint 16 is supplied from the magnetic paint supply hose 15 to the gravure roll 1 by being sandwiched between the paint supply auxiliary roll 13 and the gravure roll 1, and the doctor blade 12
Uncoated base film after the layer thickness is regulated by
It is supplied to the surface of 31A (lower surface in the figure).

Base film 31B coated with magnetic paint
Passes through the guide roller 40, passes through the drying section 44, and the magnetic paint is dried by hot air to form the magnetic sheet 31C, and the magnetic layer is flattened through the calendar section 45 composed of a large number of rolls 46, and the magnetic layer 31 is formed on the hub 47. It is wound. The magnetic sheet 31C wound around the hub 47 is cut into a predetermined width in the next step and wound again to form a pancake.

As described above, in this example, the undesired magnetic paint does not scatter from the end face of the gravure roll and the end face of the doctor blade in the coating part. It is possible to prevent a decrease in yield and a decrease in quality. Further, it is possible to shorten the cleaning work time of the worker and contribute to the improvement of the operating rate. The structure of the apparatus in FIG. 8 is common to Examples 2 to 4 described later.

Embodiment 2 In this embodiment, instead of supporting the sleeve on the gravure roll via a bearing, the sleeve fixed to the coating device is fitted onto the end of the gravure roll.

That is, as shown in FIG. 5, the gravure roll, the seal plate, and the doctor blade used are the gravure roll 1, the seal plate 4, and the doctor blade 12 in the first embodiment. However, in this example, since the bearing fitted on the small diameter portion 1d of the gravure roll is not used, the small diameter portion 1d does not require a male screw for nut screwing.

The sleeve 22 is fixed to, for example, a housing (not shown) of the coating device, and is provided with the gravure roll 1 and the central axis line CL.
And the small diameter part 1d of the gravure roll.
It is designed to be fitted on the outside with a gap. Sleeve 22
The outer diameter is the same as that of the sleeve 2 shown in FIGS. An elastic body 27 similar to the elastic body 7 in FIGS. 1 to 3 is provided on the sleeve 22 by coating.

Others are the same as those in the first embodiment shown in FIGS. That is, during coating, the gravure roll 1
Rotates, the doctor blade 12 moves from the virtual line position to the solid line position, the elastic body 27 is deformed so as to be crushed by the doctor blade 12, and the sleeve 22 is stationary. The extra magnetic paint 16b flowing laterally along the doctor blade 12 flows over the surface of the elastic body 27 which is stationary, falls downward, and does not scatter.

Embodiment 3 In this embodiment, instead of the doctor blade 12 in Embodiment 1 shown in FIGS. 1 to 3, a doctor longer than the doctor blade 12 and contacting the entire length of the gravure roll including an elastic body is used. I'm using a blade. Others are the same as in the first embodiment. 6 is a sectional view similar to FIG. 1, and FIG. 7 is a perspective view similar to FIG.

During coating, the gravure roll 1 rotates,
The doctor blade 32 presses the elastic body 7 over the entire length,
Extra magnetic paint 16 that has flowed laterally along the doctor blade 32 (direction along the central axis CL of the gravure roll)
b does not flow down along the stationary end surface 7a of the elastic body 7 and the peripheral surface of the cover 5 and does not scatter.

Example 4 This example is an example in which the cover 5 (see FIG. 6) of Example 3 is provided with a pan for receiving the magnetic paint that has leached out.
Others are the same as in the third embodiment.

FIG. 8 is a sectional view similar to FIG. A paint receiver 10 having an L-shaped cross section is attached to the surface of the cover 5, and a pan 11 is constituted by the paint receiver 10, the paint receiving attachment portion 5a of the cover 5 and the end surface 7a of the elastic body 7.

Excess paint 16b flowing out along the doctor blade 32 (along the central axis CL of the gravure roll)
Is collected in the pan 11 without scattering and the doctor blade 32 is separated from the gravure roll 1 when the application of the magnetic coating material to one roll of the base film is completed. Then, the rotation of the gravure roll 1 is stopped, the paint receiver 10 is removed from the cover 5, and the accumulated magnetic paint 16b is collected.

Although the embodiments of the present invention have been described above, various modifications can be added to the above embodiments based on the technical idea of the present invention.

For example, the elastic body provided on the sleeve may be provided by coating, or the sleeve may be press-fitted into a cylindrical elastic body so as to fix the two to each other.

Further, as the material of the elastic body, an appropriate material can be selected as long as it is used as a cushion material. As the material of the seal plate 4, an appropriate material can be used as a seal material with a low coefficient of friction. The bearing may be a roller bearing or a slide bearing. Magnetic paint 16
In addition to the magnetic paint supply hose as in the above embodiment, other magnetic paint supply means may be used.

Further, the present invention can be applied not only to the gravure roll but also to another method such as a method using a reverse roll. Further, the present invention can be applied to the coating of other coatings (for example, coating of photographic emulsion) in addition to the coating of the magnetic coating on the base film.

[0051]

According to the present invention, since the non-rotating portion which is in the non-rotating state at the time of coating is provided at the end of the coating roll in the axial direction, the surface of the coating roll flows along the coating thickness regulating member. When the excess paint reaches the non-rotating portion, centrifugal force does not act on the non-rotating portion, and the above-mentioned extra paint does not scatter.

As a result, it is possible to prevent the excessive coating material from being scattered and adhered to the object to be coated or the coating layer to deteriorate the quality. Further, wasteful consumption of the paint due to scattering is prevented, which is economically advantageous. Further, there is no interruption of the coating work for cleaning the scattered paint adhering to the component parts of the apparatus, and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a relationship between a gravure roll and a doctor blade according to a first embodiment.

FIG. 2 is a perspective view showing a relationship between the gravure roll, a doctor blade, and a paint supply auxiliary roll.

FIG. 3 is a sectional view of the gravure roll.

FIG. 4 is a front view of a main part of the coating apparatus.

5 is a sectional view similar to FIG. 1 according to a second embodiment.

6 is a sectional view similar to FIG. 1 according to a third embodiment.

FIG. 7 is a perspective view showing a relationship between the gravure roll and a doctor blade.

FIG. 8 is a sectional view similar to FIG. 1 according to a fourth embodiment.

FIG. 9 is a front view of the main parts of the magnetic sheet manufacturing apparatus according to the first embodiment.

FIG. 10 is a front view of a main part of a coating device according to a conventional example.

FIG. 11 is a perspective view similar to FIG. 7.

FIG. 12 is a perspective view similar to FIG. 7 according to another conventional example.

FIG. 13 is a perspective view similar to FIGS. 7 and 12 according to still another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gravure roll 1a ... Coating part 1b ... Groove 1c ... Non-coating part 1d ... Bearing mounting part 1e ... Shaft part 2, 22 ... Sleeve 3 ... Bearing 4・ ・ ・ Seal plate 5 ・ ・ ・ Bearing cover 7, 27 ・ ・ ・ Elastic body 10 ・ ・ ・ Paint receiver 11 ・ ・ ・ Pan 12, 32 ・ ・ ・ Doctor blade 13 ・ ・ ・ Paint supply auxiliary roll 14 ・ ・ ・Backup roll 16 ... magnetic paint 16a ... magnetic paint used for coating 16b ... extra magnetic paint 31A ... uncoated base film 31B ... coated base film d ... step CL: Central axis of gravure roll

Claims (5)

[Claims] 1. A coating apparatus having a coating roll and a coating thickness regulating member facing the coating roll, wherein a roll end in the axial direction of the roll in a region where the coating thickness regulating member faces the coating roll. The coating device is characterized in that the portion is configured as a non-rotating portion that is in a non-rotating state at least during coating. 2. The coating roll is a gravure roll, and non-rotating portions provided at both ends of the gravure roll are sleeve members supported by bearings fixed to a rotating shaft of the coating roll. The coating device according to claim 1, wherein the regulating member is a doctor blade. 3. The method according to claim 1, wherein an elastic body is provided on a surface of the non-rotating portion at least in a region facing the coating thickness regulating member, and the coating thickness regulating member is pressed by the elastic body. Coating device. 4. The outer diameter of the non-rotating portion is larger than the outer diameter of the coating roll so that the elastic body projects beyond the surface of the coating roll when the coating thickness regulating member is not in contact with the elastic body. The coating apparatus according to claim 3, wherein the coating apparatus is also large. 5. The sealing device according to claim 1, wherein a sealing means having an outer peripheral surface substantially the same as the outer peripheral surface of the coating roll is interposed between the coating roll and the non-rotating portion. Coating device.