“…Further description of FFF technology may be found e.g., in [ 13 , 14 ] and references therein. Polylactic acid (PLA) [ 15 , 16 , 17 , 18 , 19 ], acrylonitrile butadiene styrene (ABS) [ 20 , 21 , 22 , 23 , 24 ], polyethylene terephthalate (PET) [ 25 ], polyethylene terephthalate glycol (PET-G) [ 26 , 27 , 28 ], polypropylene (PP) [ 29 , 30 ], and viscoelastic thermoplastic elastomers like thermoplastic polyurethane (TPU) [ 31 , 32 ] belong to the most common thermoplastics applied in FFF technology.…”