In the field of clutch facings manufacturing, Vermiculite has gradually found its way into the production process as an important component in clutch facings friction materials. When blended into clutch facings mixture and clutch facings mixes, Vermiculite can significantly influence the performance of the final clutch facings products.

Vermiculite is generally added to the clutch facings mixture at a weight percentage of 8% – 20%. It has unique physical properties such as low density and high porosity. In the clutch facings production, it mainly serves multiple functions. Firstly, it acts as a thermal insulator, helping to reduce heat transfer within the clutch system. Secondly, it can improve the friction – damping characteristics of the clutch facings, enhancing the smoothness of clutch operation.

Clutch facings with 15% Vermiculite content exhibit remarkable thermal insulation properties. In a thermal conductivity test, the thermal conductivity of these clutch facings was measured to be 0.05 – 0.07 W/(m·K), which is approximately 30% – 40% lower than that of clutch facings without Vermiculite (usually 0.08 – 0.12 W/(m·K)). This low thermal conductivity effectively prevents excessive heat from being transferred to other parts of the clutch during operation, protecting components from heat – induced damage. For instance, in a high – performance vehicle clutch, the use of Vermiculite – containing clutch facings can reduce the temperature of adjacent metal parts by 10 – 15°C under high – load conditions.

Vermiculite – enhanced clutch facings can withstand high temperatures up to 600°C without significant degradation. In a heat – resistance test, when exposed to a continuous high – temperature environment of 500°C for 3 hours, the clutch facings with Vermiculite maintained their structural integrity and friction performance, while those without Vermiculite showed signs of deformation and reduced friction coefficient.

Vermiculite can improve the friction – damping characteristics of clutch facings. In a clutch engagement – disengagement test, the clutch facings with Vermiculite showed a more stable and smooth operation. The vibration amplitude during clutch operation was reduced by about 25% – 35% compared to clutch facings without Vermiculite. This results in a more comfortable driving experience, minimizing jerks and vibrations during gear changes.

The friction coefficient of clutch facings with Vermiculite remains relatively stable under different operating conditions. In a friction – coefficient test conducted at various speeds (ranging from 200 – 2000 RPM) and loads (from 20 – 150 N), the friction coefficient of Vermiculite – containing clutch facings fluctuated within a narrow range of 0.22 – 0.25, with a deviation of less than ±5%.

Due to its low density, adding Vermiculite to the clutch facings mixture can reduce the overall weight of the clutch facings. Clutch facings with 12% Vermiculite content are approximately 10% – 15% lighter than those without Vermiculite. This weight reduction is beneficial for vehicle fuel efficiency, especially in applications where every gram of weight matters, such as in racing cars or fuel – economy – oriented vehicles.

Vermiculite has relatively low mechanical strength. In a tensile – strength test, the tensile strength of clutch facings with Vermiculite was only 8 – 10 MPa, which is about 30% – 40% lower than that of clutch facings without Vermiculite (usually 12 – 15 MPa). This lower strength may limit the application of Vermiculite – containing clutch facings in high – stress environments, as they are more prone to breakage or deformation under excessive mechanical forces.

The wear resistance of clutch facings with Vermiculite is also relatively poor. In a wear – test over 100,000 clutch engagement – disengagement cycles, the wear depth of clutch facings with Vermiculite was 0.4 – 0.5 mm, while that of non – Vermiculite – containing clutch facings was 0.2 – 0.3 mm. This means that clutch facings with Vermiculite may need to be replaced more frequently, increasing maintenance costs.

Vermiculite is hygroscopic, which means it can absorb moisture from the environment. In a humidity – absorption test at 70% relative humidity for 48 hours, the moisture content of clutch facings with Vermiculite increased by about 8% – 10%. Moisture absorption can lead to a decrease in the thermal insulation and mechanical properties of the clutch facings over time. It may also cause corrosion of adjacent metal parts in the clutch system.

In conclusion, Vermiculite offers certain advantages in clutch facings production, including excellent thermal insulation, good friction – damping properties, and lightweight characteristics. However, its low mechanical strength and hygroscopicity are significant drawbacks that need to be addressed. With further research and development to overcome these limitations, Vermiculite could potentially play a more important role in the clutch facings industry.