Figure 2.

IR intensity profiles for ABS printed at 230 °C and 100 mm/s. From ROIs corresponding to fig. 1b. The IR intensity of printing layer (L_P) drops quickly while the intensity of sublayers L_P−1 and L_P−2 appear to increases instantly. The sudden increase in L_P−1 and L_P−2 is due to reflected IR photons from the extrusion head. Following the sudden increase a more sublet peak in intensity occurs for both L_P−1 and L_P−2 each lagging behind the appearance of the L_P.