Tipboonsri Ponlapath, Pramoonmak Supaaek, Uawongsuwan Putinun, Memon Anin
Department of Industrial Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Thanyaburi, Phathum Thani 12110, Thailand.
Department of Materials and Production Technology Engineering, King Mongkut's University of Technology North Bangkok (KMUTNB), Bangkok 10800, Thailand.
Polymers (Basel). 2023 Dec 27;16(1):83. doi: 10.3390/polym16010083.
Thermoplastic pultrusion is a suitable process for fabricating continuous unidirectional thermoplastics with a uniform cross-section, high mechanical properties due to continuous fiber reinforcement, low cost, and suitability for mass production. In this paper, jute and glass fibers were reinforced with a polypropylene matrix and fabricated using the thermoplastic pultrusion process. The volumetric fraction of the composite was designed by controlling the filling ratio of the reinforcing fiber and matrix. The effects of molding parameters were investigated, such as pulling speed and molding temperature, on the mechanical properties and microstructure of the final rectangular profile composite. The pulling speed and molding temperature varied from 40 to 140 mm/min and 190 to 220 °C, respectively. The results showed that an increase in molding temperature initially led to an increase in mechanical properties, up to a certain point. Beyond that point, they started to decrease. The resin can be easily impregnated into the fiber due to the low viscosity of thermoplastic at high temperatures, resulting in increased mechanical properties. However, the increase in molding temperature also led to a rise in void content due to moisture in jute fiber, resulting in decreased mechanical properties at 210 °C. Meanwhile, un-impregnation decreased with the increase in molding temperature, and the jute fiber began to degrade at high temperatures. In the next step, with varying pulling speed, the mechanical properties decreased as the pulling speed increased, with a corresponding increase in void content and un-impregnation. This effect occurred because the resin had a shorter time to impregnate the fiber at a higher pulling speed. The decrease in mechanical properties was influenced by the increase in void content and un-impregnation, as the jute fiber degraded at higher temperatures.
热塑性拉挤成型是一种适合制造具有均匀横截面、由于连续纤维增强而具有高机械性能、低成本且适合大规模生产的连续单向热塑性塑料的工艺。在本文中，黄麻和玻璃纤维用聚丙烯基体增强，并采用热塑性拉挤成型工艺制造。通过控制增强纤维和基体的填充比例来设计复合材料的体积分数。研究了成型参数，如牵引速度和成型温度，对最终矩形型材复合材料的机械性能和微观结构的影响。牵引速度和成型温度分别在40至140毫米/分钟和190至220℃之间变化。结果表明，成型温度的升高最初会导致机械性能的提高，直至达到某一点。超过该点后，它们开始下降。由于热塑性塑料在高温下粘度较低，树脂可以很容易地浸渍到纤维中，从而提高机械性能。然而，成型温度的升高也由于黄麻纤维中的水分导致孔隙率增加，从而在210℃时导致机械性能下降。同时，未浸渍随着成型温度的升高而降低，并且黄麻纤维在高温下开始降解。在下一步中，随着牵引速度的变化，机械性能随着牵引速度的增加而降低，孔隙率和未浸渍相应增加。出现这种效果是因为树脂在较高牵引速度下浸渍纤维的时间较短。机械性能的下降受到孔隙率和未浸渍增加的影响，因为黄麻纤维在较高温度下会降解。
