Page 282 - IJB-9-4

International Journal of Bioprinting 3D printing of continuous fiber reinforced PLA/PGA composites

Figure 1. Experimental setup and printing principle. (A) Experimental setup and (B) printing principle. Abbreviations: PGA, polyglycolic acid; PLA,
polylactic acid.

Figure 2. Morphology of polyglycolic acid (PGA) suture. (A) Section morphology and (B) surface morphology.

2. Materials and methods as shown in Figure 2. This PGA suture was made up of
bundles of fine woven fibers.
2.1. Experimental setup and materials
Figure 1A shows the self-developed 3D printer for printing 2.2. Specimen fabrication
continuous fiber-reinforced composites. The 3D printer The process parameters studied in this work include
was driven by a three-axis closed-loop computer numerical layer thickness (H), printing spacing (S), printing speed
control (CNC) system. The PLA filament was pushed into (V ), and filament feeding speed (V ). Through the pre-
a nozzle with a heater by a filament feeder. There was a experiment, the process parameters that can lead to fiber
f
p
small inclined hole on the side of the nozzle, which was the breakage, nozzle clogging, and very poor printing quality
channel for the PGA fiber to enter the nozzle. The PGA fiber were eliminated, and the range of process parameters
was wrapped by the molten PLA in the nozzle, extruded that can achieve continuous printing was obtained. In
from the nozzle under the pressure of the material pushed general, the filament feeding speed should match other
into the nozzle from the filament inlet, and deposited on main process parameters. The range of values that can be
the hotbed. A high-speed camera was set on the side of taken for filament feeding speed is small, because a very
the worktable to observe the deposition process of the slow filament feeding speed will cause a discontinuous
material extruded from the nozzle. The printing principle deposition line, and a very fast filament feeding speed will
is illustrated in Figure 1B. cause nozzle clogging. The values of parameters shown in
A PLA filament with a diameter of 1.75 mm was used Table 1 were selected based on preliminary results. Single-
as the matrix material. The reinforcing fiber was a PGA factor experiments were conducted to study the effects of
medical absorbable suture (Shandong Boda medical the printing parameters on the mechanical properties of the
supplies Co., Ltd. China), with a diameter of 0.15 mm. The composite specimens. All the experiments were conducted
cross-sectional and surface morphology of the PGA suture using a nozzle with an outlet diameter of 0.4 mm, a printing
were observed using a scanning electron microscope, temperature of 210°C, and a hotbed temperature of 40°C.

Volume 9 Issue 4 (2023) 274 https://doi.org/10.18063/ijb.734