Can demixing occur in an ribbon mixer or double shaft paddle blender?
While demixing is less likely in amixer or double shaft paddle blender than in a tumble blender, it can still occur. During mixing a or paddle blender fluidizes the materials. If the batch is discharged during operation, mixing – while not totally random – is relatively uniform, without segregation. However, when the mixer stops operating, the fluidized mass settles, and heavier particles drop to the vessel’s bottom, creating stratified particle concentrations. You can avoid such demixing by discharging the mixer during operation. If the normal mixing speed creates discharge problems, such as dusting, try using a two-speed motor to decrease the ribbon agitator speed during discharge.