EP0884142A1 - Arrête de lame améliorée - Google Patents

Arrête de lame améliorée Download PDF

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Publication number
EP0884142A1
EP0884142A1 EP98304533A EP98304533A EP0884142A1 EP 0884142 A1 EP0884142 A1 EP 0884142A1 EP 98304533 A EP98304533 A EP 98304533A EP 98304533 A EP98304533 A EP 98304533A EP 0884142 A1 EP0884142 A1 EP 0884142A1
Authority
EP
European Patent Office
Prior art keywords
razor blade
coating
blade according
cutting edge
tip
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.)
Withdrawn
Application number
EP98304533A
Other languages
German (de)
English (en)
Inventor
Randy Nicolosi
Brian G. Balistee
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Warner Lambert Co LLC
Original Assignee
Warner Lambert Co LLC
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 Warner Lambert Co LLC filed Critical Warner Lambert Co LLC
Publication of EP0884142A1 publication Critical patent/EP0884142A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
    • B26B21/00—Razors of the open or knife type; Safety razors or other shaving implements of the planing type; Hair-trimming devices involving a razor-blade; Equipment therefor
    • B26B21/54—Razor-blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
    • B26B21/00—Razors of the open or knife type; Safety razors or other shaving implements of the planing type; Hair-trimming devices involving a razor-blade; Equipment therefor
    • B26B21/54—Razor-blades
    • B26B21/58—Razor-blades characterised by the material
    • B26B21/60—Razor-blades characterised by the material by the coating material

Definitions

  • This invention relates to the forming and coating of blade edges to modify the cutting performance of the blade edge.
  • Razor blade manufacturers have over the years attempted various means of improving shave performance.
  • the primary goal of the manufacturers has been to improve shave performance and comfort by reducing the required cut force and increasing the life of the blade edge.
  • efforts at improving shave performance and reducing cut force have focused on providing edges with thinner, and theoretically sharper, edge profiles than prevailing blades. Since the thinner edges are weaker than their thicker counterparts, there have been efforts to simultaneously increase the strength of the edge.
  • cut force one means of reducing cut force is to modify the geometry of the razor blade edge. It has been found that reducing the width of the blade edge for some distance back from the tip will improve shave performance by cut force reduction. However, reduction in the edge width also weakens the edge and leads to more rapid deterioration due to mechanical deformation during cutting.
  • a typical razor blade edge has a wedge shape with a preferred included angle of approximately 20 degrees.
  • This wedge may be further characterized by its tip radius, which is the radius of curvature of the ultimate cutting tip, and the thickness of the edge for a distance back from the ultimate tip.
  • the tip radius is specified as being less than 500 ⁇ .
  • the edge thickness is a function of distance from the ultimate edge.
  • T2 and T10 may be defined as the width of the edge 2 microns and 10 microns back from the ultimate edge respectively.
  • Typical razor blades have T2 values in the range of from 0.85 - 1.1 ⁇ and T10 values in the range of 3.3-4.0 ⁇ .
  • Standard mechanical grinding and honing operations give the edge a bit of a convex shape which has been described as a "gothic arch" shape.
  • Most razor blades have a thin layer of chromium on the cutting edge to increase the blade's corrosion resistance and to provide a good base for the application of a lubricating polymer such as polytetrafluoroethylene (PTFE).
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • a razor blade as set out in Claim 1.
  • a razor blade as set out in Claim 14.
  • Preferred embodiments of the invention are directed to a blade edge with improved shave performance and a method of manufacturing such blades.
  • the tip thickness, tip radius and cut force are increased, either by application of a first, non-polymeric coating or by some other means, and then the blade is coated with a second non-polymeric adherent coating having a very low coefficient of friction.
  • Suitable materials for the second coating include the class of carbon films which include diamond, amorphous diamond, and diamond like carbon (DLC). Another material with a suitably low coefficient of friction is Molybdenum disulfide.
  • the thickness of the coating need only be such that a continuous film, typically less than 500 ⁇ , is formed over the blade edge up to and including the ultimate tip.
  • the aspect ratio of this film is approximately 1: 1; there is no need for the high aspect ratios claimed in previous disclosures.
  • the blade is then coated with a lubricating polymer, such as PTFE, as is standard practice in the industry.
  • PTFE lubricating polymer
  • the resulting blades cut with a significantly lower cut force than comparable blades without the low coefficient of friction film.
  • the blade performs as if the edge were sharper and thinner while retaining the original edge geometry. Because the edge is of at least standard thickness it retains the hardness and durability of a regular edge.
  • a preferred embodiment of the invention emphasizes edge durability.
  • the edge is made thicker than usual via coating or grinding. Normally the thickening would have the effect of increasing the cut force and compromising shave performance, However, the addition of the coating of this invention reduces the cut force to a nominal level thus restoring shave comfort.
  • Such coated blades last significantly longer and provide better shave performance than their uncoated counterparts by virtue of their thicker and stronger edge.
  • the blade edge of the present invention comprises a razor blade having an increased tip thickness and tip radius, a reduced cutting force and a longer usable life.
  • a substrate is provided in which the portion which is to be the cutting edge is prepared with a profile either nominal to or thicker than that of prevailing blades, resulting in increased tip thickness, tip radius, cut force and coefficient of friction.
  • the increased thickness may be achieved in various manners, but a preferred method for achieving this shape is by appropriately grinding or stropping the edge.
  • a further preferred method of producing this shape is by depositing an inner coating of suitable thickness onto the edge of the blade.
  • This coating may consist of virtually any compatible material including oxides, carbides, nitrides, borides, metals and any combinations thereof, preferred materials include ceramics, chromium, chromium/platinum, and chrome nitride.
  • the primary criteria for this coating are that it adheres to the steel substrate and that the coating of this invention adheres to it.
  • a coating of up to 1500 angstroms of chromium is applied to the edge of a ground blade.
  • the actual thickness of the coating may vary depending on a number of variables, including the starting edge shape, and a thicker or thinner coating may be used as desired.
  • the result of the initial thickening step is a blade edge which has increased tip thickness, increased strength, increased tip radius, is less sharp than before and exhibits a correspondingly higher cut force.
  • a thickened blade edge would be less desirable for cutting hair in that it would tend to "pull" the hair and thus prove uncomfortable during wet shaving.
  • the edge is coated with an outer coating of a thin film of a non-polymeric material which has a very low coefficient of friction.
  • the outer coating may be deposited by ion beam sputtering, magnetron sputtering, laser beam ablation, vacuum arc deposition, or any other suitable process.
  • the thickness of this non-polymeric coating is preferably less than about 1500 angstroms and an aspect ratio (tip thickness/flank thickness) of about 1:1 is preferably obtained.
  • the thickness of the non-polymeric coating is in the range of from 100 - 1000 angstroms.
  • a preferred value for the low coefficient of friction is less than about 0.3 and preferably less than 0.2.
  • Preferred materials having such a low coefficient for the thin film coating are amorphous diamond, diamond-like carbon (DLC), molybdenum disulfide, or any other similar material.
  • the preferred thin film coating material is amorphous diamond.
  • Amorphous diamond comprises a nonhydrogenated version of DLC with at least 40% sp3 carbon bonding, a hardness of at least 45 gigapascals and a modulus of at least 400 gigapascals.
  • standard DLC has a hardness of only about 30 gigapascals.
  • the resultant blade edge has a further increased tip radius and tip thickness over the blade edge having no coating or the inner coating alone, and has a cut force which is significantly lower than that of the blade edge having the first coating alone.
  • the blade edge may be further coated with a lubricious polymer to further reduce the cut force. Because this coating has been shown to pull back from the edge the presence of the hard, thin film of low coefficient of friction causes the blade to show a significant reduction in cut force over blades having only chromium or other conventional materials on the edge. This superiority of cut force is evident even over sharper blades using conventional coatings.
  • the blade edge is first coated with a thin film having a low coefficient of friction, such as amorphous diamond, and then with a lubricious polymer such as low molecular weight PTFE or KRYTOX 1000 to provide a shave exhibiting minimal cut force.
  • the resulting razor blade is especially advantageous for use with a wet shave razor, and one or more of such blades may be employed in a razor.
  • the blades may be employed in a wet shave razor which is either disposable, i.e. the entire razor is discarded after a certain amount of usage, or permanent which requires disposal and replacement of only the razor cartridge, but not the handle, after a certain number of uses.
  • a variety of methods are available for depositing the coating of this invention.
  • One method uses pulsed laser deposition to generate a plume of vaporized carbon ions from a solid carbon source. These ions can be directed to the edge of a blade where they will condense as a hard solid film with a suitable low coefficient of friction.
  • Another method is the use of sputtering, either RF or DC, to provide a vapor of carbon atoms which similarly condense onto the blades forming carbon films.
  • the sputtered films are not as hard as coatings prepared by other means but they may be used due to their low coefficient of friction.
  • CVD methods can be utilized, using a gaseous hydrocarbon gas as the source, but these must be done under conditions where the blades do not exceed 350°C for periods of time as this will soften the blade steel.
  • a preferred method of depositing the carbon films is by the cathodic arc method. Such a method is described fully in patent 5,458,754, assigned to Multi Arc Inc. in New Jersey and the disclosure of that patent is incorporated herein by reference. In this method carbon ions are produced with the arc vaporization of a solid graphite target. The patented method described produces amorphous diamond films with a very low coefficient of friction.
  • the blade edge which is coated with chromium has significantly increased strength over the uncoated blade edge.
  • an unused, standard blade edge will be indented to a depth of approximately 650 nanometers by a 4 gram load applied normal to the blade edge.
  • Coating with 300 ⁇ of chromium increases the edge strength as shown by a reduction in indent depth to about 610 nm, while 600 angstroms of chromium coating further reduces the indents to about 595 nm.
  • a 600 angstrom chromium coating in combination with an amorphous diamond coating of 200-300 angstroms significantly reduces the indent range to approximately 540 nm, thus illustrating that the blade of the present invention is significantly stronger than a standard blade.
  • Figure 2 illustrates the cut force of a standard blade, a less sharp blade made according to this invention, and a similar less sharp blade including the amorphous diamond coating. All blades are coated per standard process with PTFE. The standard blade edge exhibits a cut force of 2.64 lb. The less sharp blade exhibits an average cut force of 2.96 lb. The addition of 250 angstroms of amorphous diamond to the less sharp blade results in a cut force of 2.46 lb, a significant reduction over the uncoated blade. Consequently, blades made according to this invention are exceedingly durable and will continue to exhibit advantages over conventional blades for hundreds of cuts.
  • Blade edge 10 includes a substrate 11 coated with a non-polymer inner coating (not shown separately in Figure 3).
  • the material of the coating may be, for example, Chromium to a thickness of 1500 angstroms.
  • the inner coating if applied on its own to the blade edge 10 would increase the tip radius and the cut force characteristic of the blade edge 10 to higher values than those of conventional blade edges.
  • Blade edge 10 also includes an outer coating 12 of a further material having a low coefficient of friction relative to eg. human or animal skin.
  • the outer coating 12 increases the tip radius and tip thickness still further compared with a conventional blade, yet provides for a lower cut force.
  • the outer coating 12 may be of a material as specified herein.
  • the blade edge 10 is preferably manufactured in accordance with the method of the invention.

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  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physical Vapour Deposition (AREA)
  • Dry Shavers And Clippers (AREA)
  • Knives (AREA)
EP98304533A 1997-06-10 1998-06-09 Arrête de lame améliorée Withdrawn EP0884142A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US87244397A 1997-06-10 1997-06-10
US872443 1997-06-10

Publications (1)

Publication Number Publication Date
EP0884142A1 true EP0884142A1 (fr) 1998-12-16

Family

ID=25359586

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98304533A Withdrawn EP0884142A1 (fr) 1997-06-10 1998-06-09 Arrête de lame améliorée

Country Status (4)

Country Link
EP (1) EP0884142A1 (fr)
JP (1) JPH119857A (fr)
AU (1) AU738778B2 (fr)
CA (1) CA2234966A1 (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001064406A3 (fr) * 2000-02-29 2002-02-07 Gillette Co Technologie des lames de rasoir
EP1287953A1 (fr) * 2000-06-05 2003-03-05 KAI R&D CENTER CO., LTD. Lame de coupe et procede de fabrication de cette lame
EP1175973A3 (fr) * 2000-07-28 2003-05-02 Warner-Lambert Company Dispositifs d'enlèvement de cheveux avec plusieurs microlames et procédés pour leur fabrication
WO2004054402A1 (fr) * 2002-12-13 2004-07-01 Eveready Battery Company, Inc. Surface d'epilation progressive
WO2005104964A1 (fr) * 2004-04-16 2005-11-10 Synvasive Technology, Inc. Lame de scie
WO2006138153A1 (fr) * 2005-06-14 2006-12-28 The Gillette Company Lames de rasoir
CN102427918A (zh) * 2009-05-15 2012-04-25 吉列公司 剃刀刀片涂层
WO2013010072A1 (fr) * 2011-07-14 2013-01-17 The Gillette Company Lame de rasoir
WO2013010049A1 (fr) * 2011-07-14 2013-01-17 The Gillette Company Lames de rasoir présentant un important rayon d'extrémité
US9180599B2 (en) 2004-09-08 2015-11-10 Bic-Violex S.A. Method of deposition of a layer on a razor blade edge and razor blade
US11230024B2 (en) 2014-12-22 2022-01-25 Bic-Violex Sa Razor blade
CN115379933A (zh) * 2020-04-16 2022-11-22 吉列有限责任公司 用于剃刀刀片的涂层

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9808944B2 (en) * 2014-06-17 2017-11-07 The Gillette Company Llc Methods of manufacturing silicon blades for shaving razors
EP3616800B1 (fr) * 2018-08-31 2022-11-09 BIC Violex Single Member S.A. Amincissement de revêtements de lame de rasoir

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1984002104A1 (fr) * 1982-11-19 1984-06-07 Glasson Edwin Lloyd Personal R Lames de rasoir
DE3403196A1 (de) * 1984-01-31 1985-08-01 Reinhard Dr. 7101 Flein Dahlberg Spitzen und schneiden mit extremer schaerfe
US4933058A (en) 1986-01-23 1990-06-12 The Gillette Company Formation of hard coatings on cutting edges
US5032243A (en) 1988-09-19 1991-07-16 The Gillette Company Method and apparatus for forming or modifying cutting edges
US5121660A (en) 1990-03-19 1992-06-16 The Gillette Company Razor blade technology
US5142785A (en) 1991-04-26 1992-09-01 The Gillette Company Razor technology
US5232568A (en) 1991-06-24 1993-08-03 The Gillette Company Razor technology
US5295305A (en) 1992-02-13 1994-03-22 The Gillette Company Razor blade technology
US5458754A (en) 1991-04-22 1995-10-17 Multi-Arc Scientific Coatings Plasma enhancement apparatus and method for physical vapor deposition
WO1995029044A1 (fr) * 1994-04-25 1995-11-02 The Gillette Company Revetement de lames au diamant amorphe
US5488774A (en) 1990-01-24 1996-02-06 Janowski; Leonard J. Cutting edges

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1984002104A1 (fr) * 1982-11-19 1984-06-07 Glasson Edwin Lloyd Personal R Lames de rasoir
DE3403196A1 (de) * 1984-01-31 1985-08-01 Reinhard Dr. 7101 Flein Dahlberg Spitzen und schneiden mit extremer schaerfe
US4933058A (en) 1986-01-23 1990-06-12 The Gillette Company Formation of hard coatings on cutting edges
US5032243A (en) 1988-09-19 1991-07-16 The Gillette Company Method and apparatus for forming or modifying cutting edges
US5488774A (en) 1990-01-24 1996-02-06 Janowski; Leonard J. Cutting edges
US5121660A (en) 1990-03-19 1992-06-16 The Gillette Company Razor blade technology
US5458754A (en) 1991-04-22 1995-10-17 Multi-Arc Scientific Coatings Plasma enhancement apparatus and method for physical vapor deposition
US5142785A (en) 1991-04-26 1992-09-01 The Gillette Company Razor technology
US5232568A (en) 1991-06-24 1993-08-03 The Gillette Company Razor technology
US5295305A (en) 1992-02-13 1994-03-22 The Gillette Company Razor blade technology
US5295305B1 (en) 1992-02-13 1996-08-13 Gillette Co Razor blade technology
WO1995029044A1 (fr) * 1994-04-25 1995-11-02 The Gillette Company Revetement de lames au diamant amorphe

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7527628B2 (en) 1991-05-30 2009-05-05 Synvasive Technology, Inc. Surgical saw blade having at least one pair of opposed teeth shaped as right triangles
US7998158B2 (en) 1991-05-30 2011-08-16 Synvasive Technology, Inc. Surgical saw blade having at least one pair of opposed teeth shaped as right triangles
US7901424B2 (en) 1991-05-30 2011-03-08 Synvasive Technology, Inc. Surgical saw blade having at least one pair of opposed teeth shaped as right triangles
US6866894B2 (en) 2000-02-29 2005-03-15 The Gillette Company Razor blade technology
WO2001064406A3 (fr) * 2000-02-29 2002-02-07 Gillette Co Technologie des lames de rasoir
US6684513B1 (en) 2000-02-29 2004-02-03 The Gillette Company Razor blade technology
US7060367B2 (en) 2000-06-05 2006-06-13 Kai R&D Center Co., Ltd. Cutting blade and method of producing the same
EP1287953A4 (fr) * 2000-06-05 2003-10-08 Kai R&D Center Co Ltd Lame de coupe et procede de fabrication de cette lame
EP1287953A1 (fr) * 2000-06-05 2003-03-05 KAI R&D CENTER CO., LTD. Lame de coupe et procede de fabrication de cette lame
EP1175973A3 (fr) * 2000-07-28 2003-05-02 Warner-Lambert Company Dispositifs d'enlèvement de cheveux avec plusieurs microlames et procédés pour leur fabrication
WO2004054402A1 (fr) * 2002-12-13 2004-07-01 Eveready Battery Company, Inc. Surface d'epilation progressive
WO2005104964A1 (fr) * 2004-04-16 2005-11-10 Synvasive Technology, Inc. Lame de scie
EP2011444A3 (fr) * 2004-04-16 2010-02-17 Synvasive Technology, Inc. Lame de scie
US9180599B2 (en) 2004-09-08 2015-11-10 Bic-Violex S.A. Method of deposition of a layer on a razor blade edge and razor blade
WO2006138153A1 (fr) * 2005-06-14 2006-12-28 The Gillette Company Lames de rasoir
CN102427918A (zh) * 2009-05-15 2012-04-25 吉列公司 剃刀刀片涂层
CN102427918B (zh) * 2009-05-15 2015-01-28 吉列公司 剃刀刀片涂层
WO2013010049A1 (fr) * 2011-07-14 2013-01-17 The Gillette Company Lames de rasoir présentant un important rayon d'extrémité
RU2553158C1 (ru) * 2011-07-14 2015-06-10 Дзе Жиллетт Компани Бритвенные лезвия с большим радиусом острия лезвия
RU2567169C2 (ru) * 2011-07-14 2015-11-10 Дзе Жиллетт Компани Бритвенное лезвие
WO2013010072A1 (fr) * 2011-07-14 2013-01-17 The Gillette Company Lame de rasoir
US10549438B2 (en) 2011-07-14 2020-02-04 The Gillette Company Llc Razor blades having a wide facet angle
US11766797B2 (en) 2011-07-14 2023-09-26 The Gillette Company Llc Razor blades having a wide facet angle
US11230024B2 (en) 2014-12-22 2022-01-25 Bic-Violex Sa Razor blade
CN115379933A (zh) * 2020-04-16 2022-11-22 吉列有限责任公司 用于剃刀刀片的涂层

Also Published As

Publication number Publication date
JPH119857A (ja) 1999-01-19
AU6375798A (en) 1998-12-17
CA2234966A1 (fr) 1998-12-10
AU738778B2 (en) 2001-09-27

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