Tyre Reinforcing Component Plasma Coating Without RFL Adhesives

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Solution Overview

Problem

The use of Resorcinol-Formaldehyde-Latex (RFL) compositions in tyre manufacturing is toxic, unstable, and leads to environmental pollution and increased manufacturing cycle times, while alternative adhesive systems fail to match RFL's adhesion performance.

Innovation Solution

A manufacturing process using a plasma gas generated from an oxazolinic precursor to create an adhesive coating layer on polymeric elongated elements, which are then integrated into the elastomeric compound, providing effective adhesion without toxic substances and reducing manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If RFL-based adhesive compositions are used to achieve optimal adhesion between elongated elements and elastomeric compound, then adhesion performance is improved, but toxicity and environmental pollution increase

Engineering Contradiction:
Improveadhesion performanceVSAvoidtoxicity and environmental pollution
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention uses plasma treatment to activate the surface of elongated elements, creating reactive groups that enable adhesion without toxic chemicals. The plasma process converts the harmful dependency on RFL chemicals into a beneficial physical-chemical treatment that achieves equivalent or superior adhesion performance while eliminating toxicity and environmental pollution concerns

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention replaces the chemical-based RFL adhesive system with a physics-based plasma treatment system. Instead of using chemical reactions between resorcinol, formaldehyde, and latex, the patent uses plasma energy to directly modify the surface properties of elongated elements, creating adhesion-promoting functional groups through physical-chemical processes without introducing toxic substances

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

2Strength

If RFL-based adhesive compositions are used to ensure adhesion, then bonding strength is improved, but manufacturing cycle time increases due to maturation requirements

Engineering Contradiction:
Improveadhesion performanceVSAvoidmanufacturing cycle time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The plasma treatment is applied as a preliminary surface activation step before elastomeric compound application. This pre-treatment creates immediate adhesion-promoting conditions on the elongated element surface, eliminating the need for subsequent chemical maturation periods and enabling faster production cycles while maintaining strong bonding

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention skips the time-consuming maturation step required by RFL systems by using plasma treatment that provides immediate adhesion capability. The plasma process activates the surface in seconds or minutes rather than requiring hours of chemical maturation, allowing the production process to move directly to elastomeric compound application and curing

Inventive Principle:
Principle #21Skipping (Rushing through)

3Ease of manufacture

If traditional dipping methods are used to apply adhesive, then process simplicity is maintained, but adhesion performance is insufficient for difficult-to-bind materials

Engineering Contradiction:
Improveprocess simplicityVSAvoidadhesion performance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention changes the fundamental parameter of surface treatment from chemical immersion to plasma exposure. This parameter change enables effective adhesion for difficult-to-bind materials like aromatic polyamides and polyesters that resist traditional RFL treatment, while the plasma process remains relatively simple to implement and control through adjustment of power, gas flow, and exposure time

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 process achieves adhesion performance comparable to RFL systems, is environmentally friendly, and reduces manufacturing time and pollution, ensuring the structural integrity and durability of tyres.

Implementation Method 1

coating said at least one polymeric elongated element comprises: positioning said polymeric elongated element between two electrodes placed in a working chamber; introducing between said two electrodes an activator gas and a precursor gas comprising an oxazolinic precursor; generating between said two electrodes a plasma gas comprising reactive fragments of said oxazolinic precursor; depositing said reactive fragments on a free surface of said polymeric elongated element for making said adhesive coating layer

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP4171967B1Manufacturing process of a reinforcing component for a tyre, and related manufacturing process of tyres
Publication Date: 2024.06.05 PIRELLI TYRE SPA
  • EP4171967B1 patent drawingFigure 1
  • EP4171967B1 patent drawingFigure 2a~2b
  • EP4171967B1 patent drawingFigure 3a

AI summary

Manufacturing process of a reinforcing component for a tyre, the process comprising: - arranging at least one polymeric elongated element (10); - coating the at least one polymeric elongated element (10) with an adhesive coating layer for making at least one sticky elongated element (11 ); - providing an elastomeric compound comprising at least one elastomeric polymer, at least one reinforcing filler and components capable of facilitating the vulcanization; - coating the at least one sticky elongated element (11 ) with the elastomeric compound, wherein coating the at least one polymeric elongated element (10) comprises: - positioning the polymeric elongated element (10) between two electrodes (90a, 90b) placed in a working chamber (100); - introducing between the two electrodes (90a, 90b) an activator gas and a precursor gas comprising an oxazolinic precursor; - generating between the two electrodes a plasma gas comprising reactive fragments of the oxazolinic precursor; - depositing the reactive fragments on a free surface of the polymeric elongated element (10) for making the adhesive coating layer.