Development of Highloft Nonwoven Materials for Health Care Acoustics

Abstract

Noise pollution can impart hearing impairment, hypertension, ischemic heart disease, annoyance, and sleep disturbance in huma n being. Continuous hearing of sound of 90 decibels make fatigue in hearing organs. Equipment sound more than 90 decibels will lead to damage of eardrums. Prolonged sound pollution will lead to permanent hearing disability. It will also create various types of temporary physiological changes, such as hypertension, change of the rate of heart-beat, high respiratory rates, excessive perspiration and vomitary tendency in human beings. This research work has been carried out to investigate the potential of natural material for acoustic applications. The most important factor for noise reduction is mainly based on the type of raw material used and also the structure of the material. In this examination to determine the acoustic performance, jute fibre was processed with STRUTO technology. The highloft structures produced by mixing jute fibre with polyester fibre and low melt bicomponent fibre has been thoroughly studied. The results from various GSM levels also have been analyzed. The highloft materials, which is light weight showed high efficient sound absorbing ability especially with increased GSM. Sound absorption properties of samples were analyzed and the findings were tabulated. These results indicated that high loft textiles produced from jute fibre blends, can be used as a primary raw material for acoustic applications, which is low in cost, light weight and also biodegradable.

Assessing the Sound and Heat Insulation Characteristics of Nonwoven Composite Structures: Evaluation of Polypropylene (PP)/Polybutylene Terephthalate (PBT) Meltblown, Polyamide Nanofiber Inner Layers and Recycled Polyester (r-PET) Thermo Bonded Outer

“…Furthermore, increasing areal weight means also increase in thickness which yielded higher NRC. The previous studies also supported these results [4,5,8,[43][44][45][46]. Regarding the high frequencies, increasing areal weight of inner layers in composite structures delivered statistically insignificant differences for composites including non-calendered inner layers and the NRC values were kept constant although areal weight of the inner layers increased.…”

“…Furthermore prolonged exposure to excessive noise can result in health problems such as tinnitus, temporary or permanent hearing impairments, neurological problems, raised blood pressure and hypertension. Therefore noise control is essential for building, automotive and machine industries to reduce noise related problems and provide improved life quality [1][2][3][4][5][6].…”

“…However, nonwoven materials present a promising option for sound absorption due to their substantial and intricately designed internal structure, lightweight nature, cost-effectiveness, and recyclability. [4][5][6][7].…”

“…Thus, sound absorbing characteristics of nonwovens depends mainly on pore properties such as size, shape, number and it is affected by the fiber's diameter, fibers orientation and distribution. The nature of the fiber (type, surface characteristics, elasticity), length, fineness, cross section of the constituent fibers, the fiber orientation, the porosity, pore size and number, thickness, density and areal weight of the nonwovens and many other several factors determine the sound absorption characteristics of these structures [2,5,[11][12][13][14][15].…”

“…Fibers with different cross sections (round, trilobal, 4DG, hollow, hexaflower, flat) were evaluated in nonwovens for sound absorbing properties in numerous studies [36][37][38][39][40][41][42] and it was revealed that cross sections increasing surface area, pore size and thickness also increased the sound absorption coefficient. Some of the investigations focused on influence of fiber fineness, areal density, thickness, density of nonwovens manufactured with different methods like air laying, carding, needle punching, thermal bonding and vertical lapping [4,5,8,[43][44][45][46]. The studies demonstrated that thickness, areal weight and porosity and density are influential factors for sound absorbing.…”