JP2747922B2 - Method of manufacturing liner for floppy disk - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liner made of a nonwoven fabric aggregate that can be used for lining a floppy disk jacket.

(Prior art) A jacket for a floppy disk generally has a bag made of a polymer resin sheet such as a vinyl chloride resin or an ABS resin, and a liner made of a fiber sheet is bonded to the inner surface thereof. . The liner made of this fiber sheet is installed mainly for the purpose of preventing direct contact between the floppy disk and the resin sheet constituting the jacket body to avoid abrasion or damage of the floppy disk surface and cleaning the floppy disk surface. Various types of fiber sheets have been conventionally proposed. For example, JP-A-58-7705 discloses a non-woven fabric made of polyester fiber, and JP-A-54-49115 discloses a non-woven fabric made of polypropylene fiber.
No. 71280 discloses a non-woven fabric made of recycled fibrous fibers, and these methods include a method of fusing fibers together in order to stabilize the form of the non-woven fabric, and a method of bonding and fixing the fibers with an adhesive. Used.

Japanese Patent Application Laid-Open No. 61-85683 discloses that a web containing a composite fiber comprising a high melting point component and a low melting point component is heated at a temperature not lower than the melting point of the low melting point component and not higher than the melting point of the high melting point component without pressing. It is described that a method for producing a liner for a floppy disk which is treated and then embossed at a temperature equal to or higher than the melting point of the high melting point component can obtain a liner with less fluff and less fiber loss without impairing cushioning property and flexibility. .

(Problems to be Solved by the Invention) On the other hand, when a general fiber sheet according to a known technique is used as a floppy disk liner, lint is generated due to falling off of an adhesive, a fiber, and the like, and an error easily occurs.

In recent years, floppy disks have become micro-sized,
There is a major shift towards higher densities and higher speeds,
There is a strong demand for the development of a high-performance floppy disk liner that can cope with this.

In such a high-capacity type floppy disk, problems such as damage to the disk surface and the occurrence of lint have become larger and more common with conventional liners, and the performance required for the liner in the high-capacity type Are not obtained.

One way to prevent damage to the disk surface is to make the surface layer on the disk side of the liner a fibrous fiber, or to reduce the heating temperature during embossing when forming the liner. However, in this case, if the fibrous fiber is used as the surface layer, the damage to the disk surface can be prevented, but the stability of the surface layer fiber of the liner becomes insufficient, which causes lint. Also,
Even if the embossing heating temperature during the formation of the liner containing thermoplastic fibers is lowered, the liner surface can be obtained with flexibility, but the surface fiber in the non-heated part also lacks stability, and lint is increased. There is a problem as a liner for a floppy disk with a large capacity.

More importantly, the liner heated and crimped by embossing recovers elastically over time, causing the liner thickness to fluctuate slightly. For this reason, if a mechanism that makes the disc and the liner contact with each other using a lifter is used, the contact capacity with the media on the disc increases as the thickness increases, resulting in a high capacity type, such as an increase in torque. Problems have begun to arise.

(Means for Solving the Problems) The present invention relates to a nonwoven fabric aggregate comprising a high-melting fiber and a low-melting fiber and having the low-melting fiber in an inner layer, the high-melting fiber having a melting point of the low-melting fiber or higher. Floppy disk with excellent morphological stability and low lint by applying heat treatment while regulating the thickness of the fiber assembly within the temperature range below the melting point of It is a manufacturing method for obtaining a liner for use. "The gist of the present invention is a non-woven fiber aggregate composed of a high-melting fiber and a low-melting fiber, and having the low-melting fiber in the inner layer, having a melting point of the low-melting fiber or more and a melting point of the high-melting fiber or less. In a temperature range, a heat treatment is performed while regulating the thickness of the fiber assembly, and then, in a temperature range not less than the melting point of the low-melting fiber and not more than the melting point of the high-melting fiber, a partial thermocompression treatment by embossing is performed. The present invention provides a method of manufacturing a liner for a floppy disk, which can provide a liner for a floppy disk which is excellent in form stability and generates less lint.

 Hereinafter, the present invention will be described in detail.

As the fiber used in the present invention, a high-melting thermoplastic synthetic fiber such as polyester, polypropylene, polyethylene or acrylic and a low-melting thermoplastic synthetic fiber, or a mixture thereof with a fibrous fiber is used. If fibrous fibers are used as the surface layer, it is effective to soften the contact surface of the liner with the disk, but if fibrous fibers alone have insufficient form stability as a liner, It is possible to stabilize the form of the liner by mixing thermoplastic fibers. As a method of mixing, the respective fiber aggregates may be laminated and integrated. However, it is preferable to uniformly mix the fiber aggregates with cotton mixing or the like in order to prevent delamination or lint. As a low melting point fiber,
Generally known low-melting fiber or, in the case of fiber production, a thermoplastic synthetic fiber whose melting point has been lowered by using a melting point depressant in combination may be used. Concentric conjugate fibers may be used. As the low melting point fiber, those having a large difference in melting point from the mixed high melting point fiber are preferable. The fineness of the fiber used is excellent in cleaning action when used as a liner.
Those having denier or less are preferred.

In the present invention, heat treatment (preliminary heat treatment) under specific conditions before embossing is important and has the following effects.

FIG. 2 is a cross-sectional view schematically showing the form of the liner after embossing without the prior heat treatment according to the prior art, and FIG. 1 is the cross-sectional view after embossing after the preliminary heat treatment according to the present invention. FIG. 6 is a cross-sectional view schematically showing a state in the case. (1) is a thermocompression bonding portion using an embossing roll, (2) is a media contact surface of a floppy disk liner formed by a non-heating compression bonding portion of the embossing roll, and (3) is a low contact pressure portion at the non-heating compression bonding portion. The fixing portions of the melting point fibers are shown.

As shown in FIG. 2, the thermocompression bonding portion (1) of the liner that has only been subjected to the embossing treatment has the constituent fibers mutually fused and integrated, and is firmly fixed. However, on the disk contact surface (2) formed by the non-heat-compression bonding portion, the fibers constituting the surface of the liner are fixed to some extent, but the fibers constituting the interior are temporarily in a non-adhered state and loosely bonded. It is in a state of holding down. Therefore,
When the embossing is released from the pressurized state and the time elapses, the overall thickness of the liner increases due to elastic recovery, and when manufactured using this, the liner comes into strong contact with the disk and the torque increases. Easier to do. Further, the tips of the fibers forming the surface of the disk contact surface (2) are turbulent, and are susceptible to damage during high-speed rotation of the disk, which is likely to cause the fibers to drop or break.

In the present invention, as shown in FIG. 1, heat treatment of the low-melting fiber is performed by heat-treating the non-woven fiber aggregate containing the low-melting fiber before the embossing treatment in a temperature range not lower than the melting point of the low-melting fiber. At the same time, the high-melting-point fibers are fixed to each other by fusion, and the high-melting-point fibers forming the surface of the liner are heat-fixed to make the fiber form of the media contact surface (2) stronger. At this time, since the heat treatment is performed while controlling the thickness of the nonwoven fabric fiber aggregate, preliminary thickness control is possible, and the thickness control of the liner in the embossing process is facilitated.

The embossing step is not particularly limited, as long as it employs a method and conditions that are usually performed. In the case of the present invention, however, the temperature condition of embossing can be set low because the fiber form of the liner is good by the preliminary heat treatment.

Example Polyester fibers 1.5d × 51 mm having a melting point of 256 ° C. and rayon 1.5d × 51 mm were each mixed with 50% of each other on a liner surface. Polyester fibers 2d × having a melting point of 110 ° C. were formed as inner layers. A layer composed of 50 mm of 50 mm each of 51 mm and rayon 1.5 d x 51 mm is arranged on the inner surface of the liner, and the basis weight is 30 g / m ^2.
Preliminary heat treatment was performed at 130 ° C. so as to have a cloth thickness of 200 μm, and then embossing was performed at 220 ° C. As a comparative example, only the embossing was performed without performing the preliminary heat treatment. The results are shown in the table below.

(Effect of the Invention) According to the method of the present invention, prior to the embossing step, a preliminary heat treatment at a temperature equal to or higher than the melting point of the low-melting fiber constituting the nonwoven fabric fiber aggregate is performed while regulating the thickness. The embossing is performed in a state where the individual fibers constituting the non-woven fabric fiber aggregate are bonded to each other by fusion of the low-melting fibers, and the occurrence of elastic recovery after embossing can be suppressed, It is possible to prevent the fluctuation of the thickness of the liner after embossing, which is a major problem in the liner for floppy disks. In addition, since preliminary thickness regulation is performed before the embossing step, final thickness regulation in the embossing step can be performed without difficulty. Further, the preliminary heat treatment has a great effect of the present invention, such as fusion of fibers between the liners and reduction of lint.

[Brief description of the drawings]

1 is a cross-sectional view of a liner obtained by the method of the present invention, and FIG. 2 is a cross-sectional view of a liner obtained by a conventional method. 1. Heat-press bonding part 2. Media contact surface 3. Low-melting fiber fixing part

Claims (1)

(57) [Claims] 1. A nonwoven fabric aggregate comprising a high-melting fiber and a low-melting fiber, and having the low-melting fiber in an inner layer, in a temperature range from the melting point of the low-melting fiber to the melting point of the high-melting fiber, A heat treatment while regulating the thickness of the fiber assembly, and then performing a partial thermocompression treatment by embossing in a temperature range from the melting point of the low-melting fiber to the melting point of the high-melting fiber, for a floppy disk. Liner manufacturing method.