Materials & Resins # 1998 Gothenburg
Modified PVC pipes are being introduced for water reticulation where their tough, predictable behaviour offers advantages in both performance and material utilisation. CPE is one of the modifiers used, either alone or in combination with other additives. The effects of changes in processing conditions on both the phase morphology of the CPE and the physical properties of mPVC pipe have been investigated. The processing conditions were altered by varying barrel zone temperatures and screw speed. It was found that optimum pipe properties were achieved after the CPE developed a particulate phase morphology. The comparatively high 50.2 value obtained for the sample processed under the most benign conditions did not reflect its performance in the impact test or pressure tests. Further work is required to relate these results to the gelation levels of the samples.