Instrumented open-source filament extruder for research and education

Extruders are necessary equipment for 3D filament manufacturing, which is considered a clean technology, because it has less scrap and can reuse materials, increasing its life cycle. Open-source extruders are less expensive than industrial extruders. However, they have little instrumentation, which limits the analysis of the processing and, consequently, the development of new materials, screw design and process control. Therefore, this project aims to develop a low-cost extruder with a high degree of instrumentation. To achieve this, equipment with a circuit board was developed, with modularity, machine and peripherals control, process stability, and data acquisition. To validate the equipment, the processing was done at constant temperature and with flow variation. The data obtained were temperatures in different points of the barrel, the rotation speed of the extruder motor, current consumed by the motor and by the resistances, and the speed of the puller motor. Thermal images of the components were taken during processing, validating the type of material used in the parts manufactured by additive manufacturing. The ABS filament produced was analyzed by flow and surface analysis using a confocal microscope.挤出机是3D打印长丝（3D filament）制造工序中的必备设备，该工艺因废料产出少且可回收复用物料、延长产品生命周期，被视作清洁生产技术。开源挤出机的造价低于工业级挤出机，但这类设备的测控配置较为匮乏，极大限制了加工过程的分析能力，进而制约了新型材料研发、螺杆结构设计以及工艺控制技术的发展。因此，本项目旨在研发一款兼具高测控性能的低成本挤出机。为此，本项目研发了一款搭载主控电路板的新型挤出设备，其具备模块化设计、整机与外设控制、工艺稳定性保障以及数据采集功能。为验证该设备性能，本研究开展了恒温条件下的变流量挤出加工实验。本次实验采集的数据包括料筒各点位温度、挤出机电机转速、电机与加热电阻的消耗电流，以及牵引电机转速。实验过程中还采集了设备各组件的热成像图像，以验证增材制造（Additive Manufacturing）所制备零件的用材类型。本研究还借助共聚焦显微镜（confocal microscope）对制备得到的ABS丝材开展了流动性与表面形貌分析。