US2999275A - Mechanical orientation of magnetically anisotropic particles - Google Patents

Mechanical orientation of magnetically anisotropic particles Download PDF

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US2999275A
US2999275A US748705A US74870558A US2999275A US 2999275 A US2999275 A US 2999275A US 748705 A US748705 A US 748705A US 74870558 A US74870558 A US 74870558A US 2999275 A US2999275 A US 2999275A
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particles
ferrite
magnetic
permanent magnet
rolls
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Scott Jr Blume Walter
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Leyman Corp
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Leyman Corp
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C04B35/2683—Other ferrites containing alkaline earth metals or lead
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/10—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure
    • H01F1/11—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles
    • H01F1/113—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles in a bonding agent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F13/00—Apparatus or processes for magnetising or demagnetising
    • H01F13/003—Methods and devices for magnetising permanent magnets
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0273—Imparting anisotropy
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3215—Barium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3296—Lead oxides, plumbates or oxide forming salts thereof, e.g. silver plumbate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/78—Grain sizes and shapes, product microstructures, e.g. acicular grains, equiaxed grains, platelet-structures
    • C04B2235/787—Oriented grains
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S159/00—Concentrating evaporators
    • Y10S159/26—Electric field
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
    • Y10S264/58—Processes of forming magnets
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/90—Magnetic feature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49075—Electromagnet, transformer or inductor including permanent magnet or core
    • Y10T29/49076—From comminuted material

Definitions

  • J Z iami ATT02A/EY5.
  • a principal objective of the invention has been to provide permanent magnets "having excellentmagnetic prop erties but which are readily machinable whereby they may be cut to desired shapes as required by the purposes'which the magnets serve.
  • Machinable magnets have been produced by the compression or injection molding ofzmixtures of "subdivided magnetic material andplastic, .but.no method of orientation has been known to permit theutilization of thesuperior properties peculiar to ultrafine anisotropic materials in such procedures, and .the' magnets inevitablydisplay low energy products.”
  • Permanentmagnets of the ferrite materials are potentially less expensive than metal alloys such as Alnico because the materials from which the ferrites are made are much more 'abundant'and'readily available; However, because thefe'rritesare of a crystalline refractory natureto'begin with, the pressing and sintering technique This technique for preparing magnets of such non-metallic or ceramic'-.
  • the permanent magnets'of the presentinvention embody magnetically anisotropic materials and display-permanent magnetproperties comparable to or exceeding those .of: the ferromagnetic materials previously known, but they alsopossessqualities of 'machinabiiltypworke, ability, 1 or cutability which --make them" amenable to fabrication in simple or intricate shapes, as desired, by-
  • the products of the invention preferably aremade from particles of barium, strontium, or lead ferrite,"or'mixtnres thereof, but the methods of fabrication which this invention provides also may be used in the preparation of readily machinable permanent mag-' nets made from various elements, compounds, or alloys Such'as manganese-bismuth, finely divided iron, etc.
  • the products of this invention possess the im proved permanent magnet properties of past materials plus the'quality of machinability in which the past materials have beendeficient, and the finished products are limited as to shape only by the nominal costs involved in the production machining, punching, or cutting of bulk solids;
  • the essence of the present invention lies in the concept of mechanically orienting or aligning the preferred magnetic axes of the domains with respect to each other, rather than doing it magnetically by means of an external field. It has been found that much better orientation can be achieved in this manner and this method can be practiced with great economy since a magnetic field need not be maintained nor high temperature utilized.
  • alignment of the particles and the property of machinability are obtained in a permanent magnet of the consolidated powder type by a method wherein particles ground to a suitable state of fineness, preferably domain size, are disposed in an elastomeric or plastic medium, such as rubber, polyethylene, plasticized polyvinyl chloride, or the like.- Dispersed heterogeneously in this medium, the particles are relatively immobile and cannot be made favorably to respond, just as the medium itself is relatively immobile.
  • the particles or domains can be made to disarrange themselves from a heterogeneous pattern of disorganization into an orderly pattern of orientation and alignment by subjecting the composition to strong mechanical force in the nature of shearing stress such as is exerted internally and externally upon a mass as it passes through one or a series of closely spaced rollers or an extrusion plate.
  • strong mechanical force in the nature of shearing stress such as is exerted internally and externally upon a mass as it passes through one or a series of closely spaced rollers or an extrusion plate.
  • the orientation may be conducted by adding domain-sized ferrite powder to a natural rubber base and milling the resulting composition into thin sheets by means of a conventional roller-type rubber mill wherein the composition is subjected to the shearing action of dilferentially speeded rolls between which the material is passed, preferably a number of times.
  • the milling process disperses the magnetic material evenly in and throughout the rubber base, but as an incident thereof also orients the domains, so that the preferred directional axes of the individual particles are parallel to one another.
  • the immobilizing matrix may be a resinous or plastic composition, or elastomeric semi-solid, or viscous liquid in which the powder can be evenly dispersed and which is capable of hardening, setting, or being cured to a solid state.
  • the ferritic or potentially magnetic powder is dispersed in uncured rubber which, upon being milled, is cured to immobilize the particles within it.
  • Application of heat and pressure to the mass after orientation cures or stabilizes the rubber to provide the desired coherence without disdisposed domain particles to move relative to one another in response to the shear forces exerted by milling or extrusion.
  • the method of orientation provided by the present invention is equally applicable to any anisotropic magnetic material having domain-sized particles, which particles are capable of being acted upon by internal shear stresses in a manner achieving orientation.
  • the only limitation on the material is that the particles possess a preferred magnetic axis which will lie consistently on a geometrically unique axis such that the mechanical shearing forces or turning moments acting upon the particles during the orienting step will not act in any one of several directions with equal probability.
  • the desirable orientation is not disturbed by subsequent handling of the composition once it has been cured or set, as the case may be, nor does subsequent cutting or working of magnets formed from laminated sheets of the composition cause the magnets to lose their orientation or magnetic properties.
  • Localized surface shearing forces such as are set up during machining of the material, may disturb the orientation of particles in a thin layer near the surface, but such effects are negligible where the magnet is other than of very small size, since the portion of the magnet in which orientation is effected is inconsequentially small in comparison with the total volume of the magnet.
  • the product may be tropic particles of permanent magnet material is being formed into 'a sheet;
  • FIGURE 2 is a perspective view illustrating the magv netization of a laminate formed in accordance with the invention
  • FIGURE 3 is a sectional view through a cavity in which a stack of forms cut from a sheet produced in accordance with the invention are integrated under pressure and magnetized between the pole pieces of an electromagnet;
  • FIGUREr l is la .cross-sectionalview through t-an:ex-.-.. trusion :Tassernbly, and illustrates 1 an 1:. alternative: :method i;. ofzaligning':anisotropicrzparticles::of;:permanentpmagnet materialsin a martix.
  • barium .carbonate is admixedwithi ball .mill'; the preferred practice' is .to ball. millithe barium ferrite in'water for 90"hdurs, then remove the powder from the ball-mill, dry it, and .heat treat it for minutes at .a temperature of approximately ,1000 C; after-which the powder is again subjected to ball milling for. another hours.
  • bariumferritei is admixedwithi ball .mill'; the preferred practice' is .to ball. millithe barium ferrite in'water for 90"hdurs
  • the attritionmill may be comminuted in..an attrition millffo'in example, a standard Szegvariattrition mill'usingstainless steel shot for a length of-time sufficientto reduce the particles to domain size.
  • the attritionmill is in the, order is preferred.
  • the .heat. treating step. is desirable because thistreatmentincreases the coercivity of the final prod-r uct; in.,thecaseoflead ferritethe 'increasemay be as much as although the effect of the heat treatment is somewhat less incthecasemof. bariumand. strontium ferrite Itwillbe. recognized that the. foregoing method of preparing.
  • barium ferrite is offered only by way of illustratio nand that. other methods are known in the art which also be recognized that powdered barium ferrite and other ferromagneticmaterials adapted for use in the practice of this invention are available from commercial supply houses.
  • the-milled particle size should be in the 4 rangeof .5 micron, although magnets having good prop erties have been obtained using particles which in average size .were. somewhat larger.
  • the powder is dried, any lumpy agglomerations are reduced, and the powder is thenready for use.
  • the attainment of domain size maybe determined .by vmeans of periodic inspection of the material withan electron microscope or, more easily, though somewhat less accurately,rbycomparing the color of a smear .of powder ofunknown particlesize with that of a smearof powder known to be A of: domain'size, whichin the case of barium ferrite has a -.deep,red color.
  • the color of a barium ferrite powder initiallyfired at a high temperature for example, 1250'C.,- changes from black. 55
  • a suitable rubber base or matrix to which this ferrite maybe added has a composition as follows:
  • ferric oxide for example, inlthe. proportionof mol .mtrnay' be'added tothe extent .of 65%-oftthet0tal.volume of the mixture.
  • the rub-" bercomposition is sheeted off the mill,'thesheets'prefcr-' ably being thin, e.g., about'say,'.02 .03-inch. As a rule ofthumb, the thinner the sheet, the-more"easil-y the desired degree of orientation is obtained;
  • FIGUREI illustrates a presently offered explanation of the'processthrough which mechanical'domain orientation is achieved in the practice of this invention.
  • the figure is a vertical section through a conventional rubber mill.
  • Matrix ferrite mixture' is indicated generally at 1, where it collects prior to passing between the respective rolls 2 and -3.
  • Roll 2 is'rotating at a slightly greater rate than roll 3.
  • Barium ferrite plates 4 in the mixture are randomly oriented in-the mixture:
  • differential speeding of rolls produces a speed gradient within the material as it passes between them
  • a second aligning effect is believed to be conferred upon the magnetic particles in the material by reason of the reduction in thickness of the material as it passes through the rolls, whether or not they are differentially speeded.
  • the mate rial is dragged frictionally from the mass or accumulationexisting at the roll nip, and the reduction in thickness from this mass produces a speed gradient internally of the material which may be greater or less depending upon the amount of reduction in thickness.
  • the thin sheets resulting therefrom may be cured and magnetized as such or stacked up until a laminate of the desired thickness is obtained. Since the ferrite domain particles of each of the sheets are aligned so that their preferred directions are normal to the sheet, when the sheets are stacked in facial juxtaposition, the resulting laminate has a preferred magnetic direction normal to its plane surfaces. This is so, it will be seen, regardless of the number of sheets in the laminate.
  • the laminated sheets To bind'or afiix the laminated sheets to each other to form a unitary whole, the laminate is placed under a pressure of about pounds per square inch for example and heated to a temperature of about 300 F. or whatever temperature is required to eifect curing of the particular matrix composition. In this operation the laminated sheets are integrated. Magnets of the desired conifiguration may then be cut from the composite. During these operations the orientation of the particles is not disturbed because they are held immobile in the matrix.
  • FIGURE 2 shows a proper method of magnetizing a small right cylindrical magnet manufactured according to this invention.
  • 10 and 11 are the pole pieces of an electromagnet which, upon being energized, magnetizes the ferrite particle magnets in the laminate.
  • the dashed lines 12 indicate the magnetic field between the pole pieces.
  • the laminated magnet 13 is shown in the proper magnetizing position in the field, the arrow 14 indicating the preferred direction of magnetization.
  • the arrow 14, it will observed, is parallel to the lines of force 12 of the external field.
  • the pole 10 is the north pole of the electromagnet
  • the opposing face 15 of the laminated magnet 13 will be the south pole of that magnet, and so on.
  • the magnet may alternatively be formed by punching forms of the desired cross-section out of a single sheet and then laminating and curing the stacked punched-out forms. method is desirable to eliminate waste since the uncured trim readily may be reworked.
  • FIGURE 3 illustrates this procedure.
  • the punched-out forms 40 from the single sheets are stacked in a cavity 41 within a mold 42 having end pieces 43 which may be moved so as to compress the sheets within the mold. Heat is then applied in any suitable manner so as to cure the sheets.
  • a suitably magnetized specimen containing 65% barium ferrite by volume made in accordance with the method of this invention had a residual induction of about 2100 gauss, a coercivity of 1200 oersteds, and a maximum energy product of .9 10 gauss-oersteds.
  • the magnet can be handled and worked freely without danger of breakage and may readily be cut with a knife or other edged tool.
  • the same material measured at right angles to the preferred direction of mechanical alignment had a maximum energy product of 28x10 gauss-oersteds, a residual induction of 1200 gauss, and a coercivity of 800 oersteds.
  • a magnetizing field as illustrated by the lines 44 may be applied while the magnet there formed is being cured in the mold by making the end caps 43 of the mold themselves serve as the pole pieces of an electromagnet 45.
  • Example 2 This example generally follows the preceding example except that lead ferrite is substituted for barium ferrite as the magnetic material.
  • Lead ferrite may be produced as follows: 17.5 parts by weight of lead monoxide (1.5 mol PhD) is intimately mixed with 50 parts by weight of ferric oxide (6.0 mol Fe O This mixture is fired in a surrounding atmosphere of air, starting from 700 C. and increasing the temperature gradually .-to 900 C. over a period of six hours in order to produce crystalline lead ferrite. After quenching in air, the lead ferrite so produced is then milled to domain size (for example, by grinding two hours in the attrition mill,
  • 'Ihie' matrix composition --towhich the lead ferrite is add'e'd may be-the same as that-described -'-above,-- except that the Plead:- ferrite --is added in the *amount of 1 l6.0 parts by weightg- In this amount-the ferrite comprises 57% 'byevolume of-the--composite.- Other matrix ma terials may be-usedin---place of rubber-ias previously *de scribed.
  • Strontium ferrite may be the selected ferromagnetic material.
  • strontium ferrite the following procedure is satisfactory: 7.7 parts by weight of strontium carbonate (1 mol SrCO is intimately mixed with 50 parts by weight of ferric oxide (6 mol Fe O The mixture thus prepared is fired in an air atmosphere for approximately one hour at a temperature of 1250 C. and then milled and treated as described in Example 1.
  • Strontium ferrite so produced is incorporated with the rubber in the amount of 123.0 parts by weight, the weights of the other components being as specified previously. In this amount it is 62% by volume of the composite.
  • thermo-plastic or thermo-setting materials may be used to form the matrix in place of rubber.
  • the ferromagnetic material may be incorporated into a plastic of the polyvinyl chloride type.
  • a material is selected which is susceptible of being sheeted between rolls or of being extruded through a narrow orifice into elongated shapes whose surface area is great relative to their volume. The shearing forces set up within the composition during the extrusion or milling process cause local orienting movement of one portion of the composition relative to another portion, and apparently therein lies the reason for the observed orientation which takes place.
  • a method of producing permanent magnet material comprising, mixing anisotropic, substantially domain size particles of a permanent magnet material with a workable non-magnetic matrix material, and milling the resulting mixture between rolls into elongated form, whereby the preferred magnetic axes of said particles are aligned substantially perpendicularly to the surface of said elongated form, said permanent magnet material being adapted to be magnetized to form an anisotropic permanent magnet by applying to said material a magnetizing field which is directed perpendicularly to the surface of said material.
  • a method of producing permanent magnet material comprising, mixing substantially domain size particles of a material selected from the class consisting of the ferrites of barium, strontium and lead with a workable non-magnetic matrix material, and milling the resulting mixture between rolls to form an elongated body therefrom, whereby as a result of said milling said elongated body displays a preferred direction of magnetization which is substantially normal to its surface, said 3. 'A method'of producing permanentmagnet material;v
  • said-method comprising, mixin g substantially domain-size particlesrof a material selected from theclass consistingofirthe fer-rites of barium, strontiumsand lead iwithra workable.
  • non-magnetic matrix materiah and extruding thez-resu-lting mixture throughra narrow-extrus-ion orifice? having a minimum of draft and relief to form an elongated body therefrom, whereby as a result of said extrusion said elongated body displays a preferred direction of magnetization which is substantially normal to its surface, said permanent magnet material being adapted to be magnetized to form an anisotropic permanent magnet by applying to said material a magnetizing field which is directed perpendicularly to the surface of said material.
  • a method of producing permanent magnet material comprising, mixing substantially domain size particles of a material selected from the class consisting of the ferrites of barium, strontium and lead with a workable non-magnetic matrix material selected from the class consisting of rubber, elastomers, and resins, and rolling the resulting mixture between rolls to reduce its thickness and thereby form it into a sheet, whereby the preferred magnetic axes of said particles are aligned substantially normally to the surface of said sheet, said permanent magnet material being adapted to be magnetized to form an anisotropic permanent magnet by applying to said material a magnetizing field which is directed perpendicularly to the surface of said material.
  • a permanent magnet material which comprises, mixing substantially domain size particles of a material selected from the class consisting of the fer'rites of barium, strontium, and lead with a non-magnetic matrix material having the approximate workability characteristics of uncured rubber, sheeting the resulting mixture between rolls to form a magnetizable sheet having a preferred direction of magnetization which is substantially perpendicular to its surface, and laminating a plurality of such sheets stacked in facial engagement to form a thicker permanent magnet material having a preferred direction of magnetization which is substantially perpendicular to its surface, said permanent magnet material being adapted to be magnetized to form an anisotropic permanent magnet by applying to said material a magnetizing field which is directed perpendicularly to the surface of said material.
  • a method of producing permanent magnet material comprising, disposing anisotropic, substantially domain size particles of a permanent magnet substance in a workable, non-magnetic matrix, and rolling the resulting mixture between rolls to reduce the thickness of said mixture and thereby cause said mixture to become relatively thinner and more elongated, whereby the mechanical forces incidental to said rolling cause said particles to move in said matrix into positions such that the preferred magnetic axes of said particles assume substantially uniform angular relationships with the surface of said material said permanent magnet material being adapted to be magnetized to form a permanent magnet therefrom by applying to said material a magnetizing field in a direction parallel to the direction of the preferred magnetic axes of said particles.

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  • Manufacturing Cores, Coils, And Magnets (AREA)
US748705A 1958-07-15 1958-07-15 Mechanical orientation of magnetically anisotropic particles Expired - Lifetime US2999275A (en)

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US817018A US3359152A (en) 1958-07-15 1959-05-07 Machinable anisotropic magnet
DE1959L0033648 DE1302093C2 (de) 1958-07-15 1959-07-04 Verfahren zur herstellung von durch bindemittel gebundenen vorzugsgerichteten dauermagneten
NL241241A NL112334C (nl) 1958-07-15 1959-07-14
CH7575659A CH398822A (de) 1958-07-15 1959-07-14 Verfahren zur Herstellung von permanenten Magneten

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Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3066355A (en) * 1959-05-29 1962-12-04 Raytheon Co Orientation of ferromagnetic particles
US3110675A (en) * 1960-03-25 1963-11-12 Gen Motors Corp Method of fabricating ferrite bodies
US3127461A (en) * 1961-07-10 1964-03-31 Jr Walter S Blume Method of producing curved radially aligned matrix bonded fine particle permanent magnets
US3136720A (en) * 1959-12-12 1964-06-09 Baermann Max Magnetic filter
US3141050A (en) * 1960-08-16 1964-07-14 Leyman Corp Mechanical orientation of magnetically anisotropic particles
US3151703A (en) * 1962-01-02 1964-10-06 Gen Motors Corp Transmission
US3163922A (en) * 1960-12-08 1965-01-05 Gen Motors Corp Process for orienting ferrites
US3184807A (en) * 1958-11-24 1965-05-25 Goodrich Co B F Gasket containing a permanent magnet
US3207960A (en) * 1962-08-30 1965-09-21 Magic Decorator Company Mechanical magnetic solenoid device
US3208296A (en) * 1962-04-26 1965-09-28 Baermann Max Belt drive device
US3219888A (en) * 1961-06-20 1965-11-23 Robert W Waring Method of holding work
US3222205A (en) * 1963-02-15 1965-12-07 Lew W Karalus Recording tape
US3231770A (en) * 1962-11-19 1966-01-25 Kdi Corp Self-starting synchronous motor
US3250831A (en) * 1962-12-20 1966-05-10 Gen Electric Magnetic material
US3253169A (en) * 1963-02-20 1966-05-24 Cons Electronics Ind Synchronous motors
US3281511A (en) * 1964-05-15 1966-10-25 Gen Plastics Corp Method of preparing microporous tetrafluoroethylene resin sheets
US3303040A (en) * 1963-09-24 1967-02-07 Philips Corp Method of manufacturing a magnetic member having a coating of crystalline ferromagnetic material having uniaxial magnetic anisotropy
US3305380A (en) * 1963-04-08 1967-02-21 Sperry Rand Corp Magnetic film having uniformly variable hk and method therefor
US3328110A (en) * 1964-01-02 1967-06-27 Exxon Research Engineering Co Electromagnetic radiation valve
US3359152A (en) * 1958-07-15 1967-12-19 Leyman Corp Machinable anisotropic magnet
US3384795A (en) * 1966-06-10 1968-05-21 Trident Engineering Associates Ferro-plastic control devices
US3387066A (en) * 1964-08-10 1968-06-04 Plessey Uk Ltd Method for producing sintered nonmetallic magnetic materials
US3392767A (en) * 1965-11-15 1968-07-16 Gardner Denver Co Magnetic tools
DE1300052B (de) * 1963-01-25 1969-07-24 Westinghouse Electric Corp Verfahren zur Herstellung eines Ferrit-Dauermagneten hoher Koerzitivkraft
US3477948A (en) * 1965-12-13 1969-11-11 Inoue K Magnetic filter and method of operating same
US3535245A (en) * 1963-02-21 1970-10-20 Chevron Res Metal-oxide coated ferrimagnetic particles
US3546709A (en) * 1968-07-03 1970-12-15 Minnesota Mining & Mfg Hat for holding articles
US3849213A (en) * 1966-09-01 1974-11-19 M Baermann Method of producing a molded anisotropic permanent magnet
US3858514A (en) * 1972-08-28 1975-01-07 Minnesota Mining & Mfg Data accumulation system providing magnetic toner powder recording
US3889039A (en) * 1973-04-26 1975-06-10 Horizons Inc Nucleation and orientation of linear polymers
US3897288A (en) * 1969-07-31 1975-07-29 Minnesota Mining & Mfg Fastening method using polymer-based magnets
US3903228A (en) * 1970-08-12 1975-09-02 Minnesota Mining & Mfg Flexible ferrite-particle magnets
US3908065A (en) * 1974-04-15 1975-09-23 Minnesota Mining & Mfg Magnetic embossable label tape laminate
US3953251A (en) * 1974-03-25 1976-04-27 Bell Telephone Laboratories, Incorporated Method for the production of carbonyl iron containing magnetic devices with selected temperature variation
US4022701A (en) * 1974-04-26 1977-05-10 Japan Special Steel Co., Ltd. High-performance anisotropic plastics magnet and a process for producing the same
US4067810A (en) * 1976-02-09 1978-01-10 Ofco, Inc. Fluid filter magnet assembly
US4102951A (en) * 1975-05-14 1978-07-25 Monash University Calcination of basic ferric sulphates
FR2426968A1 (fr) * 1978-05-26 1979-12-21 Philips Nv Procede pour la fabrication d'aimants permanents anisotropes a liant synthetique
US4200547A (en) * 1979-01-02 1980-04-29 Minnesota Mining And Manufacturing Company Matrix-bonded permanent magnet having highly aligned magnetic particles
US4264821A (en) * 1978-01-23 1981-04-28 Agfa-Gevaert, A.G. Cassette for an X-ray film
US4408694A (en) * 1981-05-28 1983-10-11 Owens-Illinois, Inc. Reinforced plastic home canning ring
US4562019A (en) * 1979-02-23 1985-12-31 Inoue-Japax Research Incorporated Method of preparing plastomeric magnetic objects
US4857188A (en) * 1987-05-12 1989-08-15 Ishikawa Tekko Kabushiki Kaisha Iron powder attracting magnet
US4873504A (en) * 1987-02-25 1989-10-10 The Electrodyne Company, Inc. Bonded high energy rare earth permanent magnets
US4961849A (en) * 1988-12-19 1990-10-09 Hull Harold L Magnetically attached filter
US5505305A (en) * 1992-10-21 1996-04-09 Minnesota Mining And Manufacturing Company Moisture-proof resealable pouch and container
US5523549A (en) * 1994-05-25 1996-06-04 Ceramic Powders, Inc. Ferrite compositions for use in a microwave oven
US5525145A (en) * 1993-12-17 1996-06-11 Hodge; Joseph Filtering apparatus for a forced air duct grill
US5690719A (en) * 1995-10-19 1997-11-25 Hodge; Joseph Removable filter for a forced air duct grill
US5764060A (en) * 1996-03-11 1998-06-09 Minnesota Mining And Manufacturing Company Guidance system for a moving person
US5853846A (en) * 1995-10-18 1998-12-29 Minnesota Mining And Manufacturing Company Conformable magnetic articles underlaid beneath traffic-bearing surfaces
US6332862B1 (en) 1999-12-21 2001-12-25 Michael Zandman Articles of clothing incorporating magnets for therapeutic purposes
EP1184668A2 (en) * 2000-09-04 2002-03-06 Uchiyama Manufacturing Corp. Encoder made of rubber material and method of manufacturing thereof
US6468678B1 (en) 1994-11-17 2002-10-22 3M Innovative Properties Company Conformable magnetic articles for use with traffic bearing surfaces methods of making same systems including same and methods of use
US20040087983A1 (en) * 2002-09-04 2004-05-06 Yencho Stephen A. Medical device having magnetic properties
US20040251652A1 (en) * 2003-06-10 2004-12-16 Hutchinson Method of fabricating a magnetic coder device, and the device obtained thereby
US20060073774A1 (en) * 2004-09-29 2006-04-06 Chien-Min Sung CMP pad dresser with oriented particles and associated methods
US20060150854A1 (en) * 2003-07-03 2006-07-13 Spica Holding S.A. Method and means for producing a magnetically induced design in a coating containing magnetic particles
WO2012028253A1 (de) * 2010-09-01 2012-03-08 Hydac Filtertechnik Gmbh Bauteil für eine filtereinheit zur filtration von fluiden und verfahren zur herstellung eines derartigen bauteils
WO2014004595A2 (en) * 2012-06-29 2014-01-03 General Electric Company Nanocomposite permanent magnets and methods of making the same
US8893955B2 (en) 2010-10-27 2014-11-25 Intercontinental Great Brands Llc Releasably closable product accommodating package
US20150174730A1 (en) * 2013-12-20 2015-06-25 Kinik Company Low Magnetic Chemical Mechanical Polishing Conditioner
US20170275056A1 (en) * 2016-03-28 2017-09-28 Magnetnotes, Ltd. Magnetic locking reclosure for packages and methods of making the same

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JPS6025014B2 (ja) * 1978-07-07 1985-06-15 松下電器産業株式会社 ロ−ル状マグネットの製造法
DE3268714D1 (en) * 1981-11-20 1986-03-06 Goodrich Co B F Permanent magnets

Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1700208A (en) * 1926-11-19 1929-01-29 Paisseau Jean Process and apparatus for production of a substance having a nacreous and chatoyant aspect
US1763314A (en) * 1927-06-22 1930-06-10 Congoleumnairn Inc Method of and apparatus for sheeting linoleum or the like
US1991143A (en) * 1932-09-01 1935-02-12 Krupp Ag Production of finely divided magnetic bodies
US1994534A (en) * 1932-04-23 1935-03-19 Rca Corp Inductance coil and method of manufacture thereof
US2011698A (en) * 1933-06-01 1935-08-20 Vogt Hans Adhesive for magnetic cores formed of magnetic layers
US2017705A (en) * 1933-05-04 1935-10-15 British Xylonite Co Ltd Manufacture of materials for producing or detecting polarized light
US2064773A (en) * 1933-06-01 1936-12-15 Ferrocart Corp Of America Method for making magnetic cores
US2546344A (en) * 1946-12-31 1951-03-27 Univ Loudspeakers Inc Magnet structure
US2651105A (en) * 1942-04-07 1953-09-08 Electro Chimie Metal Manufacture of permanent magnets
US2694831A (en) * 1950-10-21 1954-11-23 Congoleum Nairn Inc Method of producing linoleum
US2720453A (en) * 1952-10-22 1955-10-11 Gen Aniline & Film Corp Process of preparing iron powder of improved electromagnetic and mechanical properties
GB749969A (en) * 1953-10-31 1956-06-06 Vacuumschmelze Ag Improvements in or relating to the production of laminated magnetic cores
US2751525A (en) * 1953-07-24 1956-06-19 Hartford Nat Bank & Trust Co Permanent magnet
US2848748A (en) * 1956-02-28 1958-08-26 Lloyd R Crump Method of securing permanent threedimensional patterns of magnetic fields
US2849312A (en) * 1954-02-01 1958-08-26 Milton J Peterman Method of aligning magnetic particles in a non-magnetic matrix
US2865085A (en) * 1954-07-30 1958-12-23 Westinghouse Electric Corp Preparation of magnetic materials and magnetic members
US2951246A (en) * 1946-01-30 1960-08-30 Halpern Otto Absorbent for electromagnetic waves

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE565556A (nl) * 1900-01-01
US2627097A (en) * 1951-05-25 1953-02-03 Ellis Robert Flexible magnetic closure
FR1135734A (fr) * 1954-12-13 1957-05-03 Tesla Np Aimant à ferrite
DE1033813B (de) * 1957-07-01 1958-07-10 Deutsche Edelstahlwerke Ag Verfahren zur Herstellung kunststoffgebundener Dauermagnete

Patent Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1700208A (en) * 1926-11-19 1929-01-29 Paisseau Jean Process and apparatus for production of a substance having a nacreous and chatoyant aspect
US1763314A (en) * 1927-06-22 1930-06-10 Congoleumnairn Inc Method of and apparatus for sheeting linoleum or the like
US1994534A (en) * 1932-04-23 1935-03-19 Rca Corp Inductance coil and method of manufacture thereof
US1991143A (en) * 1932-09-01 1935-02-12 Krupp Ag Production of finely divided magnetic bodies
US2017705A (en) * 1933-05-04 1935-10-15 British Xylonite Co Ltd Manufacture of materials for producing or detecting polarized light
US2011698A (en) * 1933-06-01 1935-08-20 Vogt Hans Adhesive for magnetic cores formed of magnetic layers
US2064773A (en) * 1933-06-01 1936-12-15 Ferrocart Corp Of America Method for making magnetic cores
US2651105A (en) * 1942-04-07 1953-09-08 Electro Chimie Metal Manufacture of permanent magnets
US2951246A (en) * 1946-01-30 1960-08-30 Halpern Otto Absorbent for electromagnetic waves
US2546344A (en) * 1946-12-31 1951-03-27 Univ Loudspeakers Inc Magnet structure
US2694831A (en) * 1950-10-21 1954-11-23 Congoleum Nairn Inc Method of producing linoleum
US2720453A (en) * 1952-10-22 1955-10-11 Gen Aniline & Film Corp Process of preparing iron powder of improved electromagnetic and mechanical properties
US2751525A (en) * 1953-07-24 1956-06-19 Hartford Nat Bank & Trust Co Permanent magnet
GB749969A (en) * 1953-10-31 1956-06-06 Vacuumschmelze Ag Improvements in or relating to the production of laminated magnetic cores
US2849312A (en) * 1954-02-01 1958-08-26 Milton J Peterman Method of aligning magnetic particles in a non-magnetic matrix
US2865085A (en) * 1954-07-30 1958-12-23 Westinghouse Electric Corp Preparation of magnetic materials and magnetic members
US2848748A (en) * 1956-02-28 1958-08-26 Lloyd R Crump Method of securing permanent threedimensional patterns of magnetic fields

Cited By (80)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3359152A (en) * 1958-07-15 1967-12-19 Leyman Corp Machinable anisotropic magnet
US3184807A (en) * 1958-11-24 1965-05-25 Goodrich Co B F Gasket containing a permanent magnet
US3066355A (en) * 1959-05-29 1962-12-04 Raytheon Co Orientation of ferromagnetic particles
US3136720A (en) * 1959-12-12 1964-06-09 Baermann Max Magnetic filter
US3110675A (en) * 1960-03-25 1963-11-12 Gen Motors Corp Method of fabricating ferrite bodies
US3141050A (en) * 1960-08-16 1964-07-14 Leyman Corp Mechanical orientation of magnetically anisotropic particles
US3163922A (en) * 1960-12-08 1965-01-05 Gen Motors Corp Process for orienting ferrites
US3219888A (en) * 1961-06-20 1965-11-23 Robert W Waring Method of holding work
US3127461A (en) * 1961-07-10 1964-03-31 Jr Walter S Blume Method of producing curved radially aligned matrix bonded fine particle permanent magnets
US3151703A (en) * 1962-01-02 1964-10-06 Gen Motors Corp Transmission
US3208296A (en) * 1962-04-26 1965-09-28 Baermann Max Belt drive device
US3207960A (en) * 1962-08-30 1965-09-21 Magic Decorator Company Mechanical magnetic solenoid device
US3231770A (en) * 1962-11-19 1966-01-25 Kdi Corp Self-starting synchronous motor
US3250831A (en) * 1962-12-20 1966-05-10 Gen Electric Magnetic material
DE1300052B (de) * 1963-01-25 1969-07-24 Westinghouse Electric Corp Verfahren zur Herstellung eines Ferrit-Dauermagneten hoher Koerzitivkraft
US3222205A (en) * 1963-02-15 1965-12-07 Lew W Karalus Recording tape
US3253169A (en) * 1963-02-20 1966-05-24 Cons Electronics Ind Synchronous motors
US3535245A (en) * 1963-02-21 1970-10-20 Chevron Res Metal-oxide coated ferrimagnetic particles
US3305380A (en) * 1963-04-08 1967-02-21 Sperry Rand Corp Magnetic film having uniformly variable hk and method therefor
US3303040A (en) * 1963-09-24 1967-02-07 Philips Corp Method of manufacturing a magnetic member having a coating of crystalline ferromagnetic material having uniaxial magnetic anisotropy
US3328110A (en) * 1964-01-02 1967-06-27 Exxon Research Engineering Co Electromagnetic radiation valve
US3281511A (en) * 1964-05-15 1966-10-25 Gen Plastics Corp Method of preparing microporous tetrafluoroethylene resin sheets
US3387066A (en) * 1964-08-10 1968-06-04 Plessey Uk Ltd Method for producing sintered nonmetallic magnetic materials
US3392767A (en) * 1965-11-15 1968-07-16 Gardner Denver Co Magnetic tools
US3477948A (en) * 1965-12-13 1969-11-11 Inoue K Magnetic filter and method of operating same
US3384795A (en) * 1966-06-10 1968-05-21 Trident Engineering Associates Ferro-plastic control devices
US3849213A (en) * 1966-09-01 1974-11-19 M Baermann Method of producing a molded anisotropic permanent magnet
US3546709A (en) * 1968-07-03 1970-12-15 Minnesota Mining & Mfg Hat for holding articles
US3897288A (en) * 1969-07-31 1975-07-29 Minnesota Mining & Mfg Fastening method using polymer-based magnets
US3903228A (en) * 1970-08-12 1975-09-02 Minnesota Mining & Mfg Flexible ferrite-particle magnets
US3858514A (en) * 1972-08-28 1975-01-07 Minnesota Mining & Mfg Data accumulation system providing magnetic toner powder recording
US3889039A (en) * 1973-04-26 1975-06-10 Horizons Inc Nucleation and orientation of linear polymers
US3953251A (en) * 1974-03-25 1976-04-27 Bell Telephone Laboratories, Incorporated Method for the production of carbonyl iron containing magnetic devices with selected temperature variation
US3908065A (en) * 1974-04-15 1975-09-23 Minnesota Mining & Mfg Magnetic embossable label tape laminate
US4022701A (en) * 1974-04-26 1977-05-10 Japan Special Steel Co., Ltd. High-performance anisotropic plastics magnet and a process for producing the same
US4102951A (en) * 1975-05-14 1978-07-25 Monash University Calcination of basic ferric sulphates
US4067810A (en) * 1976-02-09 1978-01-10 Ofco, Inc. Fluid filter magnet assembly
US4264821A (en) * 1978-01-23 1981-04-28 Agfa-Gevaert, A.G. Cassette for an X-ray film
FR2426968A1 (fr) * 1978-05-26 1979-12-21 Philips Nv Procede pour la fabrication d'aimants permanents anisotropes a liant synthetique
US4200547A (en) * 1979-01-02 1980-04-29 Minnesota Mining And Manufacturing Company Matrix-bonded permanent magnet having highly aligned magnetic particles
AT382258B (de) * 1979-01-02 1987-02-10 Minnesota Mining & Mfg Matrixgebundener permanentmagnet
US4562019A (en) * 1979-02-23 1985-12-31 Inoue-Japax Research Incorporated Method of preparing plastomeric magnetic objects
US4408694A (en) * 1981-05-28 1983-10-11 Owens-Illinois, Inc. Reinforced plastic home canning ring
US4873504A (en) * 1987-02-25 1989-10-10 The Electrodyne Company, Inc. Bonded high energy rare earth permanent magnets
US4857188A (en) * 1987-05-12 1989-08-15 Ishikawa Tekko Kabushiki Kaisha Iron powder attracting magnet
US4961849A (en) * 1988-12-19 1990-10-09 Hull Harold L Magnetically attached filter
US5687848A (en) * 1992-10-21 1997-11-18 Minnesota Mining And Manufacturing Company Moisture-proof resealable pouch and container
US5704480A (en) * 1992-10-21 1998-01-06 Minnesota Mining And Manufacturing Company Moisture-proof resealable pouch and container
US5505305A (en) * 1992-10-21 1996-04-09 Minnesota Mining And Manufacturing Company Moisture-proof resealable pouch and container
US5525145A (en) * 1993-12-17 1996-06-11 Hodge; Joseph Filtering apparatus for a forced air duct grill
US5523549A (en) * 1994-05-25 1996-06-04 Ceramic Powders, Inc. Ferrite compositions for use in a microwave oven
US5665819A (en) * 1994-05-25 1997-09-09 Ceramic Powders, Inc. Ferrite compositions for use in a microwave oven
US6468678B1 (en) 1994-11-17 2002-10-22 3M Innovative Properties Company Conformable magnetic articles for use with traffic bearing surfaces methods of making same systems including same and methods of use
US5853846A (en) * 1995-10-18 1998-12-29 Minnesota Mining And Manufacturing Company Conformable magnetic articles underlaid beneath traffic-bearing surfaces
US5690719A (en) * 1995-10-19 1997-11-25 Hodge; Joseph Removable filter for a forced air duct grill
US5764060A (en) * 1996-03-11 1998-06-09 Minnesota Mining And Manufacturing Company Guidance system for a moving person
US5917326A (en) * 1996-03-11 1999-06-29 Minnesota Mining And Manufacturing Company Guidance system for a moving person
US6332862B1 (en) 1999-12-21 2001-12-25 Michael Zandman Articles of clothing incorporating magnets for therapeutic purposes
US6592959B2 (en) 2000-09-04 2003-07-15 Uchiyama Manufacturing Corp. Encoder made of rubber material and method of manufacturing thereof
EP1184668A2 (en) * 2000-09-04 2002-03-06 Uchiyama Manufacturing Corp. Encoder made of rubber material and method of manufacturing thereof
EP1184668A3 (en) * 2000-09-04 2003-03-26 Uchiyama Manufacturing Corp. Encoder made of rubber material and method of manufacturing thereof
US20040087983A1 (en) * 2002-09-04 2004-05-06 Yencho Stephen A. Medical device having magnetic properties
US7001402B2 (en) * 2002-09-04 2006-02-21 Cardica, Inc. Medical device having magnetic properties
US20040251652A1 (en) * 2003-06-10 2004-12-16 Hutchinson Method of fabricating a magnetic coder device, and the device obtained thereby
US7452492B2 (en) * 2003-06-10 2008-11-18 Hutchinson Method of fabricating a magnetic coder device, and the device obtained thereby
US7691468B2 (en) * 2003-07-03 2010-04-06 Sicpa Holding S.A. Method and means for producing a magnetically induced design in a coating containing magnetic particles
US20060150854A1 (en) * 2003-07-03 2006-07-13 Spica Holding S.A. Method and means for producing a magnetically induced design in a coating containing magnetic particles
US20060073774A1 (en) * 2004-09-29 2006-04-06 Chien-Min Sung CMP pad dresser with oriented particles and associated methods
US20090186561A1 (en) * 2004-09-29 2009-07-23 Chien-Min Sung CMP Pad Dresser with Oriented Particles and Associated Methods
US7491116B2 (en) 2004-09-29 2009-02-17 Chien-Min Sung CMP pad dresser with oriented particles and associated methods
US8043145B2 (en) 2004-09-29 2011-10-25 Chien-Min Sung CMP pad dresser with oriented particles and associated methods
US8298048B2 (en) 2004-09-29 2012-10-30 Chien-Min Sung CMP pad dresser with oriented particles and associated methods
WO2012028253A1 (de) * 2010-09-01 2012-03-08 Hydac Filtertechnik Gmbh Bauteil für eine filtereinheit zur filtration von fluiden und verfahren zur herstellung eines derartigen bauteils
US8893955B2 (en) 2010-10-27 2014-11-25 Intercontinental Great Brands Llc Releasably closable product accommodating package
WO2014004595A2 (en) * 2012-06-29 2014-01-03 General Electric Company Nanocomposite permanent magnets and methods of making the same
WO2014004595A3 (en) * 2012-06-29 2014-05-15 General Electric Company Nanocomposite permanent magnets and methods of making the same
US9373433B2 (en) 2012-06-29 2016-06-21 General Electric Company Nanocomposite permanent magnets and methods of making the same
US20150174730A1 (en) * 2013-12-20 2015-06-25 Kinik Company Low Magnetic Chemical Mechanical Polishing Conditioner
US9475171B2 (en) * 2013-12-20 2016-10-25 Kinik Company Low magnetic chemical mechanical polishing conditioner
US20170275056A1 (en) * 2016-03-28 2017-09-28 Magnetnotes, Ltd. Magnetic locking reclosure for packages and methods of making the same

Also Published As

Publication number Publication date
DE1302093B (de) 1969-12-18
NL112334C (nl) 1966-01-17
CH398822A (de) 1966-03-15
DE1302093C2 (de) 1977-04-14

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