Bronze chips

Bronze chips, an alloy primarily of Copper-Tin (Cu-Sn), are a high-performance multifunctional additive with three key roles:

• Superior Thermal Management: Bronze possesses excellent thermal conductivity. Its function is to efficiently dissipate heat from the friction interface, protecting the phenolic resin from degradation, which results in greater resistance to fading and lower wear at high temperatures.
• Mechanical Reinforcement: It provides great toughness and structural integrity to the composite, improving its hot compression resistance and preventing crack propagation.
• Friction Stabilization: The tin in the alloy helps to form stable oxide tribofilms at high temperatures, contributing to a more consistent coefficient of friction (µ) and reducing vibrations (NVH).

Although both are copper alloys and perform similar functions, the key difference lies in the second alloying metal (Tin vs. Zinc) and its high-temperature behavior:

• High-Temperature Performance: Bronze (Cu-Sn) generally offers superior performance to brass (Cu-Zn) under high thermal stress. Tin forms more stable oxides with better lubricating properties at high temperatures than zinc.
• Mechanical Properties: Bronze is typically harder and more wear-resistant than brass.
• Application: For these reasons, bronze is considered a more "premium" option, preferred in higher-performance formulations (e.g., OE, premium aftermarket) where high-temperature stability is critical, while brass is an excellent choice for solid performance across a wide range of standard applications.

This is one of RIMSA's core competencies. Transforming a recycled material into a high-specification raw material requires deep process knowledge:

• Source Selection and Control: It starts with a rigorous selection of suppliers and recycled material sources to ensure a high-quality base.
• Advanced Processes: RIMSA applies advanced sorting, cleaning, drying, and morphological control processes to eliminate impurities and ensure that each batch meets the required chemical and physical specifications.
• Lot-to-Lot Consistency: The result is a product with a controlled particle size distribution (PSD) and consistent chemical composition, ensuring predictable and reliable performance in the customer's final formulation.

This is a critical consideration for the formulator:

• Copper Content: Like brass, the copper present in bronze counts towards the "Copper-Free" regulation (SAE J2975). The dosage must be adjusted to comply with Level B (<5% Cu) or Level N (<0.5% Cu).
• Lead (Pb) Content: Certain grades of recycled bronze may contain traces of lead. RIMSA, through its strict quality control, manages and controls this element. For applications requiring a guaranteed lead-free solution, RIMSA offers high-performance alternatives such as ecoBronze.

The choice of chip size is a fine-tuning parameter:

• Coarse Grades: Maximize mechanical reinforcement and thermal conductivity by creating more effective "bridges" for heat.
• Fine Grades: Improve dispersion in the mix, leading to greater homogeneity, better processability (compaction), and often better NVH behavior. The choice will depend on the desired balance between thermal-mechanical performance and comfort.