A sound absorber is a type of acoustic insulation that absorbs sound rather than blocking it or reducing its energy (dampening). Materials of construction include open-cell acoustical foams and optional facings that can tune out specific frequencies or that reflect heat, support cleaning, or provide a decorative finish.

Elasto Proxy makes custom sound absorbers and also supplies standard products to manufacturers. This article contains answers to some frequently asked questions (FAQs) about this type of acoustical insulation. Keep reading to learn more, or contact us if needs a standard or custom sound absorber.

How does a sound absorber work?

Sound energy passes through the open cells of a sound-absorbing foam. The sound absorber converts this energy into small amounts of low-grade heat that is dissipated. Because the acoustical foam manufacturer carefully controls the uniformity of each open cell, the sound absorption levels are highly predictable.

What are some examples of sound-absorbing foams?

A sound absorber is usually made of open-cell polyester, polyurethane, urethane, or melamine foams. Each of these materials has different properties, some of which provide additional forms of protection. For example, melamine foam is also thermally insulating and flame-retardant.

What are some types of sound absorber facings?

Vinyl is a commonly used facing material because it can absorb low frequencies and is easy to clean. Fabrics are also used and can provide a decorative finish. Because some sound absorbers also need to provide thermal insulation, aluminum foil can also be used for the facing material.

How are sound absorbers made?

It’s a multi-step process. First, foams and facings are laminated together to form an “insulation sandwich”. Individual sound absorbers are to size. Elasto Proxy uses fast, precise water jet cutting for material conversion and can apply a removal liner with a pressure-sensitive adhesive (PSA) for ease of installation.    

custom sound absorber
This custom sound absorber shows Elasto Proxy's lamination, water jet cutting, and PSA capabilities.

Where are sound absorbers installed?

Sound absorbers are installed at the source of the sound and its receiver. For example, with diesel-powered heavy equipment, sound absorbers are installed in the engine bay and in the cabin where the operator sits.  

How do you select the right sound absorber for your application? 

Each application is different, but this list is a good place to start.

  1. What is the maximum insulation thickness that your application can support?
  2. Will the product remain stationary, or will it be subject to opening, closing, and bending?
  3. Will you install the sound absorber where there’s vibration?
  4. Are you trying to insulate an area where there’s airflow resistance, or can the air move freely?
  5. Do you need a sound-absorbing foam that also provides thermal insulation or flame resistance?
  6. Do you need a product that resists washdowns or has a decorative finish?
  7. Do you need facing materials that can absorb specific frequencies?

Contact Elasto Proxy is you need assistance with this process.

What if you don’t need a custom sound absorber?

Elasto Proxy can make custom sound absorbers for you, but we also offer these standard products.

  • SH100-54-PVTBL consists of a polyether or polyurethane foam and a PVC-coated fabric. The charcoal-colored facing material contains a series of small holes for enhanced noise control. This product meets various flammability standards.
  • SH-250-60-PVTM (FM-ZM) consists of a sound-absorbing foam that’s bonded to a vinyl facing with small holes for enhanced acoustical properties. It provides an attractive appearance to cabin interiors.
  • SH-1000-54-ZZUT consists of a sound-absorbing foam that’s heat-laminated to a urethane film or a matte facing that is available in different colors and provides resistance to moisture, dirt, and most petroleum products.
  • SH-2000-48-MEZT is a lightweight, fire-resistant melamine foam that also provides thermal insulation. It can be combined with facing materials like aluminum foil, which reflects radiant heat and provides chemical resistance. Applications include engine bay insulation.   

Is it possible to get samples of these products?

Yes. If you’re a manufacturer, request the Elasto Insulation Bag. It contains samples of sound absorbers s and other types of acoustic, thermal, and thermal-acoustic insulation. Plus, we can include samples of edge tri, bulb trim, or D-shaped profiles with adhesives if you need them.   

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