Single Fiber Cutting Force Measurement with Follicle Simulation

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Solution Overview

Problem

Current methods for measuring cutting forces on single fibers, such as the wool felt cutter test, are limited in differentiating between blades with small force differences, do not accurately simulate hair cutting within a follicle, and cannot measure dynamic cutting actions or the effects of fiber type, physiology, or blade oscillation.

Innovation Solution

A method and apparatus that involves a fiber mount with a sensor to measure cutting forces on a single fiber, where the fiber is held within a sleeve to simulate follicle anchorage, and a blade mount that allows for adjustable angles and motion, enabling precise measurement of cutting forces across various fiber types and blade conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the wool felt cutter test is used to measure cutting force, then the force on the blade can be measured, but the measurement precision is insufficient to differentiate between blades with small force differences

Engineering Contradiction:
Improvecutting force measurement precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the measurement from a bulk material test (wool felt) to a single fiber test, isolating the cutting action on individual fibers to achieve higher measurement precision. This allows differentiation of small force differences between blades by eliminating the averaging effect of cutting through multiple fibers simultaneously.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a controlled test environment that copies real-world cutting conditions (hair in follicle, skin anchorage) using simplified models (single fiber in mount with simulated anchorage). This allows precise measurement while maintaining relevance to actual application conditions.

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If the wool felt cutter test is used, then cutting force can be measured, but it cannot accurately simulate hair cutting within a follicle or determine fiber anchorage effects

Engineering Contradiction:
Improvesimulation of real-world cutting conditionsVSAvoidinformation about fiber anchorage and cutting location
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent prepares the fiber mount in advance with simulated follicle anchorage structures before inserting the fiber. This preliminary setup ensures that the fiber is properly anchored at known locations and orientations, allowing accurate simulation of real-world cutting conditions and preservation of anchorage information during the cutting measurement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fiber mount acts as an intermediary between the single fiber and the cutting blade, providing simulated follicle anchorage and controlling fiber position. This intermediary structure preserves information about anchorage effects and cutting location that would otherwise be lost in bulk material tests.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a single fiber measurement system is used, then measurement precision improves, but the ability to take rapid multiple measurements from a single fiber is limited

Engineering Contradiction:
Improvecutting force measurement precisionVSAvoidrate of multiple cutting force measurements
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent employs dynamic positioning systems that allow rapid adjustment of blade and fiber mount positions during measurement sequences. This enables multiple cutting measurements to be taken from different locations on the same fiber without manual repositioning, maintaining high measurement precision while significantly increasing productivity through automated dynamic control.

Inventive Principle:
Principle #15Dynamics

4Reliability

If the fiber is held rigidly in the fiber mount, then measurement stability improves, but the fiber may be pulled out during the cutting process

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidfiber anchorage strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The fiber mount provides localized anchorage forces at specific points along the fiber, rather than rigid constraint throughout. This creates zones of controlled flexibility that prevent fiber pull-out during cutting while maintaining sufficient stability for accurate force measurement. The anchorage strength is optimized locally at the insertion points.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fiber mount incorporates cushioning elements that absorb the shock and lateral forces generated during blade cutting. This beforehand cushioning prevents fiber pull-out by dissipating cutting forces before they can exceed the anchorage strength, while maintaining measurement reliability through stable force transmission to the sensor.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate, sensitive measurement of cutting forces on single fibers, allowing for differentiation between blades and simulation of real-world cutting conditions, including dynamic motions and different fiber properties, with the ability to measure multiple cutting forces rapidly and with high sensitivity.

Implementation Method 1

at least one sensor connected to the fiber mount is provided. The blade is moved toward the fiber and cuts the fiber. The cutting force on the fiber is measured with the sensor.

Methodology Applied
Scientific EffectCapacitive sensing: Capacitance

Data Source

PatentEP3260832B1Method for measuring fiber cutter force
Publication Date: 2021.05.26 THE GILLETTE CO
  • EP3260832B1 patent drawingFigure 1
  • EP3260832B1 patent drawingFigure 2
  • EP3260832B1 patent drawingFigure 3

AI summary

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.