Pulsed Laser Deposition of Thin PTFE Films on Razor Blades

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Solution Overview

Problem

Existing methods for applying PTFE coatings on razor blades result in thick coatings that are uncomfortable during the first shave, and solvent-based thinning methods are costly and environmentally challenging.

Innovation Solution

A pulsed laser deposition method using lasers at wavelengths of 190 nm to 1075 nm to form thin, uniform PTFE films with thicknesses less than 100 nm on multi-faceted substrates like razor blades, reducing friction and cutting forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If PTFE coating is applied to razor blade edges to reduce friction and cutting forces, then shaving comfort is improved, but the coating becomes too thick causing discomfort and pain during the first shave

Engineering Contradiction:
Improveshaving comfortVSAvoidcoating thickness control
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies pulsed laser deposition to precisely control the coating thickness parameter, achieving uniform thin films of 50-200 nanometers. This parameter control allows the coating to be thin enough to provide comfort from the first shave while still providing sufficient friction reduction and cutting force reduction throughout the blade's life.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the conventional mechanical spray coating system with a pulsed laser deposition system. This substitution enables atomic-level precision in coating thickness control, eliminating the thickness variation and excess material deposition problems associated with spray methods, thereby achieving optimal thin film coverage that provides comfort from the first shave.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If solvent treatment is used to thin the PTFE coating layer, then initial cutting forces are reduced, but the process becomes costly and environmentally challenging

Engineering Contradiction:
Improveinitial cutting force reductionVSAvoidprocess cost and environmental impact
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent applies pulsed laser deposition beforehand to create the correct thin coating thickness directly during the coating process. This preliminary action eliminates the need for subsequent solvent treatment steps, reducing both process cost and environmental impact while achieving the desired low initial cutting forces from the first shave.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the solvent treatment step from the manufacturing process by directly depositing the correct thickness of PTFE coating using pulsed laser deposition. This extraction eliminates the need for expensive and environmentally challenging solvent-based thinning processes while maintaining the benefit of reduced initial cutting forces.

Inventive Principle:
Principle #2Taking out (Extraction)

3Force

If thick PTFE coating is applied to provide sufficient friction reduction, then cutting force reduction is improved, but the first shave becomes uncomfortable due to excessive coating thickness

Engineering Contradiction:
Improvecutting force reductionVSAvoidfirst shave comfort
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent precisely controls the coating thickness parameter using pulsed laser deposition, achieving the optimal range of 50-200 nanometers. This parameter optimization balances two competing requirements: providing sufficient cutting force reduction through adequate PTFE coverage while maintaining first shave comfort by limiting the maximum thickness to prevent excessive softness and discomfort.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses vacuum environment in pulsed laser deposition to control the deposition process, allowing precise control over coating thickness and uniformity. This vacuum-based approach enables the formation of consistently thin films that provide the right balance between cutting force reduction and first shave comfort, eliminating the need to choose between thick coatings for force reduction or thin coatings for comfort.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 consistently produces high-quality, low-friction, and uniform PTFE coatings that provide optimal comfort and performance from the first shave and throughout the life of the blade.

Implementation Method 1

pulsed laser deposition (PLD) using lasers at wavelengths of 190 nm to 1075 nm

Methodology Applied
Scientific EffectPulsed laser deposition: Pulsed Laser Deposition

Implementation Method 2

irradiating a fluorocarbon polymer target with pulses of laser radiation

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

establishing a vacuum pressure of 1.333×10^-1 to 1.333×10^-4 Pascal in the reaction chamber

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP4494771A1Pulsed laser deposition of fluorocarbon polymers on razor blade cutting edges
Publication Date: 2025.01.22 EDGEWELL PERSONAL CARE BRANDS LLC
  • EP4494771A1 patent drawingFigure 1~2
  • EP4494771A1 patent drawingFigure 3
  • EP4494771A1 patent drawingFigure 4

AI summary

The present invention relates to a process for forming a thin film of polytetrafluoroethylene on a substrate having multiple facets. The method comprises the following steps: providing a polytetrafluoroethylene target, wherein said target is doped with graphite; positioning the substrate proximate to the polytetrafluoroethylene target in a vacuum chamber at a pressure of 1.333×10-2 Pascal to 1.333×10-4 Pascal; irradiating the polytetrafluoroethylene target at a wavelength of 240 nm to 360 nm for a pulse length of 100 femtosecond to 500 picoseconds, at an intensity of 1 microjoule to 100 microjoules per pulse length, at a repetition rate of from 1 kHz to 10 Hz, for a time sufficient to deposit a polytetrafluoroethylene film on the substrate; and forming a substantially uniform polytetrafluoroethylene thin film on one more facets of the substrate, wherein the film has a thickness of less than 100 nm.