PSI - Issue 28

D. Rigon et al. / Procedia Structural Integrity 28 (2020) 1655–1663 Rigon et al. / Structural Integrity Procedia 00 (2019) 000–000

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3. Static mechanical properties The mechanical properties of virgin and recycled ABS (i.e. vABS and rABS) produced by conventional manufacturing (Injection Moulding, IM) and FDM are reported in Table 1 and summarized in Fig. 3. As it can be seen, σ UTS of the IM_rABS is in good agreement with the scatter of the vABS.

Table 2. Mechanical properties of virgin and recycled polypropylene (PP) produced by FMD and IM.[15][16][17][18] Material Technology infill density [%] specimen orientation infill pattern E [GPa] σ Y [MPa] σ UTS [MPa] ε B [%] references vPP IM \ \ \ 2.2 n.a. 33.5 n.a.

Pegoretti and Ricco (2000)

1.3 1.4 n.a. n.a.

31.6

31.6

n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.

Fu et al. (2000)

n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.

41 33 21 33

Carneiro et al. (2015) Abdelhaleem et al (2017) Abdelhaleem et al (2017) Carneiro et al. (2015) Carneiro et al. (2015) Carneiro et al. (2015) Carneiro et al. (2015) Carneiro et al. (2015)

rPP vPP

IM

\

\

\

FDM

100

F

0°

1.22 0.98 1.03 1.05 1.02

45° 90°

31.9 32.7 31.5 27.6

0°/90°

±45°

60

max. and min value of PP (IM) (Table 2)

50

40

30

σ UTS [MPa]

40%

20

10

0

Figure 4. Ultimate tensile strength results of virgin and recycled PP produced by IM and FDM (see ref. in table 2). The PP_IM is taken as the reference materials, where the dotted lines refer to the minimum and maximum value found in the list of refs. reported in table 2. For the other bars, the error is equal to one standard deviation of the results (data are taken from the Refs. reported in table 2) All ultimate tensile strength results relevant to FDM_vABS specimens are lower than the reference scatter of the IM_vABS and, as can be appreciated from Fig 3, they show a dependency on the infill pattern. In particular, the best σ UTS is obtained for the 0°-oriented rasters with respect to the load direction (FDM_0°_vABS) of fig. 3, see Fig. 2a for the infill pattern nomenclature). Whereas the lowest values were obtained for the FDM_45°_vABS FDM_90°_vABS, more precisely, 63% and 66% lower than the minimum value relevant to IM ABS. Furthermore, the same trend can be observed on Young’s modulus (see Table1). Finally, the σ UTS of FDM_±45°_rABS agrees with the recycled ABS and with the scatter of the IM_vABS. Notably, there is a significant difference between the σ UTS of