基于狼尾草纤维的3D打印复合线材制备与工艺优化  

Preparation and process optimization of 3D printing composite wire based on pennisetum fiber

作　　者：吴庆定[1] 唐小杰 李佩 张嘉文 郝飒 刘克非 WU Qingding;TANG Xiaojie;LI Pei;ZHANG Jiawen;HAO Sa;LIU Kefei(Research Institute of Material Forming Technology,Central South University of Forestry and Technology,Changsha 410004,Hunan,China)

机构地区：[1]中南林业科技大学材料成形技术研究所,湖南长沙410004

出　　处：《中南林业科技大学学报》2021年第9期166-178,共13页Journal of Central South University of Forestry & Technology

基　　金：湖南省重点研发计划项目(2019GK2244);湖南省自然科学基金/常德市联合基金项目(2020JJ6065);湖南省交通运输厅科技进步与创新项目(201731)。

摘　　要：【目的】拓展狼尾草的高值清洁利用领域,丰富FDM 3D打印耗材品种,制备具有木质感的3D打印复合线材。【方法】以狼尾草纤维为基材,经改性后与聚乳酸(PLA)复合,采用挤出法制备1.75 mm规格3D打印狼尾草/PLA复合线材,并通过3D打印实践优化3D打印工艺参数;借助Design Expert软件优化狼尾草纤维改性碱处理工艺;利用ANSYS FLUENT软件对狼尾草/PLA复合线材挤出熔融段流场进行数值模拟,分析其初始加热温度、螺杆转速和机筒温度等工艺参数对线材挤出过程的影响,进而优化线材挤出工艺;借助扫描电子显微镜(SEM)分析狼尾草/PLA复合材料断口形貌特征,解析其强韧化成因。【结果】狼尾草纤维的最优碱处理工艺参数为:碱液浓度3.5%,处理温度60℃,处理时间4.2 h。狼尾草/PLA复合线材挤出成形最优工艺条件为:流道初始温度165℃,螺杆转速为8 rad/s,机筒温度为180℃。制备的1.75 mm规格狼尾草/PLA复合线材应用于3D打印实践时,打印工艺参数推荐值为:填充率60%,层高0.3 mm,打印速度30 mm/s,打印温度210℃。狼尾草/PLA复合材料的SEM断口形貌具有韧性断裂特征,成就了1.75 mm规格狼尾草/PLA复合线材良好的冲击韧性。【结论】经碱处理后的狼尾草纤维随着部分半纤维素、灰分等组分的去除,其纹孔得以打开,与PLA的亲和力得以增强,制备的狼尾草/PLA复合线材及其3D打印试件强度高,韧性好,木质感强,可用于各种家居及办公家具摆件、汽车驾驶室用饰条与饰件、各类机电设备操控手柄等产品的生产,应用前景广阔。【Objective】To expand the field of high-value clean utilization of Pennisetum,enrich the varieties of FDM 3D printing consumables,and prepare 3D printing composite wire with woodiness.【Method】Pennisetum fiber was used as the base material,which was modified and compounded with polylactic acid(PLA).Pennisetum/PLA composite wire with 1.75mm size was prepared by extrusion method,and the 3D printing process parameters were optimized through 3D printing practice.Design Expert software was used to optimize the alkali treatment process of pennisetum fiber.The numerical simulation of the flow field in the extrusion melting section of the composite wire of pennisetum/PLA was carried out by using ANSYS Fluent software,in order to analyze the influence of the process parameters such as the initial heating temperature,screw speed and barrel temperature on the extrusion process of the wire,and then optimize the wire extrusion process.The fracture morphology of Pennisetum/PLA composite was analyzed by scanning electron microscope(SEM),and the causes of strengthening and toughening were analyzed.【Result】The optimum alkali treatment parameters of pennisetum fiber are as follows:alkali concentration 3.5%,treatment temperature 60℃,and treatment time 4.2 h.The optimal extrusion process conditions of pennisetum/PLA composite wire are as follows:initial temperature of the flow passage 165℃,screw speed 8 rad/s,and barrel temperature 180℃.When the 1.75 mm pennisetum/PLA composite wire is applied to 3D printing practice,the recommended printing process parameters are as follows:filling rate 60%,layer height 0.3mm,printing speed 30 mm/s,printing temperature 210℃.SEM fracture morphology of Pennisetum/PLA composite has ductile fracture characteristics,which makes pennisetum/PLA composite wire with 1.75 mm size have good impact toughness.【Conclusion】After alkali treatment,with the removal of hemicellulose and ash,the pores of pennisetum fiber are opened and its affinity with PLA is enhanced.The prepared pennisetum/PLA

关 键 词：狼尾草纤维 木质复合材料 3D打印线材 工艺优化 数值模拟 

分 类 号：S781.2[农业科学—木材科学与技术]