FAQ

What is the sound absorption coefficient?

The sound absorption coefficient α is the ratio of absorbed sound energy to incident sound energy. For complete reflection α=0, for complete absorption α=1. Since the sound absorption coefficient depends on frequency, it is measured in third octave bandwidth in the frequency range of 100 to 5000Hz.

What are the fundamental differences between polyurethane, polyethylene and melamine based foams?

Polyurethane foam (PU) has an open cell structure and so is used as acoustic foam for sound absorption.

Polyethylene foam (PE), in contrast, has a closed cell structure with good thermal insulation properties. Because of its superior compressive strength, PE foam is often used for impact protection in vehicle interiors.

Melamine is a flexible, open cell foam made from melamine resin with excellent flame resistance and is most commonly used for thermal insulation and sound absorption.

What is the difference between polyether polyurethane and polyester polyurethane acoustic foams?

Polyether polyurethane foam has the characteristics:
soft feel, flexible, fine open cell structure

Polyester polyurethane foam has the characteristics:
firm feel, rough open cell structure and therefore a somewhat higher degree of absorption than polyether based products

What do the different fire protection standards mean?

Basically, all our sound insulation materials are suitable for use in mechanical engineering and vehicle construction based on the requirements of DIN 75 200 and FMVSS 302.

Materials for use in railway vehicle construction require certification based on DIN 5510-2 or other relevant national standards, such as NF F 16-101.

The DIN 4102 standard was set up to test the fire behaviour of building materials and elements. It primarily applies to materials classed as building components, such as wall and ceiling panels.

How do you fit the sound insulation materials?

In most cases, the materials are permanently attached to objects with a high-quality self-adhesive based on acrylate.

Depending on the installation situation (e.g. horizontally suspended), the dead load and the ambient conditions, some cases may require additional mechanical fixing of the sound insulation materials.

Powder-coated surfaces with lotus effect may cause adhesion problems. Talk to us if this occurs.

Heavy foils without self-adhesive system have a high dead weight and so are permanently attached using two-component polyurethane adhesive from our range.

Always make sure to read our instructions for use.

Instructions on processing

Do the glass fibre products pose a health risk?

We only use continuous filament (textile glass fibres) as man-made mineral fibres (MMMF).

The continuous filaments in our thermal insulation materials are produced from suitable raw materials in a process called mechanical drawing. This results in an almost uniform, generally round, cross-section, with a fibre diameter of 5 - 24 µ.

Under both German and EU laws, our continuous filament products are currently exempt from classification in a health risk category.

We cannot rule out that the handling of our thermal insulation materials may cause itching. As a precaution, we would recommend using appropriate protective equipment such as dust masks, goggles, long work gloves and use hand cream when processing and fitting our products. Contact your health and safety officer for further advice!