الفهرس 
Introduction and Problem IdentificationOnly 14 pages are availabe for public view
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Abstract
This work presented an investigation of the effects of process parameters on the quality characteristics of polymeric parts produced by micro injection moulding (µIM) with two different materials. Four injection moulding process parameters (injection velocity, holding pressure, melt temperature and mould temperature) were investigated using Polypropylene (PP) and Acrylonitrile Butadiene Styrene (ABS). Three key characteristics of the moulding were evaluated with respect to process settings and the material employed: part mass, flow length and flash formation. The experimentation employs a test part with four micro fingers with different aspect ratios (from 21 up to 150) and was carried out according to the Design of Experiments (DOE) statistical technique. The results show that holding pressure and injection velocity are the most influential parameters on part mass with a direct effect for both materials. Both parameters have a similar effect on flow length for both PP and ABS at all aspect ratios and have higher effects as the feature thickness decreased below 300 µm. The study shows that for the investigated materials the injection speed and packing pressure were the most influential parameters for increasing the amount of flash formation, with relative effects consistent for both materials. Higher melt and mould temperatures settings were less influential parameters for increasing the flash amount when moulding with both materials. Of the two investigated materials, PP was the one exhibiting more flash formation as compared with ABS, when corresponding injection moulding parameters settings for both materials were considered.The Aim of the thesis Improve the understanding of the behaviour of polymer melt filling by mean of statistically designed moulding experiments in different micro cantilever/fingers cavities using different polymers materials and to process them with the same range of the processing conditions using part mass, flow length and flash formation as part quality outputs. Runner mass and injection pressure will also be investigated.Identify which process parameters are the most influential during the filling stage of the microinjection moulding process.