Sound Absorbing Composite Using Sponge Iron Welding Additive

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing structure-borne noise-damping composite materials face issues with uneven distribution and chemical reactions of welding additives, leading to poor processing behavior and adverse effects on electrical conductivity and adhesion, as well as limited welding ranges and potential harm from welding fumes.

Innovation Solution

Incorporating sponge iron as a welding additive in the polymer layer, with specific weight and size characteristics, to ensure even distribution and improved welding properties, including electrical conductivity and wide welding ranges, while maintaining mechanical properties and avoiding harmful fumes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If welding additives with high specific weight are added to the polymer layer, then electrical conductivity and welding suitability are improved, but the distribution of pigments becomes uneven and heterogeneous

Engineering Contradiction:
Improvewelding suitabilityVSAvoidhomogeneity of pigment distribution
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the specific weight parameter of the welding additive from high (conventional filler metals) to low (sponge iron with approx. 2.85 g/cm³). This parameter change enables homogeneous distribution in the polymer layer while maintaining adequate electrical conductivity for resistance welding, resolving the contradiction between welding suitability and composition homogeneity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If certain filler metals are added to improve welding properties, then electrical conductivity increases, but harmful chemical reactions with the polymer occur affecting adhesion and consistency

Engineering Contradiction:
Improvewelding propertiesVSAvoidchemical reactions with polymer
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent uses sponge iron, a inexpensive and chemically stable material, as a replacement for conventional filler metals that cause harmful chemical reactions. Sponge iron provides adequate electrical conductivity for welding without reacting adversely with the polymer, eliminating harmful factors while maintaining welding properties.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If conventional welding additives are used, then welding capability is achieved, but the welding range is limited and processing behavior is poor

Engineering Contradiction:
Improvewelding capabilityVSAvoidwelding range
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent changes the electrical conductivity parameter by using sponge iron with controlled content (0.1 to 30.0% by weight, preferably 0.5 to 10.0%) and specific physical properties (average diameter < 0.2 mm, preferably < 0.1 mm). This parameter optimization expands the welding range and improves processing behavior while maintaining adequate welding capability.

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 use of sponge iron allows for simplified processing, expanded welding ranges, controlled weld areas, and no adverse effects on adhesion, enabling the composite material to be used in various constructions requiring resistance welding without harmful fumes or mechanical impairment.

Implementation Method 1

To improve the electrical conductivity and adjust the suitability for resistance welding of a composite material, welding additives are added to the polymer layer

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

Welding consumables with a high specific weight compared to plastic show very unfavorable settling behavior in the liquid or molten polymer

Methodology Applied
Scientific EffectGravitational settling: Settling

Implementation Method 3

Connecting the structure-borne sound-damping composite material to other components, for example by welding, in particular resistance welding

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3206869B1Sound absorbing composite
Publication Date: 2018.12.05 THYSSENKRUPP AG

AI summary

The invention relates to a composite material comprising at least two metallic layers and at least one polymer layer disposed between the metallic layers, the polymer layer comprising at least a welding additive. The aim of the present invention is to propose a composite material which overcomes the disadvantages of the prior art. Said aim is achieved by a composite material having the features of patent claim 1.