FDM filament is supplied by ColorFabb under the reference
“Woodfill fine” with a diameter of 2.85 mm ± 0.1 mm. Woodfill fine
filament is described as a blend of poly(lactic acid) (PLA) and
poly(hydroxyalkanoate) (PHA) matrix, reinforced with recycled wood
fibres. The fibre content, evaluated by chloroform dissolution of matrix
and differential weighting, corresponds to a weight fraction of 15.2 ±
0.9%. This content is within the range given by the manufacturer
(10–20 wt%), but appears rather low compared to other commercial
products such as Laywoo® (40 wt% wood fibre) or EasyWood Coconut
from FormFutura (40 wt% coconut fibre).
Unlike other studies on multimaterial printing [12], we chose a
monomaterial to improve recyclability at the end of life and also reduce
delamination between bilayers when the hygromorph biocomposites
are printed