Home / Knowledge / News / Textiles / Technology to check acoustic levels of textile fabrics

Technology to check acoustic levels of textile fabrics

05
Jul '12
Sound-absorbing functions or the suppression of unwanted noise are often an integral requirement of equipment and clothing for military use. The extent of the sound-absorbing qualities of a material and which noises are caused by wind or movement can now be investigated using the acoustic test apparatus at the Hohenstein Institutes in Bönnigheim (Germany). The experts at Hohenstein specialise in particular in determining the acoustic properties of moving textile materials.

Using the new test methods, the experts can determine the suitability of a tent material or interior vehicle lining in protecting against sound waves, for example. On one hand, this is important with regard to protection against eavesdropping from modern directional microphones.

On the other hand, the concentration of sound levels is reduced by between 20 and 30 % at levels above 40 decibels (approximately the level of a radio at normal room volume). Therefore, passive noise protection is absolutely essential in order to prevent (as far as possible) carelessness by troops and supply units as a result of noise.

However, the noise created by equipment must also be controlled and minimised depending on their areas of use. Active noise protection prevents soldiers from being detected prematurely by electronic monitoring systems or enemy soldiers as a result of crackling or rustling combat dress or grinding boots when nearing their intended target. The “acoustic camouflage” of combat dress is therefore an important addition to the classical camouflage print.

When measuring sound absorption and transmission, the materials are clamped in a sample holder between a loudspeaker and highly sensitive measuring microphone so that they can be optimised accordingly.

The extent (in decibels) that the material reduces or absorbs the acoustic signal is measured in a frequency spectrum between 200 and 20,000 Hz. A key advantage here is the small sample size – even sizes of 10 x 10 cm are sufficient for testing. Samples with very different material thicknesses can also be inspected.

In active noise measurement, the textiles are automatically moved or crumpled together and the noises which occur within the audible frequency range are determined. In order to be able to simulate practical walking movements on fitted garments, boots or complete clothing systems, the mobile mannequin “Charlie” or a special boot model are used in some inspections. The noises generated by the mechanical testing equipment are measured in advanced and excluded from the final results.

The aeroacoustic test determines the frequency spectra of the often disturbing background noise of air flow in textiles. The Hohenstein Institute test apparatus is able to investigate virtually all samples ranging from small laboratory samples up to complete components and can simulate wind speeds of up to 140 km/h. The noises that occur are analysed using a computer program in order to determine their frequency range. These resulting comparative figures then enable materials to be optimised for the most diverse of uses.

As well as capturing the global acoustic properties of textile fabrics, the locally triggered causes of disruptive noises can also be determined. This knowledge can then be used to optimise textiles and components even more.

Hohenstein Institute


Must ReadView All

US President Joe Biden. Pic: Shutterstock

Textiles | On 29th Jul 2021

Proposed amendments to raise US content in federal purchases announced

The United States has decided to raise US-made content in government...

Pic: Shutterstock

Apparel/Garments | On 29th Jul 2021

Uninterrupted supply chain crucial for Vietnam amid ongoing COVID wave

Ensuring that the supply chain of Vietnam is not interrupted amid the ...

Pic: Moschino

Fashion | On 29th Jul 2021

Italy’s Aeffe buys remaining 30% stake in Moschino for full ownership

Italian luxury fashion company Aeffe has acquired fashion house...

Interviews View All

Vandana Narang, National Institute of Fashion Technology

Vandana Narang
National Institute of Fashion Technology

Campus placements are low due to lockdowns

Textile Industry, Head honchos

Textile Industry
Head honchos

Marry with brand ethos

Footwear Industry, Footwear Retailers

Footwear Industry
Footwear Retailers

Still struggling to mop up higher sales

Dhruv Toshniwal & Udit Toshniwal,

Dhruv Toshniwal & Udit Toshniwal

Launched a year ago, Fashions Pvt Limited conceptualises and sees D2C...

Dhirubhai & Arvind Shah,

Dhirubhai & Arvind Shah

It supplies synthetic fabrics to top international brands like M&S,...

Noemi Sanchez,

Noemi Sanchez

Established since 1846, Evlox is a specialised denim manufacturer with its ...

Shlomzion Chen, Seevix

Shlomzion Chen
Seevix

Seevix Material Sciences Ltd, which develops and manufactures synthetic...

Thomas Ong P S, NanoTextile

Thomas Ong P S
NanoTextile

Malaysian company NanoTextile Sdn Bhd taps into the potentials of...

Kevin Young & Tom Lucas, Web Industries

Kevin Young & Tom Lucas
Web Industries

Web Industries is a precision formatter of nonwoven materials used in baby ...

Anjali Bhaskar, Samatvam

Anjali Bhaskar
Samatvam

Samatvam, a womenswear brand that blends age-old craftsmanship with modern ...

Niti Singhal, Twee In One

Niti Singhal
Twee In One

Best known for convertible clothing, Indian brand Twee In One by designer...

Ruma Devi, Gramin Vikas Evam Chetna Sansthan

Ruma Devi
Gramin Vikas Evam Chetna Sansthan

Ruma Devi is a jet-setting promoter of artisans who has empowered...

Press Release

Press Release

Letter to Editor

Letter to Editor

RSS Feed

RSS Feed

Submit your press release on


editorial@fibre2fashion.com

Letter To Editor






(Max. 8000 char.)

Search Companies





SEARCH

Leave your Comments


July 2021

Subscribe today and get the latest update on Textiles, Fashion, Apparel and so on.


Advanced Search