Abstract:
This research studies the noise absorption efficiency of the polyurethane foam waste
sceens. Thickness noise absorbing sceens is 0.25 inches, 0.5 inches, 1 inches and 2 inches, with 4
case studies in working machines. Case 1: Open all 3 pumps for 3 types of work (Cutting steel,
chipping steel and lapping steel). Case 2: Open all 3 pumps for cutting steel. Case 3 Open all 3
pumps for chipping steel and Case 4: open all 3 pumps for lapping steel. The population in study
consisted 66.7 percent male and 33.3 percent female, average age 23 -49 years and 8.3 years of
work small part pump department, in a steel furniture factory in Samut Prakan Province. Before
installing noise level of 82.8-92.5 dBA, the noise characteristics are continuous noise (Non
steady state noise). After this study results that Case 1: The sceens is best noise reduce is 2 inches
thick, reducing to 2.0-4.1 dBA. Case 2: The sceens is best noise reduce is 0.25 inches thick and 1
inches thick, reducing to 1.4-4.6 dBA. Case 3: The sceens is best noise reduce is 1 inches thick,
reducing to 2.0-4.1 dBA. Case 4: The sceens is best noise reduce is 2 inches thick, reducing to 1.5
to 3.0 dBA. When tested with Paired t-Test statistics comparing noise frequency absorbing of best
thickness results is Case 1, the thickness of 2 inches at the frequency of 500 Hz and 2,000 Hz is
significantly different at the level of 0.05 (p = 0.015 and p = 0.016, respectively) but found that at
frequencies 1,000 Hz and 4,000 Hz there is no different Case 2, with a thickness of 0.25 inches at
the frequency of 1,000 Hz, 2,000 Hz and 4,000 Hz, is significantly different at the level of 0.05 (p
= 0.001 p = 0.037 and p = 0.032, respectively) but found that at a frequency of 500 Hz, there is no
different and the thickness of 1 inch at the frequency of 1,000 Hz and 2,000 Hz is significantly
different at the level of 0.05 (p = 0.001 and p = 0.011, respectively) but found that at 500 Hz and 4,000 Hz, there is no different Case 3, with a thickness of 1 inch at the frequency of 1,000 Hz,
2,000 Hz and 4,000 Hz, is significantly different at the level of 0.05 (p = 0.001 p = 0.025 and p =
0.038, respectively) but found that At a frequency of 500 Hz, there is no different Case 4, at a
thickness of 2 inches at a frequency of 500 Hz, was significantly different at the level of 0.05 (p =
0.001) but found that at 1,000 Hz, 2,000 Hz and 4,000 Hz, there is no different. Therefore, this
study it recommended that polyurethane foam waste materials, reducing noise with personal
protective equipment in factory.