260
S. X. Drakopoulos et al.
Fig. 12 A biaxial stretching machine [53]. Reproduced with permission from Ryroluoto et al.
European Polymer Journal, 2017, 95, 606–624
performed a thorough comparison (averaging 70 production samples) between the
dielectric breakdown strength values of oriented and unoriented polypropylene films
[68]. The enhancement in the dielectric breakdown strength upon orientation, shown
in Fig. 13, is attributed to the transformation of the spherulitic crystalline morphology
to a highly ordered fibrillar network, consisting of oriented crystallites [53]. As in
the case of polyethylene composites, the improvement of the dielectric breakdown
Fig. 13 Dielectric breakdown strength of unoriented and biaxially oriented polypropylene packaging films [68]. J.L Nash, Polymer Engineering and Science, 1988, 28, 862–870. Reproduced with
permission
S. X. Drakopoulos et al.
Fig. 12 A biaxial stretching machine [53]. Reproduced with permission from Ryroluoto et al.
European Polymer Journal, 2017, 95, 606–624
performed a thorough comparison (averaging 70 production samples) between the
dielectric breakdown strength values of oriented and unoriented polypropylene films
[68]. The enhancement in the dielectric breakdown strength upon orientation, shown
in Fig. 13, is attributed to the transformation of the spherulitic crystalline morphology
to a highly ordered fibrillar network, consisting of oriented crystallites [53]. As in
the case of polyethylene composites, the improvement of the dielectric breakdown
Fig. 13 Dielectric breakdown strength of unoriented and biaxially oriented polypropylene packaging films [68]. J.L Nash, Polymer Engineering and Science, 1988, 28, 862–870. Reproduced with
permission