JPH02306486A - Liner for floppy disk - Google Patents

Abstract

PURPOSE:To reduce the contact pressure produced when a liner and a disk are revolved with a contact secured between them by using an unwoven fabric consisting substantially of nylon fibers to the disk contact surface. CONSTITUTION:A parallel card web is produced with a single fiber degree of 2 deniers, the fiber length of 51mm, and the 10g/m<2> weave of nylon-6 fiber 100wt%. Then another parallel card web is produced with a rayon fiber of 1.5 deniers, the fiber length of 51mm, and the 12g/m<2> weave of 100wt%. Then the parallel card webs of nylon-6 fiber are added on and under the other type of card web for production of a lamination card web. Then an emboss process is applied to the surface of the lamination card web via a pair of rolls at 220 deg.C roll surface temperature, with 25kg/cm nip line pressure, and at 30m/min working speed. Thus an unwoven fabric is obtained and used as a disk contact surface. As a result, the wear of a disk can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a nonwoven fabric (industrial application field) used as a wiper for magnetic recording media known as computer diskettes.
liner).

(Prior art) Floppy disks used for computer data processing are protected by a jacket made of vinyl chloride resin or a hard case jacket molded from ABS resin, which has a liner on the inside. . In particular, the importance of the liner is extremely important in that it minimizes the generation of dust on the liner itself due to abrasion with the disk surface, avoids scratches on the disk surface, and cleans the disk surface. As capacity increases, its importance increases.

Various liners have been proposed in the past.

For example, U.S. Pat.
According to the publication, cellulose fibers, which have lower abrasion resistance than other textile fibers, are arranged on the disk, and thermoplastic fibers are arranged in the middle layer to maintain the fabric strength of the liner, and thermocompression bonding is used. A liner has been proposed in which the liner is bonded in dots to obtain a laminated structure with partial depressions and depressions on both the front and back sides, or a liner is made in which cellulose fibers and nylon-6 are mixed and the surface is made uneven by dot adhesion.

(Problems to be Solved by the Invention) The basic idea of the prior art is to prioritize the wear of the disk over the wear of the liner caused by rotational contact with the disk.

However, if we consider the relationship between the disk and the liner, both disk wear and liner wear essentially reduce the performance of the floppy disk. Disk wear reduces recording/playback performance, and disk wear debris can interfere with the transmission of information in the read/write head of a computer disk drive. Furthermore, liner abrasion similarly impedes the transmission of information in the above-mentioned head, and also contributes to accelerating disk abrasion depending on abrasion dust of the liner.

The present invention has been made in consideration of the above points, and it is an object of the present invention to provide a liner that maintains disk protection and cleanability over a long period of time by minimizing disk wear and liner wear.

(Means and Effects for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a non-woven fabric in which the disk contact surface is substantially composed of nylon fibers, and the non-woven fabric is non-melt crimped, fused crimped. In addition, at least one side of the nonwoven fabric has an uneven shape, and the concave portion has a crimped part on one or both of the non-fused crimped and fused crimped parts. be. Further, the area of the recessed portion is in the range of 10 cm to 50 cm6 of the nonwoven fabric.

Further, the present invention is a floppy disk liner in which the nylon fiber is a composite fiber in which the sheath portion is nylon and the core portion is polyester, and the compression property value of the nonwoven fabric is in the range of 5 to 15. These are the means to solve the above problems. The present invention will be explained in more detail below.

Among textile fibers, nylon fiber is one of the textile materials that is suitable as a material for liners for floppy disks, which require strong wear resistance and cleaning properties.

The present invention has completed a floppy disk liner using this nylon fiber as the main raw material.

For the liner structure to prevent wear of the disk and liner as much as possible, firstly, it is important to use a fiber material with excellent wear resistance on the surface of the liner that comes into contact with the disk.

A liner made of a fibrous material such as cellulose fiber, which has relatively poor abrasion resistance, is different from the liner's construction idea of preventing scratches on the disk instead of abrasion of the liner due to contact rotation with the disk and generation of abrasion dust, as mentioned earlier. As a result, the liner wears out and generates abrasion dust, which deteriorates the performance of the floppy disk. Therefore, in the present invention, the problem is solved by using nylon fiber as a material that has excellent wear resistance, self-lubricating properties, and relatively excellent compressive elasticity.

Second, the surface that comes into contact with the disk needs to be flexible and have cushioning properties that fit the liner as a whole. By doing so, the contact pressure between the liner and the disk during contact rotation is alleviated, thereby preventing wear of the disk.

In the present invention, the structure of the liner is solved as follows for these purposes.

The floppy disk liner (hereinafter referred to as FD liner) made of the nonwoven fabric of the present invention maintains its shape by heat-pressing the fibers together. In other words, the shape is maintained by either non-melting crimping, molten crimping, or both of the nylon fibers used on the surface that contacts the disk and/or the thermoplastic synthetic fibers used in other layers. It is something that

Bonding between fibers using an adhesive or solvent to maintain the shape improves the shape stability, but the entire FD sealiner hardens, impairing the flexibility and elasticity of the nylon fibers and other constituent fibers. This reduces the cushioning properties of the liner, which adversely affects disc wear and cleaning performance.

In addition, at least one surface of the FD liner is heated and pressed into an uneven shape to form a convex portion that is not partially press-bonded, thereby maintaining the cushioning properties of the entire nonwoven fabric, and since the fibers constituting the convex portion are not fixed, it is relatively easy to use. It has a structure that can freely respond to stress, which suppresses disk wear and improves cleaning performance. Therefore, the recesses are as small as possible and uniformly distributed, and
Preferably, it is in the range of 0.

If the area of the recesses is less than 10 mm, the effect of stabilizing the shape is small and lint and fuzz are likely to occur. On the other hand, if the coefficient is 50 or more, the FD liner becomes hard, which results in adverse effects on disk wear and cleaning performance.

Since the fibers constituting the convex portions are substantially nylon fibers, the advantages of nylon's excellent flexibility and compressive elasticity can be utilized. Furthermore, the FD liner of the present invention has a compression characteristic value (described later) representing the cushioning properties of the liner under low loads in the range of 5 to 15. When the compression characteristic value is less than 5, the cushioning properties of the liner are poor, and the contact pressure generated when the disk rotates cannot be alleviated, which tends to cause disk wear. Further, if the same value is 15 or more, the vibration of the disk rotation cannot be controlled and the generated torque becomes unstable. As the nylon fiber of the present invention, nylon-6 and nylon-66, which are commonly used as textile fibers, can be used.

The above-mentioned "substantially" means that the nylon fiber has a modulus of 60 or more, preferably 70 or more. Further, as the nylon fiber, it is also possible to use a composite fiber in which the above-mentioned nylon is in the surface layer of the fiber and other synthetic fiber is arranged in the core. In this case, it is more preferable to use a conjugate fiber in which a polyester core is arranged as a combination because it has excellent morphological stability against changes in the environment. It is also good to use the nylon fiber after heat treating it for the same purpose as above.

As described above, the structure of the FD liner of the present invention includes substantially nylon fibers on the disk contact surface, and the FD liner as a whole only needs to have a structure that satisfies the above-mentioned compression property values. The surface layer may be made of nylon fibers, and the lower layer may optionally contain other textile fibers so as to satisfy the above conditions.

(Example) EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Nylon-6 with single fiber fineness of 2 denier and fiber length of 51 m1
A parallel carded web of 100 wt/mm fiber was created. Next, a rayon fiber of 1.5 denier, fiber length 51 w, 100 wt, and a basis weight of 12 t/m was prepared.
A parallel carded web of No. 2 was prepared, and the above-mentioned parallel carded web of nylon-6 fiber was placed on top of the above-mentioned web to obtain a laminated carded web. Next, the laminated card web was coated with a steel embossing roll having a large number of rectangular protrusions with a width of 1.0 m and a length of 15 m on the surface, and the area of the protrusions being 25 qb of the total area, and a steel roll with a smooth surface. Embossing was performed using a pair of rolls consisting of a combination of the following: a surface temperature of 220°C, a nip linear pressure of 25 kg/cm, and a processing speed of 30 m/min to obtain nonwoven fabric A. As a comparative example, a laminated card web was prepared by using the above card web and arranging the rayon fiber card web at the top and bottom and the nylon-6 fiber card web at the middle layer. Processing was performed under the same embossing conditions to obtain non-edge fabric B.

As another comparative example, the upper and lower card webs of non-woven fabric B were made of 80 wt% polyester fibers with a single fiber fineness of 1.5 denier and a fiber length of 51 strands, and a single fiber fineness of 1.5 denier.
A nonwoven fabric O'It''4 processed under the same embossing conditions as above using a parallel web of 1091m'' in which rayon fiber B 20 wt4 with a fiber length of 515w is uniformly mixed.
Ta. Table 1 shows the results of evaluations of jackets in which each nonwoven fabric was shaped into convexes and convexes, with the tail surface as the disk contact surface and the substantially flat surface as the jacket contact surface.

Table 1 In Table 1, the damage to floppy disks and the amount of lint on the disk surface are determined by (J Engineering 5-L- [1849, T Engineering 5-L
-0823) was determined visually.

The compression characteristic value was determined using the following formula.

tl - t2 Compression characteristic value - □ However, tI: Right bank of the non-woven fabric at a load of 2 f/cm (p-) t2: Right bank of the non-woven fabric at a load of 89/cm (
μm) Example 2 Single fiber fineness 2.0 denier, fiber length 51 corners nylon-6
Fiber (180℃ x 5 minutes dry heat treatment) 75wt, single fiber fineness 1.5 denier, fiber length 51cm rayon fiber A30
A parallel carded web with a basis weight of 1597 m2 was prepared by uniformly mixing rayon fibers of 50 wt.
Uniformly mix 50 wt% of polypropylene fibers with a single fiber fineness of 15 denier and a fiber length of 51+n to obtain a fabric weight of 179.
A parallel card web of 7 m2 was created and laminated with the card web, and the web surface of the non-nylon-6 fiber 70 wt4 was subjected to uneven patterning using the embossing roll of Example 1 to obtain a non-woven fabric. Ta. As a comparative example, a nonwoven fabric E was obtained by processing under the same conditions using an embossing roll whose total area is 8, with each embossed convex having the same area. Furthermore, under the non-woven fabric processing conditions, an embossing roll was used in which the convex part of the embossing roll had a rectangular shape with a width of 2.0 m and a length of 1.0 m, and its area was 60 times the total area. A fuji fabric F was obtained under the same conditions as the fuji fabric.

The uneven surface of this nonwoven fabric is used as the disk contact surface.
Evaluation was performed on the jacket that was in contact with the jacket using its substantially flat surface as the jacket contact surface, and the results shown in Table 2 were obtained.

Table 2 ◎Excellent ○Good ΔSlightly Poor (Effects of the Invention) The liner according to the present invention generates less abrasion dust on the liner during actual running, which improves information transmission and proper busy operation of the read/write heads of disk drives. b. It also has excellent cushioning properties and can protect media from abrasion caused by contact rotation with the liner over a long period of time, making it exceptional as a liner for high-density, high-capacity media, especially media over 2MB. It has the following effects.

Claims (5)

[Claims] (1) A liner for a floppy disk, characterized in that the disk contacting surface is a nonwoven fabric made essentially of nylon fibers, and the nonwoven fabric has a non-melting crimped portion and/or a molten crimping portion. (2) The nylon fiber according to the first claim is a floppy disk liner, wherein the nylon fiber is a composite fiber having a sheath portion of nylon and a core portion of polyester. (3) The compression property value of the nonwoven fabric according to the first claim is 5 to 1.
Floppy disk liner in the 5 range. (4) A liner for a floppy disk, in which the nonwoven fabric according to claim 1 has an uneven shape on at least one surface, and the concave portion is a non-melting crimping portion and/or a molten crimping portion. (5) The area of the concave portion according to the fourth claim is 10 to 5 of the nonwoven fabric.
Liner for floppy disks in the 0% range.