Embedded-Conductor Heatable Pipe With Hydrolysis-Resistant Copolyamide

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Solution Overview

Problem

Current heatable pipes for diesel fuel and SCR systems face challenges with high temperature deformation, limited hydrolysis resistance, and poor mechanical properties, particularly low elongation at break and impact resistance, which can lead to mechanical damage and failure.

Innovation Solution

A heatable pipe design featuring a layer of partly aromatic copolyamide with specific monomer units and an olefinic copolymer impact modifier, embedded with a metallic conductor between electrically insulating inner and outer layers, providing high heat distortion temperature, improved hydrolysis resistance, and enhanced mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If normal resistance heating means are wound around the fluid pipe, then the pipe can be heated, but the device complexity increases and the heating efficiency is reduced

Engineering Contradiction:
Improveheating capabilityVSAvoidheating structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The heating function is extracted from an external heating device and integrated directly into the pipe wall by embedding conductive elements within the pipe structure, eliminating the need for separate external heating apparatus

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The heating function is merged with the pipe structure itself by incorporating conductive elements during pipe manufacturing, creating an integrated heatable pipe where the heating capability becomes an inherent property of the pipe rather than an add-on component

Inventive Principle:
Principle #5Merging (Combining)

2Use of energy by moving object

If conductors are embedded in a conductive polymer layer, then heating efficiency improves, but the electrical contact between the matrix and conductor becomes problematic

Engineering Contradiction:
Improveheating efficiencyVSAvoidelectrical contact reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

A conductive polymer layer serves as an intermediary between the metal conductors and the pipe matrix, providing both electrical conductivity for efficient heating and mechanical bonding for reliable electrical contact, thus resolving the contradiction between heating efficiency and contact reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If aliphatic polyamides are used for the pipe material, then the pipe has good mechanical properties, but the hydrolysis resistance is limited when exposed to high temperatures

Engineering Contradiction:
Improvemechanical propertiesVSAvoidhydrolysis resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The pipe uses a composite structure combining aliphatic polyamide for the matrix (providing mechanical properties) with conductive polymer material (providing electrical conductivity and enhanced thermal stability), creating a material system that achieves both good mechanical properties and improved hydrolysis resistance at high temperatures

Inventive Principle:
Principle #40Composite materials

4Temperature

If the pipe is exposed to high temperatures, then the heating function works, but the conduit material deforms or fails due to temperature peaks

Engineering Contradiction:
Improveheating functionVSAvoidconduit material stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The pipe material parameters are changed by using high-melting-point aliphatic polyamides (PA11, PA12) with specific thermal properties and conducting polymer materials that maintain structural stability at elevated temperatures, allowing the pipe to withstand temperature peaks during heating operation without deformation or failure

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 solution achieves a heatable pipe with high elongation at break, improved thermal and mechanical stability, and resistance to hydrolysis, reducing the risk of thermal or mechanical damage and ensuring reliable operation in harsh conditions.

Implementation Method 1

a conductor for electrical current which is embedded between an electrically insulating outer layer and an electrically insulating inner layer

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS10139022B2Heatable pipe
Publication Date: 2018.11.27 EVONIK OPERATIONS GMBH

AI summary

A heatable pipe contains a layer (layer I) of a moulding compound containing at least 40 wt. % of the following components: 1) 60 to 99 parts by wt. of a copolyamide based on hexamethylenediamine, terephthalic acid and an aliphatic dicarboxylic acid having 8 to 19 carbon atoms, and 2) 40 to 1 parts by wt. of an olefinic copolymer as impact modifier, wherein the parts by wt. of 1) and 2) sum to 100; and a conductor for electrical current which is embedded between an electrically insulating outer layer and an electrically insulating inner layer. The heatable pipe exhibits a high heat distortion temperature, very good impact resistance and a high elongation at break and is used for producing an SCR conduit, a conduit for diesel fuel or a conduit for a fuel cell system.