Copper-Free NAO Friction Material Manufacturing via Thermoset-Plastic Composite Binder
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Solution Overview
Problem
Conventional manufacturing methods for copper and elemental copper-free Non-Asbestos-Organic (NAO) friction materials for brake pads and drum brake shoes fail to provide sufficient fade resistance and mechanical strength, leading to potential cracking and brake noise issues.
Innovation Solution
A manufacturing method involving a mixing step followed by a kneading step where the raw friction material mixture is heated and pressed in a sealed kneader to create a dense structure, and then hot-pressed to produce a friction material with improved heat dissipation and mechanical strength, using a thermosetting resin binder and specific fiber and friction modifier compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If copper is removed from NAO friction material to address environmental concerns, then environmental compatibility is improved, but fade resistance deteriorates due to reduced heat dissipation capability
Solution Approach 1:
The patent uses a composite binder system combining thermoplastic resin (5-20 parts) and thermosetting resin (80-95 parts) to create a multi-phase material structure. This composite approach allows the thermoplastic component to enhance heat dissipation and fade resistance while the thermosetting resin provides binding functionality, achieving copper-free formulation with improved thermal performance.
Solution Approach 2:
The patent modifies the chemical composition parameters of the binder system by specifying precise weight ratio ranges of thermoplastic to thermosetting resin components. This parameter optimization enables control over thermal conductivity and heat dissipation characteristics, compensating for the removal of copper while maintaining fade resistance through compositional tuning.
2Device complexity
If conventional mixing and pre-forming steps are used without kneading, then manufacturing complexity is reduced, but mechanical strength deteriorates leading to cracking
Solution Approach 1:
The patent introduces a kneading step performed before hot press molding to pre-distribute the binder components and friction modifiers uniformly throughout the friction material composition. This preliminary mixing action ensures homogeneous material structure that prevents cracking during subsequent molding and curing processes, eliminating the need for additional reinforcement steps.
Solution Approach 2:
The patent replaces conventional mechanical mixing methods with a kneading process that uses controlled thermal and mechanical energy input in a specific sequence. This substitution transforms the mixing mechanism from simple mechanical stirring to a thermomechanical kneading process that enhances material homogeneity and structural integrity.
3Device complexity
If thermosetting resin binder is used without thermoplastic resin, then binder simplicity is improved, but heat dissipation capability deteriorates causing increased brake fade
Solution Approach 1:
The patent creates a composite binder system where thermoplastic resin (5-20 parts by weight) and thermosetting resin (80-95 parts by weight) work synergistically. The thermoplastic component provides enhanced heat dissipation pathways and thermal stability, while the thermosetting resin ensures strong bonding, achieving balanced thermal and mechanical performance.
Solution Approach 2:
The patent assigns different functional qualities to different binder components: the thermoplastic resin specifically addresses heat dissipation and thermal conductivity requirements, while the thermosetting resin handles binding and structural integrity. This functional differentiation allows each component to optimize its local performance contribution.
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 results in friction materials with enhanced fade resistance and mechanical strength, reducing the likelihood of cracking and improving brake performance without using copper or elemental copper.
Implementation Method 1
The molded friction material is heated in a heat chamber to complete curing of a thermosetting resin as a binder involved in the friction material
Implementation Method 2
A fading phenomenon is caused due to a decomposition gas generated as an organic substance in the friction material is decomposed when the temperature and the load of the friction material become higher; however, the copper with the high thermal conductivity is added in the friction material, and the heat dissipation of the friction material itself increases to restrict the generation of the decomposition gas
Data Source
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AI summary
[Object] To provide the manufacturing method for a copper and elemental copper free NAO friction material providing an excellent fade resistance and high mechanical strength. [Means to Resolve] This manufacturing method includes the mixing step of mixing the raw friction material compounds to obtain the raw friction material mixture, the kneading step to apply the raw friction material mixture in the sealed type kneader to knead while maintaining the melting temperature of the thermosetting resin in the kneader or higher but lower than the curing temperature under the predetermined pressure to obtain the kneaded raw friction material, the sizing step of sizing the kneaded raw friction material to obtain the raw friction material granulation article, and the hot press molding step of filling the raw friction material sized particles in the molding die to hot press molded by the press machine.