Table 4.

Additive composite materials for FDM.

Material	Authors	Percentage Added and Description of the Additives	Notes (The Increase/Decrease of the Mechanical Properties are Considered Relative to Pure ABS)
ABS + carbon fibers	Ning et al. (2015) [119]	3, 5, 7.5, 10, 15 wt.%; 150 μm and 100 μm in length with a common diameter of 7.2 μm	150 μm: Maximum tensile strength value—42 MPa at 5 wt.% 150 μm: Maximum Young’s modulus value—2.5 GPa at 7.5 wt.% Results of 150μm long fibers’ addition are higher than of 100μm long fibers
	Tekinalp et al. (2014) [118]	10, 20, 30, 40 wt.%; the fibers’ length—200–400 μm.	40 wt.% resulted in the clogging of the nozzle (thus the author disregarded the results of the specimens made with 40 wt.%). Orientation of the fibers was along the load-bearing direction The increase of tensile strength was from 30 MPa to approximately 60 MPa at 30 wt.% The increase of tensile modulus was from 2 GPa to approximately 13 GPa at 30 wt.%
	Shofner et al. (2003) [117]	10 wt.% only; the average diameter—100 nm, length—100 μm	Tensile strength increased by 39% (from 26.9 MPa to 34.7 MPa) Tensile modulus increased by 60% (from 0.49 GPa to 0.79 GPa)
ABS + carbon nanotubes (CNT)	Sezer, H.K., and Eren, O. (2019) [121]	1, 3, 5, 7, 10 wt.%; average diameter—9.5 nm; average length—1.5 μm; surface area—250–300 m2/g	Tensile strength increased by 28.8% (up to 58 MPa) at 7 wt.% and raster angle [0, 90] Young’s modulus increased by 66.8% (up to approximately 1980 MPa) at 10 wt.% and raster angle [0, 90] Specimens printed at raster angle of [0, 90] performed better in mechanical properties testing than at [−45, 45]
	Dul et al. (2018) [120]	1, 2, 4, 6, 8 wt %; average diameter—9.5 nm; average length—1.5 μm; surface area—250–300 m2/g	Elastic Modulus increased by 19% (approximately from 2207 MPa to 2650 MPa) at 8 wt.% Tensile strength was not provided buy yield strength increased from 42.8 MPa to 47.1 MPa at 6 wt.%
ABS + ZnO	Aw et al. (2017) [122]	8, 11, 14 wt.%; Particle’s size < 100 μm	Tensile strength increased from about 10 to 16 MPa at 11 wt.%
	Torrado et al. (2015) [123]	2 wt.% only; ZnO nanorods were used (no information about the size)	Tensile strength decreased from 33.96 MPa to 20.7 MPa when specimen was printed horizontally. Tensile strength decreased from 17.73 MPa to 7.41 MPa when specimen was printed vertically
DulABS + graphene	Dul et al. (2016) [128]	2, 4, 8 wt.%; average lateral dimension –5 μm, thickness—6–8 nm, the surface area—120–150 m2/g.	MFI (Melt Flow Index) was studied, and it was revealed that specimens with 8 wt.% had low MFI, hence the authors disregarded the results of 8 wt.% Tensile strength decreased from 38.8 to 35.9 MPa at 4 wt.% when specimens were printed horizontally. Tensile strength decreased from 23.8 to 13.4 MPa at 4 wt.% when specimens were printed vertically. Young’s modulus increased from 1866 to 2463 MPa at 4 wt.% when specimens were printed horizontally. Young’s modulus increased from 1687 to 2151 MPa at 4 wt.% when specimens were printed vertically.
PC + ABS + graphene	Tambrallimath et al. (2019) [116]	0.2, 0.4, 0.6, 0.8 wt.%; PC:ABS = 70:30; No dimensions of graphene platelets were provided	Young’s modulus increased from 2531 to 4038 MPa at 0.8 wt.% Tensile strength was not studied
ABS + OMMT	Weng et al. (2016) [133]	1, 3, 5 wt.%; No dimensions of OMMT nanoparticles were given	OMMT stands for organic modified montmorillonite. Montmorillonite belongs to the group of phyllosilicates. Tensile strength increased from 27.59 MPa to 39.48 MPa at 5 wt.% Elastic modulus increased from 1.2 GPa to 3.6 GPa at 5 wt.%
ABS + BAK + Al2O3 + SiC	Singh et al. (2019a) [125]	BAK: fixed value of 10 wt.%; Al2O3: 0, 5, 10 wt.%; SiC: 0, 5, 10 wt.%; No dimensions were given	BAK stands for bakelite. It is a thermoset and was used as a filler in ABS matrix for recycling purposes. For one specimen Al2O3 and SiC were added in the same quantity. For example, 70% of ABS + 10% of BAK + 10% of Al2O3 + 10% of SiC Maximum strength at peak was 24 MPa at composition of 90%(ABS) + 10%(BAK)
	Singh et al. (2019b) [126]		The specimens were studied at different infill ratios and infill speeds. Maximum tensile strength of reinforced material was slightly less than that of pure ABS: 21.8 and 22.4 MPa respectively. Maximum tensile strength was observed at composition of 70%(ABS) + 10%(BAK) + 10%(Al2O3) + 10%(SiC); infill ratio of 80 and infill speed of 50 mm/s