Friction Material Hot Blending for Thermal Conductivity
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Solution Overview
Problem
Existing friction materials for braking elements lack stability and performance without asbestos and copper, leading to increased wear and fragility, and existing solutions are complex and costly.
Innovation Solution
A method involving hot blending with a roll blender at atmospheric pressure, followed by grinding and traditional blending, to create a friction material with improved thermal conductivity and mechanical strength, using organic and metallic fibers, binders, and fillers, without the need for sealed chambers or excessive processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If copper-free friction materials are used to meet environmental standards, then environmental compliance is improved, but thermal conductivity decreases and fragility increases
Solution Approach 1:
The patent uses a composite material system combining organic fibers (cellulose, aramid), inorganic fillers (barium sulfate, calcium carbonate), and metallic powders (aluminum, iron, steel) to replace copper fibers. This composite approach maintains mechanical strength and thermal conductivity without using copper or asbestos, achieving both environmental compliance and performance requirements.
Solution Approach 2:
The patent modifies the chemical composition parameters of the friction material by adjusting the types and proportions of binders (phenolic resins, polyamides), fibers, and fillers. By changing these compositional parameters, the material achieves adequate thermal conductivity and mechanical strength without copper fibers, resolving the contradiction between environmental compliance and performance.
2Ease of manufacture
If conventional mixing methods are used for copper-free friction materials, then manufacturing simplicity is maintained, but micro gas bubbles form reducing heat dissipation
Solution Approach 1:
The patent applies a preliminary vacuum treatment step before molding to remove air bubbles from the friction material mixture. This preliminary action prevents bubble formation that would otherwise trap heat and reduce thermal conductivity, ensuring proper heat dissipation while maintaining a relatively simple manufacturing process.
Solution Approach 2:
The patent utilizes the phase transition of air from dissolved/gas phase to removed phase through vacuum treatment. By applying vacuum, air bubbles are extracted from the mixture before molding, preventing thermal insulation defects and ensuring adequate heat dissipation in the final product.
3Duration of action of moving object
If repeated braking operations are performed without adequate heat dissipation, then braking intervals are extended, but thermal buildup increases reducing braking efficiency
Solution Approach 1:
The composite friction material incorporates thermally conductive inorganic fillers (barium sulfate, aluminum oxide) and metallic powders (aluminum, iron, steel) that form a thermal conduction network. This network efficiently dissipates heat generated during braking, preventing thermal buildup and maintaining consistent braking intervals even under repeated operation.
Solution Approach 2:
The patent recreates the thermal management function previously provided by copper fibers through a different material system. By combining thermally conductive fillers and metallic powders in a matrix of organic fibers and binders, the material copies the heat dissipation capability of copper-free formulations while avoiding copper's environmental issues.
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 method produces a stable and efficient friction material with reduced wear and consistent braking performance, meeting environmental and health standards while simplifying the manufacturing process.
Implementation Method 1
hot blending with a roll blender at atmospheric pressure... to create a friction material with improved thermal conductivity
Implementation Method 2
followed by grinding and traditional blending, to create a friction material with improved thermal conductivity and mechanical strength
Implementation Method 3
molding under pressure, at a temperature equal to or higher than a polymerization or curing temperature of the organic binder
Data Source
AI summary
Method for manufacturing an asbestos-free friction material having as component materials inorganic and/or organic and/or metallic fibers, at least one organic binder, at least one friction modifier or lubricant and at least a filler or abrasive. The raw components of the friction material are mixed together to obtain a raw mixture which is then molded to obtain a block or layer of friction material. The mixing step includes a first step of hot blending of at least part of the organic binder with at least part of the other components of the friction material by a rolling mill blender that is open to atmospheric pressure at a temperature lower than the polymerization temperature of the organic binder but greater than or equal to its softening temperature, in order to obtain a semifinished solid product. A second step of grinding the semifinished solid product reduces the product to a powder.