DESIGN FEATURES OF A SINGLE-SCREW EXTRUDER FOR MANUFACTURING COMPOSITE FILAMENT BASED ON ABS THERMOPLASTIC REINFORCED WITH CARBON AND KEVLAR FIBERS

Abstract

This article discusses the design features of a single-screw extruder for producing composite filament based on an ABS thermoplastic matrix reinforced with short carbon and Kevlar fibers. Such a composite is characterized by increased impact toughness, tensile strength, and elastic modulus compared to pure ABS. Kevlar fibers provide high impact energy absorption capacity due to their microfibrillar structure, preventing crack propagation, while carbon fibers increase stiffness. The composites are compatible with FDM printing, improve interlayer adhesion, and reduce the coefficient of friction, making them promising for friction parts, robotics, and mechanical engineering. Producing standard-diameter filament requires specialized equipment. Screw extrusion is optimal because it provides heating, mixing, melting, and extrusion of the mixture. The screw generates shear heating, supplemented by heaters. The screw consists of feed, compression, and metering zones with an optimal compression ratio that accounts for the thermal sensitivity of the matrix and the abrasiveness of the fillers. The clearance between the screw and the barrel prevents backflow. The temperature profile creates a gradient from the feed zone to the metering zone for controlled melting without degradation. Gravimetric feeding, the absence of filters, pre-drying of ABS, cooling, and laser diameter control ensure process stability. The system includes a feed hopper, forming head, cooling system, diameter sensor, and winding unit. Analysis confirmed the design’s effectiveness for producing reinforced filaments with predictable mechanical properties. The results are applicable to the additive manufacturing of high-reliability, impact-resistant structural elements in industries where lightness, strength, and resistance to dynamic loads are critical.