Radial and axial die pressures during solid phase compaction of polymeric powders

As part of a research programme to investigate the feasibility of producing components by the solid phase compaction of polymeric powders, measurements have been made of the local radial and axial pressures in a specially instrumented die. During single end die compaction, the highest axial pressures occur close to the die wall at the upper (moving punch) and on the centre line of the compact at the lower punch. The radial pressure distribution may be linear or non-linear depending on the compaction conditions and the maximum radial pressure occurs below the top surface of the compacts. The structural variations of the compacts, as determined by microhardness measurements, were found to be consistent with pressures recorded along the die wall and compaction punches.