Plasma Surface Activation for Low-Heat Resin Joining

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Solution Overview

Problem

Existing adhesive-free resin joining methods using ultraviolet rays or ionized gas cause thermal alteration and deterioration of optical properties and mechanical strength due to penetration or particle collisions.

Innovation Solution

An apparatus and method involving a surface treatment mechanism that generates ionized gas to activate resin surfaces separately from the electrode unit, followed by a joining mechanism to bond resin members at low temperatures, using a member holding mechanism to reduce thermal and particle impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ultraviolet rays are used for surface treatment to activate resin surfaces, then adhesion force is improved, but optical properties deteriorate due to penetration and deep modification layers causing yellowing

Engineering Contradiction:
Improveadhesion forceVSAvoidoptical properties
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent introduces ionized gas as an intermediary substance to transfer activation energy to the resin surface without direct contact. The ionized gas plasma reacts with the resin surface through chemical interactions, achieving surface activation and improved adhesion force while avoiding the penetration and deep modification problems caused by ultraviolet ray direct exposure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the ultraviolet radiation mechanism with an ionized gas plasma mechanism. Instead of using electromagnetic radiation (ultraviolet rays) to activate the surface, the invention uses ionized gas particles and reactive species that chemically interact with the resin surface, providing activation without the harmful penetration effects.

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

2Strength

If ionized gas is applied directly to the resin surface for surface treatment, then surface activation is achieved, but thermal alteration occurs due to heating from charge accumulation

Engineering Contradiction:
Improvesurface activationVSAvoidthermal alteration
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent introduces a space between the ionized gas generation source and the resin surface, using this space as an intermediary region. The ionized gas is generated in this space and then contacts the resin surface, allowing surface activation while preventing direct heat transfer and charge accumulation on the resin, thus avoiding thermal alteration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a space gap beforehand between the ionized gas source and the resin surface to cushion against thermal effects. This pre-established space acts as a buffer zone that prevents direct thermal contact and charge accumulation, protecting the resin from heating while still allowing ionized gas to activate the surface.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If resin members are heated to melting temperature for joining, then joining force is improved, but thermal alteration occurs affecting optical properties and mechanical strength

Engineering Contradiction:
Improvejoining forceVSAvoidoptical properties and mechanical strength
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies surface treatment with ionized gas beforehand to activate the resin surfaces before joining. This preliminary activation creates a chemically reactive surface layer that enhances adhesion, allowing the joining process to proceed at lower temperatures without requiring heating to melting point, thus avoiding thermal alteration of the resin properties.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the joining temperature parameter from high temperature (melting point) to low temperature processing. By combining ionized gas surface activation with low-temperature pressing, the invention achieves strong joining force without subjecting the resin to thermal alteration that would degrade optical and mechanical properties.

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

Produces a joined-resin product with high quality and strong joining force without deteriorating optical or mechanical properties.

Implementation Method 1

a surface treatment mechanism comprising an electrode unit generating ionized gas

Methodology Applied
Scientific EffectIonized gas generation: Plasma

Implementation Method 2

an electrode unit generating ionized gas

Methodology Applied
Scientific EffectElectrical discharge: Electric Arc

Implementation Method 3

the surface treatment mechanism activating a surface to be joined of the resin member held by the member holding mechanism, by the ionized gas generated by the electrode unit

Methodology Applied
Scientific EffectSurface activation: Plasma

Implementation Method 4

a joining mechanism bonding the two or more resin members together where at least one of surfaces to be joined facing each other is activated by the surface treatment mechanism

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 5

bonding the two or more resin members together at the respective surfaces to be joined

Methodology Applied
Scientific EffectDiffusion welding: Diffusion Welding

Data Source

PatentEP4116069B1Resin joined body production device and resin joined body production method
Publication Date: 2025.09.10 TORAY INDUSTRIES INC
  • EP4116069B1 patent drawingFigure 1
  • EP4116069B1 patent drawingFigure 2
  • EP4116069B1 patent drawingFigure 3

AI summary

Provided is an apparatus for producing an adhesion-free joined-resin product and a method for producing the joined-resin product having strong joining force without deteriorating optical properties and decreasing mechanical strength of resin members. The apparatus for producing the joined-resin product according to the present invention is an apparatus for producing a joined resin product in which two or more resin members are joined and includes a surface treatment mechanism and a joining mechanism. The surface treatment mechanism includes an electrode unit generating ionized gas and a member holding mechanism arranged at a position separated from the electrode unit by a space and holding the resin member, and activates a surface to be joined of the resin member held by the member holding mechanism, by the ionized gas generated by the electrode unit. The joining mechanism bonds the two or more resin members together where at least one of surfaces to be joined each other is activated by the surface treatment mechanism, at the respective surfaces to be joined.