CO4750687A1 - Metodo y aparato para fabricar herramientas abrasivas - Google Patents

Metodo y aparato para fabricar herramientas abrasivas

Info

Publication number
CO4750687A1
CO4750687A1 CO97049948A CO97049948A CO4750687A1 CO 4750687 A1 CO4750687 A1 CO 4750687A1 CO 97049948 A CO97049948 A CO 97049948A CO 97049948 A CO97049948 A CO 97049948A CO 4750687 A1 CO4750687 A1 CO 4750687A1
Authority
CO
Colombia
Prior art keywords
fiber
zag
parallel
uniform
weft
Prior art date
Application number
CO97049948A
Other languages
English (en)
Inventor
Nicolas Avril
Jane L Cercena
Elinor B Keil
David G Lund
Karen M Conley
L Salek Bethany
Original Assignee
Norton Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Norton Co filed Critical Norton Co
Publication of CO4750687A1 publication Critical patent/CO4750687A1/es

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
    • B29C53/56—Winding and joining, e.g. winding spirally
    • B29C53/564—Winding and joining, e.g. winding spirally for making non-tubular articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D18/00—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
    • B24D18/0081—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for of wire-reinforced grinding tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/06—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental
    • B24D5/08—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental with reinforcing means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/12—Cut-off wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/02—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising combinations of reinforcements, e.g. non-specified reinforcements, fibrous reinforcing inserts and fillers, e.g. particulate fillers, incorporated in matrix material, forming one or more layers and with or without non-reinforced or non-filled layers
    • B29C70/021—Combinations of fibrous reinforcement and non-fibrous material
    • B29C70/025—Combinations of fibrous reinforcement and non-fibrous material with particular filler
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
    • D04H3/04—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments in rectilinear paths, e.g. crossing at right angles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
    • B29K2105/10—Cords, strands or rovings, e.g. oriented cords, strands or rovings
    • B29K2105/101—Oriented
    • B29K2105/108—Oriented arranged in parallel planes and crossing at substantial angles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/736—Grinding or polishing equipment
    • 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
    • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
    • Y10T156/10—Methods of surface bonding and/or assembly therefor
    • Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Manufacturing & Machinery (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Mechanical Treatment Of Semiconductor (AREA)

Abstract

Un método para fabricar una rueda abrasiva delgada utilizandoun disco de refuerzo de fibra tramada al azar uniforme, que comprende las etapas de: a) extraer una primera porción de una fibra de una pluralidad de medios de soporte para crear una primera disposición de fibra paralela en zig-zag teniendo una periferia-circular; b) extraer por lo menos una porción adicional de la fibra en la pluralidad de medios de soporte en una dirección desde aproximadamente 45° aproximadamente 134° relativa a la primera disposición de fibras paralela en zing-zag para crear por lo menos una disposición de fibra paralela en zig-zag adicional teniendo una periferia circular, y formando así un disco de refuerzo comprendiendo una disposición de fibra tramada al azar uniforme; c) añadir por lo menos una capa de una mezcla de componentes de adhesivo orgánico y granos abrasivos a por lo menos un disco de refuerzo para formar un laminado uniforme; moldear el laminado uniforme bajo presión para formar una rueda abrasiva delgada reforzada de fibra tramada al azar; y curar la rueda abrasiva delgada reforzada de fibra tramada al azar.
CO97049948A 1996-08-30 1997-08-28 Metodo y aparato para fabricar herramientas abrasivas CO4750687A1 (es)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/706,085 US5913994A (en) 1996-08-30 1996-08-30 Method for fabricating abrasive discs

Publications (1)

Publication Number Publication Date
CO4750687A1 true CO4750687A1 (es) 1999-03-31

Family

ID=24836168

Family Applications (1)

Application Number Title Priority Date Filing Date
CO97049948A CO4750687A1 (es) 1996-08-30 1997-08-28 Metodo y aparato para fabricar herramientas abrasivas

Country Status (22)

Country Link
US (3) US5913994A (es)
EP (1) EP0923428B1 (es)
JP (2) JP3556675B2 (es)
KR (1) KR100312672B1 (es)
CN (1) CN1066379C (es)
AR (1) AR009343A1 (es)
AT (1) ATE226871T1 (es)
AU (1) AU712146B2 (es)
BR (1) BR9713183A (es)
CA (1) CA2260096C (es)
CO (1) CO4750687A1 (es)
DE (1) DE69716751T2 (es)
DK (1) DK0923428T3 (es)
ES (1) ES2185989T3 (es)
NO (1) NO990954L (es)
PL (1) PL185308B1 (es)
PT (1) PT923428E (es)
RU (1) RU2162790C2 (es)
SK (1) SK285011B6 (es)
TW (1) TW375557B (es)
WO (1) WO1998008655A1 (es)
ZA (1) ZA977369B (es)

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW550141B (en) * 1999-07-29 2003-09-01 Saint Gobain Abrasives Inc Depressed center abrasive wheel assembly and abrasive wheel assembly
FR2843758B1 (fr) * 2002-08-22 2005-03-11 Eads Launch Vehicles Procede pour la realisation d'une preforme textile multidirectionnelle et piece en materiau composite incorporant ladite preforme
US20060288993A1 (en) * 2005-06-27 2006-12-28 Anthony Baratta Tools and methods for making and using tools, blades and methods of making and using blades
US8151783B2 (en) * 2005-06-27 2012-04-10 Husqvarna Outdoor Products Inc. Tools and methods for making and using tools, blades and methods of making and using blades
US20060288992A1 (en) * 2005-06-27 2006-12-28 Anthony Baratta Tools and methods for making and using tools, blades and methods of making and using blades
ES2320944A1 (es) * 2005-12-02 2009-05-29 Fpk, S.A. Pieza composite reforzada por una parte de fibra realizable mediante diversos procesos de bobinado o aplicacion directa de filamentos unidireccionales de fibra, y sus metodos de fabricacion.
KR100764035B1 (ko) * 2005-12-23 2007-10-09 동영다이아몬드공업(주) 석재 가공용 연마구의 제조방법
EP1849588B1 (en) * 2006-04-27 2011-06-01 AKsys GmbH Method of manufacture of a composite part
US7869896B2 (en) * 2006-08-24 2011-01-11 Jtekt Corporation Tangential grinding resistance measuring method and apparatus, and applications thereof to grinding condition decision and wheel life judgment
US8808412B2 (en) * 2006-09-15 2014-08-19 Saint-Gobain Abrasives, Inc. Microfiber reinforcement for abrasive tools
DE102008011517A1 (de) * 2008-03-02 2009-09-03 Schottdorf, Bernd, Dr. Verfahren, Vorrichtung und Stützstruktur sowie deren Verwendung zur Herstellung eines Faserverbundteils
US8641481B2 (en) * 2008-12-30 2014-02-04 Saint-Gobain Abrasives, Inc. Reinforced bonded abrasive tools
EP2177318B1 (en) * 2009-04-30 2014-03-26 Saint-Gobain Abrasives, Inc. Abrasive article with improved grain retention and performance
CN102548714B (zh) * 2009-08-03 2015-04-29 圣戈班磨料磨具有限公司 具有特殊孔隙率变化的研磨工具
EP2461943B1 (en) * 2009-08-03 2018-10-03 Saint-Gobain Abrasives, Inc. Abrasive tool having controlled porosity distribution
FR2954723B1 (fr) * 2009-12-29 2012-04-20 Saint Gobain Abrasives Inc Article abrasif comprenant un espace creux entre ses faces avant et arriere, et procede de fabrication
DE102012101721B4 (de) * 2012-03-01 2017-11-02 Benteler Automobiltechnik Gmbh Verwendung eines Wickelrahmens zur Herstellung eines Faserverbundwerkstoffbauteils
DE102012101724B4 (de) * 2012-03-01 2017-02-23 Benteler Automobiltechnik Gmbh Faserwerkstoffrohling zur Herstellung eines Faserwerkstoffverbundbauteils
DE102012101726B4 (de) * 2012-03-01 2016-11-10 Benteler Automobiltechnik Gmbh Verfahren zur Herstellung eines Faserwerkstoffrohlings
RU2497652C1 (ru) * 2012-04-16 2013-11-10 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Самарский государственный технический университет" Способ упрочнения абразивных кругов
DE102013110186B4 (de) * 2013-09-16 2016-11-03 Benteler Automobiltechnik Gmbh Vorrichtung und Verfahren zur Herstellung eines Faserhalbzeuges
US20160257081A1 (en) * 2013-10-31 2016-09-08 United Technologies Corporation A method for selective placement of reinforcing fibers in polymeric components
DE102015103161B4 (de) 2015-03-04 2017-04-20 Benteler Automobiltechnik Gmbh Faserwickelanlage sowie Verfahren zur Herstellung eines Faserwerkstoffrohlings
DE102016208232A1 (de) * 2016-05-12 2017-11-16 Airbus Operations Gmbh Verfahren und Vorrichtung zur Herstellung eines Halbzeugs
US10773469B2 (en) * 2017-02-21 2020-09-15 Seriforge Inc. Systems and methods of converting fiber into shaped fabric plies for composite preforms and products
EP3470557A1 (de) * 2017-10-12 2019-04-17 Lenzing Aktiengesellschaft Spinnvorrichtung und verfahren zum anspinnen einer spinnvorrichtung

Family Cites Families (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3116986A (en) * 1960-03-25 1964-01-07 Cincinnati Milling Machine Co Method of making cold-molded abrasive wheel
US3146560A (en) * 1960-06-14 1964-09-01 Rexall Drug Chemical Abrasive products
US3121981A (en) * 1960-09-23 1964-02-25 Rexall Drug Chemical Abrasive wheels and method of making the same
DE1291648B (de) * 1962-12-04 1969-03-27 Itt Ind Gmbh Deutsche Schleifscheibe mit Verstaerkungsgeflecht
US3262230A (en) * 1964-02-10 1966-07-26 Norton Co Reinforcement of molded abrasive articles
US3477180A (en) * 1965-06-14 1969-11-11 Norton Co Reinforced grinding wheels and reinforcement network therefor
US3425884A (en) * 1967-11-06 1969-02-04 Crompton & Knowles Corp Method of making an open mesh,rigid,glass fiber reinforced resin structure
US3686048A (en) * 1969-10-14 1972-08-22 Air Logistics Corp Fiber reinforced parallel resinous structure fabrication
US3645833A (en) * 1970-05-20 1972-02-29 Us Army Article and method of quasi-isotropic core filaments
US3838543A (en) * 1970-05-25 1974-10-01 Norton Co High speed cut-off wheel
US3755054A (en) * 1971-07-19 1973-08-28 J Medney Resin bonded glass fiber fence
US3772126A (en) * 1971-10-21 1973-11-13 M & M Intern Plastics Inc Apparatus and method for making fiberglass grating
US3793783A (en) * 1972-10-02 1974-02-26 Norton Co Segmental cut-off grinding wheel
US4021209A (en) * 1975-07-23 1977-05-03 Federal-Mogul Corporation Aramid fiber reinforced abrasive wheel
JPS5632293Y2 (es) * 1976-09-13 1981-07-31
AT355448B (de) * 1977-09-23 1980-03-10 Swarovski Tyrolit Schleif Verfahren zum impraegnieren von armierungs- fasern, armierungsgeweben, vliesen od.dgl.
US4230461A (en) * 1977-09-29 1980-10-28 Eli Sandman Company Abrasive wheels
FR2432364A1 (fr) * 1978-08-04 1980-02-29 Swarovski Tyrolit Schleif Meule comportant des grains abrasifs, un agglomerant et des fibres a haute resistance
US4259089A (en) * 1978-08-10 1981-03-31 Tyrolit Schleifmittelwerke Swarovski K.G. Grinding wheel containing grain-coated reinforcement fibers and method of making it
DE2942217A1 (de) * 1978-10-18 1980-04-30 Daichiku Co Ltd Hochgeschwindigkeitsschleifstein und verfahren zu seiner herstellung
US4253850A (en) * 1979-08-17 1981-03-03 Norton Company Resin bonded abrasive bodies for snagging metal containing low abrasive and high filler content
DE3003666A1 (de) * 1980-02-01 1981-08-06 Richard 4937 Lage Pott Gelege zur herstellung einer verstaerkung von im wesentlichen aus flaechen bestehenden bauteilen und eine vorrichtung zur herstellung desselben
US4350497A (en) * 1980-09-08 1982-09-21 Abraham Ogman Reinforced grinding device
US4800685A (en) * 1984-05-31 1989-01-31 Minnesota Mining And Manufacturing Company Alumina bonded abrasive for cast iron
DE3404871A1 (de) * 1983-02-14 1984-08-23 Rands, Mary, Los Angeles, Calif. Schleif-, hon- oder abreibkoerper
US4657563A (en) * 1985-10-31 1987-04-14 Norton Company Resin bonded grinding wheels with fillers
US4715150A (en) * 1986-04-29 1987-12-29 Seiken Co., Ltd. Nonwoven fiber abrasive disk
US5015540A (en) * 1987-06-01 1991-05-14 General Electric Company Fiber-containing composite
US4989375A (en) * 1988-05-28 1991-02-05 Noritake Co., Limited Grinding wheel having high impact resistance, for grinding rolls as installed in place
DE3819199A1 (de) * 1988-06-06 1989-12-07 Leurop Leutheusser Kg Verfahren zur herstellung von glasfaserronden fuer schleif- oder trennscheiben und vorrichtung zur durchfuehrung des verfahrens
GB8822520D0 (en) * 1988-09-26 1988-11-02 Tech Textiles Ltd Process for continuously forming reinforced plastics articles
GB9008293D0 (en) * 1990-04-11 1990-06-13 Ferodo Ltd Fabrication of friction elements
DE4234083A1 (de) * 1992-10-09 1994-04-14 Olbo Textilwerke Gmbh Verfahren und Vorrichtung zum Legen von Fäden
US5431596A (en) * 1993-04-28 1995-07-11 Akita; Hiroshi Grinding wheel and a method for manufacturing the same
ATE169266T1 (de) * 1994-10-18 1998-08-15 Leurop Leutheusser Kg Schleifm Verfahren und vorrichtung zur kontinuierlichen herstellung von glasfaserronden für schleif- und trennscheiben
DE19549078C2 (de) * 1995-12-29 2000-06-29 Gerd Muennekehoff Verfahren und Vorrichtung zum Herstellen von gitternetzartigen Fadengelegen

Also Published As

Publication number Publication date
PL185308B1 (pl) 2003-04-30
PT923428E (pt) 2003-03-31
JP2004160657A (ja) 2004-06-10
SK22299A3 (en) 2000-03-13
KR100312672B1 (ko) 2001-11-03
PL331758A1 (en) 1999-08-02
AU712146B2 (en) 1999-10-28
CA2260096C (en) 2003-06-03
US5913994A (en) 1999-06-22
NO990954D0 (no) 1999-02-26
JP3556675B2 (ja) 2004-08-18
AU4157497A (en) 1998-03-19
KR20000029793A (ko) 2000-05-25
DE69716751D1 (de) 2002-12-05
RU2162790C2 (ru) 2001-02-10
ES2185989T3 (es) 2003-05-01
US6162322A (en) 2000-12-19
EP0923428B1 (en) 2002-10-30
CN1066379C (zh) 2001-05-30
DE69716751T2 (de) 2003-07-03
TW375557B (en) 1999-12-01
US6609964B1 (en) 2003-08-26
JP2000503606A (ja) 2000-03-28
EP0923428A1 (en) 1999-06-23
NO990954L (no) 1999-02-26
ATE226871T1 (de) 2002-11-15
WO1998008655A1 (en) 1998-03-05
BR9713183A (pt) 1999-11-03
CA2260096A1 (en) 1998-03-05
AR009343A1 (es) 2000-04-12
DK0923428T3 (da) 2003-03-03
SK285011B6 (sk) 2006-04-06
CN1228728A (zh) 1999-09-15
ZA977369B (en) 1998-02-19

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