Product specifications for:
Acoustic Panels and Components of Wooden Barriers
1.1. Wooden Panels
These soundproofed panels, with high sound absorbing and sound insulating power, are made of a box-shaped solid wood support frame with minimum cross-section of 100×80 mm., are coupled jointed to improve stability. Inside the frame shall be placed the sound-absorbing and sound-insulating material.
The side facing the noise source is made of polyethylene decorated textile with colored stripes or wooden strips autoclave treated rounded or of similar finish, with minimum dimension of 25×55 mm.; the back paneling is made of wooden slats of minimum thickness of 20 mm. snapped together and fixed to the frame, the backing is made of wooden boards with minimum thickness of 20 mm. coupled jointed and fixed to the box-shaped frame with gaskets and fasteners.
The acoustic tile is made is made of natural fiber or polyester of the appropriate thickness and density to acts as sound absorber due to its porosity and resonance.
The material shall not decay, shall be weather and chemical agents resistant, fire proof or self-extinguishing, and shall not emit harmful toxic gas.
The material shall be placed at a distance from the back of panels using wood spacers and wrapped in a protective anti-dust and thick weave sheet attached to the frame.
Due to the weather exposure the barrier shall be made of good quality wood accurately treated.
Maintenance Treatment. The wood shall be resistant to decay and to the UV sun rays aging effects, therefore it shall be treated with specialty products in accordance to regulations DIN 68800 and UNI EN 350-1-2 to prevent fungi growth.
The wood shall be treated with inorganic salts.
Firstly it shall be treated with deep autoclave vacuum under pressure, or equivalent methods, with new generation natural substances having no chrome or arsenic.
Screws. Stainless steel screws are recommended to join wood pieces. Metal cramps are not permitted.
Gaskets. Plastic or rubber gaskets shall be flexible and unchanged over time. They shall be soundproofing and placed where needed to prevent sound transmission, especially in the joins between the wood slats and the frame and between slats.
To ensure traffic safety in case of fire, the panels (though flammable) shall be fire resistant (Class 1 flammability rating required).
The panels shall be easily disassembled and replaced in case of damage; therefore the panels shall be of adequate size, so that they can be mounted without using equipment which could hamper vehicular traffic.
Special care shall be applied to the joins, in consideration of possible swelling and shrinking of the material.
The wooden panels shall always meet and guarantee the acoustics certifications expressed in the regulation EN 1793-1-2-3.
They shall also meet the minimum values listed in the European regulation (PR – ENV 1793-5).
Reflection Index – db ≥ 3;
Sound Insulation Index – db ≥ 30.
1.2. Structure
The supporting structure of the soundproofing wooden panels shall be made of HEA metal profiles with an anchor base plate appropriate to the size of the barrier, and minimum dimension of mm. 250×280 and thickness of 15 mm.
The base plate shall be fixed to the HEA profiles with bead welding and anchored with two angled base plates of 160×90 mm. in size and 10 mm. thick.
Alternatively, the steel posts can be immersed in concrete wells with minimum depth of 500 mm.
1.3. Certifications
As final acceptance of the sound proofing panels and of its components, Alfakel shall provide results of technical tests conducted by authorized and/or licensed institutions to validate the technical specifications of the materials.
The wooden barriers shall meet the following certifications, in compliance with European laws: UNI EN 1793-1-2-3:1999 – PR.ENV 1793 – 5:2001 EN 1794-1:1998 ANNEX 1 – EN 1794-1:1998 ANNEX C – EN 1794-2:1998 – EN 1794-2:1998 ANNEX A.
A) Acoustic Certifications
The panels’ acoustic certifications – Results of Technical Tests – shall be conducted in reverberating chamber, as prescribed by European laws UNI EN 1793-1-2-3:1999 and also in the field (in conditions comparable to real vehicular traffic) as prescribed in the European regulation (PR – ENV 1793-5:2001).
B) Certifications of Mechanical Strength and Resistance
- Wind stress resistance according to EN 1794-1:1998, ANNEX A with impact load of 250 Kg/sq.m, maximum temporary deflection of 30 mm. per panel.
- Falling stones impact resistance compliant with EN 1794-1:1998 ANNEX C with positive result.
- Brush fire resistance compliant with EN 1794-2:1998 ANNEX A. The final test results shall meet the following minimum requirements: the front compliant with Class 1 regulation, the back compliant with Class 3 regulation.
