This paper presents a study of the effect of an external magnetic field on the distribution and orientation of magnetic particles in co-injection moulding. The orientation of the magnetic particles was determined using optical microscopy and image analysis techniques. The external magnetic field was placed in the tool cavity and used to magnetize the particles and to generate the necessary magnetic field gradient to manipulate them. The ferromagnetic nickel particles remained magnetic enough to overcome the strong drag forces imposed on them by the polymeric fluid matrix and to be orientated by the permanent magnet in the tool.
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Public domain program developed at the US National Institutes of Health. Available from the internet by anonymous FTP from zippy. nimh. gov or on floppy disk from the national Technical Information Service, Springfield, VA, part number PB95–500195GEI.
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