(663g) Effect of Feed Frame Design and Operating Parameters On Powder Attrition, Particle Breakage and Powder Properties
Powder flowability is affected both by powder material properties and by the equipment used for processing the material. This dependence of powder flow properties on multiple variables is important for the effective manufacturing of compacts in the pharmaceutical, food, agrochemical, cosmetics, and consumer product industries. In all of these applications, consistent flow of powders into the small die of a tablet press is key to producing tablets with consistent properties.
Manufacturers often use mechanical devices, called ?feed frames? or ?feed shoes? to maintain an adequate supply of powder to fill the dies of the tablet presses. Interestingly, the almost no published work on these critical devices is available. Our work focuses on studying the effect of the feed frame speed, die table speed, and material properties on the powder flow behavior when moving into the dies. In particular, we focus on attrition of friable materials as they flow through the feed frame. We measure the particle size distribution (PSD) and its impact on powder flow behavior as a function of feed frame speed and rotating table speed. of the granular material processed by the feedframe. Granular materials with different PSD, different lubricant concentration, and different active ingredient (acetaminophen) concentrations were tested. The PSD results demonstrated that for friable granulated materials, passage through the feed frame indeed changes the PSD. Outlet PSD depends on the initial particle size distributions, feed frame RPM, and residence time in the Feed Frame, which is affected also by tablet size and compression speed.