Acoustic Materials

When the sound intensity is more, then it gives the great trouble or nuisance to the particular area like auditorium, cinema hall, studio, recreation center, entertainment hall, college reading hall. Hence it is very important to make that area or room to be sound proof by using a suitable material called as ‘Acoustic material’. It is measured in decibles (db).

Acoustic material play a vital role in the various area of building construction. In studio, class room, reading hall, cinema theatre, more concentration is required to listen, hence the acoustics treatment is provided so as to control the outside as well as inside sound of the various building until such that sound will be audiable without any nuisance or disturbance.

Types of Acoustic Material

• Acoustic plaster.
• Acoustic tiles.
• Perforated plywood.
• Fibrous plaster.
• Staw board.
• Pulp board.
• Compressed fibre board.
• Hair felt.
• Cork board slabs.
• Foam glass.
• Asbestos cement boards.
• Thermocoal.
• Foam plastic.
• Chip boards.
• Gasket cork sheet.
• Hair felt.
• Acoustic foam.

Properties of Acoustic Material

• Sound energy is captured and adsorbed.
• It has a low reflection and high absorption of sound.
• Higher density improves the sound absorption efficiency at lower frequencies.
• Higher density material help to maintain a low flammability performance. Hence acoustic material should have higher density.
• It controls the sound and noise levels from machinery and other sources for environmental amelioration and regulatory compliance.
• Acoustic material reduces the energy of sound waves as they pass through.
• It suppresses echoes, reverberation, resonance and reflection.

Uses of Acoustic Material

• Acoustic materials can be used for noise reduction and noise absorption.
• It makes the sound more audiable which is clear to listen without any disturbances.
• It suppresses echoes, reverboration, reflection and resonance.
• Important specifications for noise reduction and noise absorption products include noise attenuation and noise reduction coefficient.
• A vinyl acoustic barrier blocks controls airborne noise (street traffic, voices, music) from passing through a wall ceiling or floor.
• Acoustic foam and acoustic ceiling tiles absorb sound so as to minimize echo and reverboration within a room.
• Sound proof doors and windows are designed to reduce the transmission of sound.
• Building techniques such as double wall construction or cavity wall construction and staggering wall studs can improve the sound proofing of a room.
• A sound proof wall (treated by a accurate material) can incorporate sound proofing and acoustic materials to meet desired sound transmission class (STC) values.

Acoustic Materials Available in Market

1. Basotect®

Basotect® is a light weight open cell foam, which is made from melamine resin. It is flexible, easy to handle. It is easy to cut and install. It is available in sheet form and also available in pre-cut or profiled to size and shape. The natural colour of the foam is light grey, although it is also available in a range of functional or decorative facings and fabrics that can he sprayed with flexible PVC coating. It is designed for use in thermal and acoustic insulation applications.

Properties of Basotect®

• It is flame resistant.
• It has high sound absorption.
• It is heat resistant.
• It has light weight.
• It has good thermal insulation.

Applications of Basotect®

• It is used in building services like arid ceiling panels for office and conference suit etc.
• It is extensively used in recording studios for the work of wall panels, ceiling tiles and anechoic wedges.
• It is used in engine room and accommodation areas of marine ship.
• It is used in automotive for car trim engine and under bonnet panels.
• It has industrial applications and used as enclosure linings and suspended absorbers.

2. Sound Fibre Rock

Sound fibre rock is made from non-combustible rock fibre. It is available in four different thickness. It is supplied in slabs of size 1000 x 600 mm. The slabs can also be supplied as part of an acoustic composite product with lead or polymeric barries.

Properties of sound fibre-rock

• It is resistance to high temperature.
• It has excellent sound and thermal qualities.
• It is simple to cut and install.

Applications of sound fibre- rock

• Since it has excellent sound and thermal qualities, making it an ideal choice for cavity wall, floor and ceiling insulation.
• Sound fibre rock slabs are particularly suitable for acoustic infill in partitions and ceilings, provided a high level of control of both airborne and structure born sound.
• It is also suitable for acoustic absorption in the linings of buildings, with the 600 N /m³ slabs being particularly good in sound studios.
• The 450 N/m³ slabs can also be used to firestop small voids, in particular the gap under pitched roof in dwellings.

3.DMP2 Damping Mat

DMP2 damping mats are light in weight and PVA-based, visco-elastic polymer. It is designed for use in acoustic applications where a high level of vibration damping is required. These type of material come with a self-adhesive backing. It is available in standard sheet sizes of 1600 x 1000 mm or die- cut to shape.

Applications of DMP2 damping mats

• It is extensively used to reduce vibration in sheet metal and other resonant surfaces such as vehicle body parts, machine panels, steel sinks and table etc.
• DMP2 damping mats are particularly suitable for clean- room environments.

4. Damping mats (DM3, DM5, DM5A, DM 10)

Damping mats are manufactured from bitume with added mineral fillers and synthetic rubber forming a highly visco-elastic product. It is available in four standard grades. Damping mats come with self-adhesive backing.

Applications of damping mats :

• Barrier mats are used to reduce vibration in sheet, metal and other resonant surfaces such as vehicle body parts, machine panels, steel sinks and table etc.
• It improves the sound insulation by adding mass to the structure.

5. Sound Fibre-Poly

It is manufactured from non-irritating water repellent polyester fibres. It is designed for use in acoustic and thermal insulation applications. It can be supplied in sheet form in packs 10 or cut to a specific size and shape. It can also be supplied in fabric wrapped form for architectural applications or with other performances enchanting facings.

Properties of Sound fibre-poly

• It is rot proof, odourless, non-hygroscopic , will not sustain vermin.
• It will not encourage the growth of fungi or bacteria.
• It is dimensionally stable under varying conditions of temperature and humidity.
• For long term protection, it should be stored in a dry well ventilated area.

Applications of sound fibre-poly

• Sound fibre-poly sheets are particularly suitable for architectural building applications such as wall or ceiling panels.
• It is also used in low temperature heating and ventilation equipment.

6. Insulation blankets

There are two types of insulation blankets with a name of SCL and SCP. There are noise insulation quilted blankets. SCL and SCP can be supplied in standard sheet size of 2000 x 1200 mm or can be supplied as individually tailored parts to suit for particular application. Blankets can be stitched and edge bound and can also be supplied with eyelets or velcro for fixing. SCl and SCP are also available with other higher performance facings.SCL is manufactured from two layers of quilted glass fibre and a lead core with hardwearing PVC coated glass cloth material on outside. SCP is manufactured from two layer of quilted glass fibre and a polymer barrier core with hardwearing PVC coated glass cloth material on the outside. These are high performance blankets offer a cost effective alternative to SCL.

Properties of Insulation Blankets

• They are extremely flexible with a high degree of durability.
• They are fire resistant and also resistant to most common fluids, mineral oil and petroleum.

Application of Insulation Blankets

SCL are high performance insulation blanket which are designed for under bonnet vehicle installations, plant equipments, agricultural vehicles and industrial pumps.

7. Barrier Mats

It consist of thermoplastic polymer with phthalate esters and mineral fillers, making it an extremely durable and flexible product. It is available plain, self-adhesive backed or with a reinforced class ‘0’ foil facing. It is available in thickness of 2.5 mm and 4.5 mm.

Properties of Barrier mats

• It is black in colour.
• Its density varies from 50 N/m² to 100 N/m².
• Its hardness is 90°.
• It is resistant to fire.
• Its operating temperature is 90°C for extended period and 120°C for short period.

Application of Barrier mats

Barrier mats are designed to add mass and reduce noise transmission on various products, including mechanical and electrical equipment, automotive components and extensively within the building industry on walls, floors and ceilings etc.

8. Sound lag

Sound lag L and P are the two types of noise insulation blankets. Sound lag L is manufactured from two layers of glass fibre with a lead core and a reinforced class `0′ foil, vapour barrier outer coverings. The inner layer of glass fibre is quilted with a scrim backing to prevent fibre breakout. Sound lag P is a cost effective, flexible polymeric barrier mat, faced with class ‘0’ foil vapour barrier and non-irritant polyster fibre inner layer.

Applications of sound lag

• It is designed to control noise breakout from ducting and pipe work by extremely wrapping to contain the noise within the duct.
• It enjoy a decoupled mass technique i.e. heavy barrier layer isolated from the duct or pipe surface by a resilient layer of insulation acting like spring.
• Sound Lag L is used in applications requiring a high level of thermal insulation and improved sound absorption.
• It has a good acoustic performance.

9. Sound foam, S

It is a flexible open cell polyurethane foam, offering excellent sound absorbing qualities over a wide range of frequencies. It is available plain or self-adhesive backed. It is easy to handle and to cut and install. It can be available in sheet form from 6 mm to 100 mm thick, or it can also be available die – cut to size and shape. It can also be available as part of acoustic composite product with leadpolymeric barriers or damping sheets.

Applications of sound foam S

•  It is a self-extinguishing acoustic foam.
• It is used extensively in the motor industry for vehicle and compressors, generators, enclosures.

10. Sound foam, 0

It is flexible open cell polyurethane foam, offering excellent sound absorbing qualities over a wide range frequencies. It is available plain or self- adhesive backed. It is easy to handle and to cut and install. It is a black non- flammable acoustic foam. It is impregnated with fire retardant chemicals which enables the material to achieve class ‘0’ fire rating as defined by the building regulations.

Application of sound foam 0

• It is extensively used in air conditioning and air handling system, ducting and also compressors, generators, enclosures and other applications.

Most common application areas of Acoustic Material

• Home theatre acoustics.
• Wall sound proofing.
• Ceiling sound proofing.
• Studio Acoustics.
• Floor and football sound proofing.
• Office and conference room acoustics.
• Industrial acoustics.
• Pipe sound proofing.
• Church and place of worship acoustics.
• Restaurant and lounge acoustics.

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