Development of sustainable wood-fibre-reinforced PLA filament for dekstop 3D printing
Gariga, Oleg (2026)
Kandidaatintyö
2026
School of Energy Systems, Konetekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2026042835448
https://urn.fi/URN:NBN:fi-fe2026042835448
Tiivistelmä
Fused filament fabrication (FFF) increasingly relies on bio-based filaments such as polylactic acid (PLA), but processing data for natural-fibre-reinforced PLA on desktop single-screw extruders remain limited, and the viability of recycled PLA as a matrix is poorly documented. This thesis develops and characterises wood-fibre-reinforced PLA filament produced on desktop equipment, for both virgin and recycled PLA matrices at four fibre loadings (0, 5, 10, 15 wt%).
Virgin and recycled PLA pellets (the latter ground from failed laboratory prints) were dried, dry-blended with wood fibre, and compounded on a single-screw extruder. Tensile coupons (ASTM D638 Type IV) were printed on a Creality K1 Max and tested on a Shimadzu AGS-X, with one specimen per group instrumented with paired axial and transverse extensometers.
Virgin PLA showed a non-monotonic response to fibre loading: Young's modulus, peak strength, maximum load and strain at break were highest at 5–10 wt% and fell below the neat baseline at 15 wt%. Recycled PLA behaved differently: the neat recycled filament outperformed all three reinforced recycled formulations, interpreted as a print-quality artefact of fixed-temperature FFF across matrices of different melt viscosity rather than a property gain from recycling. All virgin filaments met the ±0.05 mm diameter tolerance; only neat recycled PLA did. Under the conditions tested, up to 10 wt% is practical for virgin PLA on single-screw equipment, while recycled PLA is best used neat.
Virgin and recycled PLA pellets (the latter ground from failed laboratory prints) were dried, dry-blended with wood fibre, and compounded on a single-screw extruder. Tensile coupons (ASTM D638 Type IV) were printed on a Creality K1 Max and tested on a Shimadzu AGS-X, with one specimen per group instrumented with paired axial and transverse extensometers.
Virgin PLA showed a non-monotonic response to fibre loading: Young's modulus, peak strength, maximum load and strain at break were highest at 5–10 wt% and fell below the neat baseline at 15 wt%. Recycled PLA behaved differently: the neat recycled filament outperformed all three reinforced recycled formulations, interpreted as a print-quality artefact of fixed-temperature FFF across matrices of different melt viscosity rather than a property gain from recycling. All virgin filaments met the ±0.05 mm diameter tolerance; only neat recycled PLA did. Under the conditions tested, up to 10 wt% is practical for virgin PLA on single-screw equipment, while recycled PLA is best used neat.