In the complex and crucial domain of clutch facings production, White Rock Wool has emerged as a material with unique properties that can significantly impact the performance of clutch facings friction materials. When integrated into clutch facings mixture and clutch facings mixes, it brings about a series of characteristics that are both advantageous and, to some extent, challenging.

White Rock Wool is typically incorporated into the clutch facings mixture at a proportion of 10% – 25% by weight. Its fine – fiber structure and distinct chemical composition endow it with functions that are highly relevant to clutch facings. It mainly serves as a thermal regulator, a mechanical reinforcer, and a contributor to the friction – coefficient stability of the clutch facings.

Clutch facings with 15% White Rock Wool content exhibit remarkable high – temperature tolerance. In a standard high – temperature test, these clutch facings can withstand temperatures up to 900°C without experiencing significant degradation of their mechanical and frictional properties. In contrast, clutch facings without White Rock Wool start to show signs of deformation and a decline in friction performance at around 650°C. This high – temperature resistance is crucial during high – speed driving or heavy – duty operations when the clutch generates substantial heat.

The thermal conductivity of clutch facings containing White Rock Wool is impressively low. Measured at room temperature, it ranges from 0.03 – 0.04 W/(m·K), which is approximately 40% – 50% lower than that of clutch facings without it (usually 0.06 – 0.08 W/(m·K)). This low thermal conductivity effectively inhibits heat transfer from the clutch facings to other components in the clutch system. For example, in a commercial vehicle clutch test, the use of White Rock Wool in the clutch facings reduced the temperature of the adjacent clutch housing by 20 – 25°C under high – load conditions, thus extending the lifespan of other components.

White Rock Wool significantly enhances the tensile strength of clutch facings. In a tensile – strength test, clutch facings with 20% White Rock Wool content demonstrated a tensile strength of 15 – 18 MPa, which is about 30% – 40% higher than that of clutch facings without White Rock Wool (usually 10 – 12 MPa). This increased tensile strength enables the clutch facings to better withstand the mechanical stresses during clutch engagement and disengagement, reducing the risk of breakage and wear.

The fatigue resistance of clutch facings is also improved with the addition of White Rock Wool. In a fatigue – test over 200,000 clutch engagement – disengagement cycles, the clutch facings with White Rock Wool showed only minor signs of wear and tear, while those without it exhibited significant fatigue – induced damage, such as cracks and material detachment.

White Rock Wool contributes to the stable friction coefficient of clutch facings. In a friction – coefficient test conducted under various speeds (ranging from 100 – 2500 RPM) and loads (from 15 – 200 N), the friction coefficient of clutch facings with White Rock Wool fluctuated within a narrow range of 0.25 – 0.28, with a deviation of less than ±3%. This stable friction coefficient ensures smooth and reliable clutch operation, minimizing the occurrence of sudden jerks or slips during gear changes.

White Rock Wool is relatively brittle, and its fibers can be easily broken under mechanical stress. In a bending – test, when the clutch facings with White Rock Wool were subjected to repeated bending forces, the number of broken fibers increased by about 15% – 20% after 50,000 cycles. This brittleness may gradually affect the long – term performance of the clutch facings, as broken fibers can lead to a decrease in mechanical strength and friction – coefficient stability.

During the manufacturing process and clutch operation, there is a risk of White Rock Wool fragmentation. Fragmented particles can potentially cause damage to the mating surfaces in the clutch system. In a wear – test, the mating steel surface showed a wear depth of 0.1 – 0.2 mm more when paired with clutch facings containing fragmented White Rock Wool compared to those without such fragmentation.

During the production and handling of White Rock Wool in the clutch facings manufacturing process, fine fibers can be released into the air. Inhalation of these airborne fibers over a long period may pose a risk to the respiratory health of workers. In a workplace air – quality monitoring study, the concentration of White Rock Wool fibers in the air during production was measured to be 0.5 – 1.0 fibers per cubic centimeter, which is above the recommended safe limit in some regions.

The disposal of clutch facings containing White Rock Wool at the end of their life cycle also presents challenges. Due to its non – biodegradable nature, improper disposal can lead to environmental pollution. Special disposal methods, such as high – temperature incineration or landfill in designated areas, are required, which increase the disposal cost and complexity.

In conclusion, White Rock Wool offers significant advantages in the production of clutch facings, including superior thermal resistance, enhanced mechanical strength, and a stable friction coefficient. However, its brittleness and environmental/health concerns are factors that need to be carefully addressed. With continuous research and the development of appropriate manufacturing and disposal techniques, White Rock Wool has the potential to further improve the quality and reliability of clutch facings friction materials.