In industrial noise reduction and architectural acoustics, ceramic fiber cotton leverages its porous structure and fiber properties to serve as a premium material offering both thermal insulation and sound absorption capabilities. The fiber diameter of ceramic fiber cotton directly influences its internal pore distribution and sound energy dissipation efficiency. Understanding the acoustic performance differences among ceramic fiber cotton with varying fiber diameters is crucial for precisely matching noise reduction requirements. This comparative experiment selected ceramic fiber wool with three representative fiber diameters: 3μm ultra-fine, 6μm standard, and 10μm coarse. Using professional acoustic testing equipment, the sound absorption performance differences were analyzed across the common acoustic frequency range of 250Hz–4000Hz.
Prior to testing, all ceramic fiber cotton samples underwent standardized preparation: each fiber diameter type was processed into 50mm-thick, 128kg/m³ density standard specimens, ensuring consistency in all critical parameters affecting sound absorption except fiber diameter. The impedance tube method was employed for testing. Following GB/T 18696.1 standards, the sound absorption coefficients of each specimen were measured at frequencies of 250Hz, 500Hz, 1000Hz, 2000Hz, and 4000Hz. Each frequency point was tested three times, with the average value taken as the final data to minimize random errors.

Comparative analysis of low-frequency (250Hz-500Hz) sound absorption performance indicates that ceramic fiber batting with smaller fiber diameters delivers superior acoustic absorption. The 3μm ultra-fine ceramic fiber cotton achieved an absorption coefficient of 0.32 at 250Hz, rising to 0.45 at 500Hz. The 6μm standard ceramic fiber cotton recorded absorption coefficients of 0.25 and 0.38 at the same frequencies, respectively. while the 10μm coarse fiber type only reached 0.18 and 0.29. This occurs because the ultra-fine fiber diameter creates a denser pore structure within the ceramic fiber cotton. During low-frequency propagation, sound waves more readily collide with the fine fibers, generating friction that converts acoustic energy into dissipated heat. In contrast, the larger pores in coarse fiber ceramic fiber cotton allow low-frequency sound waves to pass through more easily, resulting in lower sound absorption efficiency.
The mid-frequency range (1000Hz-2000Hz) represents the optimal performance zone for ceramic fiber cotton, with performance differences between fiber diameters further widening. Ultra-fine 3μm ceramic fiber wool achieves a sound absorption coefficient exceeding 0.85 at 1000Hz and reaches 0.92 at 2000Hz, approaching the level of ideal sound-absorbing materials. Standard 6μm ceramic fiber wool registers coefficients of 0.72 and 0.81 in this frequency range, while coarse 10μm fiber yields 0.58 and 0.65. At mid-frequencies, sound wave wavelengths align more closely with the pore dimensions within the ceramic fiber batting. This increases the number of reflections and scatterings within the pores. The ultra-fine fiber’s denser structure further extends the sound wave propagation path, significantly enhancing energy dissipation efficiency and resulting in markedly superior sound absorption performance.
In high-frequency (4000Hz) sound absorption comparisons, the differences among the three ceramic fiber batting types narrowed, though the ultra-fine type maintained its lead. The sound absorption coefficient for 3μm ultra-fine ceramic fiber cotton is 0.88, 0.80 for 6μm standard type, and 0.73 for 10μm coarse fiber type. Although high-frequency sound waves carry greater energy and are readily dissipated by the pore structures of all ceramic fiber cottons, the ultra-fine fibers maintain superior sound absorption due to their larger surface area and broader contact with sound waves.
Overall, under identical thickness and density conditions, the sound absorption performance of ceramic fiber cotton significantly improves as fiber diameter decreases. The 3μm ultra-fine type demonstrates optimal sound absorption across the entire frequency range, making it particularly suitable for scenarios demanding high low-frequency noise reduction (e.g., industrial plants, air conditioning rooms). The 6μm standard type offers higher cost-effectiveness and can be used in general spaces requiring mid-to-high frequency noise reduction (e.g., conference rooms, home soundproofing). 10μm coarse-fiber ceramic fiber wool is better suited for scenarios prioritizing thermal insulation while providing basic noise reduction (e.g., outer layers of high-temperature pipelines). These comparative results provide a scientific basis for selecting ceramic fiber wool tailored to different noise reduction scenarios, helping achieve a balance between precise noise reduction and cost optimization.