Copper-Free Brake Pad Friction Material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-asbestos friction materials for brake pads struggle to replicate the performance characteristics of copper and titanate-containing materials, such as high friction coefficient, longevity, minimal rotor wear, and low brake dust, while being cost-effective and efficient in production.
Innovation Solution
A friction material composition comprising a binder, aramid fibers, metal sulfides, abrasives, and rubber powder, with minimal or no copper, titanates, and metal fibers, processed using a combination of mixing, pressing, and curing operations, which results in a cost-effective brake pad with improved efficiency and low scrap rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If copper is used in non-asbestos friction materials, then reinforcing strength, friction coefficient at high temperatures, heat transfer properties, and longevity are improved, but cost increases
Solution Approach 1:
The patent changes the material composition parameters by replacing copper with a combination of steel wool (0.1-5% by weight) and specific fiber content (3-15% by weight), adjusting the reinforcement mechanism while maintaining performance at lower cost
Solution Approach 2:
The patent uses cheaper alternative materials (steel wool and standard fibers) that can provide adequate reinforcement strength without the high cost of copper, accepting that these materials may have different service life characteristics
2Temperature
If titanates are used in non-asbestos friction materials, then high temperature stability and uniform transfer layer formation are improved, but cost increases
Solution Approach 1:
The patent modifies the thermal performance parameters by using a controlled combination of steel wool and fibers with specific properties, achieving adequate high-temperature stability without expensive titanate additives
Solution Approach 2:
The patent attempts to copy the functional benefits of titanates (heat resistance and transfer layer formation) using cheaper materials that can replicate these effects through different mechanisms
3Ease of manufacture
If steel fibers are used in place of copper and titanates, then cost is reduced, but rotor wear increases and dust generation increases
Solution Approach 1:
The patent applies local quality by using steel wool (0.1-5% by weight) in specific small amounts rather than bulk steel fibers, concentrating the reinforcement function where needed while minimizing harmful wear and dust generation
Solution Approach 2:
The patent creates a composite material system combining steel wool with organic fibers (cellulose, aramid, or polyacrylonitrile) to achieve a balanced formulation that provides reinforcement while reducing the harmful effects associated with pure steel fiber formulations
4Ease of manufacture
If high amounts of cashew dust are used in copper-free friction materials, then copper content is reduced, but processing complexity increases and scrap rates increase
Solution Approach 1:
The patent extracts the problematic processing requirements associated with high cashew dust formulations by using a more straightforward combination of steel wool and conventional fibers that can be processed using standard brake pad manufacturing methods
Solution Approach 2:
The patent uses readily available, inexpensive materials (steel wool and common fibers) that simplify the supply chain and processing compared to specialized materials like cashew dust, reducing both complexity and scrap rates
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 friction material achieves performance characteristics similar to copper and titanate-containing materials, with a 30-50% cost reduction and 25% lower scrap rates, passing vehicle application tests for stopping distance, life, and noise, while maintaining minimal rotor wear and brake dust.
Implementation Method 1
a binder; a fiber; a lubricant including at least one sulfide; at least one abrasive; a filler including rubber powder
Implementation Method 2
a lubricant including at least one sulfide
Implementation Method 3
at least one abrasive
Implementation Method 4
at least one abrasive
Implementation Method 5
a filler including rubber powder
Data Source
Figure 1
AI summary
A metal fiber, copper, and titanate free non-asbestos friction material for brake pads is provided. The friction material includes a binder, such as a phenolic resin, forming 16-24% by volume; a fiber, such as aramid fiber, forming 4-12% by volume; a lubricant, such as a blend of antimony tri-sulfide and another metal sulfide, forming 2-5% by volume; and at least one abrasive, such as a blend of mineral fiber, magnesium oxide, and mica, forming 10-22 % by volume. The friction material further comprises rubber powder in an amount of at least 4 % by volume. The brake pad can be formed by a cost effective process consisting essentially of mixing the ingredients, pressing and curing the friction material to a backing plate, and post baking the brake pad.