ผลกระทบของการเติมวัสดุเศษเหลือจากธรรมชาติที่มีปริมาณเซลลูโลสสูงในวัสดุผสมต่อสมบัติการหน่วงของการติดไฟและการขยายตัวทางความร้อน

Abstract

The objective of this research is to investigate the effects of wood plastic composites (WPCs) reinforced with three types of natural fibers from agricultural waste; coconut fiber (COF), palm oil fiber (PF) and corn fiber (CF) on the mechanical, physical, thermal and flammability properties by mixing recycled polypropylene plastic (rPP) with the fibers, coupling agent and lubricant. The percentages of recycled polypropylene are 50%, 60% and 70%, natural fiber (NF) contents are in the range of 45%-48%, 35%-38%, and 25%-28%, coupling agent (MAPP) is in the range of 1%-4% and lubricant (L) is 1%. The composite materials were manufactured into panels by using a twin-screw extruder and hot press machine. The data were statistical y analyzed by analysis of variance (ANOVA) and the Tukey’s multiple comparison tests to detect the significant differences between groups. It was found that WPCs with 3% of coupling agent obtained the best mechanical properties and the amount of natural fiber had significant effect on the flexural, tensile, compressive and surface hardness properties of WPCs. The flexural, tensile and compressive strength are reduced when the amount of natural fibers increased in contrast to the surface hardness and modulus values that increased. For the mechanical properties, it was found that the flexural strength, tensile strength, compressive strength and surface hardness of WPCs reinforced with coconut fiber (rPP/COF) obtained the best when compared to those of WPCs reinforced with oil palm fiber (rPP/PF) and corn fiber (rPP/CF). For the physical properties, it was found that the surface roughness significantly increased as the amount of wood fiber was increased. For the thermal properties, no significant differences were found between groups in thermal stability test. But it was found that the thermal expansion of WPCs with higher fiber content was lower. For the flammability properties, it was found that WPCs with lower fiber content were less flammable. In addition, when comparing WPCs from the natural fibers using the composition ratio at rPP70NF26M3 which obtained the best in mechanical, physical, thermal expansion and flammability properties with the medium density fiberboard standard (TIS.966-2547) and flat pressed fiberboard standard (TIS.876-2547), it was found that WPCs with this composition ratio met the both criteria. In terms of production costs, no significant differences were found between groups as the production cost of rPP/COF is 25.57 baht per piece, rPP/PF is 24.73 baht per piece and rPP/CF is 24.41 baht per piece.