The mechanism and processing characteristics of a novel intensified granulation technique are evaluated. This intensification technique is based on the non-isothermal flow induced phase inversion (FIPI) phenomenon. Poly(ethylene glycol) (PEG) with an average molecular weight 10(4) and calcium carbonate powder (mean particle size 2.7 mum) were used as binder and filler to prepare granules. The granulation experiments were carried using a Haake extruder (Rheomex 252) which connected to a granulator of a new design. The extruder produced a homogenous PEG and calcium carbonate paste and fed it to the granulator. When the paste was subjected to a temperature gradient field with a superimposed repeated shear and extensional deformation, solidification, granule nucleation and subsequent macroscopic fragmentation (referred to as crumbling) occurred to give granular particles. The mechanism of granulation has been discussed. The granule size and size distribution characteristics under different process conditions have been evaluated. The novelty of this research lies in the granulator design and the mechanism of the granulation process. Temperature differential and repeated deformation are the two primary factors for the granulation process. Particle size distribution and crumbling area depend on the concentration of PEG, the clearance between rotor and stator, and the extrusion speed. If a so called 'crumbling agent', in the form of fine particles, is added to the newly formed granules, these granules are coated with the crumbling agent forming a core-shell type of granulated particles. (C) 2003 Kluwer Academic Publishers.