Feed frame is a device used in rotary tablet presses to drive the powders into compression dies. It applies shear forces to the powders as they are stirred around the feed frame chambers. This study focused on understanding the particle attrition, powder properties and the flow property changes of the material processed. The results demonstrated that the impact of the feed frame and die disk on the particle size distribution (PSD) outlet depended on the initial mean particle size, the die size and the powder outlet position. It also impacted the flow properties. The scale-up effect using a feed frame for a high production tablet press shows a significant increment in powder attrition. (C) 2012 Elsevier B.V. All rights reserved.