Aperture Blade Shaving Kit Reducing Skin Irritation

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Solution Overview

Problem

Conventional hair removal devices with straight linear blades cause skin irritation due to high pressure and shear rates, especially when used at angles other than perpendicular to the blade, leading to nicks and cuts, and require specialized lubrication to reduce irritation.

Innovation Solution

A shaving aid composition and kit featuring a treatment sheet with aperture blades that allow for safe hair removal in any direction, utilizing a shaving aid composition with a polar component of surface free energy between 30 to 80 mJ/m², providing lubrication and cushioning, and a hair removal device with a planar treatment sheet and metallic frame member for reduced pressure and increased safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional straight linear blades are used at a clearance angle of 20° to achieve a close shave, then hair removal efficiency is improved, but skin irritation and nicks increase

Engineering Contradiction:
Improvehair removal efficiencyVSAvoidskin irritation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The blade is divided into multiple aperture blades arranged in a circular pattern, each contributing to the cutting action. This segmentation allows the cutting function to be distributed across multiple smaller edges rather than concentrated on a single large blade, reducing the harmful pressure on any one point of the skin while maintaining effective hair removal

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of positioning the blade edge at an angle (20° clearance angle) to achieve cutting efficiency, the invention inverts the approach by placing the aperture blades parallel to the skin surface (0° clearance angle). The cutting action is achieved through the aperture geometry and blade movement rather than through a traditional angled edge, thereby eliminating skin irritation while maintaining hair removal effectiveness

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If the contact area between blade and skin is reduced to increase cutting precision, then shaving precision is improved, but pressure on skin increases causing irritation

Engineering Contradiction:
Improveshaving precisionVSAvoidpressure on skin
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The total cutting action is segmented across multiple aperture blades distributed around the treatment sheet. Each aperture blade has a small contact area for precise cutting, but the cumulative contact area of all aperture blades provides sufficient skin support to distribute and reduce pressure, preventing the high pressure that causes irritation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-point or linear contact model to a distributed areal contact model. The aperture blades create multiple discrete contact points arranged in a two-dimensional pattern across the treatment sheet, transforming the pressure distribution from concentrated to distributed, thereby reducing peak pressure while maintaining cutting precision

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If treatment sheet transparency is increased to improve visibility, then user comfort is improved, but skin support is reduced allowing skin bulging and irritation

Engineering Contradiction:
Improveuser comfortVSAvoidskin safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The treatment sheet is designed with non-uniform optical properties: the substrate material providing skin support has reduced transparency to maintain structural integrity and skin support, while the aperture regions remain transparent to allow visibility of the cutting action. This local differentiation of transparency ensures both skin safety and user comfort are achieved in their respective zones

Inventive Principle:
Principle #3Local quality

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

The solution enables a safe and efficient shave by reducing skin irritation and pressure, allowing the use of the device in multiple directions with a larger contact area and lower shear rates, maintaining lubrication and cushioning, and supporting skin safety and hair removal efficiency.

Implementation Method 1

This shaving aid fluid forms a liquid film between the blade edge and the skin to protect the skin from direct contact and it lubricates the skin

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

it lubricates the skin which reduces the skin bulging into the gaps between the blades

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 3

The aperture blades can be used in any direction resulting in a more efficient shaving

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4385487A1Shaving aid composition and shaving kit
Publication Date: 2024.06.19 THE GILLETTE CO
  • EP4385487A1 patent drawingFigure 1
  • EP4385487A1 patent drawingFigure 2
  • EP4385487A1 patent drawingFigure 3

AI summary

The present invention refers to a shaving aid composition and a shaving kit comprising a hair removal device comprising a planar treatment sheet with aperture blades.