In a plant producing corrugated cardboard, a single facer is a very powerful noise source potentially causing sound nuisance for the personnel operating in the vicinity (in production halls) and sometimes also for the neighborhood. It is often necessary to use in such cases a high-tech soundproofing equipment to ensure the conformity of the facility with respect to the legislation on noise in workplaces and sometimes also with respect to the regulations in terms of fight against domestic noise.
ITS will participate in the construction of an enclosure for a single facer (corrugated cardboard industry) near Nantes in the region Pays de Loire (France).
This soundproofing device will offer a sound reduction particularly important at medium and high frequency where the maximum of the noise emission of the enclosed noisy equipments is, requiring a specific design and a specific construction of the partitions of this enclosure.
Walls and roofs will be made with modular metallic acoustic insulation panels, with (from the inside to the outside):
- a layer of mineral wool (surfaced by a glass veil and protected by a perforated sheet) of density specifically selected to allow both absorption of the sound waves emitted by the machine (their reflection would result in an increase in the noise level inside the enclosure and therefore, all other things being equal, outside i.e. where operators are likely to be inconvenienced or even in a situation of hearing trauma) and to help limit sound transmission
- a non-perforated steel sheet, of suitable thickness for sound attenuation
Removable elements (for maintenance) and doors will be made on the same principle or (if their area is limited) with a solid sheet on the interior side ; metal glazed frames will be manufactured with multilayer safety glazing (in the event of breakage of the glass, the fragments will remain glued to a central frame). In addition to the acoustic performance associated with the quality of studies, manufacturing and assembly, the choice of dimensions and locations of this equipment will condition the quality of the enclosure both for operating the machine and for works during production stoppages, which must of course be limited to the minimum.
The implementation of a performing and well soundproofed ventilation system will be one of the key fators for success of this project, equally with the noise reduction resulting from the implementation of industrial soundproofing construction systems because the production quality depends on it (heat energy and humidity related to the process must be properly evacuated).
To do this, several insufflation fans will allow (in the lower part, in the corners) the production of air inside the enclosure and a (larger) fan (if possible: in the center of the roof) will allow an appropriate renewal of air, baffle silencers (i.e with sound-absorbing separators) allowing the limitation of noise (that of the corrugator, and that of the fans - which, in practice, is far from being negligible) through the openings (otherwise, the acoustic performance of the enclosure would be adversely affected). .
Related features such as visibility for the operation of the machines, access for maintenance work, disassembly of some subsets of the soundproofing equipments ... will be integrated according to the needs for this enclosure for a single facer.
The design and construction of such hardware for protection against noise at work, particularly in the corrugated cardboard industry, is a major activity for ITS and its business partners: spread the word !