PSI - Issue 68

Carlos Fernandes da Silva et al. / Procedia Structural Integrity 68 (2025) 1252–1258 C. F. das Silva et al. / Structural Integrity Procedia 00 (2024) 000–000

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Table 1. Sample designation scheme, resin contents (in weight %) and densities. The densities are estimated. Sample weight % PET weigth % PA 66 weight % PA 6T6I

ρ [g cm − 3 ]

PET

100

0

0

1.400

A1 A2 A3 A4 B1 B2 B3 B4

97.5

2.5

0 0 0 0

1.394 1.387 1.374 1.348 1.395 1.389 1.378 1.356

95 90 80

5

10 20

97.5

0 0 0 0

2.5

95 90 80

5

10 20

◦ C (533 K), zone 2 - 260 ◦ C (533 K), zone 3 - 265 ◦ C (538 K), zone 4 - 270 ◦ C (543 K) and zone 5 (extrusion matrix) - 270 ◦ C(543K). The used extrusion matrix produces sheets with a retangular cross section with 0.8 mm thickness and 40 mm width, the films were further rolled after passing the extrusion matrix to the appropriate thickness and immediately cooled in water, to simulate the process used for PET packages. The films were collected in rolls using a winder after the water cooling stage. The winder stretched the films deforming them by cold drawing. The final thickness of the obtained film was measured by a standard micrometer and the films with thickness under 0.15 mm were discarded. Maximum obtained thickness was 0.35 mm.

3. Sample extraction and notching

In order to warrant the repeatability in the produced samples, stainless steel templates were laser machined to cut strips with 120 mm length and 25 mm width from the films and to guide the action of the blade during notching. This procedure allowed to produce the samples with precise dimensions both for the external dimensions and in the ligament length ( b = 8 mm) and also the perfect alignment of the lateral notches. Notching was produced using a surgical scalpel nr. 11, which was substituted for a new blade after every 10 cuts. Figure 1(a) show an example of sample extracted from group A1 blend. Details of the processing of the films will be subject of a separate publication.

(a) (b) Fig. 1. Example of a produced sample corresponding to the A1 blend, showing the dimensions (a) and Setting of a sample in the machine, for the tensile test (b).