Sound Absorption Behavior Related to Reduce the Melamine-Urea-Formaldehyde (MUF) Adhesives for the Coffee Silver Skin Board Production

ABSTRACT

The development of sound-absorbing panels which used coffee-silver-skin (CS) and melamine-urea-formaldehyde (MUF) as a composite board was studied. In this experiment, the objective was to examine the impact on the sound absorption coefficient (SAC) when incorporating wood husk into the composite board, specifically in the cases of CS (100%) and CS (90%) mixed with wood husk (10%), while simultaneously reducing the amount of MUF adhesive and adding corn starch (25%). It was observed that as the MUF content of the board decreased to 75%, the sound absorption coefficient average (SAA) were found to be 0.59 and 0.62 for the middle- and high-frequency ranges, respectively. For the frequency range higher than 3.15 kHz, the maximum SAC value of sample boards was 0.91 and the noise reduction coefficient (NRC) value was 0.47. While, the result showed the maximum SAC and the NRC value of sample boards were 0.93 and 0.48, respectively above the frequency range higher than 1.25 kHz for decreasing the MUF adhesive of board to 50%. Similarly, the addition of wood husk and corn starch mixed to CS could increase the SAA value of sample boards in the middle- and high-frequency range.

摘要

研究了以咖啡银皮（CS）和三聚氰胺脲醛（MUF）为复合材料的吸声板的研制. 在本实验中，目的是检验将木壳掺入复合板时对吸声系数（SAC）的影响，特别是在CS（100%）和CS（90%）与木壳（10%）混合的情况下，同时减少MUF粘合剂的量并添加玉米淀粉（25%）. 观察到，当板的MUF含量降低到75%时，发现中高频范围的平均吸声系数（SAA）分别为0.59和0.62. 对于高于3.15 kHz的频率范围，样品板的最大SAC值为0.91，降噪系数（NRC）值为0.47. 同时，结果表明，在将板的MUF粘合剂降低到50%的高于1.25 kHz的频率范围内，样品板的最大SAC和NRC值分别为0.93和0.48. 同样，在CS中加入木壳和玉米淀粉可以提高中高频范围内的样品板的SAA值.

KEYWORDS:

• Sound absorption
• melamine-urea-formaldehyde
• coffee silver skin
• natural fiber composite
• corn starch
• wood husk

关键字:

• 吸声
• 三聚氰胺脲醛
• 咖啡银色皮肤
• 天然纤维复合材料
• 木质外壳

Acknowledgments

The authors extend their appreciation to Aica Hatyai Co., Ltd. and Ban Tham Sing Coffee Group Community Enterprise for their generous support in providing raw materials for this research. Special thanks to Rajaman- gala University of Technology Phra Nakhon (RMUTP)and King Mongkut's Institute of Technology Ladkrabang (KMITL), Prince of Chumphon Campus, for providing the invaluable opportunity to conduct this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).