Cosmetic Applicator Surface Roughness Control

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Solution Overview

Problem

Conventional cosmetic product applicators lack optimal surface roughness and interaction with makeup areas, leading to inefficient product transfer and applicator longevity issues.

Innovation Solution

A method for manufacturing cosmetic product applicators with a specific surface roughness, characterized by an arithmetic average height between 15.0 and 30.0 µm, achieved through additive synthesis and post-processing techniques like powder bed fusion and sandblasting, to enhance contact friction and product transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional applicators with smooth surfaces are used, then manufacturing is simple and成本低, but product transfer efficiency is poor and applicator longevity is reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidproduct transfer efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying the surface roughness parameter of the applicator from conventional smooth surfaces (Ra < 10 µm) to a controlled rough surface (Ra = 15-30 µm). This parameter change optimizes the balance between manufacturing feasibility and product transfer efficiency, allowing the applicator to effectively pick up and deposit cosmetic products while maintaining manufacturing practicality through established sandblasting processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sandblasting treatment is applied as a preliminary action during the manufacturing process to pre-establish the optimal surface roughness before the applicator enters service. This preliminary surface preparation ensures that the applicator is pre-conditioned for optimal product transfer performance, eliminating the need for field adjustments or repeated gestures by users.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If surface roughness is increased to improve product transfer, then contact friction with makeup area improves, but large cavities may trap product and reduce applicator lifespan

Engineering Contradiction:
Improveproduct transfer efficiencyVSAvoidapplicator lifespan
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The patent precisely controls the surface roughness parameter within the range Ra = 15-30 µm and limits maximum pit depth to less than 200 µm. This parameter optimization creates sufficient surface irregularities to enhance product transfer through increased contact friction with eyelashes, eyebrows, or lips, while preventing excessive cavities that would trap product and cause premature wear. The controlled parameter range achieves the optimal balance between productivity and durability.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If additive synthesis with controlled surface roughness is used, then product transfer efficiency improves, but manufacturing process complexity increases

Engineering Contradiction:
Improveproduct transfer efficiencyVSAvoidmanufacturing process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The sandblasting treatment is integrated as a standard preliminary step in the additive manufacturing process workflow. By establishing the surface roughness control procedure as part of the baseline manufacturing process, the patent avoids creating a complex multi-step post-processing regimen. The process complexity is managed by incorporating surface preparation into the standard manufacturing sequence rather than adding separate complex treatment stages.

Inventive Principle:
Principle #10Preliminary action

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 method results in improved product transfer efficiency, reduced repetition of makeup gestures, and extended applicator lifespan by optimizing surface roughness and contact area, while maintaining cost-effectiveness.

Implementation Method 1

The applicator is manufactured by additive synthesis, preferably by powder bed fusion

Methodology Applied
Scientific EffectPowder bed fusion: Selective Laser Sintering

Implementation Method 2

sandblasting

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP3487357B1Cosmetic product applicator
Publication Date: 2023.04.26 CHANEL PARFUMS BEAUTE SAS
  • EP3487357B1 patent drawingFigure 1~3
  • EP3487357B1 patent drawingFigure 4A~4D
  • EP3487357B1 patent drawingFigure 5A~5D

AI summary

The cosmetic product applicator (1) has an arithmetic mean height Sa of a surface of the applicator in at least one portion A of the applicator that is strictly greater than 10.0 μm, this height being calculated in accordance with the following formula: in which: A is the portion of the applicator in question, and x, y and z represent the coordinates of the surface of the applicator in an orthogonal system of Cartesian coordinates, with z corresponding to a measurement axis of the height.