PSI - Issue 41

Cosmin-Florin Popa et al. / Procedia Structural Integrity 41 (2022) 557–563 Author name / Structur l Integrity Procedia 00 (2019) 000–00

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Fig. 5. a) Deflection – Impact Force and b) Deflection – Impact Energy curves of the specimens from PETG with different thicknesses

Fig. 6 presents the average of maximum impact force and impact energy and the standard deviation for specimens printed from PLA and PETG with different thicknesses. As expected, the results show a trend of linear growth with thickness. The PLA specimens with 10 mm thickness shown a greater spread of the results. An increase in thickness of the PLA specimens, causes observable deterioration of the maximum impact force for printed materials while the PETG specimens presents a small spread of the results. If the average of the maximum impact force in case of 6 mm thickness for PLA printed specimens is 105.29 N, for PETG printed specimens is 91.15 N and the trend is linear growth. Although the maximum force is higher for PLA specimens, in case of deflection PETG specimens presents upper deflection values. For example, in case of 10 mm thickness the average of deflection for PETG specimen is 0.842 mm against 0.678 mm for PLA specimens. Likewise for 6 mm thickness the average of deflection for PETG specimen is 0.581 mm against 0.497 mm for PLA specimens. Taking into account this results, the trend for the impact energy is to have similar values for both materials as can be observed in Fig. 6b.

Fig. 6. a) Average of the maximum impact force and standard deviation and b) Average impact energy and standard deviation for the specimens from PLA and PETG with different thicknesses

Fig. 7 shows the average of IZOD impact strength in KJ/m 2 . The IZOD impact strength average for PLA specimens with 6 mm thickness, has lower value than for PETG specimens. For 8 mm and 10 mm thicknesses the impact strength average increases, being for PLA specimens a little higher than for PETG specimens. Nevertheless, if we look to the standard deviation from the Fig. 7 we can conclude that the value of the IZOD impact strength have similar results for both materials PLA and PETG. The difference between those materials are in maximum impact force and in the deflection. The difference between this materials consists in the maximum impact force that can be absorbed by the specimens and in the maximum deflection respectively.