2.3. Tensile Testing of the Pattern-Embedded Specimens

The designed specimens were 3D printed, molded, and subjected to tensile tests. The Agilus (box) and VeroCyan (pattern) were printed simultaneously by the Objet500 connex3 (Stratasys, Ltd., Eden Prairie, MN, USA). The print direction was perpendicular to the tensile direction, and all specimens were produced in the same direction. Five Agilus–VeroCyan specimens were printed for each pattern. The Ultimaker3 printed the TPU 95A pattern for the Dragonskin 30–TPU 95A specimen. The mold was designed to center the pattern in the Dragonskin 30 silicone molding. The Ultimaker 3 printed all the pattern molds with polylactic acid, as shown in Figure 5. The two components comprising the Dragonskin 30 raw materials were placed in a syringe, and air bubbles were removed using the vacuum chamber. After placing the pattern on the mold and sealing it, it was filled with the Dragonskin 30 silicone using a two-component gun and cured for one day at room temperature. Five Dragonskin 30–TPU 95A specimens were also produced using the same procedure. The produced Agilus–VeroCyan and Dragonskin 30–TPU 95A specimens are shown in Figure 5.

3D printed specimen mold and pattern-embedded specimens: (a) 3D printed specimen mold for Pattern A with major axis alignment; (b) 3D printed pattern-embedded specimens; and (c) silicon-molded pattern-embedded specimens.

For examining the effect of patterning, the pattern was printed on the TPU 95A, and a tensile test was performed. Five TPU 95A-patterned specimens were printed for each of the five patterns evaluated in this study and with two thicknesses (0.7 mm and 1.4 mm) using the Ultimaker3 (Figure 6). The tensile testing was performed using the ST-1001 testing machine, which pulled each specimen at 50 mm/s, yielding a stress-strain curve for each specimen type.

3D printed pattern-specimens of TPU 95A.