MPPs are sheet materials (from 0.5 to 2mm thick) with perforations of diameter ranging from 0.1 mm to 1.0 mm.
These very small perforations provide sound absorption characteristics with viscous losses happening as air passes through the holes. Although they can absorb sound alone, they can also be associated with porous materials to increase their sound absorption performance.
This type of material is relatively new and manufacturing has become possible with more recent perforation technologies. Micro-holes can be created with hot and cold needle perforators, punch, laser drilling or CNC drilling machines.
MPP systems can be used for walls and ceilings.
What materials are Micro-Perforated Panels made from?
MPPs can be made with various types of materials, wood veneer, plastic, polycarbonate and metal being the most common.
What are the advantages of using Micro-Perforated Panels?
MPPs have many advantages as follows:
with the holes not being visible from a certain distance, they can provide a relatively smooth finish.
With the right materials like honeycomb or perforated materials with larger holes, MPP systems can be made very strong whilst remaining relatively light.
They can be fire-resistant.
Without any porous absorber behind, they are dust and moisture resistant. This is particularly useful for applications where porous materials are not permitted such as engine compartments, hospitals, pharmaceutical facilities, food processing/production facilities, etc.
When made of transparent materials, they can be installed in front of large glazed areas without losing too much light.
Their sound absorption is customisable.
Their shape can be customisable.
What are the sound absorption characteristics of Micro-Perforated Panels?
MPPs are effectively Helmholtz resonators. Therefore, like any acoustic resonator, they have a peak absorption around a certain frequency.
However, the sound absorption can be broadened when a porous absorber is installed behind.
The sound absorption performance of MPP systems can range from Class C to Class A.
Their sound absorption characteristics can be tuned by changing the following:
the thickness of the sheet material.
the diameter of the holes.
the distance between the holes.
the density of the perforations.
the number of MPPs in the system (usually 1 or 2).
the distance between the MPPs.
the distance between the MPP(s) and the hard surface behind.
the presence/absence of a porous material between the MPP(s) and the hard surface.
Calculation methods exist to predict their sound absorption characteristics with good accuracy. This means the perforations (as well as the shape) could be customised to follow a specific interior design.
What about the sustainability of Micro-Perforated Panels?
See the Environmental Product Declarations for some product examples.
Note: the above information is drawn from review of product information and the following documents:
Acoustic Absorbers and Diffusers – Theory, Design and Application (Third Edition) – T.J. Cox and P. D’Antonio
Sound Materials – A Compendium of Sound Absorbing Materials for Architecture and Design – Tyler Adams