Vacuum Plasma Etching for Ceramic Layer Removal on Watch Parts

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Solution Overview

Problem

Existing methods for removing ceramic layers from watch components are either mechanically or chemically damaging, leading to aesthetic deterioration and wastage of defective parts, as they either mechanically degrade the components or uniformly damage lower layers during the removal process.

Innovation Solution

A controlled vacuum plasma treatment method using chemically reactive gases to selectively remove ceramic layers, minimizing damage to underlying layers and allowing for the reuse of defective parts by reintroducing them into the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If mechanical polishing is used to remove the transmission layer, then the ceramic material can be removed, but the component is mechanically degraded (twisting, matting) and aesthetics are deteriorated

Engineering Contradiction:
Improveremoval of ceramic transmission layerVSAvoidaesthetic quality of component surface
Core Design Contradiction:
Loss of substanceVSShape

Solution Approach 1:

The patent replaces mechanical polishing with chemical etching using hydrofluoric acid to remove the ceramic transmission layer. This chemical process selectively dissolves the ceramic material without mechanically degrading the underlying metal components, thereby preserving the aesthetic quality and structural integrity of the watch part while achieving complete layer removal.

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

Solution Approach 2:

The patent changes the removal mechanism from mechanical to chemical by using hydrofluoric acid etching. This parameter change allows selective removal of the ceramic layer based on chemical reactivity differences between the ceramic material and the metal underlying layers, preventing mechanical damage such as twisting and matting while maintaining surface aesthetics.

Inventive Principle:
Principle #35Parameter changes

2Loss of substance

If wet etching with hydrofluoric acid is used to remove the ceramic layer, then the ceramic material can be removed, but the entire watch part including lower layers and metal decoration is uniformly damaged

Engineering Contradiction:
Improveremoval of ceramic transmission layerVSAvoidselectivity of etching process
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent applies local quality by using a mask with specific patterns to control where the hydrofluoric acid etching occurs. The mask allows the etching solution to contact only the ceramic transmission layer in specific areas while protecting the metal decoration and underlying layers in other areas, thereby achieving selective removal without uniform damage to the entire watch part.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces a mask as an intermediary element between the etching solution and the watch part. This mask selectively exposes only the ceramic transmission layer to the hydrofluoric acid while protecting the metal decoration and underlying layers, enabling precise control over the etching process and preventing unwanted damage to non-ceramic materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of substance

If the transmission layer is removed to recover a reusable blank, then material waste is reduced, but numerous processing steps are generated and health risks arise from ceramic microparticle emissions

Engineering Contradiction:
Improverecovery of reusable blankVSAvoidceramic microparticle emissions
Core Design Contradiction:
Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent replaces mechanical removal methods that generate ceramic microparticles with chemical etching using hydrofluoric acid. This chemical process dissolves the ceramic transmission layer into soluble compounds that can be easily rinsed away, eliminating the generation of harmful ceramic dust particles while still enabling recovery of the reusable metal blank for further processing.

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

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 effectively removes ceramic layers with minimal damage to underlying materials, preventing harmful emissions and enabling the reuse of parts, thus reducing waste and maintaining aesthetic quality.

Implementation Method 1

a step of treating the layer of ceramic material by vacuum plasma formed from at least one flow of injected gas chemically reactive with said ceramic material in order to carry out controlled physicochemical etching of the layer of ceramic material

Methodology Applied
Scientific EffectVacuum plasma: Plasma

Implementation Method 2

the vacuum plasma treatment will chemically recombine the layer of ceramic material with the reactive gas to remove the vast majority of the layer of ceramic material

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP4485088A1Method for removing ceramic material
Publication Date: 2025.01.01 RICHEMONT INTERNATIONAL SA
  • EP4485088A1 patent drawingFigure 1~2
  • EP4485088A1 patent drawingFigure 3
  • EP4485088A1 patent drawing

AI summary

The invention relates to a controlled removal process of a layer of ceramic material on a part (1) using vacuum plasma treatment in order to achieve a controlled physico-chemical etching of the ceramic material layer.