Title: Reducing variation in tensile impact testing of plastics

Authors: Hari Prasad; Narayana Rao; Prasanta Mukhopadhyay

Addresses: SABIC Research and Technology Pvt Ltd, Anekal Taluk, Off Sarjapura-Attibele, State Highway, Bengaluru-562125, Karnataka, India ' SABIC Research and Technology Pvt Ltd, Anekal Taluk, Off Sarjapura-Attibele, State Highway, Bengaluru-562125, Karnataka, India ' SABIC Research and Technology Pvt Ltd, Anekal Taluk, Off Sarjapura-Attibele, State Highway, Bengaluru-562125, Karnataka, India

Abstract: Polymeric materials are characterised using various analytical techniques, the interest in this work emanates from tensile impact studies. Tensile impact properties have been a critical factor in evaluating polymeric material brittleness or ductility changes. High variation of this test leads to difficulty in formulation optimisation, targeted for applications demanding mechanical designs and integrity. The objective of this study is to understand the different factors affecting the variation in the test results. A systematic statistical analysis with multiple samples showed that specimen alignment in the test fixture was a major source of error. Modifications to the test fixture were carried out to address this issue. Statistical analysis of the data indicated that the data spread was significantly reduced and sample mean was not shifted post-machine modification. Product benchmark report estimated process capability increase in the Z value from 0.843 to 2.192, post-instrument modification (67% improvement in process capability).

Keywords: statistical process control; SPC; risk priority number; RPN; failure mode effective analysis; FMEA; standard deviation; homogeneity of variance; HOV.

DOI: 10.1504/IJPQM.2019.097766

International Journal of Productivity and Quality Management, 2019 Vol.26 No.2, pp.190 - 205

Available online: 01 Feb 2019 *

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