Conductive Fiber Heating in Vehicle Sandwich Panels

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Solution Overview

Problem

Existing sandwich panels with heating functions for vehicles face challenges in being compact, reliable, and cost-effective, with complex connection technologies and a risk of gas or liquid leakage, and require additional height and expensive manufacturing processes.

Innovation Solution

A sandwich panel with a flat fiber network of electrically conductive fibers embedded in a polymer matrix, acting as a heating resistor, which is integrated into the structural composite, providing a robust and flexible heating solution without separate conductor tracks, and using fiber-reinforced plastic cover layers for reduced height and enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a full-metal sandwich construction with corrugated aluminum core and channels for gaseous or liquid media is used, then heating function is achieved, but connection technology becomes complex and risk of leakage increases

Engineering Contradiction:
Improveheating functionVSAvoidconnection technology
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical system of channels and fluid circulation with an electrical heating system. Instead of using gaseous or liquid media flowing through channels in the core, the invention embeds electrically conductive fibers directly into the sandwich panel structure, converting thermal energy delivery from a fluid-based mechanical system to an electrical system. This eliminates the need for complex connection technology and leakage-prone channels while maintaining the heating function.

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

Solution Approach 2:

The patent changes the fundamental parameter of heat delivery from convective/radiative heating via fluid media to resistive heating via electrically conductive fibers. By embedding conductive fibers within the sandwich panel layers, the system transforms the heating mechanism from an external fluid circulation system to an integrated electrical resistance heating system, thereby simplifying the overall structure and eliminating leakage risks.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If electrical PTC heating elements are provided on an additional heating plate, then heating function is achieved with easier maintenance, but manufacturing cost increases and additional height is required

Engineering Contradiction:
Improveheating functionVSAvoidmanufacturing cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent merges the heating function with the structural sandwich panel itself by embedding electrically conductive fibers within the panel layers. Instead of adding a separate heating plate as an additional component, the heating elements are integrated directly into the sandwich panel construction, combining structural support and heating functions in a single unified structure. This eliminates the need for additional height and reduces manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sandwich panel is designed to serve multiple functions simultaneously: structural support, insulation, and heating. By embedding electrically conductive fibers within the panel layers, the same structural component performs both mechanical support and thermal generation functions, eliminating the need for separate heating plates and reducing overall system complexity and manufacturing cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Temperature

If heating wires are arranged in serpentine or meandering manner, then heating function is achieved, but structure becomes complex and subsequent mechanical processing is impaired

Engineering Contradiction:
Improveheating functionVSAvoidstructural integrity
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent replaces the non-uniform serpentine or meandering wire arrangement with a homogeneous distribution of electrically conductive fibers throughout the sandwich panel structure. Instead of concentrated heating wires following complex paths, the conductive fibers are evenly dispersed and embedded within the panel layers, creating a uniform heating effect while maintaining structural homogeneity and integrity throughout the entire panel.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The patent uses composite materials by embedding electrically conductive fibers within the sandwich panel's structural layers. This composite approach integrates the heating function into the material structure itself rather than adding separate wire elements, allowing subsequent mechanical processing without impairing either the heating function or structural integrity. The conductive fibers become an integral part of the composite panel structure.

Inventive Principle:
Principle #40Composite materials

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 achieves a compact, reliable, and cost-effective heating system with improved mechanical stability, even heat distribution, and tolerance to localized damage, while avoiding the risks of leakage and additional height, making it suitable for structural components in vehicles.

Implementation Method 1

at least one heating layer which can be used as an electrical heating resistor

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3279055B1Sandwich panel with heating function for vehicles
Publication Date: 2021.02.24 EURO COMPOSITES
  • EP3279055B1 patent drawingFigure 1~2C
  • EP3279055B1 patent drawingFigure 3
  • EP3279055B1 patent drawingFigure 4

AI summary

The invention relates to a sandwich panel (10) with a heating function for a vehicle, in particular as a structural floor panel for a rail vehicle. The sandwich-structured layered panel has an upper face layer (12), a lower face layer (16), and a sandwich core (14). Furthermore, the sandwich structure comprises at least one electrical heating layer (20) between the two face layers (12, 16). According to the invention, a planar fiber network (60) made of electrically conductive fibers (62), in particular carbon fibers, is used as the heating layer (20).