Plasma Cord Coating Device for Tire Reinforcement

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Solution Overview

Problem

Existing methods for reinforcing rubber articles, such as tires, face challenges in achieving high and consistent adhesion of reinforcement cords to rubber over time, often relying on expensive cobalt compounds that can cause aging issues and environmental concerns.

Innovation Solution

A plasma cord coating device with parallel plate electrodes and dielectric barriers, using conveyor foils to maintain a plasma treatment zone and inject gas directly, allowing for continuous cord coating without fouling, thereby improving adhesion and reducing the need for costly cobalt compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional coating methods using cobalt compounds are used, then adhesion properties are improved, but environmental harm and aging problems increase

Engineering Contradiction:
Improveadhesion propertiesVSAvoidenvironmental harm and aging
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the coating compound by replacing cobalt-based bonding promoters with alternative compounds such as zinc salts, manganese salts, or organic bonding promoters. This parameter change maintains adhesion properties while eliminating the harmful effects and aging problems associated with excess cobalt compounds.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If plasma coating is used to reduce cobalt compounds, then environmental impact is reduced, but coating uniformity and adhesion consistency may worsen

Engineering Contradiction:
Improveenvironmental impactVSAvoidadhesion consistency
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention applies preliminary plasma treatment to the cord surface before coating to activate the surface and create anchoring sites. This preliminary action ensures that the reduced-cobalt coating compounds achieve uniform distribution and consistent adhesion, preventing variability in coating quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention replaces conventional mechanical or chemical coating methods with plasma-based coating technology. Plasma coating provides uniform deposition of coating compounds on the cord surface through physical and chemical interactions, ensuring consistent adhesion properties without the environmental harm of traditional methods.

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

3Productivity

If continuous plasma coating is implemented, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improvecoating speedVSAvoidplasma generation system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention implements a continuous plasma coating system where cords pass through a plasma treatment zone without interruption. The plasma generator operates continuously, maintaining a stable plasma field that coats cords as they move through the system, thereby achieving high productivity while the standardized design keeps device complexity manageable.

Inventive Principle:
Principle #20Continuity of useful action

4Strength

If cobalt salt is increased to maximize bonding strength, then adhesion is improved, but cost and environmental harm increase

Engineering Contradiction:
Improvebonding strengthVSAvoidcobalt salt quantity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The invention changes the chemical parameters by substituting cobalt salt with alternative bonding promoter compounds such as zinc salts, manganese salts, or organic compounds. This parameter change maintains the necessary bonding strength through equivalent or superior chemical mechanisms while reducing the quantity of harmful substances and associated costs.

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 device enables efficient, uniform plasma coating of cords from all sides in a single pass, enhancing adhesion properties while minimizing environmental impact and reducing maintenance intervals, thus improving the productivity and cost-effectiveness of the coating process.

Implementation Method 1

a plasma generator where atmospheric plasma can be generated from an atomized mixture

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

a dielectric barrier discharge apparatus is disclosed, said apparatus comprising a quartz tube with aluminum tape electrodes wrapped at a spaced interval on the exterior of the tube

Methodology Applied
Scientific EffectDielectric barrier discharge:

Implementation Method 3

a gas supply means for directing or injecting gas into the plasma treatment zone, wherein said gas supply means is positioned upstream of the plasma treatment zone with respect to the direction of transport

Methodology Applied
Scientific EffectGas injection:

Implementation Method 4

a pair of driven conveyor (belt) foils comprising a first foil and a second foil, wherein the first foil (movably) extends through the gap and covers the first dielectric barrier and the second foil (movably) extends through the gap and covers the second dielectric barrier

Methodology Applied
Scientific EffectConveyor belt transport:

Data Source

PatentEP3865292B1A plasma cord coating device
Publication Date: 2023.06.07 THE GOODYEAR TIRE & RUBBER CO
  • EP3865292B1 patent drawingFigure 1
  • EP3865292B1 patent drawingFigure 2
  • EP3865292B1 patent drawingFigure 3~4

AI summary

The present invention is directed to a plasma cord coating device comprising a pair of opposite and parallel plate electrodes having a first electrode and a second electrode, a pair of planar and parallel dielectric barriers including a first dielectric barrier and a second dielectric barrier, wherein the first electrode is covered by the first dielectric barrier on a side facing the second electrode and the second electrode is covered by the second dielectric barrier on a side facing the first electrode so as to form a gap between the first and the second dielectric barriers. Moreover, the device comprises a pair of driven conveyor foils comprising a first foil and a second foil, wherein the first foil extends through the gap and covers the first dielectric barrier and the second foil extends through the gap and covers the second dielectric barrier so as to form a plasma treatment zone between the first foil and the second foil. Furthermore, the device comprises transport means for continuously transporting, in a direction of transport and spaced apart from the first foil and the second foil, at least one cord through the plasma treatment zone, and a gas supply means for directing gas into the plasma treatment zone, wherein said gas supply means is positioned upstream the plasma treatment zone with respect to the direction of transport. Furthermore, the present invention is directed to a method of coating a cord with said plasma cord coating device, as well as a cord reinforced product obtained with said method.