Professional paper
Viskoznost – jednostavni kriterij pri konstruiranju kalupa za injekcijsko prešanje plastomera
Muralidhar LAKKANNA
; National Institute of Technology Karnataka, Department of Mechanical Engineering Surathkal, Mangaluru 575025, Karnataka, India
G. C. Mohan KUMAR
; National Institute of Technology Karnataka, Department of Mechanical Engineering Surathkal, Mangaluru 575025, Karnataka, India
Ravikiran KADOLI
; National Institute of Technology Karnataka, Department of Mechanical Engineering Surathkal, Mangaluru 575025, Karnataka, India
Abstract
Thermoplastics are available in abundance with immense properties variations, but only few are processed by injection moulding. So this manuscript deals with this issue by proposing a design criteria contingent to a particular combination of material properties, machine specifi cations and moulding features. Pertinently embracing their behavioural relationships a unique analytical design criterion was deduced directly from fi rst principles. Comprehending injection conduit to an analogous capillary tube; as well as cognising generalized Newtonian concept for thermoplastic melts with power-law description of in-situ rheological behaviour. The proposed criterion being simple and generic easily adapts in early mould design itself and comprehends entire range of thermoplastic in-situates. Hereafter any thermoplastics could be injection moulded by contingently designing an exclusive mould feed system for it. This percipience was elucidated by continuously sensitising a hypothetical intervene across all thermoplastics while explicitly appraising, why melt kinesis lacunae can never be fully rectifi ed, despite manipulating process parameters many times? Finally, the manuscript extends hereto-believed linear relationship between runner-conduit size and in-situ melt state to direct exponential proportionality with discrete slope and altitude for each thermoplastic behaviour.
Keywords
Injection moulding; Melt viscosity; Runner conduit; Thermoplastics
Hrčak ID:
137301
URI
Publication date:
28.3.2015.
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