Abstract: The present invention relates to razor blade cutting edges and methods of producing edges exhibiting improved shave performance longevity and lower cutting forces. Conventional razor blades have increasing cutting forces with use due to the outer coating wear and adhesion loss. Blade edges produced according to the novel process exhibit significantly lower cutting forces when subjected to wool felt cutting shaving simulation, which correlates to more comfortable shaves initially and over the life of the blades. The present invention treats razor blade edges having a first adherent polyfluorocarbon coating with a first solvent to partially remove the polyfluorocarbon coating, adds a second polyfluorocarbon coating, heats, and treats the blade edge with a second solvent providing a final blade edge having a thin, uniform polyfluorocarbon coating.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has thicknesses of 1.60-1.75 micrometers and 9.25-10.00 micrometers measured at a distance of four and forty micrometers from the blade tip, respectively. A ratio of the thickness measured at four micrometers to the thickness measured at forty micrometers is between 0.165-0.185. The substrate thickness is about 2.70-3.00 micrometers at eight micrometers from the blade tip, about 4.44-5.00 micrometers at sixteen micrometers from the blade tip with a thickness ratio measured at four micrometers and eight micrometers between 0.56-0.62, and a thickness ratio measured at four micrometers and sixteen micrometers between 0.32-0.40. The blade edge shape is defined by equation w=adn where “a” is between 0.50-0.62 and “n” is between 0.76-0.80. An included angle of less than 7° is measured at a distance of forty micrometers or greater from the blade tip. A nitrided substrate may also be provided.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has thicknesses of 1.60-1.75 micrometers and 9.25-10.00 micrometers measured at a distance of four and forty micrometers from the blade tip, respectively. A ratio of the thickness measured at four micrometers to the thickness measured at forty micrometers is between 0.165-0.185. The substrate thickness is about 2.70-3.00 micrometers at eight micrometers from the blade tip, about 4.44-5.00 micrometers at sixteen micrometers from the blade tip with a thickness ratio measured at four micrometers and eight micrometers between 0.56-0.62, and a thickness ratio measured at four micrometers and sixteen micrometers between 0.32-0.40. The blade edge shape is defined by equation w=adn where “a” is between 0.50-0.62 and “n” is between 0.76-0.80. An included angle of less than 7° is measured at a distance of forty micrometers or greater from the blade tip. A nitrided substrate may also be provided.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip is provided where the substrate is comprised of a molybdenum (Mo) content of about 1.6% to about 5% by weight of composition and thicknesses of 1.60-1.75 ?m and 9.25-10.00 ?m measured at a distance of 4 and 40 ?m from the blade tip, respectively. This thickness ratio is between 0.165-0.185. The substrate thickness is about 2.70-3.00 ?m at 8 ?m from the blade tip, about 4.44-5.00 ?m at 16 ?m from the blade tip with a thickness ratio measured at 4 ?m and 8 ?m between 0.56-0.62, and a thickness ratio measured at 4 ?m and 16 ?m between 0.32-0.40. The edge shape may be defined by equation w=adn with “a” between 0.50-0.62 and “n” between 0.76-0.80. A semi-included angle less than 7° is measured at a distance of 40 ?m or greater from the blade tip. This substrate will have substantially no cracks.

Abstract: A razor blade that includes a substrate with a cutting edge, the substrate includes (a) a thin-film of a first material disposed thereon, the thin-film having a thickness less than 1 ?m; (b) a mixed nitride-thin-film interregion disposed at or adjacent a surface of the thin-film and a surface of the substrate; and (c) a nitride region disposed adjacent the mixed nitride-thin-film interregion.

Abstract: A razor blade that includes a substrate with a cutting edge, the substrate includes (a) a thin-film of a first material disposed thereon, the thin-film having a thickness less than 1 ?m; (b) a mixed nitride-thin-film interregion disposed at or adjacent a surface of the thin-film and a surface of the substrate; and (c) a nitride region disposed adjacent the mixed nitride-thin-film interregion.

Abstract: Razors cartridges including a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap are provided. A first blade defines a blade edge nearest the guard and a second blade defines a blade edge nearest the cap. The first blade has a cutter force less than the cutter force of the second blade.

Abstract: The present invention relates to razor blade cutting edges and methods of producing edges exhibiting improved shave performance longevity and lower cutting forces. Conventional razor blades have increasing cutting forces with use due to the outer coating wear and adhesion loss. Blade edges produced according to the novel process exhibit significantly lower cutting forces when subjected to wool felt cutting shaving simulation, which correlates to more comfortable shaves initially and over the life of the blades. The present invention treats razor blade edges having a first adherent polyfluorocarbon coating with a first solvent to partially remove the polyfluorocarbon coating, adds a second polyfluorocarbon coating, heats, and treats the blade edge with a second solvent providing a final blade edge having a thin, uniform polyfluorocarbon coating.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has thicknesses of 1.60-1.75 micrometers and 9.25-10.00 micrometers measured at a distance of four and forty micrometers from the blade tip, respectively. A ratio of the thickness measured at four micrometers to the thickness measured at forty micrometers is between 0.165-0.185. The substrate thickness is about 2.70-3.00 micrometers at eight micrometers from the blade tip, about 4.44-5.00 micrometers at sixteen micrometers from the blade tip with a thickness ratio measured at four micrometers and eight micrometers between 0.56-0.62, and a thickness ratio measured at four micrometers and sixteen micrometers between 0.32-0.40. The blade edge shape is defined by equation w=adn where “a” is between 0.50-0.62 and “n” is between 0.76-0.80. An included angle of less than 7° is measured at a distance of forty micrometers or greater from the blade tip. A nitrided substrate may also be provided.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has a thickness of between about 1.3 and 1.6 micrometers measured at a distance of four micrometers from the blade tip, a thickness of between about 2.2 and 2.7 micrometers measured at a distance of eight micrometers from the blade tip, a thickness of between about 3.8 and 4.9 micrometers measured at a distance of sixteen micrometers from the blade tip, a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at eight micrometers from the blade tip of at least 0.55 and a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at sixteen micrometers from the blade tip of at least 0.30.

Abstract: A razor blade including a substrate with a coating joined to the substrate defining a coated blade. The coated blade including a cutting edge being defined by a blade tip having a tip radius of from 50 to 350 angstroms. The coated blade having a pair of first facets extending from the blade tip and a pair of second facets extending from the respective first facets, a facet angle from 90° to 135°, a facet width from 0.38 micrometers to 0.65 micrometers a wedge angle from 5° to 30°, and a thickness of between 0.8 and 1.5 micrometers measured at a distance of 1 micrometer from the blade tip.

Abstract: A razor blade including a substrate with a coating joined to the substrate defining a coated blade. The coated blade including a cutting edge being defined by a blade tip having a tip radius of from 500 to 1500 angstroms. The coated blade having a thickness of between 0.3 and 0.5 micrometers measured at a distance of 0.25 micrometers from the blade tip, a thickness of between 0.4 and 0.65 micrometers measured at a distance of 0.5 micrometers from the blade tip, a thickness of between 0.61 and 0.71 micrometers measured at a distance of 1 micrometer from the blade tip, a thickness of between 0.96 and 1.16 micrometers measured at a distance of 2 micrometers from the blade tip, and a thickness of between 1.56 and 1.91 micrometers measured at a distance of 4 micrometers from the blade tip.

Abstract: A razor blade that includes a substrate with a cutting edge, the substrate includes (a) a thin-film of a first material disposed thereon, the thin-film having a thickness less than 1 ?m; (b) a mixed nitride-thin-film interregion disposed at or adjacent a surface of the thin-film and a surface of the substrate; and (c) a nitride region disposed adjacent the mixed nitride-thin-film interregion.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has a thickness of between about 1.3 and 1.6 micrometers measured at a distance of four micrometers from the blade tip, a thickness of between about 2.2 and 2.7 micrometers measured at a distance of eight micrometers from the blade tip, a thickness of between about 3.8 and 4.9 micrometers measured at a distance of sixteen micrometers from the blade tip, a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at eight micrometers from the blade tip of at least 0.55 and a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at sixteen micrometers from the blade tip of at least 0.30.

Abstract: Razors cartridges including a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap are provided. A first blade defines a blade edge nearest the guard and a second blade defines a blade edge nearest the cap. The first blade has a cutter force less than the cutter force of the second blade.