Abstract
Flowability of thermosetting plastics molding compound is determined mainly by the filler particle packing structure in a narrow channel. The filler packing structure in narrow channels was observed using Scanning Electron Microscope and transmitted X-ray image. For a narrow channel, the coarse particles blocked up the channel gate without fine particles among the coarse ones, and some resin flew through the openings among the filler particles trapped at the channel gate. In a middle thickness channel, fine particles filled the space among coarse ones and the high packing fraction was achieved, and almost no resin flew through the channel.
