The absorption performance of acoustical foams manufactured by thin-sheet casting (TSC) and bun-stock manufacturing process was investigated. TSC results in partially reticulated foams which posses a normal airflow resistivity that is 10 times higher than that of generic, nonacoustically rated foam sheets that are sliced from bun stock. It was found that the TSC urethane absorption of the bun-stock foam almost throughout the frequency range. The higher average normal sound absorption coefficient (ANSAC) and NRC values for thin-sheet cast foams which indicate their superior performance relative to bun sheets.
