Windscreen Wiper Blade Elastomer Damping

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Solution Overview

Problem

Conventional wiper blades experience reduced longevity and generate noise pollution due to friction with the windshield, particularly when dry, necessitating an improvement in elastomeric material formulation to enhance lifespan and reduce noise.

Innovation Solution

A formulation for wiper blades incorporating a combination of plasticizing additives with pour points below and above -50°C, specifically a high pour point ester and a low pour point naphthalic petroleum plasticizer, to enhance viscoelastic damping without compromising low-temperature elasticity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional elastomeric materials are used for wiper blades, then the blades can maintain basic elasticity, but they generate noise pollution and have reduced longevity due to friction with the windshield

Engineering Contradiction:
Improvenoise pollutionVSAvoidblade longevity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent modifies the elastomeric material composition by incorporating specific plasticizers and lubricating fillers in optimized proportions. This changes the physical and chemical parameters of the material to achieve reduced friction coefficients and improved damping characteristics, thereby reducing noise while extending blade life

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite elastomeric formulation combining base rubber with multiple additives including plasticizers, lubricating fillers, and antioxidants. This composite approach synergistically improves both noise reduction and durability properties that cannot be achieved with single-component materials

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If plasticizers are added to improve damping characteristics and reduce noise, then high-frequency vibrations are better controlled, but the elasticity of the material may be compromised

Engineering Contradiction:
Improvehigh-frequency vibrationsVSAvoidmaterial elasticity
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent carefully selects plasticizers with specific molecular weights and chemical structures to optimize the damping characteristics. By controlling the concentration and type of plasticizer, the formulation achieves improved vibration damping while preserving adequate elasticity for functional performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates different functional zones within the elastomeric material through strategic additive distribution. The plasticizers concentrate in regions where vibration damping is needed, while maintaining elasticity in areas requiring flexibility, achieving localized property optimization

Inventive Principle:
Principle #3Local quality

3Force

If lubricating fillers are incorporated to reduce friction coefficient, then the blade friction on windshield is reduced, but the wear resistance may be affected

Engineering Contradiction:
Improvefriction coefficientVSAvoidwear resistance
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

The patent selects lubricating fillers with specific surface properties and particle sizes to optimize friction reduction. The formulation balances the lubricating effect with wear resistance by choosing fillers that provide low friction without sacrificing the structural integrity and abrasion resistance of the elastomeric matrix

Inventive Principle:
Principle #35Parameter changes

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 dual-additive formulation significantly improves viscoelastic damping, reducing noise and maintaining elasticity at low temperatures, as evidenced by increased tangent δ values, ensuring quiet operation and extended blade life.

Implementation Method 1

The quantification of this damping characteristic is carried out on a dynamic mechanical viscoelasticity analyzer (or DMA according to the English acronym of Digital Mechanical Analyser) which measures the phase shift angle δ existing between a stress applied to the viscoelastic material in forced vibrations

Methodology Applied
Scientific EffectViscoelastic damping: Viscoelasticity

Implementation Method 2

Their function is to improve the damping of the high-frequency vibrations of the wiper blade, by limiting the elastic characteristic of this material and by correlatively increasing its viscous component

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 3

This thin strip allows, by deforming, the wiping blade to tilt towards the windshield, in one direction then in the other, during the to-and-fro movements of the blade

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 4

The friction of the wiping blade against the windscreen, in particular when the latter is not very wet, can generate noise pollution

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2980147B1Composition for a windscreen wiper blade
Publication Date: 2017.08.16 VALEO SYST DESSUYAGE SAS

AI summary

Formulation for the production of a wiper blade for a vehicle windshield wiper, said formulation comprising a chloroprene rubber-based elastomer material incorporating plasticizing additives, characterized in that said plasticizing additives comprise a combination of at least one first additive with a pour point below -50°C and at least one second additive with a pour point above -50°C. The first additive is preferably octyl sebacate at a concentration of 4%, and the second is a naphthalene petroleum plasticizer or a C18-C30 carboxylic triester at a concentration of 10%.