CA1074444A - Cleaning sheet and cleaning jacket for cleaning a magnetic head for flexible discs and method for cleaning a magnetic head - Google Patents
Cleaning sheet and cleaning jacket for cleaning a magnetic head for flexible discs and method for cleaning a magnetic headInfo
- Publication number
- CA1074444A CA1074444A CA242,120A CA242120A CA1074444A CA 1074444 A CA1074444 A CA 1074444A CA 242120 A CA242120 A CA 242120A CA 1074444 A CA1074444 A CA 1074444A
- Authority
- CA
- Canada
- Prior art keywords
- cleaning
- sheet
- disc
- magnetic head
- magnetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/41—Cleaning of heads
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of cleaning a magnetic head for flexible discs comprises using a cleaning sheet having a coating of a fibrous material which is provided on one or both sides of a base sheet, e.g., using an adhesive or by thermocompression bonding, and contacting the coating of the fibrous material of the cleaning sheet with the magnetic head for flexible discs with relative movement therebetween. The cleaning sheet used in the above method and a cleaning jacket comprising such a cleaning sheet inserted in a container are also disclosed.
A method of cleaning a magnetic head for flexible discs comprises using a cleaning sheet having a coating of a fibrous material which is provided on one or both sides of a base sheet, e.g., using an adhesive or by thermocompression bonding, and contacting the coating of the fibrous material of the cleaning sheet with the magnetic head for flexible discs with relative movement therebetween. The cleaning sheet used in the above method and a cleaning jacket comprising such a cleaning sheet inserted in a container are also disclosed.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention . - - --- --This invention relates to a method of cleaning a magnetic head for flexible discs and cleaning sheets and cleaning ~ackets for cleaning such magnetic heads.
1. Field of the Invention . - - --- --This invention relates to a method of cleaning a magnetic head for flexible discs and cleaning sheets and cleaning ~ackets for cleaning such magnetic heads.
2. Descri~tion of the Prior Art ~ -In recent years, video recorders for slow motion images or still images for television have been developed as one type of video recording system.
In magnetic recording systems for memory use, magnetic disc systems, magnetic tape systems, cassette tape systems and the like, are in use. Magnetic disc systems have hlgh recording density and are easily used, but are expensive. Magnetic tapes take up much space and cannot be easily used as compared with magnetic discs and the like. Cassette tape sys*ems are compact and easily used, but their recording capacity is not satis-factory and their reliability is low. ~ ~
Accordingly, flexible systems possessing the advantages ~0 of the above systems, i.e., high recording density, com-pactness and ease of handling have recently come in-to useO
In general, when a magnetic recording medium i5 used in magnetic recording for a long time while in contact with a - :
magnetic head, the magnetic recording layer is partially scraped off onto the magnetic head or a very small amount of lubricant or the like which is present in or on the magnetic recording layer accumulates on the magnetic head, resulting in a lowering of output.
Problems of partial wear of the magnetic recording layer and accumulation of lubricant can be solved by improvements ~ '"-':
' ' :.: , ' '' ' ' .
;
~L~7'~
1 in the m~gnetic reco~ding layer.
However, since magnetic recording is performed by slidlng the magnetic recording layer across the magnetic head, it is very difficul-t to make a magnetic recordiny layer so strong as to completely resist wear.
Therefore, as long as conventional magnetic recording mediums and magnetic recording systems are used, it is necessary to periodically clean the magnetic head in some suitable fashion.
In flexible disc systems, since most of the magnetic heads are located in the innermost part of ~he apparatus, one problem is that the magnetic head cannot easily be cleaned by merely using a cloth impregnated with a liquid cleaner or the like, as in the case of conventional tape recorders for open reels, cassettes, home video recorders and broadcast :
video recorders.
, ~ Furthermore, while cleaning tapes for such magnetic : .:
heads are conveniently used, such tapes comprise,-e.g., a ~-~
- .
polyester base which has applied thereto an abrasive such as fused alumlna, silicon carbide, chromium sesquioxide (Cr203) or corundum in a binder. Although a part of the magnetic recording layer and the accumulation of the lubricant can be scraped~off the magnetic head by this methodt the ma~netic head per se is disadvantageously abra~ed. This defect is also found in applying this method to heads for vi~eo magnetic sheets.
This invention provides a cleaning sheet ~or over-coming the aforesaid inconveniences and defects, which enables , . .
the cleanina of a magnetic head in a very short time without ~ -. ~: .
wearing it away. -~ ~
In magnetic recording systems for memory use, magnetic disc systems, magnetic tape systems, cassette tape systems and the like, are in use. Magnetic disc systems have hlgh recording density and are easily used, but are expensive. Magnetic tapes take up much space and cannot be easily used as compared with magnetic discs and the like. Cassette tape sys*ems are compact and easily used, but their recording capacity is not satis-factory and their reliability is low. ~ ~
Accordingly, flexible systems possessing the advantages ~0 of the above systems, i.e., high recording density, com-pactness and ease of handling have recently come in-to useO
In general, when a magnetic recording medium i5 used in magnetic recording for a long time while in contact with a - :
magnetic head, the magnetic recording layer is partially scraped off onto the magnetic head or a very small amount of lubricant or the like which is present in or on the magnetic recording layer accumulates on the magnetic head, resulting in a lowering of output.
Problems of partial wear of the magnetic recording layer and accumulation of lubricant can be solved by improvements ~ '"-':
' ' :.: , ' '' ' ' .
;
~L~7'~
1 in the m~gnetic reco~ding layer.
However, since magnetic recording is performed by slidlng the magnetic recording layer across the magnetic head, it is very difficul-t to make a magnetic recordiny layer so strong as to completely resist wear.
Therefore, as long as conventional magnetic recording mediums and magnetic recording systems are used, it is necessary to periodically clean the magnetic head in some suitable fashion.
In flexible disc systems, since most of the magnetic heads are located in the innermost part of ~he apparatus, one problem is that the magnetic head cannot easily be cleaned by merely using a cloth impregnated with a liquid cleaner or the like, as in the case of conventional tape recorders for open reels, cassettes, home video recorders and broadcast :
video recorders.
, ~ Furthermore, while cleaning tapes for such magnetic : .:
heads are conveniently used, such tapes comprise,-e.g., a ~-~
- .
polyester base which has applied thereto an abrasive such as fused alumlna, silicon carbide, chromium sesquioxide (Cr203) or corundum in a binder. Although a part of the magnetic recording layer and the accumulation of the lubricant can be scraped~off the magnetic head by this methodt the ma~netic head per se is disadvantageously abra~ed. This defect is also found in applying this method to heads for vi~eo magnetic sheets.
This invention provides a cleaning sheet ~or over-coming the aforesaid inconveniences and defects, which enables , . .
the cleanina of a magnetic head in a very short time without ~ -. ~: .
wearing it away. -~ ~
3~ SU~RY OF THE IN~ENTION ~ -;
One object of this invention is to provide a method of - 2 - ~
' ' ' 1 cleaning a magnetic head for flexible discs which cleans the magnetic head in a short time without head wear and further ~`
provides a cleaning sheet and a cleaning jacket used in said method.
The object of this invention can be accomplished by cleaning a magnetic head for flexible discs using a cleaning sheet having a coating composed of a fibrous material which is provided on one or both sides of a base sheet, e.g., using an adhesive or thermocompression bonding.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figures l and 2 are sectional vlews showing cleaning sheets of this invention.
Figure 3 is a plane view of a cleaning shee~ of thls invention.
Figure 4 is a plane view of the cleaning sheet shown --in Figures l to 3 as inserted in a container.
Figures 5(a), (b) and ~c) are sectional views of such -;
cleanlng sheets.
~ Figures 6 and 7 are sectional views of cleaning jackets of this invention as used. -~
Figures 8 and 9 are views showing preparing cleaning sheets of this invention.
~ Figure 10 lS a graph showing the relationship between the rotation rate (at 360 r.p.m.) of a conventional cleaning -jacket or the cleaning jacket of this invention and -the depth of wear of the magnetic head. --Figure 11 is a view showing preparing cleaning sheets ;- -of this invention.
Figure 12 is a sectional view of the preferred cleaning sheet.
. . ' ,' , ~
1 Figure 13 is a graph showing the relationship between rotation time (at 3,600 r.p.m.) of the cleaning sheet and the depth of wear (,um) of the magnetic head.
DETAILED DESCRIPTION OF THE INVENTION
Flexible base sheets which can be used in this invention include sheets of high molecular weight compounds, i.e., a resin or plastic film as such as commonly called, such as polyvinyl chloride, polycarbonate, acrylonitrile-styrene copolymers, ABS resin, polyester, glass-fiber-filled polyester resins or -cellulose derlvatives, cardboard, metallic sheets such as -aluminum or copper, and the like. The thickness of the base is ~
preferably about 10 !um to about 1 mm, whlch can be selec~ed ~-depending upon the use of the apparatus.
In additlon, the base sheet may have a magnetic recording layer or an antistatic layer provided on one side or - -: ~.
both sides thereof, for example, as disclosed in U.S. Patents 3,476,596 and 3,2~3,066. In this case, the coating composed of a fibrous material of this invention is provided on one ;~
side or both sides on such layers.
Fibrous materials which can be used in this invention ,. .
are essentially textiles in nature and include nonwoven materials, synthetic leathers, leathers, woven mat rials of synthetic fibers, woven materials of natural fibers and ~;
:
Japanese paper. The thickness of the fibrous materials is ~
about 20 to about 1,000 ~m, preferably 30 to lOO pm. -The nonwoven materials are fabric-like products which are made by arranging fibers such as acetate, nylon or polyester in a web or mat form by a conventional method and ~ -then bonding the fibers to each other using an adhesive such .....
as a natural latex, a synthetic latex or such in combination ..
.. ........ .
,, . . , - . . ,.,, , :
~7~
1 with a urea resin or a melamine resin adhesive, or by utilizing the adhesive force of the fibers themselves, e.g., with polyethylenes, polypropylenes and polyamides. Of the synthetic latices, acrylonitrile - butadiene copolymers and acrylonitrile are preferred, with synthetics of a molecular weight of about 800 to abou-t 10,000 being most preferred.
In addition, other nonwoven materials, e.g., those which are made through fusion bonding can also be used, e.g., polyesters, polystyrenes and polyvinyl acetate, usually a temperature of about 70 to 250C being used for the bonding.
Many of the nonwoven materials disclosed above are commercially available nonwoven closes, e.g., Vilene H-8103 (polyethylene terephthalate fiber), Vilene BX10, Vilene ~3000, Vilene #4000 (produced by Japan Vilene Co., Ltd.), Nippon Cloth ~1500, Nippon Cloth #1600 (produced by Nippon Cloth Industries Co., Ltd )), as are fibers of copolymers of polyethylene tere-phthalate (60 mol%) and rayon (40 mol%) bonded using styrene-butadiene rubber as an adhesive and formed into a sheet.
The woven materials of synthetic fibers are those -made from synthetic fibers of high molecular welght, e.g., polyamides such as nylon-6, nylon-6,6 or nylon-6,10; polyesters ~ -such as polyethylene terephthalate or polyethylene naphthalate;
polyurethanes produced by reacting hydrazine, diamine or a diol with a prepolymer formed by reacting a polyester or polyether with a diisocyanate; polyolefins such as polyethy:lene or polypropylene; polystyrene; polyvinyl chloride; poly-vinylidene chloride; polyfluoroethylene; polyacrylonitrile;
polyvinyl alcohol; etc.
The woven materials of natural fibers are those made ;
from protein fibers such as wool or silk; cellulose fibers such .- - .
.
as cotton or hemp; etc.
The Japanese papers are those made from natural fibers, cellulose fibers being preferred, using bast fibers as a raw material, digesting the ~ibers to make single fibers and then making a paper therefrom. The bast fibers consist of celluloses about 3 to 50 mm long by about 0.01 to 0.08 mm wide.
Examples of such are flax, hemp, jute, ramie, kozo, mitsumata and gampi. Of these fibers, kozo, mitsumata and gampl are preferred.
The above fibrous materials are laminated on a base sheet using an adhesive or by thermocompression bonding, typically at about 1 Kg/cm2 to about 25 Kg/cm2 and at about 70C to about 150C for about 1 to about 30 min., or the like.
In this case, it has been found that a fibrous material -impregnated wi~h a silicone oil, fluoro-oil or the like is very -useful for preventing a magnetic head from later becoming dirty. Typically impregnation is by spraying after adhering the fibers to the base sheet using about 0.5 to about 10 wt%
of the oil based on the fibrous material weight.
The aforesaid adhesives used in this invention i~clude natural latexes, synthetic latexes and such late~es in com- -bination with a urea or melamlne resin adhesive, a synthetic -rubber a polyester, a vinyl ace~ate resin, a butyral resin, ~
:
an acrylate resin, a vinyl chloride resin, a polyamide, a ;~
reclaimed rubber, starch, dextrin, glue, gum arabic , caseinO
polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, ;
rosins, wax, paraffin, epoxy resins, isocyanate resins, phenyl resins, furan resins, nitrocellulosé, etc. Preferred are .
those resins which have a softening point of about 30 to about --150C, most preferably 50 to 120C, and a molecular weight of ', : . ~ , , ,:, ,. , . . . . .... :,. ...
... . . . ..
.. .. .
1 about 1,000 to about 100,000. They are conveniently applied with a spray-gun, brush, blade, spatula, etc.
Examples of conveniently used adhesives are copolymers of vinyl chloride and vinyl acetate (about 30 to 90 wt~
vinyl acetate), copolymers of ethylene and vinyl acetate (about 30 to 90 wt~ vinyl acetate), terpene resins, copolymers of acrylonitrile and butadiene (about 20 to 40 wt% acrylonitrile) liner polyesters (copolymers of ethyleneglycol and tere-phthalic acid at a 3:2 to a 2:3 molar ratio, respectively) and polyamide terpolymer (for example, caprolactam (20 to 80 wt%): lauryollactam (5 to 70 wt%): ~-c-methyl caprolactam (5 to 60 wt%).
In the case of laminating the fibrous material on the base sheet by thermocompression bonding, the fibrous material or at least a portion of the constituents of the fibrous material, e.g., an adhesive for the fibrous or ~e-base sheet, must be a thermoplastic resin. Preferably, both the fibrous material and base sheet comprise or are made of a thermo-plastic resin.
2~ Preferred of such ther~oplastic resins have a softening point of 150C or less, an a~erage molecular weight of about 10,000 to about 200,000 and a polymerization degree of about 200 to about 500, e.g., polypropylene-vinyl chloride, copolymers, .
ABS resins, vinyl chloride vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylonitrile copolymers, acrylate-acrylonitrile copolymers, acrylate-vinylidene chloride copolymers, acrylate-styrene copolymers, methacrylate-acrylonitrile copolymers~ methacry-late-vinylidene chloride copolymers, methacrylate-styrene copol~mers, urethane elas~omers, polyamides, etc.
'~ ' . . , ,, . ~ ,, :
. ~ .. . . . . .. . . .
:, . , : . . ~ , , : .
Referring to the method of using the cleaning sheet for a magnetic head according to this invention~ in the case of video magnetic sheets, a cleaning sheet which has been prepared by laminating a fibrous material onto a base sheet and punching out the same to specified shape and dimensions is inserted so as to contact, while sliding, the head surface with the fibrous material on the cleaning sheet. When sliding con-tact is effected for several seconds to several ten seconds, typically about 3 to about 20 seconds, with 8 seconds being used in the Examples, 1C output which has been lowered due to dirt on the magnetic head can be recovered to almost 100~ of its original state.
Using the cleaning sheet prepared as above, dirt left after cleaning is avoided, while the magnetic head is not worn at all and variations in output are not observed, and, thus, very -.
satisfactory results are obtained.
The constitutions of the cleaning sheet and the cleaning jacket of this invention described hereinbefore will be explained with reference to the accompanying drawings. In the drawings, like numerals are utilized to identify like elements.
Figure 1 is a cross-sectional view of a cleaning shee~
having a cleaning layer provided on one~ide thereof, in which there is shown a cleaning la~er (of a nonwoven material) 1 and a suppor~ 2.
Figure 2 is a cross-sectional view of a cleaning sheet having cleaning layers provided on both sides thereof, in which those parts denoted by numerals 1 and 2 are the same as in Figure 1.
Figure 3 is a upper plan view of the cleaning sheet shown in Figure 1 or 2, in which there is shown the cleaning ~ `
30 layer l, a bearing aperture 4, and an aperture 5 for an index `
. .
- 8 - `
' ' : .
.. ' ." . " ' ' .
. . .
, . . :: . .. . , . ,. .. . : . . .
. .. . . . . . . . . . . . .
~L~7~
hole. Aperture 5 may be omitted where light selectors are not used.
Figure 4 is a plan view of a container (jacket) .in which the cleaning sheet shown in Figures 1 to 3 is inserted, wherein there is shown the cleaning layer 1, a container 3, an aperture 6 which is larger than the bearing apertuxe 4 of the cleaning sheet, an aperture 7 which is larger than the aperture for the light selector and an aperture 8 for a recording and reproducing head. Aperture 7 may be omitted where light selectors are not used. Moreover, in the case of a cleaning sheet as shown in Figure 2, apertures 6, 7 and 8 must be provided on both sides o~ the container 3, but for the cleaning sheet as shown in Figure 1, apertures 6, 7 and 8 can be provided only on the one side provided with the cleaning layer 1.
Figure 5(a), (b) and (c) are cross-sectional views of the cleaning sheets shown in Figures 1 to 3 as inserted in a container. Figure 5(a) shows a cleaning sheet having cleaning layers on both sides thereof, and Figures 5(b) and (cj show a cleaning sheet having a cleaning layer on one side thereof, ~
wherein those parts denoted by numerals 1 to 8 are the same as in Figures 1 to 4, and numeral 14 shows a sheet fixing hub (which simply supports the sheet). Moreover, in order to improve the rotation of the sheet, the inner surface of the container ;~ ~jacket) can be subjected to a lubrication treatment by attaching, e.g., a synthetic paper or a nonwoven material impregnated with a silicone resin, Tèflo ~or a silicone oil thereto.
The following description relates to the cleaning jacket of this invention for use with a magnetlc head for ~lexible discs, as shown in Figures 1 to 5, as mounted in a recorder for 30 ~lexlble discs. -fr~?Gle /~lark : `
~ 9~ ~
, ~
... : . . . , : ,. . . ... - .
One object of this invention is to provide a method of - 2 - ~
' ' ' 1 cleaning a magnetic head for flexible discs which cleans the magnetic head in a short time without head wear and further ~`
provides a cleaning sheet and a cleaning jacket used in said method.
The object of this invention can be accomplished by cleaning a magnetic head for flexible discs using a cleaning sheet having a coating composed of a fibrous material which is provided on one or both sides of a base sheet, e.g., using an adhesive or thermocompression bonding.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figures l and 2 are sectional vlews showing cleaning sheets of this invention.
Figure 3 is a plane view of a cleaning shee~ of thls invention.
Figure 4 is a plane view of the cleaning sheet shown --in Figures l to 3 as inserted in a container.
Figures 5(a), (b) and ~c) are sectional views of such -;
cleanlng sheets.
~ Figures 6 and 7 are sectional views of cleaning jackets of this invention as used. -~
Figures 8 and 9 are views showing preparing cleaning sheets of this invention.
~ Figure 10 lS a graph showing the relationship between the rotation rate (at 360 r.p.m.) of a conventional cleaning -jacket or the cleaning jacket of this invention and -the depth of wear of the magnetic head. --Figure 11 is a view showing preparing cleaning sheets ;- -of this invention.
Figure 12 is a sectional view of the preferred cleaning sheet.
. . ' ,' , ~
1 Figure 13 is a graph showing the relationship between rotation time (at 3,600 r.p.m.) of the cleaning sheet and the depth of wear (,um) of the magnetic head.
DETAILED DESCRIPTION OF THE INVENTION
Flexible base sheets which can be used in this invention include sheets of high molecular weight compounds, i.e., a resin or plastic film as such as commonly called, such as polyvinyl chloride, polycarbonate, acrylonitrile-styrene copolymers, ABS resin, polyester, glass-fiber-filled polyester resins or -cellulose derlvatives, cardboard, metallic sheets such as -aluminum or copper, and the like. The thickness of the base is ~
preferably about 10 !um to about 1 mm, whlch can be selec~ed ~-depending upon the use of the apparatus.
In additlon, the base sheet may have a magnetic recording layer or an antistatic layer provided on one side or - -: ~.
both sides thereof, for example, as disclosed in U.S. Patents 3,476,596 and 3,2~3,066. In this case, the coating composed of a fibrous material of this invention is provided on one ;~
side or both sides on such layers.
Fibrous materials which can be used in this invention ,. .
are essentially textiles in nature and include nonwoven materials, synthetic leathers, leathers, woven mat rials of synthetic fibers, woven materials of natural fibers and ~;
:
Japanese paper. The thickness of the fibrous materials is ~
about 20 to about 1,000 ~m, preferably 30 to lOO pm. -The nonwoven materials are fabric-like products which are made by arranging fibers such as acetate, nylon or polyester in a web or mat form by a conventional method and ~ -then bonding the fibers to each other using an adhesive such .....
as a natural latex, a synthetic latex or such in combination ..
.. ........ .
,, . . , - . . ,.,, , :
~7~
1 with a urea resin or a melamine resin adhesive, or by utilizing the adhesive force of the fibers themselves, e.g., with polyethylenes, polypropylenes and polyamides. Of the synthetic latices, acrylonitrile - butadiene copolymers and acrylonitrile are preferred, with synthetics of a molecular weight of about 800 to abou-t 10,000 being most preferred.
In addition, other nonwoven materials, e.g., those which are made through fusion bonding can also be used, e.g., polyesters, polystyrenes and polyvinyl acetate, usually a temperature of about 70 to 250C being used for the bonding.
Many of the nonwoven materials disclosed above are commercially available nonwoven closes, e.g., Vilene H-8103 (polyethylene terephthalate fiber), Vilene BX10, Vilene ~3000, Vilene #4000 (produced by Japan Vilene Co., Ltd.), Nippon Cloth ~1500, Nippon Cloth #1600 (produced by Nippon Cloth Industries Co., Ltd )), as are fibers of copolymers of polyethylene tere-phthalate (60 mol%) and rayon (40 mol%) bonded using styrene-butadiene rubber as an adhesive and formed into a sheet.
The woven materials of synthetic fibers are those -made from synthetic fibers of high molecular welght, e.g., polyamides such as nylon-6, nylon-6,6 or nylon-6,10; polyesters ~ -such as polyethylene terephthalate or polyethylene naphthalate;
polyurethanes produced by reacting hydrazine, diamine or a diol with a prepolymer formed by reacting a polyester or polyether with a diisocyanate; polyolefins such as polyethy:lene or polypropylene; polystyrene; polyvinyl chloride; poly-vinylidene chloride; polyfluoroethylene; polyacrylonitrile;
polyvinyl alcohol; etc.
The woven materials of natural fibers are those made ;
from protein fibers such as wool or silk; cellulose fibers such .- - .
.
as cotton or hemp; etc.
The Japanese papers are those made from natural fibers, cellulose fibers being preferred, using bast fibers as a raw material, digesting the ~ibers to make single fibers and then making a paper therefrom. The bast fibers consist of celluloses about 3 to 50 mm long by about 0.01 to 0.08 mm wide.
Examples of such are flax, hemp, jute, ramie, kozo, mitsumata and gampi. Of these fibers, kozo, mitsumata and gampl are preferred.
The above fibrous materials are laminated on a base sheet using an adhesive or by thermocompression bonding, typically at about 1 Kg/cm2 to about 25 Kg/cm2 and at about 70C to about 150C for about 1 to about 30 min., or the like.
In this case, it has been found that a fibrous material -impregnated wi~h a silicone oil, fluoro-oil or the like is very -useful for preventing a magnetic head from later becoming dirty. Typically impregnation is by spraying after adhering the fibers to the base sheet using about 0.5 to about 10 wt%
of the oil based on the fibrous material weight.
The aforesaid adhesives used in this invention i~clude natural latexes, synthetic latexes and such late~es in com- -bination with a urea or melamlne resin adhesive, a synthetic -rubber a polyester, a vinyl ace~ate resin, a butyral resin, ~
:
an acrylate resin, a vinyl chloride resin, a polyamide, a ;~
reclaimed rubber, starch, dextrin, glue, gum arabic , caseinO
polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, ;
rosins, wax, paraffin, epoxy resins, isocyanate resins, phenyl resins, furan resins, nitrocellulosé, etc. Preferred are .
those resins which have a softening point of about 30 to about --150C, most preferably 50 to 120C, and a molecular weight of ', : . ~ , , ,:, ,. , . . . . .... :,. ...
... . . . ..
.. .. .
1 about 1,000 to about 100,000. They are conveniently applied with a spray-gun, brush, blade, spatula, etc.
Examples of conveniently used adhesives are copolymers of vinyl chloride and vinyl acetate (about 30 to 90 wt~
vinyl acetate), copolymers of ethylene and vinyl acetate (about 30 to 90 wt~ vinyl acetate), terpene resins, copolymers of acrylonitrile and butadiene (about 20 to 40 wt% acrylonitrile) liner polyesters (copolymers of ethyleneglycol and tere-phthalic acid at a 3:2 to a 2:3 molar ratio, respectively) and polyamide terpolymer (for example, caprolactam (20 to 80 wt%): lauryollactam (5 to 70 wt%): ~-c-methyl caprolactam (5 to 60 wt%).
In the case of laminating the fibrous material on the base sheet by thermocompression bonding, the fibrous material or at least a portion of the constituents of the fibrous material, e.g., an adhesive for the fibrous or ~e-base sheet, must be a thermoplastic resin. Preferably, both the fibrous material and base sheet comprise or are made of a thermo-plastic resin.
2~ Preferred of such ther~oplastic resins have a softening point of 150C or less, an a~erage molecular weight of about 10,000 to about 200,000 and a polymerization degree of about 200 to about 500, e.g., polypropylene-vinyl chloride, copolymers, .
ABS resins, vinyl chloride vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylonitrile copolymers, acrylate-acrylonitrile copolymers, acrylate-vinylidene chloride copolymers, acrylate-styrene copolymers, methacrylate-acrylonitrile copolymers~ methacry-late-vinylidene chloride copolymers, methacrylate-styrene copol~mers, urethane elas~omers, polyamides, etc.
'~ ' . . , ,, . ~ ,, :
. ~ .. . . . . .. . . .
:, . , : . . ~ , , : .
Referring to the method of using the cleaning sheet for a magnetic head according to this invention~ in the case of video magnetic sheets, a cleaning sheet which has been prepared by laminating a fibrous material onto a base sheet and punching out the same to specified shape and dimensions is inserted so as to contact, while sliding, the head surface with the fibrous material on the cleaning sheet. When sliding con-tact is effected for several seconds to several ten seconds, typically about 3 to about 20 seconds, with 8 seconds being used in the Examples, 1C output which has been lowered due to dirt on the magnetic head can be recovered to almost 100~ of its original state.
Using the cleaning sheet prepared as above, dirt left after cleaning is avoided, while the magnetic head is not worn at all and variations in output are not observed, and, thus, very -.
satisfactory results are obtained.
The constitutions of the cleaning sheet and the cleaning jacket of this invention described hereinbefore will be explained with reference to the accompanying drawings. In the drawings, like numerals are utilized to identify like elements.
Figure 1 is a cross-sectional view of a cleaning shee~
having a cleaning layer provided on one~ide thereof, in which there is shown a cleaning la~er (of a nonwoven material) 1 and a suppor~ 2.
Figure 2 is a cross-sectional view of a cleaning sheet having cleaning layers provided on both sides thereof, in which those parts denoted by numerals 1 and 2 are the same as in Figure 1.
Figure 3 is a upper plan view of the cleaning sheet shown in Figure 1 or 2, in which there is shown the cleaning ~ `
30 layer l, a bearing aperture 4, and an aperture 5 for an index `
. .
- 8 - `
' ' : .
.. ' ." . " ' ' .
. . .
, . . :: . .. . , . ,. .. . : . . .
. .. . . . . . . . . . . . .
~L~7~
hole. Aperture 5 may be omitted where light selectors are not used.
Figure 4 is a plan view of a container (jacket) .in which the cleaning sheet shown in Figures 1 to 3 is inserted, wherein there is shown the cleaning layer 1, a container 3, an aperture 6 which is larger than the bearing apertuxe 4 of the cleaning sheet, an aperture 7 which is larger than the aperture for the light selector and an aperture 8 for a recording and reproducing head. Aperture 7 may be omitted where light selectors are not used. Moreover, in the case of a cleaning sheet as shown in Figure 2, apertures 6, 7 and 8 must be provided on both sides o~ the container 3, but for the cleaning sheet as shown in Figure 1, apertures 6, 7 and 8 can be provided only on the one side provided with the cleaning layer 1.
Figure 5(a), (b) and (c) are cross-sectional views of the cleaning sheets shown in Figures 1 to 3 as inserted in a container. Figure 5(a) shows a cleaning sheet having cleaning layers on both sides thereof, and Figures 5(b) and (cj show a cleaning sheet having a cleaning layer on one side thereof, ~
wherein those parts denoted by numerals 1 to 8 are the same as in Figures 1 to 4, and numeral 14 shows a sheet fixing hub (which simply supports the sheet). Moreover, in order to improve the rotation of the sheet, the inner surface of the container ;~ ~jacket) can be subjected to a lubrication treatment by attaching, e.g., a synthetic paper or a nonwoven material impregnated with a silicone resin, Tèflo ~or a silicone oil thereto.
The following description relates to the cleaning jacket of this invention for use with a magnetlc head for ~lexible discs, as shown in Figures 1 to 5, as mounted in a recorder for 30 ~lexlble discs. -fr~?Gle /~lark : `
~ 9~ ~
, ~
... : . . . , : ,. . . ... - .
4~
1 Figure 6 shows a jacket containing a cleaning sheet having cleaning layers on both sides thereof as shown in Figure 2 and Figures 5(a) and (b), wherein there is shown a cleaning layer l, a support sheet 2, a container 3, an idler 9, a driving motor for rotation lO, a recording and reproducing head ll, a load pad 12 to insure good contact with the head and a light selector 13.
Figure 7 shows a jacket containing a cleaning sheet having a cleaning layer on one side thereof as shown in Figure l and Figure 5(c), wherein there is shown a cleaning layer l, a support 2, a container 3, an idler 9 a driving motor for rotation lO, a recording and reproducing head ll, and a sheet fixing hub 14.
When the cleaning jacket of this invention is mounted in a recorder for flexible discs as shown in Figures 6 and 7 and then used in the same manner as in the case of magnetic discs, the recording and reproducing head 11 and the cleaning layer 1 are contacted with each other while sliding, thus cleaning the recording and reproducing head. Such sliding contact for several seconds to several ten seconds can bring about almos~ a 100%
recovery of the output which has been lowered due to dirt accumulation on the magnetic head, t~pically a mixture of ferromagnetic powder, binder and other additives.
The following examples further illustrate this invention.
It will be apparent to one skilled in the art that components, ratios of amounts, sequence of operations, and the like, shown in the examples can be changed without departing from the spirit and scope o this invention, and this invention is not limited to the following exa~ples.
EXAMPLE_l As illustrated in Figure 8, a polyvinyl chloride sheet ~, "" . '. .
- 10 ~ ", .'.
' ' :' . ' ' , .'',; ' ;,~' " ' ', ' . ' ':, 2 (50 ~m thick, 25 cm x 25 cm square; the molecular weight of the polyvinyl chloride sheet is not overly important and a con-centional PVC was used. The molecular weight is usually 10,000 to 200,000, corresponding to a polymerization degree of 200 to 2,000) and two nonwoven materials. 1 of 70~m thick (Vilene H 8103 polyethylene terephthalate fiber made by Japan Vilene Co., Ltd.) were put between two press plates (stainless steel plates) 15.
The assembly thus obtained was laminated using a hot pressing machine 16 under the following conditions: pressure of 2Kg/cm2, temperature of 120C, time of 10 minutes~ and then allowed to cool to room temperature. The press plates lS were then peeled off~ A polyvinyl chloride sheet which was laminated with the non~
woven materials 1 on both sides thereof was thus obtained.
The cleaning sheet thus obtained was punched out to a doughnut-like sheet (see Figure 3) of an outer diameter of 200 + O.5 mm and an inner diameter of 25.4 ~ O.05 mm using a punching machine for magnetic sheets. The doughnut-like sheet was assembled in a jacket as shown in ~igures 4 and 5(a) to make a cleaning jacket for use with a magnetic head for 2~ ~lexible discs.
As illustrated in Figure 9, a polyvinyl chloride sheet 2 (50 ~m thick, 25 cm x 25 cm square as in Example 1) `~
and a nonwoven material. 1 of 70~m thickness (Vilene H 8103, polyethylene terephthalate fiber made by Japan Vilene Co., ~td.3 were put between press plates (stainless steel plates) 15 At this time, mesh 17 was put between the nonwoven material 1 and the press plate 15 (in this example the mesh was steel;
the size of the mesh is generally about 1 mm to about 10 mm, -~ -preferably 1 mm to 5 mm, while the diameter of the steel wire~
is 0.2 mm to 5 mm, preferably 0.5 to 2 mm)O
:
" ' . .
, : , . . . .
`' ': ' ' ' ' ' ' -1 The assembly thus o~tained was laminated using a hot pressing machine 16 under the following conditions; pressure of 2 Kg/cm2, temperature of 120C, time of 10 minutes, and then allowed to cool to room temperature. The press plates 15 and the mesh plate 17 were peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven material 1 on one side thereof was thus obtained.
The cleaning sheet thus obtained was punched out in the same manner as in Example 1 (see Figure 3). The doughnut-like sheet thus obtained was assembled in a jacket as shown inFigures 4 and 5(b) to make a cleaning jacket for use with a magnetic head for flexible discs, which comprised a cleaning sheet of an outer diameter of 200 + 0.5 mm and an inner diameter of 25.4 -~ 0.05 mm inserted in the container.
Comparative Ex~le 1 The followin~ composition was coated on a polyvinyl chloride sheet of 50 ~m thickness so as to provide a film thickness of 10 ~m and then dried at 80C for 2 min. to prepare a cleaning sheet havin~ an abrasive layer.
parts by wei~ht . , .
Cr2O3 (abrasive of 10,000 mesh) 100 Epoxy resin ~epoxy equivalent 450 to 500j molecular weight 900, melting point 64 to 74C) 30 Polyamide resin (condensation - product of a poly-fatty acid and a diamine; amin~ value 300, avexage molecular weight 2500) 30 Vinyl chloride - vinyl acetate copolymer (VC : VAC = 87 : 13 Wt4; polymerization degree 500) 40 ;. - .:.
Methyl ethyl kekone 500 -~ 12 -,, :' , .:
. . ` ' ;, ' ,' ' ' ' ~, ': . :
1 The cleaning sheet thus obtained was punched out to the same dimensions as in Example 1, and then assembled in the same jac~et as in Example 1. The jacket was set in a recorder for flexible discs, and the cleaning sheet was contacted with a magnetic head and rotated at 360 r.p.m. with a pressure of about 2 g to about 100 g to clean the magnetic head. The cleaning effect was the same as those obtained in Examples 1 and 2 (the cleaning jackets in which the fibrous material of this invention was used under the same conditions). However, the head was remarkably worn away on repeated use, and, there-fore, the cleaning jac~et of this Comparative Example was unacceptable.
The relationship between rotation time (min) of the sheet and depth of wear ~m) of the magnetic head using the cleaning jackets of the above Examples and Comparative Example is shown in Figure 10.
From the results shown in Figure 10, it is apparent that when the cleaning jacket of the Comparative Example in which an abrasive layer was used and when the cleaning jackets of Examples 1 and 2 in which the fi~rous material of this invention was used were respectively contacted with a magnetic head and then rotated, the cleaning jacket in which the abrasive layer was used apparently caused, at the end of several ten minutes, more remarkable head wear. Thus, it was confirmed that the cleaning jacket of this invention is superior.
In addition, the cleaning jacket prepared in the manner as illustrated in Figure 9 (i.e., of Example 2) is superior in cleaning effect to one prepared in the manner as illustrated ~ j-in Figure 8, i.e., cleaning effects are improved due to ~-irregularities ~surface roughness) provided by the mesh.
.
~' ' ' . ' . ': .
: ,.
: :
:
E~YAMPLE 3 . . _._ . - .- .
As is illustrated in Figure 11, a polyvinyl chloride sheet 2 as in Example 1 (50 ~m thick, 25 cm x 25 cm square) and a nonwoven material l of 70 ~m thickness (Vilene H 8103, polyethylene terephthalate fiber made hy Japan Vilene Co., Ltd.) were put between two press plates ~sta;nless steel plates) 15.
The assembly thus obtained was treated using a hot pressing machine 16 under the following conditions: pressure of 2 Xg/cm2, temperature of 120C r time 7 minutes, and then allowed to cool to room temperature. The press plates 15 were then peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven materia:L 1 was thus obtained.
The cleaning sheet thus obtained ~a section of which is shown in Figure 12~ was punched out to a doughnut-like -sheet of an outer diameter of 200 + O.S mm and an inner diameter of 25.4 -~ 0~05 mm using a punching machine for magnetic sheets, ...
thus making a cleaning sheet for use with a magnetic head for video magnetic sheets.
As illustrated in Figure 9,~a polyvinyl chloride sheet 2 (50 pm thick, 25 cm ~ 25 cm square; the molecular weight of ~ -the polyvinyl chloride sheet is not overly important, and a . . .
conventional PVC was used. The molecular weight is usually .. .. ..
10,000 to 200,000, corresponding to a polymerization degree of ~ -.
~ 200 to 2,000) and a nonwoven material 1 of 70 ~m thickness ,. . .
(Vilen~ H ~103, polyethylene terephthalate fiber made by Japan Vilene Co., Ltd.) were put between press plates (stainless steel plates) 15. At this time, a mesh 17 as in Example 2 was put between the nonwoven material 1 and the press plate 15.
- 14 - ;
.
.; . , . , . . ; ~, ` ~
:, ~ .. ..
- - \
~7~
1 The assembly thus o~tained was treated using a hot pressing machine under the following conditions: pressure of 2 Kg/cm2, temperature of 120C, tlme of 7 minutes, and then allow to cool to room temperature. The press plates 15 and the mesh plate 17 were then peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven material was thus obtained.
The cleaning sheet thus obtained was punched out in the same manner as in Example 3 to make a cleaning sheet of an outer diameter of 200 ~ 0.5 mm and an inner diameter 25.4 +
0.05 mm for use with a magnetic head for vîdeo magnetic sheets.
Comparative Exam~
The following composition was coated on a polyvinyl chloride sheet of 50 pm thickness so as to provide a film thick- -ness of 10 pm and then dr;ed to prepare a cleanlng sheet having an abrasive layer.
parts by weight Cr2O3 ~abrasive of 10,000 mesh) 100 Epoxy resin ~epoxy equ;valent 450 to 500, molecular weighO
900, melting point 64 to 74 C) 30 Polyamide resin (condensation product of a poly-fatty acid and a diamine; amine value 300, average molecular welght 2500) 30 Vinyl chloride - vinyl acetate copolymer (VC : V~C - 87 : 13 wt%; polymerization degree 5003 40 Methyl ethyl ketone 500 The cleaning sheet was punched out to the same dimensions as in Example 3, then set in a recorder for magnetic sheets, and contacted with a magnetic head and rotated at 3,600 r.p.m.
3n at a pressure of from about 1 g to about 100 g for cleaning the . ~ . .
1 magnetlc head. As a result, the cleaning effect was the same as those obtained in Examples 3 and 4 ~the cleaning sheets in which the fibrous material of this invention was used at the same conditions). However, the head was remarkably worn away on repeated use, and therefore, the cleaning sheet of khis Comparative Example was unaccepta~le.
The relationship between rotation time (min) of the cleaning sheet and depth of wear ~m) of the magnetic head using the cleaning sheets of Examples 3 and 4 and Comparative Example 2 is shown in Figure 13~
From the results shown in Figure 13, it is apparent that when the cleaning sheet of Comparative Example 2 (in which the abrasive layer was used) and the cleaning sheets of Examples 3 and 4 (in which the fibrous material of this invention was used) were respectively contacted with a magnetic head and rotated, the cleaning sheet having the abrasive layer,at the end of several ten minutes, caused remarkable wear of the head. Thus, it was confirmed that the cleaning sheet of this :
invention is superior thereto.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
:
~ 16 -
1 Figure 6 shows a jacket containing a cleaning sheet having cleaning layers on both sides thereof as shown in Figure 2 and Figures 5(a) and (b), wherein there is shown a cleaning layer l, a support sheet 2, a container 3, an idler 9, a driving motor for rotation lO, a recording and reproducing head ll, a load pad 12 to insure good contact with the head and a light selector 13.
Figure 7 shows a jacket containing a cleaning sheet having a cleaning layer on one side thereof as shown in Figure l and Figure 5(c), wherein there is shown a cleaning layer l, a support 2, a container 3, an idler 9 a driving motor for rotation lO, a recording and reproducing head ll, and a sheet fixing hub 14.
When the cleaning jacket of this invention is mounted in a recorder for flexible discs as shown in Figures 6 and 7 and then used in the same manner as in the case of magnetic discs, the recording and reproducing head 11 and the cleaning layer 1 are contacted with each other while sliding, thus cleaning the recording and reproducing head. Such sliding contact for several seconds to several ten seconds can bring about almos~ a 100%
recovery of the output which has been lowered due to dirt accumulation on the magnetic head, t~pically a mixture of ferromagnetic powder, binder and other additives.
The following examples further illustrate this invention.
It will be apparent to one skilled in the art that components, ratios of amounts, sequence of operations, and the like, shown in the examples can be changed without departing from the spirit and scope o this invention, and this invention is not limited to the following exa~ples.
EXAMPLE_l As illustrated in Figure 8, a polyvinyl chloride sheet ~, "" . '. .
- 10 ~ ", .'.
' ' :' . ' ' , .'',; ' ;,~' " ' ', ' . ' ':, 2 (50 ~m thick, 25 cm x 25 cm square; the molecular weight of the polyvinyl chloride sheet is not overly important and a con-centional PVC was used. The molecular weight is usually 10,000 to 200,000, corresponding to a polymerization degree of 200 to 2,000) and two nonwoven materials. 1 of 70~m thick (Vilene H 8103 polyethylene terephthalate fiber made by Japan Vilene Co., Ltd.) were put between two press plates (stainless steel plates) 15.
The assembly thus obtained was laminated using a hot pressing machine 16 under the following conditions: pressure of 2Kg/cm2, temperature of 120C, time of 10 minutes~ and then allowed to cool to room temperature. The press plates lS were then peeled off~ A polyvinyl chloride sheet which was laminated with the non~
woven materials 1 on both sides thereof was thus obtained.
The cleaning sheet thus obtained was punched out to a doughnut-like sheet (see Figure 3) of an outer diameter of 200 + O.5 mm and an inner diameter of 25.4 ~ O.05 mm using a punching machine for magnetic sheets. The doughnut-like sheet was assembled in a jacket as shown in ~igures 4 and 5(a) to make a cleaning jacket for use with a magnetic head for 2~ ~lexible discs.
As illustrated in Figure 9, a polyvinyl chloride sheet 2 (50 ~m thick, 25 cm x 25 cm square as in Example 1) `~
and a nonwoven material. 1 of 70~m thickness (Vilene H 8103, polyethylene terephthalate fiber made by Japan Vilene Co., ~td.3 were put between press plates (stainless steel plates) 15 At this time, mesh 17 was put between the nonwoven material 1 and the press plate 15 (in this example the mesh was steel;
the size of the mesh is generally about 1 mm to about 10 mm, -~ -preferably 1 mm to 5 mm, while the diameter of the steel wire~
is 0.2 mm to 5 mm, preferably 0.5 to 2 mm)O
:
" ' . .
, : , . . . .
`' ': ' ' ' ' ' ' -1 The assembly thus o~tained was laminated using a hot pressing machine 16 under the following conditions; pressure of 2 Kg/cm2, temperature of 120C, time of 10 minutes, and then allowed to cool to room temperature. The press plates 15 and the mesh plate 17 were peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven material 1 on one side thereof was thus obtained.
The cleaning sheet thus obtained was punched out in the same manner as in Example 1 (see Figure 3). The doughnut-like sheet thus obtained was assembled in a jacket as shown inFigures 4 and 5(b) to make a cleaning jacket for use with a magnetic head for flexible discs, which comprised a cleaning sheet of an outer diameter of 200 + 0.5 mm and an inner diameter of 25.4 -~ 0.05 mm inserted in the container.
Comparative Ex~le 1 The followin~ composition was coated on a polyvinyl chloride sheet of 50 ~m thickness so as to provide a film thickness of 10 ~m and then dried at 80C for 2 min. to prepare a cleaning sheet havin~ an abrasive layer.
parts by wei~ht . , .
Cr2O3 (abrasive of 10,000 mesh) 100 Epoxy resin ~epoxy equivalent 450 to 500j molecular weight 900, melting point 64 to 74C) 30 Polyamide resin (condensation - product of a poly-fatty acid and a diamine; amin~ value 300, avexage molecular weight 2500) 30 Vinyl chloride - vinyl acetate copolymer (VC : VAC = 87 : 13 Wt4; polymerization degree 500) 40 ;. - .:.
Methyl ethyl kekone 500 -~ 12 -,, :' , .:
. . ` ' ;, ' ,' ' ' ' ~, ': . :
1 The cleaning sheet thus obtained was punched out to the same dimensions as in Example 1, and then assembled in the same jac~et as in Example 1. The jacket was set in a recorder for flexible discs, and the cleaning sheet was contacted with a magnetic head and rotated at 360 r.p.m. with a pressure of about 2 g to about 100 g to clean the magnetic head. The cleaning effect was the same as those obtained in Examples 1 and 2 (the cleaning jackets in which the fibrous material of this invention was used under the same conditions). However, the head was remarkably worn away on repeated use, and, there-fore, the cleaning jac~et of this Comparative Example was unacceptable.
The relationship between rotation time (min) of the sheet and depth of wear ~m) of the magnetic head using the cleaning jackets of the above Examples and Comparative Example is shown in Figure 10.
From the results shown in Figure 10, it is apparent that when the cleaning jacket of the Comparative Example in which an abrasive layer was used and when the cleaning jackets of Examples 1 and 2 in which the fi~rous material of this invention was used were respectively contacted with a magnetic head and then rotated, the cleaning jacket in which the abrasive layer was used apparently caused, at the end of several ten minutes, more remarkable head wear. Thus, it was confirmed that the cleaning jacket of this invention is superior.
In addition, the cleaning jacket prepared in the manner as illustrated in Figure 9 (i.e., of Example 2) is superior in cleaning effect to one prepared in the manner as illustrated ~ j-in Figure 8, i.e., cleaning effects are improved due to ~-irregularities ~surface roughness) provided by the mesh.
.
~' ' ' . ' . ': .
: ,.
: :
:
E~YAMPLE 3 . . _._ . - .- .
As is illustrated in Figure 11, a polyvinyl chloride sheet 2 as in Example 1 (50 ~m thick, 25 cm x 25 cm square) and a nonwoven material l of 70 ~m thickness (Vilene H 8103, polyethylene terephthalate fiber made hy Japan Vilene Co., Ltd.) were put between two press plates ~sta;nless steel plates) 15.
The assembly thus obtained was treated using a hot pressing machine 16 under the following conditions: pressure of 2 Xg/cm2, temperature of 120C r time 7 minutes, and then allowed to cool to room temperature. The press plates 15 were then peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven materia:L 1 was thus obtained.
The cleaning sheet thus obtained ~a section of which is shown in Figure 12~ was punched out to a doughnut-like -sheet of an outer diameter of 200 + O.S mm and an inner diameter of 25.4 -~ 0~05 mm using a punching machine for magnetic sheets, ...
thus making a cleaning sheet for use with a magnetic head for video magnetic sheets.
As illustrated in Figure 9,~a polyvinyl chloride sheet 2 (50 pm thick, 25 cm ~ 25 cm square; the molecular weight of ~ -the polyvinyl chloride sheet is not overly important, and a . . .
conventional PVC was used. The molecular weight is usually .. .. ..
10,000 to 200,000, corresponding to a polymerization degree of ~ -.
~ 200 to 2,000) and a nonwoven material 1 of 70 ~m thickness ,. . .
(Vilen~ H ~103, polyethylene terephthalate fiber made by Japan Vilene Co., Ltd.) were put between press plates (stainless steel plates) 15. At this time, a mesh 17 as in Example 2 was put between the nonwoven material 1 and the press plate 15.
- 14 - ;
.
.; . , . , . . ; ~, ` ~
:, ~ .. ..
- - \
~7~
1 The assembly thus o~tained was treated using a hot pressing machine under the following conditions: pressure of 2 Kg/cm2, temperature of 120C, tlme of 7 minutes, and then allow to cool to room temperature. The press plates 15 and the mesh plate 17 were then peeled off. A polyvinyl chloride sheet which was laminated with the nonwoven material was thus obtained.
The cleaning sheet thus obtained was punched out in the same manner as in Example 3 to make a cleaning sheet of an outer diameter of 200 ~ 0.5 mm and an inner diameter 25.4 +
0.05 mm for use with a magnetic head for vîdeo magnetic sheets.
Comparative Exam~
The following composition was coated on a polyvinyl chloride sheet of 50 pm thickness so as to provide a film thick- -ness of 10 pm and then dr;ed to prepare a cleanlng sheet having an abrasive layer.
parts by weight Cr2O3 ~abrasive of 10,000 mesh) 100 Epoxy resin ~epoxy equ;valent 450 to 500, molecular weighO
900, melting point 64 to 74 C) 30 Polyamide resin (condensation product of a poly-fatty acid and a diamine; amine value 300, average molecular welght 2500) 30 Vinyl chloride - vinyl acetate copolymer (VC : V~C - 87 : 13 wt%; polymerization degree 5003 40 Methyl ethyl ketone 500 The cleaning sheet was punched out to the same dimensions as in Example 3, then set in a recorder for magnetic sheets, and contacted with a magnetic head and rotated at 3,600 r.p.m.
3n at a pressure of from about 1 g to about 100 g for cleaning the . ~ . .
1 magnetlc head. As a result, the cleaning effect was the same as those obtained in Examples 3 and 4 ~the cleaning sheets in which the fibrous material of this invention was used at the same conditions). However, the head was remarkably worn away on repeated use, and therefore, the cleaning sheet of khis Comparative Example was unaccepta~le.
The relationship between rotation time (min) of the cleaning sheet and depth of wear ~m) of the magnetic head using the cleaning sheets of Examples 3 and 4 and Comparative Example 2 is shown in Figure 13~
From the results shown in Figure 13, it is apparent that when the cleaning sheet of Comparative Example 2 (in which the abrasive layer was used) and the cleaning sheets of Examples 3 and 4 (in which the fibrous material of this invention was used) were respectively contacted with a magnetic head and rotated, the cleaning sheet having the abrasive layer,at the end of several ten minutes, caused remarkable wear of the head. Thus, it was confirmed that the cleaning sheet of this :
invention is superior thereto.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
:
~ 16 -
Claims (8)
1. A method of cleaning a magnetic head in a magnetic recording system of the type in which a flexible record disc is positioned within a cartridge and said cartridge is fixedly positioned with respect to a magnetic head which has access to a portion of the flexible magnetic disc through an opening within a portion of the cover, and said flexible magnetic disc is pressed during rotation against said magnetic head to effect transducing, said method comprising:
replacing said flexible magnetic record disc with a cleaning sheet disc of corresponding size within said cartridge, and pressing said cleaning sheet disc against said magnetic head, said cleaning sheet disc having a sheet base and at least the surface facing said magnetic head being composed of a fibrous material; and rotating said cleaning sheet disc while in contact with said magnetic head for a few tens of seconds to clean said magnetic head without abrading same.
replacing said flexible magnetic record disc with a cleaning sheet disc of corresponding size within said cartridge, and pressing said cleaning sheet disc against said magnetic head, said cleaning sheet disc having a sheet base and at least the surface facing said magnetic head being composed of a fibrous material; and rotating said cleaning sheet disc while in contact with said magnetic head for a few tens of seconds to clean said magnetic head without abrading same.
2. A method as claimed in claim 1, wherein said fibrous material is adhesively fixed to said sheet base.
3. A method as claimed in claim 1, wherein said fibrous material is thermocompression bonded to said sheet base.
4. A method as claimed in claim 1, wherein the sheet base has the thickness of about 10 µm to about 1 mm and comprises one material of the group consisting of a polymeric sheet, cardboard and a metallic sheet.
5. A method as claimed in claim 1, wherein said fibrous material is selected from the group consisting of a nonwoven material, a synthetic leather, a leather, a woven material of synthetic fibers, a woven material of natural fibers and a Japanese paper.
6. A cleaning cartridge for cleaning a magnetic head of a magnetic recording system, said recording system being of the type comprising a rotary flexible magnetic record disc, a jacket for containing said disc, means for fixing said jacket with respect to a transducer head such that the transducer head contacts a portion of the flexible magnetic disc through an opening within said jacket, and means for rotating said flexible magnetic disc while pressing said flexible magnetic disc against said magnetic head through said jacket opening, said cleaning cartridge comprising:
a cartridge jacket;
a cleaning sheet disc of a size corresponding to said flexible magnetic record disc positioned within said cartridge jacket for rotation with respect thereto by said means for rotating, said cleaning sheet disc including a base and having a substantially continuous surface of nonwoven fibrous material provided on at least the side of the cleaning sheet base, said cartridge jacket having an opening through which said transducer head may be inserted to contact said nonwoven fibrous material and be cleaned thereby.
a cartridge jacket;
a cleaning sheet disc of a size corresponding to said flexible magnetic record disc positioned within said cartridge jacket for rotation with respect thereto by said means for rotating, said cleaning sheet disc including a base and having a substantially continuous surface of nonwoven fibrous material provided on at least the side of the cleaning sheet base, said cartridge jacket having an opening through which said transducer head may be inserted to contact said nonwoven fibrous material and be cleaned thereby.
7, A cleaning cartridge as claimed in claim 6 wherein said fibrous material is adhesively fixed to said sheet base.
8. A cleaning cartridge as claimed in claim 6 wherein said fibrous material is thermocompression bonded to said sheet base.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15339074 | 1974-12-17 | ||
| JP1718875U JPS5198531U (en) | 1975-02-05 | 1975-02-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1074444A true CA1074444A (en) | 1980-03-25 |
Family
ID=26353674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA242,120A Expired CA1074444A (en) | 1974-12-17 | 1975-12-17 | Cleaning sheet and cleaning jacket for cleaning a magnetic head for flexible discs and method for cleaning a magnetic head |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1074444A (en) |
| DE (1) | DE2556919A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4704648A (en) * | 1985-03-12 | 1987-11-03 | Visa Technologies, Inc. | Laminated head cleaning disk |
| US4916564A (en) * | 1983-11-18 | 1990-04-10 | Ryan Plastics Ireland Limited | Cleaning apparatus for a disc drive |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1586055A (en) * | 1978-03-29 | 1981-03-18 | Burroughs Corp | Cleaning disc assembly for magnetic transducers |
| US4375658A (en) * | 1981-01-14 | 1983-03-01 | Verbatim Corporation | Cleaning disk |
| DE8110630U1 (en) * | 1981-04-08 | 1982-01-07 | Agfa-Gevaert Ag, 5090 Leverkusen | CLEANING TAPE FOR MAGNETIC HEADS |
| IE832705L (en) * | 1983-11-18 | 1985-05-18 | Ryan Plastics Ireland | Cleaning apparatus for a disc drive |
| GB8428012D0 (en) * | 1984-11-06 | 1984-12-12 | Cooper A A | Computer head cleaning means |
| JPH0418130Y2 (en) * | 1985-10-19 | 1992-04-22 | ||
| US5075919A (en) * | 1986-10-27 | 1991-12-31 | International Paper Company | Transducer head cleaning disk |
-
1975
- 1975-12-17 CA CA242,120A patent/CA1074444A/en not_active Expired
- 1975-12-17 DE DE19752556919 patent/DE2556919A1/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4916564A (en) * | 1983-11-18 | 1990-04-10 | Ryan Plastics Ireland Limited | Cleaning apparatus for a disc drive |
| US4704648A (en) * | 1985-03-12 | 1987-11-03 | Visa Technologies, Inc. | Laminated head cleaning disk |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2556919A1 (en) | 1976-06-24 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |