Polymer Lighting Device Sealed Layer for Moisture Barrier

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Solution Overview

Problem

Motor vehicle lighting and signaling devices face issues with moisture ingress due to temperature changes, leading to condensation and degradation of lighting quality, despite attempts to seal the internal chamber to prevent water and pollutants.

Innovation Solution

A sealed layer made of crosslinked polymer material, treated by ion bombardment, is applied to the internal surfaces of the device's polymer components to prevent water molecules from entering the chamber, combined with optional dehumidification and ventilation systems to manage humidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the internal chamber is completely sealed to prevent water and pollutant infiltration, then protection against degradation is improved, but pressure balance deteriorates due to temperature changes causing deformation

Engineering Contradiction:
Improveprotection against water and pollutant infiltrationVSAvoidpressure balance stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies a sealed layer specifically to the polymer material surfaces facing the chamber interior, rather than sealing the entire chamber. This localized treatment creates water-resistant zones at critical interfaces while leaving other areas permeable for pressure equalization, resolving the contradiction between protection and pressure balance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a composite structure by combining polymer material with a sealed layer (through crosslinking or coating). This composite approach provides both the protection benefits of sealing and the pressure balance benefits of polymer permeability, simultaneously addressing both requirements.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If the chamber is sealed to prevent moisture ingress, then protection against condensation is improved, but moisture management deteriorates due to trapped humidity from temperature cycles

Engineering Contradiction:
Improveprotection against moisture ingressVSAvoidmoisture management capability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The sealed layer is applied locally to polymer surfaces that are most susceptible to moisture absorption and transmission into the chamber. This selective sealing prevents moisture ingress at critical points while allowing the overall chamber to breathe and manage humidity through controlled pathways.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies the permeability parameter of the polymer material by applying a sealed layer, changing it from fully permeable to selectively permeable. This parameter change enables the material to block water molecules while still allowing vapor transmission for humidity management.

Inventive Principle:
Principle #35Parameter changes

3Shape

If a hydrophilic varnish is applied to prevent water droplet formation, then aesthetic appearance is improved, but moisture barrier effectiveness deteriorates due to uniform water film formation

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidmoisture barrier effectiveness
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

Instead of using a hydrophilic varnish that attracts and spreads water into a uniform film, the patent applies a hydrophobic sealed layer that repels water molecules. This inverted approach prevents water adhesion and droplet formation at the molecular level, providing both aesthetic and protective benefits.

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

Solution Approach 2:

The patent extracts the water barrier function from the aesthetic surface treatment. Rather than relying on varnish to simultaneously provide appearance and protection, the sealed layer provides the protective barrier function, allowing the aesthetic surface to be optimized separately for appearance.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of manufacture

If polymer material walls are used for the casing, then manufacturing ease is improved, but water resistance deteriorates due to polymer porosity allowing water penetration

Engineering Contradiction:
Improvemanufacturing ease of polymer casingVSAvoidwater resistance
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite structure by combining standard polymer material with a sealed layer. This allows the benefits of easy polymer manufacturing to be retained while adding the water resistance properties of the sealed layer, achieving both manufacturing ease and water protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The sealed layer is applied locally to the internal surfaces of the polymer casing that face the chamber. This localized treatment provides water resistance at the critical interfaces where moisture ingress is most likely, while maintaining the overall polymer structure and its manufacturing advantages.

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 effectively prevents water from entering the chamber, reducing condensation and maintaining lighting quality while allowing pressure balance, thus addressing the issue of moisture-induced degradation.

Implementation Method 1

the sealed layer is a surface layer of the element made of polymer material, crosslinked by exposure to ion bombardment so as to be sealed against the passage of water molecules

Methodology Applied
Scientific EffectIon bombardment: Ion Beam

Implementation Method 2

the water having penetrated the walls of the casing is prevented from coming out towards the interior of the casing

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP3250852B1Lighting and/or signalling device for a motor vehicle and manufacturing method
Publication Date: 2022.09.21 VALEO VISION SA
  • EP3250852B1 patent drawingFigure 1~2

AI summary

The invention relates to a lighting and/or signalling device for a motor vehicle, comprising an inner chamber (3) housing an optical system (4) and at least one element (1) made of polymer material having a surface directed towards the inside of the chamber (3), characterised in that said surface, which faces the inside of the chamber, is provided with a sealed layer (5) forming a barrier preventing water molecules from entering the chamber (3). The invention also relates to the method for manufacturing such a device.