PSI - Issue 72

Miloš Vorkapić et al. / Procedia Structural Integrity 72 (2025) 470 – 478

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composite materials such as PLA/CF. It allows for model fabrication within a maximum volume of 256 × 256 × 256 mm³, with a layer resolution ranging from 0.12 mm to 0.28 mm and a print speed adjustable between 10 mm/s and 500 mm/s.

Table 1. Essential characteristics for PLA/CF

Filament type

PLA - Carbon Fiber Infill (PLA/CF)

Surface Density

Matte

1.22 g/cm³

Melting temperature

165 °C

Drying settings (Blast Drying Oven)

55 °C, 8 h

Nozzle temperature

210 - 240 °C 35 - 45 °C < 200 mm/s

Recommended Printing Settings

Bed temperature (with glue)

Printing speed

The specific printing parameters for sample fabrication are provided in Table 2. The selected printing parameters were similar to those reported by Wang (2024) to ensure producing high-quality prints with superior mechanical properties suitable for diverse industrial and functional uses, and to generally used technology for 3D printing of similar materials (Limpas et al. (2024), El Deeb et Al (2024) and Malbašić et al. (2023)).

Table 2. 3D printing parameters

Layer Height

0.12; 0.28 30%; 90%

Space infill density Space infill pattern

Grid

Infill direction

-45/+45

Infill/wall overlap

15%

Speed initial layer speed Speed layer infill speed

50 mm/s 80 mm/s

Travel speed Bad adhesion Top shell layers

max. 500mm/s

Brim

5 5

Bottom shell layers Temperature nozzle Temperature plate

235 °C

55 °C

Samples were printed in three different orientations (XY, XZ, and YZ), as illustrated in Figure 1(a). Specimens were printed for the mechanical tests,in accordance with appropriate standards (ISO 527-2 (2012), ASTM D256-23-1 (2023), ASTM D638-22 (2022)). A total of 27 dog-bone-shaped samples were printed, each with a length of 80 mm, width of 10 mm, and thickness of 4 mm. Additionally, 27 samples were produced for Charpy impact testing, measuring 60 × 10 × 4 mm. All samples underwent thermal treatment at -30°C, +20°C, and +50°C. Figure 1(b) and (c) depict the fabricated dog-bone-shaped samples and Charpy impact test specimens printed in the XZ plane. Nine samples were fabricated per series for each defined printing orientation. In order to get an insight in the effect of the CFs presence and to assess the thermo-mechanical resistance of the prepared composites, the following characterization techniques were applied: - Fourier-transform infrared spectroscopy (FTIR) analysis was done to examine the interaction PLA / CF, on a Thermo Nicolet iS10 device with ATR (Attenuated Total Reflection) sampling technique;