Automotive Multilayer Structure Balancing Strength and Low Weight

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Solution Overview

Problem

Existing automotive components face challenges in achieving lightweight, structurally resistant, and flexible structures that provide effective sound absorption and thermal insulation while being environmentally sustainable, as they often suffer from 'sandwich fragility' and high material density, which compromises their integration and performance.

Innovation Solution

A multilayer structure comprising outer non-woven layers and intermediate layers of glass wool fiber and polyurethane scraps, with the polyurethane layers derived from automotive waste, achieving a density range of 20 to 30 g/l and a compression set of 1000-1200 g/cm², is assembled via thermocompression molding to create a lightweight, resilient, and acoustically and thermally efficient automotive component.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional inorganic compounds with thermosetting resins and glass fibers are used, then structural strength and stability are improved, but vehicle weight increases and environmental sustainability deteriorates

Engineering Contradiction:
Improvestructural strengthVSAvoidvehicle weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent uses a composite material system consisting of polyurethane foam core combined with fabric layers (such as polyester, cotton, or recycled textiles) bonded with adhesives. This composite structure achieves the required structural strength and stability while significantly reducing weight compared to traditional inorganic compounds with thermosetting resins and glass fibers. The fabric layers provide reinforcement and the polyurethane foam provides structural support, creating a lightweight yet strong composite material suitable for automotive applications.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If traditional multilayer thick structures are used, then sound absorption and thermal insulation are improved, but bending stiffness decreases and structural properties are reduced

Engineering Contradiction:
Improvesound absorptionVSAvoidbending stiffness
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies local quality by differentiating the functions of different layers in the multilayer structure. The polyurethane foam core provides sound absorption and thermal insulation properties, while the fabric layers (particularly if they include glass fiber-reinforced materials or tightly woven textiles) provide bending stiffness and structural strength. This functional differentiation allows each layer to optimize its specific property without compromising the overall structure, resolving the contradiction between sound absorption and bending stiffness.

Inventive Principle:
Principle #3Local quality

3Weight of moving object

If polyurethane lightweight foams are used, then vehicle weight is reduced, but structural weakness and sandwich fragility increase

Engineering Contradiction:
Improvevehicle weightVSAvoidstructural reliability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent combines polyurethane foam with fabric layers (such as polyester, cotton, or recycled textiles) to create a composite structure that maintains the lightweight advantage of the foam while adding structural reinforcement through the fabric layers. The fabric layers prevent sandwich fragility and structural weakness by providing tensile strength and rigidity to the otherwise soft foam material, thus achieving both weight reduction and structural reliability.

Inventive Principle:
Principle #40Composite materials

4Loss of substance

If automotive production scraps and waste materials are recycled, then environmental sustainability is improved, but manufacturing complexity and quality control increase

Engineering Contradiction:
Improvewaste reductionVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of substanceVSEase of manufacture

Solution Approach 1:

The patent specifies particular parameter ranges for the recycled polyurethane foam, including density (20-50 kg/m³) and thickness (5-20 mm), to ensure consistent performance despite variations in the recycled material source. By controlling these key parameters and selecting appropriate fabric layers and adhesives, the manufacturing process achieves quality consistency while utilizing recycled automotive production scraps, thus balancing environmental sustainability with manufacturing ease.

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 multilayer structure achieves balanced integration of thermal, acoustical, and mechanical functions, providing lighter, more sustainable components with improved resilience and flexibility, while maintaining structural integrity and reducing vehicle weight.

Implementation Method 1

at least one intermediate layer β, made of a glass wool fiber

Methodology Applied
Scientific EffectSound absorption: Acoustic Absorption

Implementation Method 2

at least one intermediate polyurethane layer γ... at least one intermediate layer β, made of a glass wool fiber

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4010185B1A multilayer structure for automotive components
Publication Date: 2025.10.22 ADLER EVO SRL
  • EP4010185B1 patent drawingFigure 1~2
  • EP4010185B1 patent drawingFigure 3~4
  • EP4010185B1 patent drawingFigure 5~6

AI summary

The invention concerns a multilayer structure comprising: - two outer layers α1, made of a non-woven material; - at least one intermediate layer β, made of a glass wool material; - at least one intermediate polyurethane layer ; wherein the at least one intermediate polyurethane layer γ is made of polyurethane deriving from polyurethane automotive scraps, and wherein the at least one intermediate polyurethane layer γ has a density value in the range from 20 to 30 g/l.