Silicate Fibre Masterbatch Process for Tyre Elastomers

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Solution Overview

Problem

The incorporation of powdery needle-shaped silicate fibres in elastomeric compositions for tyres is challenging due to their high powdery nature, leading to difficulties in handling, dosage, dispersability, contamination, and potential toxicity, with existing methods like continuous thermomechanical mixing requiring strict conditions and high energy consumption.

Innovation Solution

A discontinuous process for preparing a solid master elastomeric composition with high fibre content and uniformity, using a weight ratio of silicate fibres to elastomer latex of at least 0.5:1, maintaining the pH between 7.5 and 12.0, and adjusting the volumetric ratio to facilitate uniform coagulation and separation without the need for acids or salts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If powdery needle-shaped silicate fibres are directly mixed in solid elastomeric matrix using classic batch mixers, then the fibres can be incorporated into the elastomeric material, but the fibres are difficult to handle and add to mixers, creating problems with dosage, dispersability, contamination, and potential toxicity

Engineering Contradiction:
Improveease of handling fibresVSAvoidtoxicity and contamination
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical state parameter of the silicate fibres from dry powder to wet form (suspension in water or other liquid). This parameter change transforms the difficult-to-handle powdery material into an easier-to-manage liquid suspension, resolving the handling and safety issues while maintaining the reinforcing properties of the fibres

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a liquid medium (water or other liquid) as an intermediary substance to carry the silicate fibres. This intermediary allows the fibres to be transported and mixed more easily, preventing direct contact with operators and eliminating the harmful effects associated with handling dry powdery fibres

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If continuous thermomechanical mixing is used to incorporate fillers into elastomeric materials, then the mixing process can be continuous, but the process requires considerable energy and strict controlled conditions

Engineering Contradiction:
Improvecontinuous mixing capabilityVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent uses hydraulic mixing by incorporating fibres into a liquid elastomeric matrix (latex suspension) rather than using mechanical continuous mixers. This hydraulic approach allows for easy mixing and incorporation without the high energy consumption and complex equipment required by continuous thermomechanical mixing processes

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the consistency parameter of the elastomeric matrix from solid to liquid (latex suspension). This parameter change enables simpler, lower-energy mixing processes while maintaining the ability to produce continuous elastomeric materials with incorporated fibres

Inventive Principle:
Principle #35Parameter changes

3Strength

If high fibre content is incorporated into the elastomeric composition, then the mechanical properties and abrasion resistance are improved, but the handling and dispersability become more difficult

Engineering Contradiction:
Improvemechanical propertiesVSAvoiddispersability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent changes the physical state parameter of both the fibres and the elastomeric matrix to liquid/wet form. This allows high fibre content to be incorporated easily since the liquid suspension form eliminates the handling and dispersability problems associated with high concentrations of dry powdery fibres, while still achieving the desired mechanical reinforcement

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

This process allows for the production of concentrated and uniform master batches with nearly quantitative yields, enabling easy incorporation of silicate fibres into elastomeric compositions, improving mechanical and abrasion resistance while reducing rolling resistance and hysteresis in tyres.

Implementation Method 1

incorporation of them in solid master compositions (masterbatch MB)... incorporating of the fibres in the form of wet fibres, i.e. with a high content of residual water

Methodology Applied
Scientific EffectSuspension: Suspension

Implementation Method 2

maintaining or bringing the pH of the aqueous suspension to a value comprised between 7.5 and 12.0... to yield a final suspension (C) allowing said elastomeric composition to precipitate and separate

Methodology Applied
Scientific EffectCoagulation: Coagulation

Implementation Method 3

maintaining or bringing the pH of the aqueous suspension to a value comprised between 7.5 and 12.0... allowing said elastomeric composition to precipitate and separate from said final suspension

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP3558703B1Elastomeric compositions comprising silicate fibres with needle-shaped morphology of nanometric size and tyres for vehicles that comprise them
Publication Date: 2022.03.09 PIRELLI TYRE SPA
  • EP3558703B1 patent drawingFigure 1
  • EP3558703B1 patent drawingFigure 2

AI summary

The present invention regards a solid master elastomeric composition (masterbatch, MB) comprising silicate fibres with needle-shaped morphology of nanometric size, characterised by high fibre content and uniformity, a process advantageous for the preparation thereof and its use in manufacturing tyres for vehicles. Advantageously the present elastomeric composition allows minimising the drawbacks associated with the handling of the powdery fibres in the manufacturing of compounds for tyres, without altering the final performances thereof.