JP2006501034A - Zirconia base blade and foil for leather and method for producing the same - Google Patents

Abstract

  A stabilized or partially stabilized zirconia paste can be screen printed onto a hydrophilic film in the form of a mesh. Upon firing, this becomes a very sharp foil (10, 110, 210, 310) for electrical leather with excellent wear resistance. Stabilized or partially stabilized zirconia is also screen printed onto a wettable plastic film and then fired to produce a low cost razor blade with excellent edges. A curved razor blade (310), which incorporates an array of holes (312) each having a knife edge periphery (324), provides greater cutting force and greater skin surface accommodation than single and double edges. .

Description

  The present invention relates generally to leather blades and foils, and more particularly to leather zirconia base blades and foils, and methods of making the same.

  This application is based on British Provisional Application No. 02272712.2 filed on October 1, 2002 entitled “Zirconia Leather Blade”, and United Kingdom Provisional Application filed on October 10, 2002 entitled “Ceramic Leather Blade” No. 0223567.9, UK Provisional Application No. 0233882.2 filed Oct. 16, 2002, entitled “Perforated Leather Blade”, the disclosures of which are incorporated herein by reference.

  Electric leather with a cutting foil and wet shaving leather with a cutting blade have been used for many years. For electric leather, it has a perforated foil and cutter. The foil is usually electrocast from nickel, which gives a very sharp edge but has insufficient hardness. Electrical leather foil is usually manufactured by electroforming nickel. This is a relatively expensive process and the hardness of the resulting nickel cutting edge is not very high.

  With respect to wet shaving leather, leather blades traditionally have a straight cutting edge extending along the length of the laser head. Safety leather has a guard to adjust the position of the skin with respect to the cutting edge, so that the cutting edge moves across the skin and cuts the protruding hair. Such leather blades are traditionally manufactured from high quality carbon steel. Innovations using stainless steel involve the difficulty of forming and retaining very sharp edges. The ground ceramic leather blades are not round but tend to have an irregular microstructure, so they dig into the skin rather than slip on the skin.

  The main object of the present invention is therefore to provide zirconia base blades and foils and methods for their production which overcome the above-mentioned drawbacks of conventional leathers.

  The present invention includes a method of manufacturing a foil for electrical leather. Prepare a substrate containing a flammable surface. Zirconia-based ink is used to create a foil plan form on a flammable surface such that ink flow under surface tension creates a sharp edge in the foil. The foil plan foam is fired to burn away the flammable surface so that the zirconia forms a durable foil that maintains sharpness over repeated use. The zirconia-based ink can include partially stabilized or fully stabilized zirconia. Printing of foil plan forms can be accomplished by screen printing or vacuum forming. For example, the flammable surface includes a highly surface finished plastic film and is preferably hydrophilic.

  The present invention also includes a method of making a wet shaving leather blade. Prepare a substrate containing a flammable surface. A zirconia base ink is formed on the flammable surface such that the ink slightly wets the substrate and the edges of the ink to form a plurality of sharp, pointed meniscuses that serve as cutting surfaces. The ink is baked to burn away the flammable surface and hardened to a rounded sharp edge on a plurality of meniscuses. Preferably, the sharp edge of the meniscus has a radius of about 50 nm or less.

  The present invention further includes a blade for wet shaving leather that is bidirectional and includes a substrate that is curved along the direction of movement of the blade to follow the contours of the user's skin. The blade substrate defines a plurality of holes each having a peripheral edge. The leading part of the hole in the direction of blade movement serves as a guard, and the trailing part of the hole serves as a cutting edge. Preferably, the substrate comprises partially stabilized or fully stabilized zirconia. The holes are arranged in an array evenly or zigzag. The shape of the hole may be, for example, a rectangle or a rhombus.

  According to the invention, the electric leather foil can be made of zirconia ceramics. Zirconia may be partially or fully stabilized. The foil can be produced by screen printing a foil plan form on a hydrophilic surface with zirconia based ink so that the ink flow under surface tension produces a very sharp edge in the ceramic foil. The planar hydrophilic surface can be flammable and therefore disappears during firing. The surface is preferably a plastic film with a good surface finish. The foil network can be biaxially spread to follow the skin. The cutter may also be in the form of a zirconia foil. Zirconia printing and plastic films are formed before firing. Vacuum formation may be appropriate. Appropriate binders and plasticizers in the zirconia ink prevent cracking of the ceramic print during the forming process.

  Partially stabilized zirconia has the hardness and toughness of tool steel. It has excellent wear resistance and gets very sharp edges. It is very expensive, but the amount in the leather foil is negligible and can be manufactured cheaper than electroforming.

  The leather foil pattern can be precisely screen printed on a plastic film using zirconia ink. If the film is slightly hydrophilic, it can be constructed by adjusting the ink properties so that the edges of the print can move slightly under the influence of surface tension to give a very sharp edge. Even low-cost plastic films may have a surface finish that approaches optical quality, and zirconia printing accurately reproduces this.

  The printed plastic film can be fired in a conventional manner. Plastic is burned away at low temperatures, and zirconia forms very thin foils that are extremely tough. It maintains its sharpness for a long time.

  The foil pattern is printed in a way that allows the biaxial spread to follow the skin contour. Cutters in foil foam can also be manufactured to follow the outer foil and provide a flexible cutting surface.

  If desired, the printed plastic can be vacuum formed. This allows the formation of a cutter that raises the contour used in current multi-head shavers. The foam can also be utilized to help maintain dimensional stability during the firing process.

  Furthermore, according to the present invention, the razor blade can be manufactured from a ceramic ink that is screen printed onto a flammable surface and then fired. The ceramic is preferably stabilized or partially stabilized zirconia. The combustible surface is preferably a highly surface finished plastic film. Ink excipients and flammable surfaces can be selected such that the ink wets the flammable surface.

  Stabilized zirconia forms a very good cutting blade. It is very strong, tough and hard. For thin sheets it is very flexible. It has been found to be an excellent medium for making leather blades. The raw material is very expensive compared to steel and is expensive for a diamond processing machine. Cutting edges in zirconia are traditionally produced by a diamond machine, but this process forms fine, irregular edges that tend to dig into the skin rather than slip on the skin. Of course, this is terrible for leather blades.

  Ceramic ink screen printing is a known mass production technique in hybrid electronics. This creates a very finely tuned thin film at a very low cost. The ink contains fine powder ceramics in a binder and a solvent. The ink composition can be selected to slightly wet the substrate and print flow edges to form a sharply pointed meniscus. Upon firing, the substrate disappears and the meniscus forms a very sharp edge. In the firing process, fine powder particles are sintered into a solid mass. This process can be used to form an edge on a finely rounded blade. In recent milling processes, the particle size of the powder can be tens of nanometers. Thus, firing can be performed to produce a blade having an edge radius of about 50 nanometers or less.

  Ceramics has a substrate surface finish on the printing side so that it can approach the optical quality for many plastic films. If this is the side facing the skin, a very smooth blade results. Screen printing produces very thin layers with excellent reproducibility. A thin zirconia blade of about 0.025 mm can be realized. By using a thin blade with the smallest width, an inexpensive blade cost can be realized.

  This manufacturing technique offers the advantage of a large sized mass that results in low raw material costs and without a finishing process.

  Further in accordance with the present invention, a metal or ceramic razor blade can be bent to define a plurality of holes or slots, some or all of which incorporate cutting edges at some or all of their perimeters. For example, with reference to FIG. 1A, a razor blade is generally indicated by reference numeral 10. The blade 10 defines a plurality of holes or rectangular slots 12, which preferably form an array. As shown in FIG. 1A, the array of slots 12 includes five stages 14, 16, 18, 20, 22. However, the array may include fewer or more stages than those shown without departing from the scope of the present invention. The peripheral edge of the slot 12 serves as a cutting edge that is tightly protected within the slot. As a result, the blade edges no longer require close protection.

  With respect to the direction of movement of the blade during the shaving operation indicated by arrow A, the longer edges of the rectangular slot 12 are the trailing edge 24 and the leading edge 26. The blade 10 further defines interconnecting the spokes 28 between the shorter edges 30 of the rectangular slot 12 to enhance the rigidity of the blade. The peripheral edge 32 of the blade 10 can be used to hold the blade in leather.

  The leading edge 26 serves as a guard, and the trailing edge 24 serves as a cutting edge. However, the blade 10 may be used in the opposite direction as indicated by arrow A. When used in such an opposite direction, edge 24 is a leading edge that serves as a guard and edge 26 is a trailing edge that serves as a cutting edge.

  Turning to FIG. 1B, a blade according to another embodiment of the present invention is indicated generally by the reference numeral 110. The same components as shown in FIG. 1A are indicated with the same reference numbers preceded by “1”. The blade 110 defines a plurality of holes or zigzag rectangular slots that form an array. As shown in FIG. 1B, the array of slots 112 includes five stages 114, 116, 118, 120, 122. Slots in adjacent steps are aligned in a zigzag relationship with each other to provide a consistent cutting surface along the direction of the blade across the surface along the direction of motion.

  As in the previous embodiment, the peripheral edge of the slot 112 serves as a cutting edge. With respect to the direction of blade movement during the shaving operation indicated by arrow A, the longer edges of the rectangular slot 112 are the trailing edge 124 and the leading edge 126. The blade 110 further defines an interconnect spoke 128 between the shorter edges 130 of the rectangular slot 112 to enhance the rigidity of the blade. The periphery 132 of the blade 110 can be used to hold the blade in leather.

  The leading edge 126 serves as a guard, and the trailing edge 124 serves as a cutting edge. However, the blade 110 may be used in the opposite direction indicated by arrow A. When used in such an opposite direction, edge 124 is a leading edge that serves as a guard and edge 126 is a trailing edge that serves as a cutting edge.

  Turning to FIG. 1C, a blade according to a further embodiment of the invention is indicated generally by the reference numeral 210. The same components as those shown in the previous embodiment are indicated with the same reference numbers preceded by “2”. The blade 210 defines a plurality of holes or zigzag diamond-shaped slots 212 that form an array. The blade 210 also preferably defines a partial or semi-diamond slot 213 at the end of the array to provide a cutting surface that is evenly distributed between the sides of the blade. As shown in FIG. 1C, the array of slots 212 includes five stages 214, 216, 218, 220, 222. Slots in adjacent steps are aligned in a zigzag relationship with each other to provide a consistent cutting surface along the direction of the blade across the surface along the direction of motion.

  Similar to the previous embodiment, the peripheral edge of the slot 212 serves as a cutting edge. With respect to the direction of blade movement during the shaving operation indicated by arrow A, the diamond-shaped slot 212 includes trailing edges 224 and 225 and leading edges 226 and 227, respectively. The periphery 232 of the blade 210 can be used to hold the blade in leather.

  The leading edges 226 and 227 serve as guards, and the trailing edges 224 and 225 serve as cutting edges. However, the blade 210 may be used in a direction opposite to the direction indicated by arrow A. When used in such an opposite direction, edges 224 and 225 are leading edges that serve as guards and edges 226 and 227 are trailing edges that serve as cutting edges.

With reference to FIG. 2, a blade according to the present invention may have a generally curved surface so that blades of various angles are exposed to the skin. The curved blade 310 defines an array of holes or slots 312 that contact the user's skin 313 during a shaving operation. As shown in FIG. 2, the array of slots 312 includes five stages 314, 316, 318, 320, and 322.
With respect to the direction of blade movement during the shaving operation indicated by arrow A, the bristles 323 shown are cut by the trailing or cutting edge 324 of one hole 312. The curvature and flexibility of the blade 310 can be predetermined to provide maximum performance for following the skin profile. Several cutting edges 324 may be in contact with the skin at the same time. The leading edge 326 of the hole or slot 312 adjusts the approach of the skin 313 to the cutting edge 324 of the hole 312. The blade can be made of metal by electroforming or by grinding a recess into a flat shim. The blade can also be formed by screen printing ceramic ink as an array of holes, followed by firing the print. The rheology of the ink may be predetermined so that the flow around the wet print can form a meniscus that becomes a polished leather edge during firing. The ceramic is preferably a partially stabilized or fully stabilized zirconia ceramic. Ceramics may also be ground or polished after firing if desired.

  Leather blades have traditionally straight cutting edges. An array of holes according to the present invention with cutting edges at the periphery provides a longer cutting edge per square millimeter of blade and provides a tighter adjustment of the angle at which the skin strikes the blade. This results in faster and closer shaving while reducing the chance of hurting the skin.

  In a metal blade, such an array can be formed by electroforming. Electroforming is relatively expensive for disposable blades, but nickel, the only real metal for this technology, is not exceptionally difficult. Alternatively, an array of indentations is formed in a planar metal shim, and then the raised bumps are ground to form a hole surrounded by a cutting edge.

  A better method is to screen print the blade pattern with a partially stabilized zirconia ink. If the rheology of the ink and the nature of the substrate are carefully chosen, the printing edges will flow to form a wet meniscus. Upon firing, the meniscus naturally produces a polished leather edge.

  As will be appreciated by those skilled in the art, various modifications and alternatives may be made to the above-described embodiments of the present invention without departing from the scope of the present invention. Accordingly, the foregoing portion of the specification is to be taken by way of example for limited recognition.

FIG. 1A is a plan view of a razor blade substrate according to the present invention that defines an array of rectangular slots that serve as cutting edges. FIG. 1B is a plan view of a razor blade substrate according to another embodiment of the present invention that defines an array of zigzag rectangular slots that serve as cutting edges. FIG. 1C is a plan view of a razor blade substrate according to yet another embodiment of the present invention that defines an array of diamond shaped slots that serve as cutting edges. 2 is an elevational and cross-sectional view of the razor blade of FIG. 1 showing the curved outer shape of the blade in contact with the user's skin.

Claims (23)

A method of manufacturing a foil for electric leather,
Providing a substrate including a flammable surface;
Forming a foil plan foam on the flammable surface using the zirconia base ink such that a flow of the zirconia base ink under surface tension produces a sharp edge of the foil;
Firing the foil plan foam to burn off the flammable surface so that the zirconia forms a durable foil that maintains sharpness with repeated use;
Having a method.   The method of claim 1, wherein the forming step comprises screen printing the foil plan form on the combustible surface.   The method of claim 1, wherein the forming step vacuum forms the foil planform on the combustible surface.   The method of claim 1, wherein the zirconia base ink comprises partially stabilized zirconia.   The method of claim 1, wherein the zirconia-based ink comprises fully stabilized zirconia.   The method of claim 1, wherein the combustible surface is hydrophilic.   The method of claim 1 wherein the combustible surface is a highly surface finished plastic film. A method of manufacturing a blade for wet shaving leather,
Providing a substrate including a flammable surface;
Applying the ink on the flammable surface such that the zirconia base ink slightly wets the substrate and the edge of the ink to form a plurality of sharply pointed meniscuses that serve as cutting surfaces;
Firing the ink to burn off the flammable surface and curing rounded sharp edges on the plurality of meniscuses;
Having a method.   The method of claim 8, wherein the forming step comprises screen printing the zirconia base ink on the combustible surface.   The method of claim 8, wherein the zirconia base ink comprises partially stabilized zirconia.   The method of claim 8, wherein the zirconia-based ink comprises fully stabilized zirconia.   The method of claim 8, wherein the combustible surface is hydrophilic.   9. The method of claim 8, wherein the flammable surface is a highly surface finished plastic film.   9. The method of claim 8, wherein the sharp edge of the meniscus has an edge radius of about 50 nanometers or less. A substrate that is curved along the direction of movement of the blade to follow the contour of the user's skin, wherein the blade substrate defines a plurality of holes each having a peripheral edge;
Acting as a guard, leading part of the hole in the direction of movement of the blade,
A trailing portion of the hole serving as a cutting edge;
A blade for wet shaving leather.   The blade for wet shaving leather according to claim 15, wherein the substrate contains zirconia.   The blade for wet shaving leather according to claim 16, wherein the zirconia is partially stabilized.   The blade for wet shaving leather according to claim 16, wherein the zirconia is sufficiently stabilized.   The blade for wet shaving leather according to claim 15, wherein each of the holes is generally rectangular.   16. A blade for wet shaving leather according to claim 15, wherein each said hole is generally diamond-shaped or partially diamond-shaped.   The blade for wet shaving leather according to claim 15, wherein the holes defined by the substrate are arranged in an array.   The blade for wet shaving leather according to claim 21, wherein the array includes steps along the direction of movement of the blades and adjacent steps are zigzag to each other. The portion of the hole that serves as a guard becomes the portion of the hole that serves as a cutting edge when the direction of movement of the blade is reversed, and the portion of the hole that serves as a cutting edge The blade for wet shaving leather according to claim 15, which becomes a portion of the hole that serves as a guard when the direction of movement of the blade is reversed.

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