Evaluating and Modifying Johanson's Rolling Model to Improve its Predictability

Modifications to Johanson's roll compaction model for improved relative density predictions

“…Bi et al's experiments provide similar observations [16]. For example, the current study uses Avicel PH-102 (FMC-BioPolymer, PA, USA), which gives a best fit to Equation Figure 5.3.…”

“…The compressibility (fitting) constant for this case is K = 5.08. Compressibility constants between 4.5 and 5.9 were reported by Bi et al [16] in their experiments using formulations consisting of several materials, including Avicel PH-102. Nesarikar et al [22] also reported compressibility constants of between 4 and 6 in their formulations, which contained equal amounts of Avicel PH-102 and lactose as well as other components.…”

“…The approach used here is similar to the one proposed recently by Bi et al [16], who make use of a mass correction factor. The implementation here, however, is different and is described in detail in Chapter 5.…”

“…Bi et al [16] included a mass correction factor f  in the mass conservation equation (Equation (5.6)) in order to account for the fact that the mass in each of the elements may vary due to multi-dimensional flow,…”

“…This inaccuracy has been shown to be due to the onedimensional flow assumption in the model. Bi et al [16] proposed the use of a mass correction factor to account for multi-dimensional flow effects; however, the expression reported in their publication has derivation errors. In the present work, a mass correction approach is also used, but unlike Bi et al's work, the dependence of the mass correction factor on position within the roll compactor is accounted for.…”