In a printing workshop, a rotary press 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 a noise barrier for an offset rotary press near Laval in the county of Mayenne in the region Pays de la 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 noise barrier wall.

Attached to an independent metal frame, they will be made (except for the glazed parts, which will be in laminated glazing) of metallic sound insulation panels, which will have several layers (from the inside to the outside):

  • a steel sheet, perforated, intended to ensure the mechanical protection of the intermediate layer (below)
  • an intermediate layer based on mineral wool, surfaced by a glass veil, with sound absorption properties (the sound absorption coefficient reaches 100% at high frequencies) and with a high density to oppose the transmission sound
  • a non-perforated steel sheet, the mass desnity of which (10 kg/m2) shall be predominant in obtaining a significant sound reduction (also conditioned by a tight assembly: on the one hand between panels, and on the other hand at the limits of the construction)

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 nosie barrier wall for an offset rotary press.

A major aspect for the success of such a project will be the arrangement and the extent of the glazed parts of the anti-noise wall, necessary for the visual inspection of different parts of the machine (laminated glass will make it possible to obtain sound reduction equivalent to that of parts made with metallic soundproofing panels, the debris remaining stuck to a central frame in the event of glass breakage); making the right choices in this area requires experience that ITS's human resource is not without.

Employees exposure to noise risks will considerably be reduced after this industrial soundproofing action and acoustical comfort at workplaces will be significantly increased, in accordance with Directive 2003/10/EC of the European Parliament and of the Council of 6 February 2003 concerning the minimum health and safety requirements relating to the exposure of workers to the risks due to physical agents (noise) [1] for:

  • the peak sound pressure (ρpeak): maximum value of the instantaneous sound pressure measured with the frequency weighting C
  • the daily noise exposure level (L EX, 8h) (dB (A) ref 20 µPa): time-weighted average of noise exposure levels for a nominal eight-hour working day

Such a project is a good illustration of the know-how of ITS and its business partners in the field of protection against noise at work places.

Protection of workers against noise end faq

[1] exposure limit values: LEX, 8h = 87 dB (A) and ρpeak = 200 Pa respectively; higher exposure values triggering the action: LEX, 8h = 85 dB (A) and ρpeak = 140 Pa respectively; lower exposure values triggering the action: LEX, 8h = 80 dB (A) and ρpeak = 112 Pa respectively