1. PET Acoustic Panels: Typical Sound Absorption Coefficients
The sound absorption coefficient (α) of PET (polyester fiber) panels typically ranges between 0.6–1.0 across frequencies, depending on thickness, density, and surface treatment.
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For example, in tests compliant with ENISO 354:2003 (type E mounting), a common PET panel achieves an average α of 0.7 (100-5000Hz) and a noise reduction coefficient (NRC) of 0.8, meeting Class B per ENISO 11654:1997.
2. Density vs. Sound Absorption: Does a “Peak” Exist?
Density plays a complex role:
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Low density (e.g., <1350gsm): Airflow resistance is too low, reducing mid/high-frequency absorption.
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Increasing density: Improves airflow resistance, enhancing absorption—especially in mid-frequencies (500-2000Hz).
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Peak threshold: Beyond ~2200gsm, increased density shows diminishing returns. The relationship plateaus due to limited pore connectivity and excessive material compaction.
Practical Insight:
In PET panels with densities between 1350–2200gsm, the absorption coefficient variation is minimal (<5%). This suggests that once structural integrity is achieved, further density increases may not justify cost or weight tradeoffs.
3. Testing Principles: How Are These Values Measured?
Key standards for PET panels:
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ENISO 354:2003: Measures absorption in a reverberation chamber (Type E mounting simulates wall/ceiling installations).
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ENISO 11654:1997: Calculates NRC by averaging α at 250Hz, 500Hz, 1kHz, and 2kHz.
Why It Matters:
These standards ensure comparability across products. Always check if a supplier provides third-party test reports!
4. Real-World Implications
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For architects/designers: Focus on panel thickness and surface perforation design (larger/more pinholes → better high-frequency absorption).
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For installers: Density matters less once within the 1350–2200gsm range—prioritize fire ratings or aesthetics.
“If you’re curious about PET panel testing data or want to dive deeper, our team published a full technical report here with detailed NRC/α curves across densities. Feel free to DM for specific scenarios!”