In the mould pressing process, because the mutual friction between different powder particles and die walls, lead to stress on the punch transmit out of accordance with Pascal’s principle, receive different stress in various point of briquetting.

It’s generally speaking that the location which further away the pressing punch is the pressure is more smaller, this pressure lost called pressure drop.Friction between different powder particles and die walls is the mainly reason lead to no uniform pressure distribution. The thinner the powder particle is the more complex the shape will be, the bigger the pressure drop is, and the further distance away punch will be.