soundproof curtain Certified: The documentation that a reputable manufacturer must provide
In a professional context, the “soundproofing” label affixed to a curtain has no documentary value. There are no regulations governing its use. A reputable manufacturer does not simply display the label; it provides a supporting documentation package to substantiate it. This package consists of three specific, verifiable, and traceable elements.
Three Things to Demand
- The report number of an ISO/IEC 17025-accredited laboratory
- The applicable test standard and the Rw/maximum value distinction
- An industrial property right certifying the R&D effort
The Minimum Technical Documentation: Three Non-Negotiable Elements
1. A report from an ISO/IEC 17025-accredited laboratory
Only a report issued by a laboratory accredited under ISO/IEC 17025 constitutes admissible evidence in a prescription file. In Belgium, the competent accreditation body is BELAC; in France, it is COFRAC. The report bears a unique number, assigned upon completion of the tests, which can be provided upon request. Any reference to “in-house tests” or “proprietary certification” does not replace this third-party accreditation.
2. The test standard and the fundamental distinction between Rw and the maximum value
Textile acoustics involves two distinct standards, depending on the desired objective:
- NBN EN ISO 10140-2: Sound attenuation—reduction of sound passing through the textile assembly. This is the relevant parameter for any application aimed at reducing external noise.
- ISO 354 / EN ISO 354: Sound absorption—echo reduction within a space. These two quantities are not interchangeable and must not be presented together without an explicit distinction.
Within the same attenuation ratio, two values coexist and do not refer to the same reality:
Overall Rw rating — a weighted value calculated across the entire audible spectrum (125 Hz to 3,150 Hz). Representative of actual effectiveness under normal usage conditions. Expressed with its adaptation factors C and Ctr: Rw(C;Ctr).
Maximum value — peak attenuation measured at a specific frequency, typically in the high-frequency range (3,000 to 5,000 Hz). Higher than Rw, but not representative of overall performance. A reputable manufacturer always specifies the corresponding frequency.
Rw(C;Ctr) = 14(−1;−3) dB
Maximum attenuation: 28.2 dB at 5,000 Hz
Standard: NBN EN ISO 10140-2:2010
Laboratory: Daidalos Peutz — BELAC ISO/IEC 17025 Accreditation
Report No. A-2020LAB-060-I766-44092_E
3. The manufacturing patent: an indicator of a structured R&D approach
A patent application filed and granted for the multilayer construction of a acoustic curtain attests to an innovative approach that has been formally recognized by an intellectual property office. It involves an examination of novelty and inventive step by independent experts. It is a sign of industrial integrity distinct from performance certifications: it focuses on design, not on measurements.
Cotton Silence Patent: EP 3 440 965 (European Patent Office) — a multilayer technical textile composite with combined acoustic and thermal performance.
The Cotton Silence Report: Three Configurations Tested
The Cotton Silence tests were conducted by the Daidalos Peutz laboratory (Belgium), which is BELAC-accredited in accordance with ISO/IEC 17025, in accordance with the NBN EN ISO 10140-2:2010 standard. Three distinct configurations were subjected to independent testing.
| Configuration | Report | Overall Rw Index | Max. attenuation |
|---|---|---|---|
| 4 layers | I766 | Rw(C; Ctr) = 14(−1; −3) dB | 28.2 dB at 5,000 Hz |
| 5 layers | I767 | Rw 15 dB | 34.2 dB |
| 7 layers | I768 | Rw 16 dB | 33.8 dB |
Daidalos Peutz — BELAC ISO/IEC 17025 — NBN EN ISO 10140-2:2010 — Reports A-2020LAB-060-I766/I767/I768-44092_E. Weight of the 4-layer composite: 1.35 kg/m². 5- and 7-layer configurations are available upon request.
Five Questions About the Statute of Limitations
| Question | Expected response | Warning Signal |
|---|---|---|
| Weight per square meter of the finished product? | Value in kg/m² for the complete assembly | "Heavy fabric" without a number |
| Laboratory and Accreditation? | Lab name + BELAC or COFRAC | In-house testing, non-accredited laboratory |
| Report number? | Contact number | No number, “confidential” |
| Which standard was applied? | ISO 10140-2 or ISO 354, depending on the objective | No standards cited |
| Is Rw different from the maximum value? | Global Rw + frequency of the maximum value | Single value without frequency |
Frequently Asked Technical Questions
Technical specifications available
Reports I766 · I767 · I768
Patent EP 3 440 965 · Weight Specifications
Provided upon request for any proposed prescription