JP2002356256A - Device for manufacturing magnetic recording medium and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make thick magnetic recording medium and thin magnetic recording medium stably travel with corresponding tension respectively. SOLUTION: This device is provided with a first tensing means tensing a web of magnetic recording medium fed out from an unwinding roller by a designated tension and a second tensing means tensing the web of the magnetic recording means by tension greater than that of the first tensing means. The first tensing means is used in a case of a thin type magnetic recording medium and the second tensing means is used in a case of a thick type magnetic recording medium to control tension tensing the web of the magnetic recording medium according to thickness of the web of the magnetic recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for manufacturing a magnetic recording medium compatible with both a thick type and a thin type.

[0002]

2. Description of the Related Art A thin magnetic recording medium having a total thickness of, for example, 3 .mu.m or less, and a total thickness of, for example, 80 .mu.m or more used for a flexible disk, etc. Thick magnetic recording media exist.

In an apparatus for manufacturing both a thin and a thick magnetic recording medium as described above, in order to prevent the shape of the magnetic recording medium from deteriorating and to operate it stably, it is necessary to manufacture the magnetic recording medium with an unwinding tension suitable for the magnetic recording medium. It is desired to do.

In the production of a thin magnetic recording medium, the tension is as low as possible without applying a stress as much as possible. In the production of a thick magnetic recording medium, the tension is increased by applying a reverse stress, and the tension ratio is increased. The high tension is 15 or more with respect to the low tension 1.

[0005]

However, if both the low tension and the high tension are controlled by one powder brake, the low tension range of 0.13 kgfm is obtained in the powder brake standard torque characteristic (for low tension) shown in FIG. ~ 1.3kgf
m, but there is a disadvantage that the tension is considerably insufficient in a high tension range of 2 kgfm to 5 kgfm.

On the contrary, according to the powder brake standard torque characteristic (for high tension) shown in FIG. 4, the high tension region is 2 kgfm.
Stable at ~ 5kgfm, but low tension range 0.13kgfm
At ~ 1.3 kgfm, the current range of the powder brake is quite small, 0.02 A to 0.08 A, and there is a possibility that malfunction may occur under the influence of disturbance or the like, and the tension may become unstable. .

The present invention has been proposed in view of such a conventional situation. In a thick magnetic recording medium or a thin magnetic recording medium, the magnetic recording medium can be stably run at a tension corresponding to each of the mediums. It is an object of the present invention to provide a magnetic recording medium manufacturing apparatus and a manufacturing method that can be used.

[0008]

According to the present invention, there is provided an apparatus for manufacturing a magnetic recording medium, comprising: first tension applying means for applying a predetermined tension to a magnetic recording medium raw material sequentially fed from an unwinding roll; And a second tension applying means for applying a larger tension than the first tension applying means to the magnetic recording medium raw material sequentially fed out from the above. If the magnetic recording medium raw material is thin, the first In the case where the magnetic recording medium raw material is thick, the second magnetic recording medium raw material is used in accordance with the thickness of the magnetic recording medium raw material by using the second tension applying means. Is characterized in that the tension applied to is controlled.

The above-described apparatus for manufacturing a magnetic recording medium according to the present invention includes first and second tension applying means having different tensions. Since the tension to be applied is controlled,
In a thick or thin raw material of a magnetic recording medium, the raw material of the magnetic recording medium runs stably with a tension corresponding to each.

Further, the method for manufacturing a magnetic recording medium according to the present invention includes a first tension applying means for applying a predetermined tension to a magnetic recording medium raw material sequentially fed from an unwinding roll;
A manufacturing apparatus including a second tension applying means for applying a larger tension than the first tension applying means to a magnetic recording medium raw material sequentially unwound from an unwinding roll is used. When the raw magnetic recording medium is thin, the first tension applying means is used. When the magnetic recording medium raw is thick, the second tension applying means is used. The tension applied to the magnetic recording medium is controlled in accordance with the thickness of the magnetic recording medium.

In the method for manufacturing a magnetic recording medium as described above, first and second tension applying means having different tensions are used.
Since the tension applied to the magnetic recording medium raw material is controlled according to the thickness of the magnetic recording medium raw material, the thickness of the thick or thin magnetic recording medium raw material is controlled by the corresponding tension. Run the web stably.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a magnetic recording medium manufacturing apparatus and a manufacturing method to which the present invention is applied will be described.

An apparatus for manufacturing a magnetic recording medium according to the present invention comprises:
It is characterized by comprising an unwinding means for unwinding a magnetic recording medium raw material as described later. Hereinafter, the unwinding means will be described.

As shown in FIG. 1, the unwinding means 1 has a magnetic recording medium raw material roll rotation shaft 2, a low tension powder brake 3, a high tension powder brake 4, a coupling 5a. , 5b, a high tension powder brake rotation shaft fixing pin 6, a low tension powder brake rotation shaft 7, and a high tension powder brake rotation shaft 8.

The magnetic recording medium raw material 9 is wound in a roll around the magnetic recording medium raw material roll rotation shaft 2. The magnetic recording medium raw material 9 is sequentially fed from the magnetic recording medium raw material roll rotating shaft 2.

The original recording material roll rotation shaft 2 is connected to a high tension powder brake 4 via a coupling 5a. The high-tension powder brake 4 is provided with a high-tension powder brake rotation shaft fixing pin 6, and the high-tension powder brake rotation shaft fixing pin 6 is provided.
The high-tension powder brake 4 does not operate while the power brake is fixed.

Further, a low tension powder brake 3 is connected via a coupling 5b to a side of the high tension powder brake 4 opposite to the side to which the magnetic recording medium raw roll rotation shaft 2 is connected.

When the thin magnetic recording medium is unwound from the unwinding means 1, that is, when the tension applied to the magnetic recording medium 9 is controlled by the low tension powder brake 3, a low tension is applied. Powder brake 3
Is transmitted to the magnetic recording medium raw roll rotation shaft 2 via the low tension powder brake rotation shaft 7 and the high tension powder brake rotation shaft 8.

In this case, the high-tension powder brake rotating shaft fixing pin 6 is removed, and the high-tension powder brake 4 is set free. The mechanical loss (idling torque) of the high-tension powder brake 4 is reduced by magnetic recording. It is not added to the medium web 9.

On the other hand, when the thin magnetic recording medium is unwound from the unwinding means 1, that is, when the tension applied to the magnetic recording medium 9 by the high tension powder brake 4 is controlled, the high tension is applied. The powder brake rotation shaft fixing pin 6 is fixed, and the torque of the high tension powder brake 4 is transmitted to the magnetic recording medium raw roll rotation shaft 2 via the high tension powder brake rotation shaft 8.

At this time, the mechanical loss of the low tension powder brake 3 is added to the high tension powder brake rotation shaft 8 via the low tension powder brake rotation shaft 7, but the mechanical loss of the low tension powder brake 3 is reduced. Is as small as possible compared to the mechanical loss of the high-tension powder brake 4, and therefore has little effect on the movement of the high-tension powder brake 4.

As described above, according to the present invention, the unwinding means 1
However, since both the low tension powder brake 3 and the high tension powder brake 4 are provided, when manufacturing a thick type magnetic recording medium or a thin type magnetic recording medium, it is possible to cope with each magnetic recording medium raw material 9. The magnetic recording medium raw material 9 can be run stably by the tension. In particular,
When unwinding a thin magnetic recording medium, a low tension powder brake 3 is used, and when unwinding a thick magnetic recording medium, a high tension powder brake 4 is used.

FIG. 2 shows an unwinding tension control system for controlling the unwinding tension in the unwinding means 1 as described above. This unwinding tension control system 10
Unwinding means 1, tension detector 11, tension meter 1
2, 13, a tension setting device 14, a brake selector 15
, An encoder 16 and a sequencer 17.

The magnetic recording medium raw material 9 sequentially unwound from the unwinding means 1 passes over the tension detector 11 and travels in the running direction. The tension applied to the raw magnetic recording medium 9 is
First, the set tension signal set by the tension setting unit 14, the actual tension signal obtained by converting the actual tension value detected by the tension detector 11 by the tension meters 12 and 13, and the number of rotations detected by the encoder 16 are taken into the sequencer 17 and rotated. Calculate the unwinding diameter from the number. Then, a deviation value of the tension is calculated from the set tension signal and the actual tension signal, the current with respect to the torque of the powder brake is corrected based on the calculation result, and the current of the powder brake is controlled so as to maintain a constant tension. . At this time, the use torque of the powder brake standard torque characteristic shown in FIGS. 3 and 4 is applied as tension.

The number of operating torques is from the minimum unwinding diameter to
Powder brake for low tension 3 which varies between maximum diameters
When using the high-strength powder brake 4, the number of operating torques is set in the range of 0.13 kgfm to 0.3 kgfm as shown in FIG. Is preferably in the range of 2 kgfm to 5 kgfm.

The switching of the current between the low tension powder brake 3 and the high tension powder brake 4 is performed by a brake selector 1.
Switch according to the powder brake selected in step 5.

The tension meters 12 and 13 are distinguished between low tension and high tension so that the gain and bias of the actual tension signal can be individually adjusted.

As described above, according to the present invention, by switching between the low tension powder brake 3 and the high tension powder brake 4 in accordance with the magnetic recording medium sequentially fed from the unwinding roll, 9 is controlled. Specifically, when unwinding a thin magnetic recording medium, a low tension powder brake 3 is used, and when unwinding a thick magnetic recording medium, a high tension powder brake 4 is used. Thereby, in the present invention, the magnetic recording medium raw material 9 can be run stably.

In the above-described embodiment, a manufacturing apparatus having two powder brakes for low tension and high tension has been described as an example. However, the present invention is not limited to this. The present invention is also applicable to a manufacturing apparatus having more powder brakes according to the tension range to be used. Further, in the above-described embodiment, the case where the powder brake is used as the tension applying means for applying the tension to the running magnetic recording medium raw material has been described as an example, but the present invention is not limited to this. However, the present invention is also applicable to a case where a tension applying means other than the powder brake is used.

[0030]

EXAMPLES Next, examples performed to confirm the effects of the present invention will be described. In the following embodiments, specific numerical values are described, but it goes without saying that the present invention is not limited to this example.

In this experiment, a calendar processing device as shown in FIG. 5 was used as a magnetic recording medium manufacturing device. The calendering device 20 includes unwinding means 21 having the above-described powder brakes for low tension and high tension and unwinding the magnetic recording medium raw material 25, and winding means for winding the magnetic recording medium raw material. 22, a steel roll 23 disposed between the unwinding means 21 and the winding means 22
a, 23b, 23c, 23d and 23e, and a guide roll 24 for guiding the magnetic recording medium raw material 25. When a thin magnetic recording medium material 25 is used, an elastic roll is used instead of the steel rolls 23b and 23d.

<Example 1> The raw material of the magnetic recording medium serving as a sample was a thin magnetic recording medium raw material having a total thickness of 3 μm, a width of 5 inches, and a length of 3000 m.
Was used.

The conditions for processing the thin magnetic recording medium raw material include a low tension powder brake, a magnetic recording medium raw material traveling speed of 150 m / min, and an unwinding tension of 0.8 kg. The unwinding torque was 0.13 to 0.3 kgfm, and the powder brake control current value was 0.22 to 0.35 A. The unwinding torque and the powder brake control current value vary depending on the unwinding diameter of the unwinding roll. The steel roll temperature was set to 70 ° C.

Under the above conditions, the thin magnetic recording medium was calendered.

<Example 2> As a raw material of a magnetic recording medium serving as a sample, a total thickness of a thick magnetic recording medium was 80 μm, a width was 5 inches, and a length was 3000.
m. The conditions for processing the thick magnetic recording medium raw material include the use of a powder brake for high tension and the running speed of the magnetic recording medium raw material of 60%.
m / min, the unwinding tension was 25 kg, the unwinding torque was 2 to 5 kgfm, and the powder brake control current value was 0.25 to 0.6 A. The unwinding torque and the powder brake control current value vary depending on the unwinding diameter of the unwinding roll. The temperature of the steel roll was set to 90 ° C.

Under the above conditions, the thick magnetic recording medium was calendered.

<Comparative Example 1> As a raw magnetic recording medium as a sample, a thin magnetic recording medium raw material had a total thickness of 3 μm, a width of 5 inches, and a length of 3000 m.
Was used.

Further, as a calendering device, a conventional calendering device having unwinding means without powder brakes for low tension and high tension as in the present invention is used to reduce the thickness of a thin magnetic recording medium. A calendar process was performed for this.

<Comparative Example 2> As a raw material of a magnetic recording medium serving as a sample, a total thickness of a thick magnetic recording medium was 80 μm, a width was 5 inches, and a length was 3000.
m. Further, as a calendering device, using a conventional calendering device having unwinding means having no powder brake for low tension and high tension as in the present invention, a calender for thin raw magnetic recording media is used. Processing was performed.

Under the above conditions, the thick magnetic recording medium raw material and the thin magnetic recording medium raw material were subjected to a calendering treatment, and the occurrence of wrinkles during running was observed and evaluated.

In the evaluation, at the points A and B shown in FIG. 5, the surface of the magnetic recording medium was visually observed to evaluate the occurrence of wrinkles. As a result, when no wrinkles were observed, it was evaluated as ◎. In addition, when a certain level of wrinkles was observed, but the level did not cause any problem in running, it was evaluated as ○. In addition, when a wrinkle was observed and it was judged that there was a problem in running, it was rated as Δ. In addition, when traveling was impossible due to occurrence of many wrinkles, it was evaluated as x. Table 1 shows the evaluation results.

[0042]

[Table 1]

When calendering was performed using a conventional calendering apparatus having unwinding means without powder brakes for low tension and high tension, as shown in Comparative Example 1, a thin magnetic recording medium was obtained. On the other hand, the unwinding tension was unstable, so that wrinkles were slightly generated, and there was a problem in running. Further, as shown in Comparative Example 2, the raw material of the thick magnetic recording medium had insufficient unwinding tension, so that wrinkles were slightly generated, and a problem in running was observed.

On the other hand, in the calendar processing apparatus of the present invention provided with unwinding means having powder brakes for low tension and high tension, the powder brake for low tension is applied to the thin magnetic recording medium raw material shown in the first embodiment. In the case where the thick magnetic recording medium raw material shown in Example 2 was subjected to calendering using a powder brake for high tension, no wrinkles were observed, and the vehicle ran well without any problem. It was confirmed that.

Therefore, using an apparatus provided with unwinding means having powder brakes for low tension and high tension,
It was found that by selecting the powder brake to be used in accordance with the thickness of the magnetic recording medium raw material, the magnetic recording medium raw material can be satisfactorily run without causing wrinkles.

[0046]

According to the present invention, the tension applied to the raw magnetic recording medium is controlled by switching between a low tension powder brake and a high tension powder brake in accordance with the magnetic recording medium sequentially fed from the unwinding roll. . Specifically, when unwinding a thin magnetic recording medium raw material,
When unwinding a thick magnetic recording medium using a low tension powder brake, a high tension powder brake is used. As a result, in the present invention, the magnetic recording medium can be stably run.

[Brief description of the drawings]

FIG. 1 is a diagram showing one configuration example of an unwinding means according to the present invention.

FIG. 2 is a block diagram illustrating an example of an unwinding tension control system.

FIG. 3 is a graph showing standard torque characteristics of a low tension powder brake.

FIG. 4 is a graph showing standard torque characteristics of a high tension powder brake.

FIG. 5 is a diagram schematically illustrating a configuration of a calendar processing device used in an example.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 unwinding means, 2 magnetic recording medium material roll rotation axis, 3 low tension powder brake, 4 high tension powder brake, 5a, 5b coupling, 6
High tension powder brake rotation axis fixing pin, 7 Low tension powder brake rotation axis, 8 High tension powder brake rotation axis, 9 Magnetic recording media

Claims (6)

[Claims] A first tension applying means for applying a predetermined tension to a magnetic recording medium raw material sequentially fed from an unwinding roll; and a first tension applying means for applying a first tension to the magnetic recording medium raw material sequentially fed from an unwinding roll. A second tension applying means for applying a larger tension than the tension applying means, wherein the first tension applying means is used when the magnetic recording medium is thin, and the magnetic recording medium is thick. For types,
An apparatus for manufacturing a magnetic recording medium, wherein the tension applied to the raw magnetic recording medium is controlled according to the thickness of the raw magnetic recording medium by using the second tension applying means. 2. An apparatus according to claim 1, wherein said first tension applying means and said second tension applying means are powder brakes. 3. The first tension applying means and the second tension applying means are formed integrally with the unwinding roll with the same rotation axis, and are used by switching between them. The apparatus for manufacturing a magnetic recording medium according to claim 2. 4. A first tension applying means for applying a predetermined tension to a magnetic recording medium raw material sequentially fed from an unwinding roll, and a first tension applying means for applying a first tension to the magnetic recording medium raw material sequentially fed from an unwinding roll. A second tension applying means for applying a larger tension than the tension applying means; and a first tension applying means when the raw material of the magnetic recording medium is thin. If the media is thick,
A method for manufacturing a magnetic recording medium, comprising: controlling a tension applied to a raw magnetic recording medium according to a thickness of the raw magnetic recording medium by using a second tension applying means. 5. The method for manufacturing a magnetic recording medium according to claim 4, wherein said first tension applying means and said second tension applying means are powder brakes. 6. The first tension applying means and the second tension applying means are formed integrally with the unwinding roll with the same rotation axis, and are used by switching between them. The method for manufacturing a magnetic recording medium according to claim 5, wherein