Copper fibres

Copper Fiber is a very high-performance additive with two primary functions that are critical for brake performance:

• Maximum Thermal Conductivity: Pure copper offers the highest thermal conductivity among metals commonly used in friction (~400 W/m·K). Its function is to evacuate heat from the friction interface as quickly and efficiently as possible. This dramatically minimizes fading and protects the integrity of the resin matrix at high temperatures.
• Ductile and Tough Reinforcement: The fiber morphology creates a 3D metallic skeleton that endows the composite with great toughness and ductility. This increases resistance to impact fracture and crack propagation, maintaining the pad's integrity under severe conditions.

The main difference lies in thermal performance and mechanical properties:

• Thermal Conductivity: Pure copper is significantly superior to brass (~120 W/m·K) and bronze (~70 W/m·K) in heat dissipation. It is the preferred choice when managing high temperatures is the most critical factor.
• Mechanical Properties: Copper is softer and more ductile than its alloys. While bronze offers greater hardness, copper provides superior toughness, which can be beneficial for vibration damping (NVH).
• Application: Copper Fiber is the gold standard for high-performance applications (OE, racing) where its use is still permitted. Alloys like bronze and brass represent an engineering compromise to balance performance, cost, and mechanical properties.

RIMSA's expertise in processing recycled metals is key to delivering a high-specification product:

• Source Selection and Purification: A rigorous process of selecting and purifying recycled copper sources is implemented to ensure high conductivity and eliminate impurities that could affect performance.
• Morphological and Dimensional Control: Advanced processes are applied to ensure the fiber meets exact specifications for length and diameter, which is essential for homogeneous dispersion and predictable reinforcement.
• Lot-to-Lot Consistency: Thanks to this exhaustive control, RIMSA guarantees that each batch of copper fiber offers consistent thermal and mechanical performance, an indispensable requirement for original equipment manufacturers (OEMs).

This is the most important consideration for its use:

• Directly Regulated Use: Copper Fiber is the main contributor to the copper content in a formulation. Its use is intended for applications that still allow a certain percentage of this metal, according to the SAE J2975 legislation:
  • Level A: Allows up to 25% copper by weight.
  • Level B: Allows less than 5% copper by weight.
• Incompatible with Level N: This product is not suitable for "N-Level" or "Zero-Copper" formulations, which require a copper content of less than 0.5% by weight. The transition to Level N requires the complete replacement of copper fiber with other reinforcement and thermal management systems.

The fiber's geometry (length and diameter) is a determining factor in processability:

• Dispersion: Achieving a homogeneous dispersion of copper fiber is crucial to avoid the formation of nests, which can create localized hot spots and structural defects.
• Compaction: The amount and geometry of the fiber directly affect the green density (before curing) and the compressibility of the mix. An excess of fiber or an inadequate geometry can hinder compaction.
  RIMSA offers different grades to allow the formulator to find the optimal balance between maximum thermal performance and robust processability.