Granulated products, breakage

The approach taken here is to employ standard materials characterization tests to measure the materials properties of the granulated product. With this information, the mechanism of attrition, i.e., breakage versus erosion, is determined. The rate of attrition can then be related, semi-empirically, to material properties of the formulation and the operating variables of the process, such as bed depth and fluidizing velocity. 

FIG. 21-131 Breakage of Metamucil tablets under three-point loading with razor scoring. (Reprinted from Design and Optimization of Granulation and Compaction Processes for Enhanced Product Performance, Ennis, 2006, with permission ofEbG Associates. AU rights reserved.)... 

For urea conditionir, a popular practice in some countries is the inclusion of 0.3%-0.5% of formalde-f e in the final product. The formaldehyde is added to the molten urea in the form of a 37% formaldehyde solution or concentrated urea-formaldehyde (UF85 containing 26% urea, 59% formaldehyde, and 15% water). Formaldehyde addition also reduces the formation of dust in the finishing (granulation) process because the granules are harder and more resistant to abrasion and breakage than is untreated material [127,128,1291. 

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