Effectiveness of the noise absorbing box in reducing stamp lot noise in electrical welding processes: case study in an automotive parts manufacturing factory, Phra Nakhon Si Ayutthaya province

Abstract

The noise problem associated with the Stamp-Lot machine arises from its operation, where symbols are stamped with a metal needle and punched onto the metal workpiece, causing noise that affects the workers’ health and the community. This study aimed to investigate the design of a noise-absorbing box and sound-absorbing materials to reduce the noise level of the Stamp Lot machine to be within the standards. The study compared the noise level of the Stamp Lot machine before and after the noise-absorbing box was used. The researchers and the engineering department worked together to design a sound-absorbing box to suit the operation and strength of the box. The noise-absorbing box was attached to the Stamp-Lot machine in one piece, including lining the inner wall with egg-shaped sound-absorbing polyurethane. The one-group experimental method was designed for this study, comparing the results of sound measurements before and after the improvements. The results showed that the average noise level occurred (LAeq) after the installation of the noise absorbing box and the installation of absorbing material was in the range of 86.3-89.0 dB(A), which was statistically significant compared to the average sound level before the installation of the sound-absorbing box, which was between 100.4-100.7 dB(A). Noise-absorbing boxes recommend that the structure of the soundproof noise-absorbing box be designed in such a way that it is suitable for each Stamp-Lot machine. It must have a shape and size that allows flexible working and a strong appearance to increase operator confidence and satisfaction.