Antistatic Tire Tread Conductive Layer Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reduction of carbon black in tire elastomeric compounds to lower rolling resistance results in increased electrical resistance, leading to inadequate electrostatic charge dissipation, which can cause accumulation of undesirable electrical charges on vehicles during travel, and existing solutions face issues with adhesion, wear, and manufacturing complexity.
Innovation Solution
A process involving the use of ultrafine, structured carbon black with specific BET surface area and Oil Absorption Number, applied as a thin conductive layer within the tire tread band, ensuring homogeneous conductivity and adhesion without compromising wear or manufacturing simplicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If carbon black amount is reduced to lower rolling resistance, then rolling resistance decreases, but electrical resistance increases leading to inadequate electrostatic charge dissipation
Solution Approach 1:
The patent applies local quality by creating a conductive layer with specific carbon black concentration (at least 50 phr) in the tread band region where electrostatic dissipation is needed, while allowing other tire regions to use reduced carbon black formulations for low rolling resistance. This localized conductive layer ensures reliable electrostatic charge dissipation without compromising the overall low rolling resistance performance of the tire.
Solution Approach 2:
The patent uses composite materials by combining carbon black (at least 50 phr) with silica and other elastomeric compounds to create a tread band composition that simultaneously achieves both low rolling resistance and high electrical conductivity. The specific composite formulation includes carbon black, silica, and other additives in controlled amounts to balance hysteretic losses with conductive pathways for electrostatic dissipation.
2Reliability
If conductive insert is added to restore electrostatic charge release, then electrostatic dissipation is restored, but device complexity and manufacturing steps increase
Solution Approach 1:
The patent merges the electrostatic dissipation function directly into the tread band structure by incorporating a conductive layer as an integral part of the tread band during the building process. This eliminates the need for separate conductive inserts and their associated mounting steps, thereby reducing device complexity while maintaining reliable electrostatic charge dissipation capability.
Solution Approach 2:
The tread band structure serves multiple functions: it provides the primary contact surface for rolling, maintains low rolling resistance through optimized compound formulation, and simultaneously provides electrostatic charge dissipation through the integrated conductive layer. This multi-functionality eliminates the need for separate dedicated conductive components, simplifying the overall device structure.
3Reliability
If conductive material is applied to green elastomeric material before winding, then electrostatic conductivity is achieved, but adhesion deteriorates causing tearing phenomena
Solution Approach 1:
The patent applies preliminary action by incorporating the conductive layer into the green elastomeric material itself before the winding and vulcanization process. The conductive compounds are mixed into the green state material, ensuring uniform distribution and strong adhesion throughout the tread band structure before any tearing-prone operations occur during manufacturing.
Solution Approach 2:
The patent uses composite materials by formulating the green elastomeric material with conductive compounds (carbon black, silica, and other additives) to create a homogeneous conductive matrix. This composite approach ensures both electrostatic conductivity and mechanical integrity, as the conductive components are uniformly distributed and bonded within the elastomeric matrix before vulcanization, preventing adhesion deterioration and tearing.
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 solution achieves high and homogeneous electrical conductivity, preventing charge accumulation, reducing irregular wear, and simplifying the manufacturing process while maintaining tire performance and mileage.
Implementation Method 1
The electrostatic charges that accumulate on the body of the traveling vehicle are transmitted to the tyre itself through the rim of the wheel and fully cross the structure of the tyre moving through the aggregates of carbon black present in the polymeric matrix of the elastomeric material
Implementation Method 2
The electrostatic charges that accumulate on the body of the traveling vehicle are transmitted to the tyre itself through the rim of the wheel and fully cross the structure of the tyre moving through the aggregates of carbon black present in the polymeric matrix
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
The invention describes a process for manufacturing a tyre (1 ) for vehicle wheels comprising a tread band (7) at a radially outer position with respect to an inner tyre component (2, 6) of tyre (1 ) having at least one electrically conductive surface (6a). The process comprises forming an electrically conductive layer (7a) in the thickness of the tread band (7) between portions (7b, 7e) of the tread band (7) arranged at an axially contiguous position and formed by depositing at least one continuous elongated element of green elastomeric material according to contiguous circumferential coils (10). The electrically conductive layer (7a) comprises an electrically conductive material comprising at least one carbon black having a BET surface area, measured in accordance with standard ASTM D 6556-16, of at least 300 m2/g and an OAN (Oil Absorption Number) absorption value, measured in accordance with standard ASTM D2414-16, equal to or greater than 200 (ml oil/100 g carbon black).