Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
  • G11B23/02—Containers; Storing means both adapted to cooperate with the recording or reproducing means
  • G11B23/03—Containers for flat record carriers
  • G11B23/033—Containers for flat record carriers for flexible discs
  • G11B23/0332—Containers for flat record carriers for flexible discs for single discs, e.g. envelopes

Definitions

• This invention concerns recording media such as a diskette which comprises a flexible magnetic recording disk contained in a jacket to which is attached a wiping fabric in facing relationship to the disk.
• a typical diskette is disclosed in U. S. Patent No. 3,668,658.
• the wiping fabric of No. 3,668,658 comprises a porous, low-friction, anti-static material which may be a self-supporting dusting fabric.
• the wiping fabric is fused to a sheet of the jacket material in point-contact patterns.
• Ultrasonic welding is sometimes employed instead of heat.
• problems such as (1) delamination of self-supporting fabrics from the diskette jackets, (2) the fabric scratching the surface of the recording disk, especially by hard nodules created upon fusing the wiping fabric to the jacket sheet, and (3) torque variations, especially when the fiber distribution in the fabric has been nonuniform.
• a fourth problem stems from the tendency of fibers to protrude from the wiping fabric into the jacket openings, thus creating the hazard that the protruding fibers might be picked up by the drive mechanism and become trapped at the gap of the recording heads.
• the layer of fibers is economically produced by known flocking techniques and is generally here referred to as the flocked-fiber layer.
• the flocked-fiber layer does not produce noticeable scratching, does not cause any torque
• the flocked-fiber layer can be applied to a roll of the jacket material continuously to provide roll stock from which individual jacket blanks can later be die-cut.
• the flocked-fiber layer of the diskette of the present invention comprises fibers which are predominantly
• the flocked-fiber layer including an adhesive added to bond it to the jacket, may increase the thickness of the jacke.t material about 0.15-0.3 mm to
• the jacket material with its flocked-fiber layer of 0.35-0.45 mm. It may be necessary to calender the flocked-fiber layer in order to reduce it to a desired thickness, thereby bending over free ends of the fibers which otherwise tend to be
• Q..-FI layer are densely packed to about 17-102 g/m.2. if the fibers were too fine or too low in density, the recording surface might not be kept sufficiently clean, and the bonding agent might be exposed to scratch the recording surface. If the fibers were too coarse or too high in density, there might be undesirable variability in the torque required to rotate the disk.
• Especially useful fibers for the flocked-fiber layer are rayon, nylon, polyester, acrylic, cotton and mixtures thereof.
• the flocked-fiber layer may be created by conventional techniques. For example, a bonding agent may be applied to the jacket material to provide an adhesive layer which is viscous and tacky. Short, closely-spaced fibers are then embedded into the adhesive layer, each fiber being then bonded directly to the jacket material. The fibers may be attracted to the adhesive layer electrostatically or merely by gravity. It is preferred that there be a beater-bar beneath the jacket material to assist in driving the fibers into the viscous, tacky adhesive layer.
• the bonding agent preferably is a water-based adhesive.
• a hot-melt adhesive may be used.
• the use of a solvent might be hazardous if the fibers are attracted to the adhesive layer electrostatically.
• the use of a solvent to activate the jacket material to an adhesive state provides certain known economies. If the jacket material comprises paper or otherwise has a fibrous nature, an adhesive coating can serve the dual functions of integrating those fibers and adhering the flocked-fiber layer.
• the fibers of the flocked-fiber layer are treated with an anti-static agent prior to flocking in order to provide a more uniform flocked-fiber layer, as is well known in the flocking art.
• That anti-static agent also enhances the bleeding off of charges from the magnetic recording disk of the diskette. Even so, it may be desirable to apply an additional anti-static coating t the fiber-flocked layer, preferably as an in-line process. Also as an in-line process and, if desired, simultaneousl with application of an anti-static coating, a lubricant
• the flocked-fiber layer may be applied to cover one face of the jacket material, the width of which may be a multiple of the
• the fiber-flocked jacket material may then be wound up for convenient storage and shipment.
• the flocked jacket material may later be unwound and die-cut to provide individual jacket blanks, each of which is folded and adhesively bonded to itself t 5 enclose a magnetic recording disk.
• adhesive material may be applied only to selected areas of the jacket material, as by a gravure printing process, thus effecting a small raw material savings in both the adhesive material and the fibers. The need to maintain 0 registration in the die-cutting step would offset at least partially that cost saving.
• the diskette of the invention makes it more practical to use certain jacket materials that previously were believed to require uneconomical procedures, e.g., 5 paper, polycarbonate film, and biaxially-oriented polyester film.
• the adhesive base for the flocked-fiber layer can serve the additional function of stabilizing the paper, a function which previously would have required a separate operation.
• Polycarbonate 0 and polyester films have not been adaptable to prior techniques for applying wiping fabric.
• Fig. 1 schematically illustrates the application of a flocked-fiber layer to jacket material
• Fig. 2 schematically shows a diskette of the invention
• Fig. 3 is an enlarged cross-section along lines 3-3 of Fig. 2.
• jacket material 10 is unwound from a roll and coated with an adhesive composition at a hopper-fed-knife-coater 12. Fibers 14 falling from a brush hopper 16 are electrostatically attracted to the adhesive layer 18 with the aid of electrodes 19. A beater-bar mechanism 20 beneath the jacket material 10 assists in driving the fibers into the adhesive layer 18 to provide a flocked-fiber layer 22.
• An oven 24 drives off the water from the adhesive to bond the fibers to the jacket material.
• a cleaning station 26 removes loose fibers from both surfaces of the finished material which is then wound up into a roll 28.
• the finished material of the roll 28 is later unwound and die-cut to provide individual jacket blanks which are folded around a flexible magnetic recording.disk 30 to provide a diskette 32 as seen in Fig. 2.
• a series of adhesive dots 34 bond the folded edges to the surface of the jacket.
• the jacket of the diskette 32 consists of the jacket material 10 and the flocked-fiber layer 22 (which includes the adhesive layer 18).
• the jacket material 10 at one side 35 of the ' diskette extends beyond and is folded around the other side 36 of the diskette and its overlapped fiber-flocked layer 22 is bonded by the adhesive 34 to the uncoated surface of the underlying jacket material 10. A better bond has been obtained than has been experienced in bonding folded edges in the prior art.
• Example 1 Opaque plasticized polyvinyl chloride film of 0.275 mm thickness of the type used for flexible diskette jackets was knife-coated on one face with a water-borne acrylic-vinyl latex adhesive to a wet thickness of about 0.125 mm which by itself would dry to a thickness of about 0.075 mm. Random-cut cotton flock (14-24 micrometers in diameter and 0.05-0.4 mm in length) was electrostatically attracted to the adhesive coating which was tacky and viscous, and the fibers were embedded into the adhesive with the aid of beater bars. After the flocked-fiber layer coat was dried in an air-circulating oven for 2 minutes at 50°C.
• both surfaces were aggressively brushed and vacuumed to remove loose fibers, and the finished material was wound up into a stock roll.
• the stock roll was later slit to a useful width, further cleaned, and then calendered to reduce the overall thickness of the jacket material with its flocked-fiber layer to 0.45 mm. Sheets cut from the roll were stacked and placed in an oven at about 52°C. for two hours to remove the roll-induced curl.
• the sheets were die-cut to provide blanks which were folded and the two side flaps were sealed with a hot-melt adhesive.
• a magnetic recording disk was inserted, and the third flap was folded and sealed to provide finished diskettes.
• the openings in the jackets appeared to be free from any fibers protruding from the flocked-fiber layer which could not be delaminated.
• the diskettes of Example 1 appeared to be superior to any diskette now on the market.
• a number of diskettes of Example 1 were tested by rotating the jacket in the horizontal position while the disk was pinched between the two sides of the jacket as in ANSI Specification No. X3B8/78-145. Diskette users generally specify ten million rotations without any visible effect upon the magnetic recording disk.
• PET opaque biaxially-oriented polyethylene terephthalate film
• PP opaque biaxially-oriented low-density polypropylene film
• PVC opaque plasticized polyvinyl chloride film
• P-I calendered manila paper made for tabulating card use
• A water-borne acrylic latex, 49% solids
• polyvinyl chloride was the easiest to handle in folding and showed the least tendency for the fold to open upon exposure to elevated temperatures. However, polyvinyl chloride was the most susceptible to damage if exposed to unusually high temperatures which might carelessly be encountered.

Landscapes

• Nonwoven Fabrics (AREA)
• Laminated Bodies (AREA)
• Treatment Of Fiber Materials (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22313070

Family Applications (1)

Country Status (8)

Cited By (12)

Citations (10)

• 1980
  • 1980-11-24 JP JP81500447A patent/JPS56501817A/ja active Pending
  • 1980-11-24 AU AU67043/81A patent/AU6704381A/en not_active Abandoned
  • 1980-11-24 EP EP19810900237 patent/EP0042407A4/en not_active Withdrawn
  • 1980-11-24 BR BR8008993A patent/BR8008993A/pt unknown
  • 1980-11-24 WO PCT/US1980/001586 patent/WO1981001905A1/en not_active Application Discontinuation
  • 1980-11-26 CA CA000365493A patent/CA1155954A/en not_active Expired
  • 1980-12-23 ZA ZA00808050A patent/ZA808050B/xx unknown
  • 1980-12-24 IT IT8050458A patent/IT8050458A0/it unknown

Patent Citations (10)

Non-Patent Citations (1)

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