Title: Use of acoustic emission testing in injection moulding process

Authors: Tomaž Kek; Dragan Kusić; Rajko Svečko; Aleš Hančič; Janez Grum

Addresses: Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia ' TECOS Slovenian Tool and Die Development Centre, Kidričeva 25, 3000 Celje, Slovenia ' Faculty of Electrical Engineering and Computer Science, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia ' TECOS Slovenian Tool and Die Development Centre, Kidričeva 25, 3000 Celje, Slovenia ' Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia

Abstract: This paper presents the experimental results regarding acoustic emission signals measured during the injection moulding of those standard test specimens commonly used for examining the shrinkage behaviour of various thermoplastic materials. The acoustic emission was measured on a new injection mould and injection mould with the visible cracks on the cavity's surface. Two resonant 150 kHz piezoelectric AE sensors were attached to tool steel inserts via AE waveguides. The results of acoustic emission testing on the crack defected tool steel insert revealed higher acoustic emission activity compared with that captured on the brand new engraving insert under same processing conditions. Specimens produced with a new and defected tool were scanned with an optical 3D digitiser. Results of the experiments confirm that acoustic emission measuring during injection moulding of polymer materials is promising technique to characterise integrity of injection moulding tool regarding occurrence of cracks.

Keywords: acoustic emission; injection moulding; cracks; tool steel inserts; thermoplastic materials; cavity surfaces; piezoelectric sensors; nondestructive testing; NDT.

DOI: 10.1504/IJMMP.2014.066913

International Journal of Microstructure and Materials Properties, 2014 Vol.9 No.3/4/5, pp.327 - 337

Published online: 16 Jan 2015 *

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