SF – BSF series

The SF series is a family of engineered composites based on a Tin (II) Sulfide (SnS) and Iron (II) Sulfide (FeS) system. They are not a simple physical blend but a co-processed product where both sulfides are intimately linked. This composite structure ensures a synergistic and homogeneous tribochemical reaction at the braking interface.

Its main function is to act as a high-performance solid lubricant and friction stabilizer over a wide temperature range. The combined mechanism of action allows for:

• Stabilizing the Coefficient of Friction (µ): The synergistic interaction of tin and iron sulfides with the phenolic resin at high temperatures creates a very robust and stable tribofilm, resulting in excellent fade resistance.
• Reducing Wear: The formed transfer layer effectively protects both the pad and the disc, reducing wear rates, especially under demanding conditions.
• Improving NVH: By stabilizing friction and preventing in-stop variability (stick-slip), they contribute to quieter and more comfortable braking.

The SF series is designed to replace traditional lubricants like Antimony Trisulfide (Sb₂S₃) and Tin Disulfide (SnS₂), offering two crucial advantages:

• Cost and Supply Stability: Unlike antimony and tin, whose prices are subject to the high volatility of the LME (London Metal Exchange), the SF series incorporates iron sulfide, which significantly reduces dependence on these markets. This translates into a lower, more stable, and predictable final cost, and a more secure supply chain.
• High Performance without Antimony: It allows formulators to eliminate antimony (a substance under regulatory scrutiny) without compromising high-temperature performance.

The main difference is the ratio between Tin Sulfide and Iron Sulfide:

• SF50: 1:1 ratio (SnS:FeS) - Approx. 50% Tin.
• SF36: 1:2 ratio (SnS:FeS) - Approx. 36% Tin.
• SF30: 1:3 ratio (SnS:FeS) - Approx. 30% Tin.

This range allows the formulator to "tune" the balance between performance and cost. A higher tin content (SF50) generally provides maximum performance in high-temperature stability, while a higher iron content (SF30) offers the most cost-competitive solution while still maintaining performance far superior to pure iron sulfides.

The SF series is very versatile and is ideal for:

• "Copper-Free" NAO Formulations: Where a high-performance solution for high-temperature friction management is required in the absence of copper.
• Sb₂S₃ Replacement: As a "drop-in" alternative to modernize formulations and eliminate antimony, often with an improved cost/performance ratio.
• Passenger Car (PC) and Commercial Vehicle (CV) Applications: Its ability to adjust performance and cost makes it suitable for a wide range of applications, from original equipment (OE) to the aftermarket.