A method and apparatus for measuring the cutting force on a single fiber. The method includes the steps of: providing a blade having an edge; providing a fiber mount for holding the single fiber; providing at least one sensor connected to the fiber mount; providing a fiber sleeve to contain a fiber within the fiber mount to simulate the location of the hair within the hair follicle; moving the blade toward the fiber and cutting the fiber; and measuring the cutting force on the fiber with the at least one sensor.

An apparatus for testing a razor blade comprises a base, a material support table, a material sample, a transport carriage, a blade retention assembly, and a razor blade. The material support table is supported by the base. The transport carriage is movably coupled with the base and is movable with respect to the material support table between a start position and an end position. The blade retention assembly is movably coupled with the transport carriage and is movable with respect to the material support table between a blade-engaged position and a blade disengaged position. The blade retention assembly is movable together with the transport carriage between the start position and the end position. The blade is releasably attached to the blade retention assembly. The razor blade contacts the material sample when the blade retention assembly is in the blade-engaged position. Methods are also provided.

The invention features a method for determining the worn shape of a deformable body in sliding contact with a deformable substrate. A wear depth w in an inward normal direction is determined at select points on a surface of the deformable body at each point in time t by integration of the following equation:

[00001]$\frac{\mathrm{dw}}{d.Math..Math.\tau }={\mathrm{kT}}_n.Math.v^b$

where k is a material dependent variable determined by physical tests, T.sub.n is a contact pressure determined by finite element analysis of the deformable body in sliding contact with the deformable substrate at each point in time t, v is a constant sliding velocity between the deformable body and the deformable substrate, b is a constant determined by physical tests, and τ=t.sup.b is a computational time.

A handle for a shaving razor with a frame and a pod operably coupled to the frame such that the pod is configured to rotate about a first axis of rotation substantially perpendicular to the frame. The pod has a base and a retention system which applies a resistance torque upon the pod when the pod is rotated from an at rest position about said first axis of rotation. The retention system has a static stiffness of about 0.7 Nmm/deg to about 2.25 Nmm/deg as determined by at least one of a Static Stiffness Test, and a damping of from about 0.03 N*mm*sec/degree to about 0.30 N*mm*sec/degree as determined by a Pendulum Test Method.

A method of optimizing a manufacturing process or a blade array of a razor cartridge using spatial information for a tip portion of a razor blade comprises the steps of: measuring, using an atomic force microscope including a probe having a high aspect ratio of a length to a half side angle and a probe tip with a radius less than a radius of an ultimate tip of the tip portion of the razor blade, the spatial information by traversing the probe across the tip portion of the razor blade; analyzing, by one or more processors, the spatial information as measured by the atomic force microscope, to determine one or more blade characteristics; and using the blade characteristics to adjust the manufacturing process to improve a design of the razor blade or to adjust a design characteristic of the blade array to improve a design of the razor cartridge.

An apparatus for demonstrating at least a first shaving razor, having a first shaving surface with a first lubrication member, may include a first sheet of paper, a liquid composition, and a light source transmitting ultraviolet light onto the first sheet of paper. The liquid composition may include water and an ultraviolet dye. The apparatus may position the shaving razor to engage the first sheet of paper and to allow relative motion between the first lubrication member and the first sheet of paper such that the first lubrication member deposits the liquid composition onto the first sheet of paper.

A shaving demonstration method may involve providing at least a first shaving razor having a first shaving surface with a first lubrication member; exposing the first lubrication member to a composition of water and a fluorescent dye; engaging at least a first sheet of paper with at least the first lubrication member; causing relative motion between the first lubrication member and the first sheet of paper; and exposing the first sheet of paper to a light source.

An apparatus for testing a razor blade comprises a base, a material support table, a material sample, a transport carriage, a blade retention assembly, and a razor blade. The material support table is supported by the base. The transport carriage is movably coupled with the base and is movable with respect to the material support table between a start position and an end position. The blade retention assembly is movably coupled with the transport carriage and is movable with respect to the material support table between a blade-engaged position and a blade disengaged position. The blade retention assembly is movable together with the transport carriage between the start position and the end position. The blade is releasably attached to the blade retention assembly. The razor blade contacts the material sample when the blade retention assembly is in the blade-engaged position. Methods are also provided.

An apparatus for testing a razor blade comprises a base, a material support table, a material sample, a transport carriage, a blade retention assembly, and a razor blade. The material support table is supported by the base. The transport carriage is movably coupled with the base and is movable with respect to the material support table between a start position and an end position. The blade retention assembly is movably coupled with the transport carriage and is movable with respect to the material support table between a blade-engaged position and a blade disengaged position. The blade retention assembly is movable together with the transport carriage between the start position and the end position. The blade is releasably attached to the blade retention assembly. The razor blade contacts the material sample when the blade retention assembly is in the blade-engaged position. Methods are also provided.

An apparatus for testing a razor blade comprises a base, a material support table, a material sample, a transport carriage, a blade retention assembly, and a razor blade. The material support table is supported by the base. The transport carriage is movably coupled with the base and is movable with respect to the material support table between a start position and an end position. The blade retention assembly is movably coupled with the transport carriage and is movable with respect to the material support table between a blade-engaged position and a blade disengaged position. The blade retention assembly is movable together with the transport carriage between the start position and the end position. The blade is releasably attached to the blade retention assembly. The razor blade contacts the material sample when the blade retention assembly is in the blade-engaged position. Methods are also provided.