Sound is undoubtedly a very important aspect of our existence. As well as being a primary means of communication, it plays a role in geophysics; in signalling, positioning and locating. As energy, it can be used to break down solids and degas liquids. Sound waves are the result of vibrations between atoms or molecules. These vibrations are converted from kinetic energy to acoustic energy. It is this energy that allows sound waves to travel.
Despite its wide range of applications and uses, this form of energy is sometimes unwelcome and acts as a nuisance or obstacle. Noise from engines, external noise from music studios, noise from shared flats, etc. A method or technique is therefore needed to reduce or stop it. As they are waves, sound energy can be refracted, reflected and manipulated at the edges. Although it cannot be blocked completely, it can be reduced considerably. The act of eliminating, reducing or blocking sound is called soundproofing.
Now let's take a look at some of the unique sound proof materials available.
Sound Proof Material
Acoustic foams were first used in the mid 1970's. Polyurethane foams are made through basic addition polymerization reaction involving a diol or polyol, a diisocyanate, and water.Acoustic foams have mostly open cells as a result of trapped gas bubbles which pop. Air passes easily, through this type foam. Polyurethane is designed as a flexible, open-cell, porous solid. Sound energy is propagated through the material by two major methods:
Sound pressure waves pass through the fluid within the pores of the polyurethane.
Elastic stress waves are generated by pressure waves which travel through the framework of the polyurethane.
Polyurethane is very effective at attenuating high frequency sound waves, but it does not provide low frequency isolation unless sufficient thickness is used. The porous nature of polyurethane greatly reduces acoustic reflection, but this low density also allows for the transmission of acoustic energy. Acoustic foam is chemically inert but flammable. Because of its flammability. Polyurethane foam cannot be used in industry. It is more suitable for installation in rooms.
Felt is made by pressing and matting fibres together. The fibres used may be natural (mainly wool) or synthetic. Blends of the two are also common. Felt is durable and stable in the presence of moisture, lubricants, grease, salt, cleaning agents and is inert to many other chemicals. It can be bent to uneven surfaces to prevent foreign objects from intruding under load-bearing areas.
Creative designed Priting acoustic felt is Printed on solid color acoustic felt, which is A felt textile from DECO SOUND Acoustic, a sophisticated and intelligent collection of acoustic panels, compared with wall paper, the printing felt has better acoustic performance and no harmful to human.
Creative Designed Priting Acoustic Felt
Felt is almost permanently elastic because it consists of millions of individual fibres. The sound absorption properties of felt are the result of its optimum density and elasticity. The absorption of sound waves is achieved by the vibration of the individual fibres within the felt. The energy is dissipated by frictional heat loss. Due to its absorption method, a felt that is too dense will not generate sufficient vibrations. These qualities make it ideal for industrial sound insulation. Felt is also used as a dampener in musical instruments.
Custom-designed colorful acoustic felt is A textile from DECO SOUND Acoustic, a sophisticated and intelligent collection of acoustic panels, compared with regular panel, it is soft and colors looks more solid, a good option for wall covering and acoustic.
Custom-designed Colorful Acoustic Felt
Acoustic fiberglass offers the ideal combination of rigidity and light weight. Commonly known as the deformer of sound insulation, this material can be easily customised to fit in the tightest of places. Glass fibre is mainly used in rooms and halls to prevent reverberation and echoes.
Cork is an excellent natural alternative for sound insulation. This is a layer of bark tissue harvested from the cork oak. This material is to some extent fireproof, flexible and impervious to water. Cork is very effective in sound insulation, with only 3 mm of the material blocking out 10 dB of sound. This amazing ability is due to the cellular structure and composition of the cork. Air is a great insulator and cork is made up of 50% air. This makes it very light, with a density of 0.16 grams per cubic centimetre. The cells of this material are arranged like a honeycomb, containing an average of 40 million tiny air-sealed cells per cubic centimetre. When sound energy passes through the cork, the energy is converted into vibrational energy by the air molecules.
For tight spaces and corners, silicone is a good choice for soundproofing. Silicone, also known as polysiloxane, has many desirable properties. It is mainly inert, has low thermal conductivity, is waterproof, UV-protected and provides airtight insulation. Silicone has applications in sound insulation as a caulking agent. It is applied in paste form and usually cures to form a rubber coating. This coating is hermetically sealed and therefore stops sound transmission through the air. It is also a good damping material and performs well in damping mid-range frequency sounds.
Green glue is a viscoelastic compound that uses a system of Constrained Layer Damping (CLD) to isolate sound. The glue is applied (sandwiched) between two rigid materials (e.g. drywall). In the CLD system, damping occurs when the viscoelastic material is sheared. When a sound wave strikes the rigid material, it causes it to move in different directions. This movement creates shear forces within the raw glue. The polymeric design of Green Glue allows it to convert shear energy into friction energy and thus into heat. Green Glue is non-toxic; however, despite the name, it does work perfectly well as an adhesive.
