The impact of material properties and process parameters are determined using a continuum model. Normal stresses for roller compaction are calculated from Johanson's rolling theory. The boundary between the slip and nip regions is calculated using Johanson's criterion, i.e. gradients of stress in slip and nip regions are assumed to be equal at nip angle. Shear stresses are calculated from the normal stresses using the method of Schonert and Sander.

INPUT PARAMETERS:
Roll Gap / Roll Diameter,
Effective angle of friction,
Applied feed pressure,
Horizontal load ratio,
Compressibility.

OUTPUT:
Normal stress plot,
Shear stress plot,
Nip angle,
Slip region gradient plot,
Nip region gradient plot.

Variation in nip angle
with compressibility
constant

Variation in nip angle
with effective angle of
friction

Model developed by A.J. Hlinak,
pharmaHUB tool developed by K. Kuriyan,
Pharmaceutical Technology and Education Center, Discovery Park, Purdue Univeristy

Johanson, J. R. (1965) A rolling theory for granular solids. J Appl Mech, 32(4), 842-848.
Sommer, K., Hauser, G. (2003) Flow and compression properties of feed solids for roll-type presses and extrusion presses. Powder Technol, 130(1-3), 272-276.
Schonert, K., Sander, U. (2002) Shear stresses and material slip in high pressure roller mills. Powder Technol, 122(2-3), 136-144.

Researchers should cite this work as follows:

• Kamal Kuriyan (2008), "Roller Compactor," http://pharmahub.org/resources/rollr.

  BibTex | EndNote

1. Dry granulation
2. Johanson's model
3. Process modeling
4. Roller compaction