Influences of Thickness and Fabric for Sound Absorption of Biopolymer Composite

Abstract

Biopolymer foam was prepared by the reaction of bio-monomer based on vegetable oil with commercial Polymethane Polyphenyl Isocyanate (Modified Polymeric-MDI). The acoustic study of biopolymer foam was examined by impedance tube test according to the ASTM E-1050 and laminated with three types of textile such as polyester, cotton and single knitted jersey. It was revealed that the thicker the fabric the higher the sound absorption coefficient (α) at medium frequency level. The higher the number of layers or thickness of the fabric, the sound absorption through the fabric increases at medium frequency but after the maximum it remains almost unaltered. Three layer of cotton fabric gives maximum α approximately equal to 1 which is 1.104 mm thickness at frequency level of 3000-3500Hz and single knitted jersey gives maximum α at 4thlayer of 2200-2700Hz. Meanwhile , the α of biopolymer foam laminated with polyester fabric approximately equal to 1 at lower frequency level of 2000-3000Hz with lower thickness that is 0.668mm. Polyester fabric with lowest thickness shows better α at lower frequency level due to the structure of the fabric. The relationships among the fiber properties such as fiber density, fiber diameter, and fibrous material layer were considered as a factor that influences the sound absorption property.

Application of Soundproofing Materials for Noise Reduction in Dental CAD/CAM Milling Machines

“…A previous study reported that the sound absorption rate of soundproofing materials differs according to the state of attachment [19][20][21]. It also depends on the conditions of the backside of the material (the presence/absence of a back wall of the material, the characteristics of the wall, the presence of an air layer between the material and the wall, the thickness of the air layer, etc.)…”

“…Various types of soundproofing materials were tested for their noise-proofing performances. Furthermore, the sound absorption efficiency of soundproofing material varies depending on the setting, including the presence of a wall, the thickness of air layer, and the material attachment [19][20][21]. Therefore, it is critical that the soundproofing material is sparingly used in optimal spots rather than over large areas to minimize overheating, space usage, and weight.…”

“…Thicker material and higher frequency sound increase sound absorption efficiency. Moreover, inserting an air layer increases sound absorption efficiency [19][20][21]. For evaluating the performance of soundproofing materials, the experiment was focused on three conditions: the scope of soundproof frequency, the thickness, and the applicability of each soundproofing material.…”

Sound absorption and compressive property of PU foam‐filled composite sandwiches: Effects of needle‐punched fabric structure, porous structure, and fabric‐foam interface

“…Moreover, scholars have impregnated graphene oxide into PU foam to strengthen its porosity and tortuosity to improve sound absorption coefficient . Hassan et al laminated biopolymer foam, cotton fabric, and knitted fabric to enhance sound absorption at medium frequencies . Kraitape et al found that the incorporation of recycled PU foam polyol decreased the cavity size and yielded a wider cells distribution, which strengthened the tensile and compressive properties .…”

Sound Absorption Properties of Polyurethane Foams Derived From Waste Cooking Oil Incorporated With Waste Wood Fiber Filler

“…The attention on natural biomass feedstock is also on the conversion process into monomer, polymers, and composites. Several works have also been investigated with respect to the production of polyols for the PU industry which included the acid liquefaction of identified biomass residues [6,1,11].…”