Evaluation of the manufacture of sound absorbent sandwich plank made of PET/TPU honeycomb grid/PU foam

In this study, the sandwich plank consisted of 7D polyethylene teraphthalate (PET), thermoplastic polyurethane (TPU) honeycomb grid, and polyurethane (PU) foam; 7D PET and 4D low melting polyester fibers were needle-punched and thermal-treated so as to form the PET nonwoven layer. The PU foam was foamed with a different density in the mold so as to form the PU foam layer with a different thickness. Finally, PET nonwoven layer, TPU honeycomb grid, and PU foam layer comprised the PET/TPU/PU sandwich plank. The results indicated that the sound absorption coefficients of the specimens were over 0.93 for the frequencies ranging between 2000 and 4000 Hz.