Comparative accuracy analysis of continuous fiber composite printers: Coextrusion vs. dual-nozzle technology

Abstract

Material Extrusion (MEX) technology for continuous fiber reinforced thermoplastic composites (CFRTCs) is based on the extrusion of a continuous fiber to create three-dimensional composite objects layer by layer. This technology explores three distinct methods: preimpregnated filament, dual-nozzle, and coextrusion. The goal of this paper is to compare two printers, one using the dual nozzle technology and another relying on coextrusion. The first printer, Mark Two of Markforged, is based on dual-nozzle technology. The second printer, the Anisoprint Composer A4, stands out for its coextrusion method. Three adaptive Geometrical Benchmark Test Artifacts (GBTA), proposed by Spitaels et al. were fabricated with each printer to determine their dimensional performances. Measurements are taken using a Coordinate Measuring Machine (CMM) Wenzel LH 54. The overall deviation results of the two printers are around the IT14 standard. Deviations for measurements between 1 and 10 mm are greater compared to dimensions exceeding 10 mm, averaging around IT 12. Along the Y-axis, Markforged shows smaller deviations, attributed to its smaller print bed dimension compared to Anisoprint. Additionally, Zaxis deviations are lower than those along other axes, suggesting both printers have better precision in vertical build plate movement compared to print head movement. Notably, significant deviations are observed at the center of the GBTA in comparison to the other three axes (X, Y, and Z) for both printers.