Chemical treatment of wood fibers to enhance the sound absorption coefficient of flexible polyurethane composite foams

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

“…The main reason for this phenomenon was that the sound path length increased, and wave remained longer in the foam, which furthermore collided with more air molecules. Hence, the energy dissipation with a longer quarter wavelength condition increased, thus shifting the peak to the low frequency region …”

“…The cavity size of the PU foam added from 696.3 to 822.4 μm as water content increased from 0 to 1 wt%. Hence, the sound absorption was improved due to the friction of more air molecular collisions with sound waves through the porous medium . Furthermore, the sound energy can also be dissipated as heat energy by the vibrational damping motion of the cell walls.…”

“…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 . Currently, study of PU foam composites focuses on adding fillers, such as fibers, and particles, to enhance their sound absorption levels. Chen et al incorporated bamboo leaf particles into PU foam to improve sound absorption properties .…”

Nitrogen/phosphorus synergistic flame retardant-filled flexible polyurethane foams: microstructure, compressive stress, sound absorption, and combustion resistance

“…Compared with a rigid polyurethane foam, it has more diversied applications as a thermal barrier in the appliance industry and as a cushioning material; moreover, it can be used in mattresses, heat insulation pipes, automobile interiors, energy absorption, oil/heavy metal adsorption, vibration-proof packaging, construction, decoration, building roofs, and ltration. [1][2][3][4][5] The most potential hazard of FPUF is its ammability. Neat FPUF is combustible, and its LOI is lower than 19.…”

Effect of crossing film among glass fibers on blanket performance

“…Both experimental and calculative results shown that this structure have a high airflow resistance (AFR) and SAC. [15] Berardi et al reported the acoustical properties of natural fibers and compared the measured performances with the theoretically predicted ones. Some suggestions for the application of these natural fibers in buildings were reported.…”