Reliability of PVC-U Three Layer Pipes with Recycled Solid Core

Session 7B
4:30 pm

Takashi Kuriyama, Yamagata University

In order to make clear the reliability of PVC-U recycled pipes in relation to the three-layer structure, we described the deformation and fracture mechanism of wall of pipes based on non-destructive techniques of scanning acoustic microscopy (SAM). The results showed that a typical necking with stress whiting showed in the tensile deformation of normal pipe specimen, whereas the necking occurred from two sites in the three-layer pipe specimen of which was corresponded to the position of ‘spots’ in the SAM image before tensile test (fig.1).The multiple necking deformation occurred after the multiple cracking/crazing of which initiated from notwell melting powders in recycled solid core. These mechanisms prevent the brittle fracture of recycled pipes.

Takashi KURIYAMA (1) and Norio HIMUKAI (2)

1) Graduate School of Science and Engineering Yamagata University, JAPAN
2) Japan PVC Pipe and Fittings Association