Manufacturing of Filament for 4D Printing through Polyether-Type TPU/PLA Blend

Table 3

Characterization of the AFM results for the PLA, TPU, and TPU/PLA blend filaments.

Ratio of TPU/PLA; items	PLA	5 : 5	7 : 3	9 : 1	TPU
Surface area (µm^2)	400	400	400	400	401
Rq (nm)^a	10.7	1.41	4.55	5.02	17.6
Ra (nm)^b	8.32	1.18	1.99	2.08	11.8
Rmax (nm)^c	10.1	7.82	11.28	11.41	10.36

Surface area: total area of examined sample surface. Mean: the average of all Z values within the enclosed area. ^aR_q (rms): the standard deviation of the Z values within the given area. ^bR_a (mean roughness): the mean value of the surface relative to the center place. ^cR_max (max height): the difference in height between the highest and lowest points on the surface relative to the mean plane.