ANALYSIS OF FRICTION FORCES IN THE PROCESSOF FORMING MOULDING MASS

Abstract

Accelerated wear of the moulds' inner surface used in forming loose masses contributes to its frequentreplacement or regeneration. This wear is indirectly influenced by the high pressure accompanying thecompaction process, but the main cause of accelerated wear is the friction that occurs between the die and thecompacted medium. Knowing that the value of the internal pressure in the moulded medium changes withthe change of the distance from the punch, in order to properly understand the phenomena accompanying thefriction that occurs in the mould during the pressing process, its characteristics must be determined. The paperanalyses the distribution of forming pressure inside the mould during the compaction of high-silica sand. Thedeformation on the die surface was measured using strain gauges, and x-ray tomography was used to visualisethe compaction of high-silica sand during the compaction process. The usefulness of an indirect method formeasuring the friction coefficient based on the analysis of die deformation has been demonstrated.