Laser Surface Activation for PEEK-Coated Copper Wire Adhesion

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Solution Overview

Problem

Existing methods for applying PEEK coatings on wire conductors, such as copper, suffer from low adhesion strength due to physical bonding, and current techniques to improve adhesion are slow, costly, or add undesirable materials.

Innovation Solution

A laser processing system is used to activate the surface of wire conductors before coating application, increasing surface energy, removing contaminants, and enhancing roughness to improve adhesion of PEEK coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If PEEK coating is applied to wire conductor, then coating film build thickness is improved (150-200 μm), but adhesion strength deteriorates (lower than enamel)

Engineering Contradiction:

Improvecoating film build thicknessVSAvoidadhesion strength

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The patent applies preliminary surface treatment to the wire conductor before coating application. Specifically, the wire surface is subjected to corona discharge treatment or plasma treatment to increase surface energy and create anchoring sites, thereby improving PEEK coating adhesion before the coating is applied

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary surface treatment layer or modification on the wire conductor. The corona or plasma treatment creates a modified surface layer that acts as an intermediary between the wire conductor and PEEK coating, enhancing the physical bonding mechanism

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If steam cleaning or plasma activation is used to pre-clean wire conductors, then adhesion strength is improved, but production speed deteriorates (process is too slow)

Engineering Contradiction:

Improveadhesion strengthVSAvoidproduction speed

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent replaces mechanical steam cleaning systems with a corona discharge or plasma treatment system. This substitution enables continuous in-line surface treatment at production speeds while achieving the necessary surface activation for PEEK coating adhesion

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical-chemical parameters of the wire surface through corona or plasma treatment. By controlling parameters such as power density, treatment duration, and atmospheric conditions, the surface is rapidly activated without slowing down the production line

Inventive Principle:

Principle #35Parameter changes

3Strength

If bond coat such as polyester or PAI is applied prior to PEEK coating, then adhesion strength is improved, but material cost and process complexity increase (add undesirable material)

Engineering Contradiction:

Improveadhesion strengthVSAvoidprocess complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the intermediate bond coat layer from the coating process. By directly treating the wire conductor surface with corona or plasma treatment, the system achieves adequate adhesion without requiring additional bond coat materials or process steps

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent enables the wire conductor surface to serve its own adhesion preparation function through self-treatment with corona or plasma. The surface treatment is performed in-line and prepares the substrate directly for PEEK coating without requiring separate bond coat application processes

Inventive Principle:

Principle #25Self-service

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 laser surface activation method enhances the adhesion strength of PEEK coatings on wire conductors, enabling them to meet the performance requirements for high-voltage electric vehicle motors.

Implementation Method 1

one or more laser sources configured to illuminate a surface of the wire conductor with two or more laser beams

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

one or more laser processing parameters associated with the laser processing sub-system are selected to activate the surface of the wire conductor for adhesion of the coating

Methodology Applied

Scientific EffectLaser heating: Heating

Data Source

PatentUS20250342988A1Laser cleaning and activation of cu wires prior to PEEK insulation coating

Publication Date: 2025.11.06 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A coating system may include a feed mechanism including one or more rollers configured to provide a supply of a wire conductor through a working zone with a feed rate, an extruder to coat the wire conductor with a coating as the wire conductor is fed through the working zone, and a laser processing sub-system in the working zone prior to the extruder. The laser processing sub-system may include one or more laser sources to illuminate a surface of the wire conductor with two or more laser beams as the wire conductor is fed through the working zone, where laser processing parameters associated with the laser processing sub-system are selected to activate the surface of the wire conductor for adhesion of the coating. The laser processing parameters may include intensities of the two or more laser beams, spectra of the two or more laser beams, and/or the feed rate.