Acoustical foams are sound absorptive media that are designed to reduce reverberation/ amplification of airborne sound within an enclosed space, and/or, reflection of sound off otherwise hard surfaces. Depending upon the specific acoustical makeup of sound in a particular situation, acoustical foams are often faced with membranes and materials to ‘tune’ the foam to maximally absorb sound energy in specific sound frequency bands. We only stock Polyester foams that meet UL94-HF1 and which are self-extinguishing once a naked flame is removed. As all Polyurethane based foams have a high ‘smoke evolution’ in a fire situation, they are not recommended in areas where quick egress is not available. Acoustical Foams are also available in materials having better fire resistant characteristics (ie: Melamine). Micro-perforated ‘Millennium Metal’ may also be used to face metal panels to provide a fully fireproof (and weatherproof) sound absorptive surface.
Barrier materials block/reflect airborne sound due to their relatively high cross-sectional mass. The higher the mass, the greater the reduction of sound from one side of the ‘barrier’ to the other. Common materials such as concrete, sheetrock and wood make good barriers but they lack the flexibility required in many applications (ie: noise radiating off pipes and ductwork). It is these flexible barrier materials that we stock, most with a fire-resistant facing on one or both sides. They are Barium Impregnated Vinyls that are about 1/8” (3mm) thick and have a cross-sectional mass of 1#/sqft (4.88Kg/sqM). Some are reinforced with fiberglass cloth so that they can be hung as flexible ‘Acoustical Curtains’. Barriers should not be directly applied to sound generating surfaces. Doing so will reduce their effectiveness.
Composite materials combine both foams and barriers for applications where both sound absorption and blocking are required (ie: Engine Rooms) or where a thin layer (typically ¼”(6mm) ) of foam is required to ‘decouple’/separate a barrier from a surface that has some acoustical energy or a surface where one wants to reduce airborne acoustical energy energizing that surface. Barriers with a single foam decoupling layer are typically used for acoustical floor mats, ‘lagging’ ductwork, cabinets with vibrating or pulsating internal components (ie: heat pumps, control panels, fans and so on) or composited further with an outer (thicker) absorptive media.
Vibra-Sonic Control stocks a wide range of products to address the ever-evolving variety of applications.