. Author manuscript; available in PMC: 2015 Dec 1.

Published in final edited form as: J Biomed Mater Res A. 2014 Dec;102(12):4326–4335. doi: 10.1002/jbm.a.35108

Table 2.

3D Printing Processing Conditions for Uniform and Gradient PCL Scaffolds in a Full Factorial Design

Factor	Print head speed (F, mm/min)	Fiber spacing (s, mm)			Temperature (T, °C)	Operating pressure (P, psi)	Delay time between layers (D, sec)	Layer height (z, mm)^**
Factor	Print head speed (F, mm/min)	Uniform	Gradient		Temperature (T, °C)	Operating pressure (P, psi)	Delay time between layers (D, sec)	Layer height (z, mm)^**
# Levels/Factor	1	4	3	2^*	1	1	1	1
Levels	400	1.2, 1.5, 2.0, 2.5	1.5/2.0, 1.5/2.5, 2.0/2.5	(P_a), (P_b)	60	16	30 (0°), 120 (90°)	0.2 (0°), 0.6 (90°)
Total printing formulations tested					10^***

(P_a) Scaffold was tested with smaller pore size on bottom

(P_b) Scaffold was tested with smaller pore size on top

^**

(0°): 0° layer, (90°): 90° layer

^***

4 + 3 × 2 = 10 formulations