Effectiveness of Grinting Grass Composite Damper with and without Plywood on Machine Noise Intensity

Technological advances in the form of industrial noise reduction materials, especially organic fiber materials, have been widely developed because they are eco-friendly and have high sound absorption properties. This study aims to evaluate the effectiveness of grass-based composite materials as noise reducers for grinding machines by comparing two configurations: plywood-coated and uncoated. Composite samples containing grinting grass fiber, sawdust, and adhesive starch flour were formed into two variants: one coated with plywood and one without. This experimental method was used to develop composite materials for noise-absorbing partitions made of grinting grass, sawdust, and starch flour. Noise testing was conducted by measuring the decibel intensity of the machine with and without the composite damper. The results showed a decrease in noise intensity from 93,3 dB to 84,7 dB when the machine was operated with the composite plywood damper and from 93,5 dB to 86,4 dB without it. On average, composites with plywood can reduce noise intensity by 11,6 dB, while those without achieve an average reduction of 10,3 dB. Test results show that grass-based composites with plywood significantly reduce noise (p = 0.001). The highest sound absorption coefficient of 0.63 was found at a frequency of 1000 Hz. The difference is possible because plywood as an additional layer can reflect and absorb sound waves, so the results of the study show the potential use of plywood-coated grass composites as an alternative eco-friendly and efficient soundproofing material.