Optimisation of injection process parameters to minimise mould deflection: design of experiment

ABSTRACT

This research aimed to estimate the mould deflection by installing the strain gauges on the modified injection mould, which was analysed by the analysis of variance (ANOVA) method. Also, studied the correlation of the maximum mould deflection, thickness and defect of the moulded part. The optimisation of the injection parameters to minimise the mould deflection and defect was examined. There are seven processing factors with three levels of melting temperature, mould temperature, injection pressure, holding pressure, injection speed, holding time and cooling time, which are designed by using Taguchi’s experimental design. The parameter factors are statistically significant with P-values less than 0.05. The levels of those processing parameters are compared by Tukey pairwise comparisons using the Tukey method and 95% confidence. The optimum processing conditions attaining the lowest value of the maximum mould deflection of polypropylene (PP) and Acrylonitrile butadiene styrene (ABS) parts were investigated. The results showed that the mould deflection shows a good relation to those of thickness and flash defect; however, the occurrence of the short shot part presented a weak relation.

KEYWORDS:

• Injection moulding process
• mould deflection
• optimisation processing parameter
• Taguchi design of experiment

Acknowledgements

The authors gratefully thank to Plexpert (Thailand) Co., Ltd) for ABS supporting, Department of Production and Robotic engineering (KMUTNB, Thailand) and Thitichaya Duangsuwan, Lalitpat Tangkasem, Kornchawan Horprayoon for supporting and recording results.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contribution

All authors contributed equally.

Consent to participate

All authors have read and agreed to publish the manuscript.

Ethics approval

The authors hereby state that the present work is in compliance with the ethical standards.

Additional information

Funding

This work was supported by the King Mongkut's University of Technology North Bangkok.