The preparation and properties of fibers based on V-HDPE/R-HDPE mixtures with different mass ratios

In order to explore how different mass ratio combinations of virgin high-density polyethylene (V-HDPE)/recycled high-density polyethylene (R-HDPE) affect fibre and print quality, this study conducts a series of analyses. Fused deposition modelling (FDM) is a process used for fibre preparation investigation; it is possible to include five groups of ratios between R-HDPE 100% and V-HDPE 100%. The process of filament extrusion is supplemented with optical microscope observation. This helps establish a correlation between the composition and microstructure of any bio-based or crude oil-derived material; thus, it achieves a bio-based or crude oil-derived derivative. The diameter uniformity is tested; tensile strength is evaluated; printing parameters are optimized. The tensile strength of the filament reaches the maximum value (25.7 ± 1.1 MPa) when the mass ratio of V-HDPE40%/R-HDPE60%; it is higher than 38.2% that of pure R-HDPE (18.6 ± 0.8 MPa). The tensile strength of the V-HDPE60%/R-HDPE40% system stands at 24.3 ± 1.0 MPa; it rises by 30.7% against pure R-HDPE and still outperforms pure V-HDPE and low-proportion mixed systems. The average fibre diameter remains consistently within the range of 1.86–1.90 millimeters (mm) when the V-HDPE content is between 20% and 40%. Controlling the diameter to within ±0.05 mm improves the layers’ adhesion. In contrast, the V-HDPE100% group has a distinct diameter with weak interlayer adhesion. The results show that the strength of the composites increases with the rise of V-HDPE content; it reaches the maximum at 40% V-HDPE. This means that the properties of 3D printing fibers manufactured from recycled materials can be improved by controlling the mixing and printing parameters; this makes it easy to develop sustainable composite materials for aerospace and automobile manufacturing.