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1	Ultrasonic measurement of residual wall thickness during gas assisted injection moulding. Mulvaney-Johnson, Leigh, Brown, Elaine, Coates, Philip D. January 2007 (has links) No / Ultrasonic technology provides a powerful and noninvasive method of in-process measurement during injection molding and extrusion. Changes in the velocity, attenuation and reflection coefficients of high frequency sound waves can be related to the state and conditions of the materials through which they propagate. The velocity of an ultrasonic wave changes with density and elastic moduli; this allows information on solidification and material properties to be collected during the molding cycle. The time of flight of the wave is a function of velocity and path length. This paper shows that it can be correlated with the residual wall thickness of polymer in the mold during gas assisted injection molding. Olefin polymer Experimental study Non destructive method Temperature effect Thickness measurement Ultrasonic method Wall thickness Property processing relationship High density ethylene polymer Gas injection Injection molding
2	Micromoulding: extreme process monitoring and in-line product assessment. Whiteside, Benjamin R., Howell, Ken B., Martyn, Michael T., Spares, Robert 08 June 2009 (has links) No / Advances in micromoulding technology are now allowing mass production of complex, three-dimensional functional products having sub-milligram masses and carefully tailored surface finishes. In order to create a viable manufacturing process for these components, accurate process monitoring and product evaluation are essential in order to highlight process problems and production of substandard parts. The present study describes work implementing a suite of sensors on a commercial micromoulding machine for detailed process interrogation. Evaluation of demoulded products is performed with a single camera based system combined with custom software to allow for three-dimensional characterisation of products during the process. Monitoring High density ethylene polymer Modeling Olefin polymer Molding Experimental study Image analysis Three dimensional model Defect detection Optimization Temperature control Pressure control Process control Microinjection Processing parameter Injection molding
3	Effect of polymer matrix on the rheology of hydroxapatite filled polyethylene composites. Martyn, Michael T., Joseph, R., McGregor, W.J., Tanner, K.E., Coates, Philip D. January 2002 (has links) No / The effect of matrix polymer and filler content on the rheological behavior of hydroxyapatite-filled injection molding grade high-density polyethylene (HDPE) has been studied. Studies of the flow curves revealed that the matrix and the composite exhibit three distinct regions in the flow curve, namely, a pseudoplastic region at low to moderate shear rates, a plateau and a second pseudoplastic region at high shear rates. The shear stress corresponding to the plateau (Tc) is dependent on both the filler concentration and the melt temperature. Addition of HA in the HDPE matrix increases the value of Tc and decreases compressibility of the melt. An increase in temperature also raises the value of Tc. From the nature of flow curves it is concluded that the matrix polymer largely decides the rheology of the composite. Rheological properties Temperature effect Melting point Pseudoplastic fluid Flow curve Property composition relationship Isothermal compressibility Shear viscosity Shear stress Stress strain relation Injection molding Hydroxyapatite Dispersion reinforced material High density ethylene polymer Composite material Experimental study

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