JPH0664882B2 - Processing method for liner sheet for disc cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is most suitable for a floppy disk cartridge using, for example, a magnetic sheet, and in particular, it is interposed between a disk and a case and a head of the case. The present invention relates to a method for processing a liner sheet for a disc cartridge, which is made of a non-woven fabric and has a notch corresponding to the insertion hole.

[Outline of Invention]

The present invention relates to a method for processing a liner sheet for a disk cartridge, which is interposed between a disk and a case and has a cutout corresponding to a head insertion hole of the case. In the method, a press working is performed on at least the cutout of the liner sheet. At this time, the heat-melting synthetic resin film having a melting point lower than that of the fiber of the liner sheet is also preliminarily laminated in a band shape along the contour of the cutout portion of the liner sheet, and the contour is heated and pressed to form the film. The liner sheet is impregnated with the molten synthetic resin in the contour of the cutout portion of the liner sheet, and the fibers of the liner sheet are bonded to each other by the molten synthetic resin, and the cutout portion is formed along almost the center of the portion impregnated with the molten synthetic resin. By pressing, the liner sheet can be cut at least without being adversely affected by heating. The fibers fray from parts is obtained so as to be completely prevented.

[Conventional technology]

The conventional example shown in FIG. 8 is a floppy disk cartridge using a micro floppy disk made of a magnetic sheet having a diameter of 3.5 inches, and a floppy disk is housed in a case 3 composed of upper and lower halves 1 and 2 made of synthetic resin. A disc (hereinafter simply referred to as a disc) 4 is rotatably accommodated, and a pair of upper and lower liner sheets 5 are interposed between the inner surface of the upper and lower halves 1 and 2 and the disc 4.
A center core 7 made of a metal disk is fixed to the center of the disk 4, and the center core 7 is provided with a center hole 8 and an eccentric hole 9. Head insert holes 10 are provided in the upper and lower halves 1 and 2, and notches are formed in both liner seats 5 corresponding to these head insert holes 10.
Twelve are provided. Both head insertion holes 10 are configured to be opened and closed by a shutter 14. Furthermore, a circular hole 15 for inserting a turntable is provided in the central portion of the lower half 2, and circular holes 16 corresponding to the circular hole 15 and the center core 7 are also provided in the central portions of both liner sheets 5.
Is provided.

Both liner sheets 5 are formed of a fiber material which is a so-called non-woven fabric obtained by forming long fibers such as polypropylene and rayon into sheets by a method such as thermocompression bonding.
Both of these liner sheets 5 are locked to the inner surfaces of the upper and lower halves 1 and 2 by fusion bonding. That is, as shown in FIG. 9 (this is on the lower half 2 side but the same on the upper half 1 side), the liner sheet 5 is indicated by diagonal lines on the inner and outer peripheral portions and the peripheral edges of the cutout portion 12. It is fused to the inner surface of the lower half 2 by a thin diagonal perforated pattern 19.
Then, the upper and lower halves 1 and 2 are joined together from above and below to form the case 3
When assembled, both liner sheets 5 are configured to be in constant contact with the upper and lower recording surfaces of the disk 4.

Further, in order to increase the contact pressure of both liner sheets 5 with respect to the disc 4, a lifter plate 18 formed of an elastic sheet material such as a synthetic resin sheet is fixed to the inner surface of the lower half 2 by adhesion or the like. The tip portion 18a of the lifter plate 18 elastically presses a part of the lower liner sheet 5 against the lower surface of the disk 4 from below over substantially the entire width R in the radial direction of the recording surface of the disk 4. The lifter plate
The liner sheet 5 is not fused to the lower half 2 at the portion where the liner sheet 18 is disposed, and the liner sheet 5 is easily floated.

When the floppy disk cartridge is used, the center pin 8 and the eccentric hole 9 of the center core 7 are engaged with the center pin and the drive pin on the turntable of the disc player, and the drive pin drives the disc 4 to rotate. The upper and lower recording surfaces are selectively recorded or reproduced by a pair of upper and lower recording / reproducing heads which are in contact with the upper and lower recording surfaces of the disk 4 through the both head insertion holes 10 and the both cutouts 12.

When the lever is used, however, the upper and lower recording surfaces of the disk 4 are constantly in contact with both liner sheets 5 and are rotationally driven, and the load torque due to the frictional force is used to position the center of the disk 4 at the center of the turntable. It Further, when the disc 4 is rotated, both liner sheets 5 wipe off dust adhering to the upper and lower recording surfaces of the disc 4 and abrasion powder generated by contact between the disc 4 and the recording / reproducing head.

By the way, since the above-mentioned liner sheet 5 is punched from a sheet material made of a non-woven fabric by press working, as shown in FIG. 9, the fiber frayed 22 from the punched end 21 of the inner and outer peripheral portions of the liner sheet 5. Is likely to occur. And in particular, the fiber fraying 22 from the punched end 21 of the notch 12
Cause the fiber debris to enter between the recording surface of the disk 4 and the recording / reproducing head in the head insertion hole 10 and cause a dropout in which a signal is partially lost during data transfer of recording or reproduction.

The fiber fray 22 is, for example, when the die for press working has a slight chipping (chipping),
A long fiber fray 22 is generated from the punched-out end portion 21 by pulling a few fibers remaining uncut by the defective portion.

Further, when the liner sheet 5 is assembled in the case 3, if the punched end 21 is accidentally touched, a new fiber fray 22 is likely to occur. Therefore, sufficient care must be taken when assembling the liner sheet 5. Further, after the completion of the cartridge, a removal work for removing the fiber fray 22 is carried out in the final inspection, but the work is remarkably troublesome because the total inspection is performed visually.

Further, during use, the fibers of the liner sheet 5 are pushed out by the rotational driving of the disk 4, and the punched end 21 of the notch 12 is cut off.
May cause new fiber fraying 22. Since it is usually used by general users, the fiber fray 22 is hardly removed at present.

As a measure for preventing the fiber fraying 22 of the liner sheet 5 as described above, there is JP-A-60-113375. In this known example, when punching the liner sheet 5 from the sheet material by press working, as shown in FIG. 10, the sheet material is preliminarily punched into the inner and outer peripheral portions of the liner sheet 5 and the cutout portions 12 of the sheet material.
A heating and pressing process is applied along 21. According to this
The fibers of the heated and pressed portion of the liner sheet 5 are entangled with each other at a higher density than other portions, and the fibers are heat-bonded to each other, so that the fiber fraying 22 from the punched end 21 is less likely to occur when punched. Has become.

[Problems to be solved by the invention]

However, the above-described known example in which the punched end 21 of the liner sheet 5 is heated and pressed has the following problems.

That is, in order to completely prevent the fiber fraying 22, it is necessary to sufficiently raise the heating temperature by the heater to melt and bond the fibers to each other. However, in this case, if the heating temperature is set too high, the heat of the heater affects the entire liner sheet 5, and the synthetic resin fibers of the entire liner sheet 5 are thermally shrunk, and wrinkles are likely to occur in the entire liner sheet 5. . The rotation of the disk 4 may become unstable due to the wrinkles of the portion that contacts the disk 4,
There was a problem of giving scratches to.

The liner sheet 5 of this type, which is a mixed spinning of rayon fiber and polypropylene fiber, for example, has a high cleaning effect on the disk 4 when the mixing rate of the rayon fiber is high, but is easily affected by heat. Therefore, in such a liner sheet 5, the portion other than the punched end portion 21 is also melted by heating, and there is a possibility that the disc 4 is significantly scratched by hardening.

On the other hand, if the heating temperature by the heater is lowered so as not to cause the above-mentioned inconvenience, the fibers of the punched end 21 of the liner sheet 5 will not be sufficiently adhered or heat-adhered, and the above-mentioned fiber fray 22 will be Completely difficult to prevent.

Therefore, the present invention is capable of completely preventing the fraying of fibers from at least the cutout portion of the liner sheet without adversely affecting the liner sheet by heating.

[Means for solving problems]

The present invention relates to a method of processing a liner sheet for a disc cartridge, wherein at the time of pressing at least the notched portion of the liner sheet, a hot-melt synthetic resin film having a melting point lower than that of the fiber of the liner sheet is used. Is laminated in advance in a strip shape along the contour of the cutout portion of the liner sheet, and the contour is heated and pressed to impregnate the molten synthetic resin by the film into the contour of the cutout portion of the liner sheet, and the molten synthetic resin Thus, the fibers of the liner sheet are bonded to each other, and the notch is pressed along substantially the center of the portion impregnated with the molten synthetic resin.

[Action]

The present invention, the contour of the heat-meltable synthetic resin film is pre-laminated along the contour of at least the cutout portion of the liner sheet is heated and pressed, but the melting point of the film is higher than the melting point of the fiber of the liner sheet. Due to the low temperature, only the film melts and the molten synthetic resin impregnates into the cutout contours of the liner sheet and the fibers of the liner sheet are bonded together. And since the notch is pressed along almost the center of the part impregnated with the molten synthetic resin, the punched end of the notch is sheared extremely neatly, and no fiber fray occurs from the punched end. Absent.

And, since the film having a melting point lower than the melting point of the fibers of the liner sheet is melted and impregnated into the liner sheet, the heating temperature of the film may be a lower temperature than the case of melting and adhering the fibers of the liner sheet. There is no adverse effect of heat shrinking the fibers of the entire sheet and wrinkling of the entire liner sheet.

〔Example〕

An embodiment of a method of processing a liner sheet for a disc cartridge to which the present invention is applied will be described below with reference to FIGS. 1 to 7. The same parts as those of the conventional example described in the above [Prior Art] are denoted by the same reference numerals and the description thereof will be omitted.

First, FIG. 1 shows a liner sheet 5 for a floppy disk cartridge for accommodating a 3.5 inch diameter micro floppy disk. This liner sheet 5
For example, a strip-shaped long sheet material 30 made of a mixed-spun non-woven fabric of 50% rayon fiber and 50% polypropylene fiber is punched by pressing.

That is, as shown in FIG.
Is supplied from the above, is intermittently transferred in the direction of arrow a, and is wound around the winding roll 32. Further, in a state of being laminated on the upper portion of the sheet material 30, a strip-shaped long heat-meltable synthetic resin film (hereinafter, simply referred to as a film) 33 is intermittently transferred from the supply roll 34 to the winding roll 35. A heating / pressurizing unit 36 and a pressing unit 37 are sequentially arranged along the transfer path of the sheet material 30 and the film 33. Transfer positioning units 38 and 39 are arranged so as to sandwich the heating / pressurizing unit 36 and the press processing unit 37, respectively.

Then, with the intermittent transfer of the sheet material 30 and the film 33 in the direction of arrow a, first, the sheet material 30 is impregnated with the molten synthetic resin 40 of the film 33 by the heating and pressing unit 36. That is, the film 33 is the sheet material 30 (liner sheet 5)
Is a heat-meltable synthetic resin film having a melting point lower than that of the fibers of, for example, ordinary cellophane, moisture-proof cellophane,
Uniaxially stretched polyethylene, polyvinylidene chloride, soft vinyl chloride, hard vinyl chloride, etc. are applied. Film
Before being laminated on the upper portion of the sheet material 30, the 33 is approximately 1 to 3 m longer than the contours of the outer peripheral portion and the cutout portion 12 of the liner sheet 5.
A punched hole 41 having a small contour is formed. The sheet material 30 and the film 33 are transferred and positioned in a unit.
The film 33 is positioned and fixed by the 38 and laminated on the upper part of the sheet material 30 as shown in FIGS. 3A to 3B, and the film 33 is moved to the outer peripheral portion of the liner sheet 5 and the cutout by the heater 42 of the heating and pressing unit 36. In a strip shape along the contour of the part 12,
That is, the liner sheet 5 is heated and pressed in a band shape (width d is about 2 to 6 mm in the embodiment) so as to include the punched end 21. Then, since the melting point of the film 33 is lower than the melting point of the fibers of the liner sheet 5, only the film 33 is melted and the molten synthetic resin 40 is impregnated into the outer peripheral portion of the liner sheet 5 and the contour of the cutout portion 12. Then, the fibers of the liner sheet 5 are completely bonded to each other by the molten synthetic resin 40 in the strip-shaped region along the contour. The heating temperature of the heater 42 is around 100 ° C. Further, the heating / pressurizing unit 36 may be a rotary type such as a gravure roll in addition to the vertical type as shown.

Next, the sheet material 30 and the film 33 are sent to the pressing unit 37 by intermittent transfer in the arrow a direction. Then, the liner sheet 5 is pressed from the sheet material 30 and punched by the pressing unit 37. On this occasion,
The sheet material 30 is accurately positioned and fixed by the transfer positioning unit 39, and is pressed along substantially the central portion of the portion of the sheet material 30 impregnated with the molten synthetic resin 40. That is, as shown in FIG. 1, the liner sheet 5 in which the portion impregnated with the molten synthetic resin 40 along the outline of the outer peripheral portion and the cutout portion 12 remains in a band shape (width w is about 1 to 3 mm in the embodiment) is formed. Will be punched out. At this time, the circular hole 16 is also punched at the same time.

By the way, at the time of the press working, as shown in FIG. 3B, the sheet material 30 is impregnated with the molten synthetic resin 40 by the film 33, and by this molten synthetic resin 40, the fibers of the punched portion of the sheet material 30 are completely mutually. Are combined. Therefore, as shown in FIG. 4 (this shows the cutout 12), when the outer peripheral portion of the liner sheet 5 and the cutout 12 are punched by the punching dies 43, 44 of the press working unit 37, the punched end portion twenty one
Is very cleanly sheared and no fiber fraying occurs at its punched end 21. Also punching die 43,
Even if there is a slight defect in 44, since it is sheared at the portion impregnated with the molten synthetic resin 40, the fiber is not pulled without being cut, and there is no risk of long fiber fraying.

Next, the liner sheet 5 stamped from the sheet material 30 as described above is fused to the inner surface of the lower half 2 (the same applies to the upper half 1) as shown in FIG. This fusion may be performed in the same manner as in the prior art, but in the liner sheet 5 of this embodiment, the portion impregnated with the molten synthetic resin 40 along the outline of the outer peripheral portion and the cutout portion 12 is hardened, so Even if the fusion points are greatly reduced, the fixing of the lower half 2 to the inner surface is extremely reliable. Alternatively, the cured portion may be used to apply and bond an adhesive thereto.

When the liner sheet 5 is assembled into the case 3, even if the punched end 21 of the liner sheet 5 is accidentally touched, the punched end 21 is hardened by the solidification of the molten synthetic resin 40. , No new fiber fray occurs from here. Also, when using the disc cartridge,
Even if the fiber is pushed out toward the notch 12 by the rotational driving of the disc 4 that comes into contact with the liner sheet 5, the notch 12
The movement of the fibers is prevented by the molten synthetic resin 40 that has been hardened at the punched end 21 and again no new fiber fraying occurs from here.

By the way, in the liner sheet 5 made of a mixed spinning of rayon fibers and polypropylene fibers as in this embodiment, when the mixing rate of the rayon fibers is high, the cleaning effect on the disk 4 is high, but the adverse effect of heating is large. However, in this embodiment, the film 33 having a melting point lower than the melting point of the fibers of the liner sheet 5 is melt-impregnated at the time of heating and pressurizing to prevent the fibers from fraying from the punched end 21. The temperature may be lower than that when the fibers of the liner sheet 5 are melt-bonded. Therefore, even if the blending ratio of rayon fibers is as high as 50%, there is no adverse effect such as wrinkling due to heat shrinkage in the entire liner sheet 5. Also, since the molten synthetic resin 40 shrinks when it hardens,
As shown in FIG. 6, there is no inconvenience that the portion impregnated with the molten synthetic resin 40 contacts the disk 4 with the liner sheet 5 interposed in the case 3.

Next, FIG. 7 shows a liner sheet 46 for a floppy disk cartridge that accommodates a floppy disk having a diameter of 5 inches. The liner sheet 46 sandwiches the disc by interposing it on the inner surface of a case (not shown) and bending it at the center, and has a substantially rectangular shape. The liner sheet 46 is pressed from a strip-shaped long sheet material 47 similar to that described above, but the width of the sheet material 47 is used as it is in the width direction.

Then, before the liner sheet 46 is pressed from the sheet material 47, a heat-meltable synthetic resin film is applied to the sheet material 47.
Heat and pressure are applied in a state where the 48 are laminated, and the molten synthetic resin 49 by the film 48 is impregnated. That is, the molten synthetic resin 49 is impregnated in a strip shape along the outer peripheral portion of the liner sheet 46, the circular holes 16 and the contours of the notches 12. Although the sheet material 47 is not pressed in the width direction, it is impregnated with the molten synthetic resin 49. Then, the molten synthetic resin 49 is pressed along substantially the center of the impregnated portion. In the case of this embodiment, the film 48 remains on the upper surface of the liner sheet 46, which can be peeled off after the press working.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments and various effective modifications can be made based on the technical idea of the present invention.

For example, in the present embodiment, the synthetic resin made of a film was impregnated along the contours of the outer peripheral portion and the cutout portion of the liner sheet. You can do it. On the contrary, the contour of the circular hole may be included.

Further, the present invention is not limited to the method for processing the liner sheet for the floppy disk cartridge, and can be applied to the method for processing the liner sheet for the disk cartridge which accommodates various disks to be recorded or reproduced by various methods.

〔The invention's effect〕

As described above, according to the present invention, the fibers of the liner sheet are completely bonded to each other without using such a high temperature that the fibers themselves of the liner sheet are melt-bonded to each other. There is no problem that the heat of (3) affects the entire liner sheet and wrinkles are generated in the entire liner sheet due to heat shrinkage. Therefore, the rotation of the disc is extremely smooth, and there is no inconvenience that the disc is scratched. And while the cleaning effect on the disk is high, even a liner sheet using a synthetic resin fiber such as polypropylene, which is weak against heating, does not melt and harden the portion in contact with the disk,
It is possible to use a liner sheet that has an extremely high cleaning effect with peace of mind.

As described above, since fiber fraying can be completely prevented while the liner sheet is not adversely affected by heating, fiber debris can enter between the disk and the head, and a signal is partially transmitted during data transfer for recording or reproduction. It is possible to prevent the dropout phenomenon, which is caused by the loss of quality, and the quality is remarkably improved and the reliability is very high. And when assembling the liner sheet into the case, there is no need to take sufficient care not to touch the notch of the liner sheet, or to perform the removal work to remove the fiber fray at the final inspection after completion, The assembling work is simple, the working time is shortened, and the manufacturing cost can be reduced.

Further, according to the present invention, even if a minute defect occurs in the punching die for press working, there is no possibility of long fiber fraying due to this defective portion, so that the replacement cycle of the punching die can be extended. As a result, the life of the punching die can be extended.

[Brief description of drawings]

1 to 7 show an embodiment in which the present invention is applied to a method for processing a liner sheet for a floppy disk cartridge. FIG. 1 is a perspective view of the liner sheet, and FIG. FIG. 3A is a cross-sectional view of a main part in a state where films are laminated, FIG. 3B is a cross-sectional view of a main part showing a heating and pressing treatment, and FIG. 4 is a cross-sectional view of a main part showing press working. 5 is a plan view of a main portion of a liner sheet interposed in a case, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG. 7 is a plan view of a liner sheet in another embodiment. . 8 to 10 show a conventional example of a floppy disk cartridge, and FIG. 8 is an exploded perspective view of the whole,
FIG. 9 is a plan view showing a state in which the liner sheet is inserted in the case, and FIG. 10 is a sectional view of a main part of the liner sheet subjected to the heating and pressing treatment. In the reference numerals used in the drawings, 1 ... upper half 2 ... lower half 3 ... case 4 ... disk 5 ... liner sheet 10 ... head insertion hole 12 ... notch 21 ... punching end 22 ... … Fiber fraying 30 …… Sheet material 31 …… Supply roll 32 …… Winding roll 33 …… Heat-melting synthetic resin film 34 …… Supply roll 35 …… Winding roll 36 …… Heating and pressing unit 37 …… Press Processing unit 40 …… Melting synthetic resin 46 …… Liner sheet 47 …… Sheet material 48 …… Heat-melting synthetic resin film 49 …… Melting synthetic resin.

Claims (1)

[Claims] 1. A notch which is interposed in the case and faces at least one surface of a disk rotatably accommodated in the case and which corresponds to at least a head insertion hole provided in the case. In a liner sheet for a disc cartridge made of a non-woven fabric, when pressing at least the cutout portion of the liner sheet, a heat-meltable synthetic resin film having a lower melting point than the melting point of the fiber of the liner sheet is used, and this film is The contour of the liner sheet is preliminarily laminated in a strip shape along the contour of the cutout portion, so that the contour is heated and pressed to impregnate the molten synthetic resin by the film into the contour of the cutout portion of the liner sheet, and the melt synthesis thereof. The fibers of the liner sheet are bonded to each other by a resin, and almost the middle of the portion impregnated with the molten synthetic resin A method of processing a liner sheet for a disc cartridge, which is configured to press the cutout portion along the central portion.