JPH0656706B2 - Tape hub - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hub around which a magnetic tape is wound, and more particularly to a hub serving as a winding core of a long winding roll.

(Prior Art) A magnetic tape is usually manufactured as a wide tape stock in the first stage of its manufacturing process, and then processed into a desired tape width in a slitting process. In this slitting process, a plurality of cut magnetic tapes having a product width, for example, are wound around a hub to form an intermediate product (pancake).

The hub described above has, for example, a size and shape defined by the NAB standard so as to be suitable for a recording / reproducing apparatus for broadcasting, or a hub that is not available in the general market, for example, when supplying a magnetic tape from a tape maker to a cassette maker. and so on.
This hub is processed or molded from a material such as aluminum or plastic resin, and the winding surface (outer peripheral surface) around which the magnetic tape is wound generally has roughness (surface roughness).
The smaller is the better hub. That is, the smaller the roughness of the winding surface of the hub is, the less the unevenness of the winding surface is reflected on the magnetic tape. Therefore, it is possible to provide a magnetic tape having a reduced quality portion due to the image.

However, in the manufacturing process of the magnetic tape, as described above, for example, there is a work of cutting the raw material and winding it on the hub. At the beginning of the winding, a liquid such as water is generally spread on the winding surface of the hub. It is supposed to be worn, and a tape terminal is attached here to start winding. Therefore, in a conventional hub with a small winding surface roughness and good surface property, the spread liquid may be in the form of water droplets, or the liquid may be scattered by the centrifugal force due to the rotating operation of the hub, and There was a problem in pasting. Furthermore, the water droplets scattered by the rotation of the hub not only stain the mechanical equipment in the vicinity of the hub, but also the rust generated on the equipment by the water droplets adheres to the magnetic tape, causing dropout etc. at the time of recording and reproducing etc. However, it was also a cause of deteriorating the quality of magnetic tape.

Further, if the liquid is not well spread on the winding surface of the hub as described above, it becomes a very serious problem particularly in automating the winding. That is, for winding the tape after cutting the raw tape, for example, many hubs are arranged side by side to make a plurality of long winding rolls at the same time. In addition to the extremely poor workability, it is necessary to ensure that the tape terminals are securely attached to all the hubs in automation.

(Object of the invention) The present invention has been made in view of the above problems, good spreadability of liquids such as water, good adhesion of tape terminals, and liquid scattering due to rotation of the slitter. It is an object of the present invention to provide a tape hub having a suppressing effect.

(Structure of the Invention) The above object of the present invention is achieved by a tape hub characterized in that the winding surface in contact with the magnetic tape has a surface roughness in the range of 3 μm to 10 μm Rmax.

The present invention will be described below based on an embodiment illustrated in the drawings.

The hub 1 shown in FIG. 1 is of a flangeless type,
A hole 2 in which a concave portion 3 of an appropriate shape that engages with a rotary shaft is formed is provided in the central portion, and the winding surface 4 on which the magnetic tape 5 is wound has a surface roughness in the range of 3 μm to 10 μm Rmax. It has been matted. The outer diameter L of the hub 1 is, for example, 100 mm to 120 mm, and the width W of the winding surface 4 is the magnetic tape 5.
Corresponding to, for example, 9 mm to 56 mm is configured.

A plurality of hubs 1 configured as described above are provided, for example, after being cut from a tape raw material, by being mounted on a rotary shaft in the subsequent step.
The desired winding is performed according to the cutting speed, but an appropriate amount of water of about 0.01 c.c. to 0.05 c.c. is applied to each hub 1 before starting the winding by, for example, a syringe-shaped member. The tape end is wound onto the winding surface 4 by automatically supplying the magnetic tape 5 to the winding surface 4 of the rotating hub 1 so that the magnetic tape 5 is in contact with the winding surface 4 of the hub 1. The magnetic tape 5 is automatically engaged so that the magnetic tape 5 sticks to the hub 1.
Is wrapped around.

As described above, water is supplied to the winding surface 4 as a preparatory step for starting winding, but since the winding surface 4 is appropriately matted to have a surface roughness, the water does not form a water drop and the winding surface 4 does not. And is held flat on the winding surface 4 and is hardly scattered by the rotation of the hub 1. Therefore, the tape end can be securely attached to the winding surface 4, and various problems such as deterioration of equipment caused by splashing water droplets and deterioration of quality of the magnetic tape 5 can be avoided. You can

On the other hand, even if the winding surface 4 is matted, its surface roughness is suppressed to 10 μm Rmax or less as described above,
The unevenness of the winding surface 4 is not substantially reflected on the magnetic tape 5, and the quality of the magnetic tape 5 is not deteriorated.

The material of the hub 1 shown in FIG. 1 is not particularly limited, and may be made of, for example, conventionally used aluminum, other metals, alloys or various plastic resins.

Hereinafter, the present invention will be specifically described based on Examples.

(Example) The hub used was of the type shown in FIG. 1, the material was phenol resin, and the surface roughness of the winding surface was 0.5 μm to 1 μm.
5 μm Rmax, outer diameter L is 114 φmm, winding surface width W
Of 18 mm was selected as appropriate, the number of rotations of the hub was set to 500 rpm, and the spreading property of water, the state of water droplets scattered, and the state of reflection on the magnetic tape on the winding surface were observed. Table-
Shown in 1. Regarding the image of the winding surface and the image of the tape terminal, the relationship between the length from the tape terminal and the image evaluation point is shown in the graph of FIG. The image evaluation points in FIG. 2 were observed at a temperature of 50 ° C. for 24 hours, and the evaluations in Table 1 were as follows: ○: good, Δ: acceptable range, ×: bad 2 indicates that the larger the number, the better the image quality evaluation point in FIG. or,
Surface roughness can be measured at any point on the hub winding surface.
It is a value obtained by scanning the measuring means in the width direction of the winding surface.

As is clear from Table-1, samples No. 1, No. 2 and No.
In No. 3, the surface of the wound surface is good and the condition relating to tape reflection is good, but the spreadability of water and the scattering of water drops due to hub rotation are poor, and Sample No. 7 and No.
In No. 8, the spreadability of water and the scattering state of water droplets were good, but there was a large problem in tape reflection. On the other hand, for samples No. 4, No. 5 and No. 6, satisfactory results were obtained in all evaluations. Especially surface roughness is 5μm Rmax
In some cases, very good results could be obtained.

In addition, the tape image on the surface of the winding surface is 2 m in most cases, while the image on the tape end is 10 m.
It is not less than, even if the evaluation in the above table is poor, further damage is less likely to occur, and a hub having a winding surface with a small surface roughness, which was considered to be good in the past, is better. It can be seen that there is an extremely large problem in terms of automatic winding of the magnetic tape.

(Effects of the Invention) As described above, in the tape hub of the present invention, the surface roughness of the winding surface in contact with the magnetic tape is in the range of 3 μm to 10 μm Rmax. Good performance and less scattering of liquid due to rotation of hub. Therefore, it is possible to guarantee the automatic sticking of the tape terminal, and avoid troubles of mechanical equipment due to water droplet scattering and deterioration of the quality of the magnetic tape.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the tape hub of the present invention, and FIG. 2 is a graph showing the evaluation of the tape transfer due to the surface roughness of the winding surface of the hub and the tape transfer of the tape end. 1 ... Hub, 2 ... Hole, 3 ... Recess, 4 ... Winding surface, 5 ... Magnetic tape.

Claims (1)

[Claims] 1. A surface roughness of a winding surface in contact with a magnetic tape is 3
A tape hub characterized by having a structure in the range of μm to 10 μm Rmax.