Abstract
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 104 and calcium carbonate powder (mean particle size 2.7 μm) 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.
Similar content being viewed by others
References
1._ D. S. T. Hsieh, in “Controlled Release Systems: Fabrication Technology” (CRC Press, Boca Raton, 1988) Vol. 2.
C. E. Capes, in “Handbook of Powder Technology,” edited by J. C. Williams and T. Allen (Elsevier, Amsterdam, 1980) Vol. 1.
W. Pietsch, Chem. Eng. Prog. 92(4) (1996) 29.
F. Hoornaert, P. A. L. Wauters, G. M. H. Meesters, S. E. Pratsinis and B. Scarlett, Powder Technology 96 (1998) 116.
G. Akay, Polym. Eng. Sci. 34 (1994) 865.
Idem., Agglomerated Abrasive Material, US Patent no. 4 988 369 (1991) European Patent no. 307278 (1992) and Japanese Patent no. 940 37634 (1994).
Idem., in “Polymer Powder Technology,” edited by M. Narkis and N. Rosenzweig (Wiley, New York, 1998) p. 542.
Idem., Coating Process, European Patent no. 382 464 (1992), Australian Patent no. 633 299 (1993).
Idem., Polym. Eng. Sci. 30 (1990) 1361.
Idem., Chem. Eng. Sci. 53 (1998) 203.
Idem., European Patent no. 649 867 (2002).
G. Akay and L. Tong, Ind. Eng. Chem. Res. 41 (2002) 5436.
L. Tong and G. Akay, J. Mater. Sci. 37 (2002) 4985.
G. Akay and L. Tong, J. Colloid Interface Sci. 239 (2001) 342.
G. Akay, L. Tong, M. Hounslow and A. S. Burbidge, Colloid and Polymer Sci. 279 (2001) 279.
G. Akay and L. Tong, J. Mater. Sci. 35 (2000) 3699.
G. Akay, L. Tong, H. Bakr, R. A. Choudhery, K. Murray and J. Watkins, ibid. 37 (2002) 4811.
G. Akay, in “Recent Advances in Transport Phenomena,” edited by I. Dincer and M. F. Yardim (Elsevier, Paris, 2001) p. 11.
A. Casale and R. S. Porter, in “Polymer Stress Reactions” (Academic Press, New York, 1978) Vol. 1.
G. Akay, Polym. Eng. Sci. 22 (1982) 798.
I. Sekiguchi, in “Process in Powder Technology Handbook,” edited by K. Gotoh, H. Masuda and K. Higashitani (Marcel Dekker Inc., New York, 1997) Vol. 7.
G. Akay and L. Tong, in “Progress in Transport Phenomena,” edited by S. Dost, H. Struchtrup and I. Dincer (Elsevier, Paris, 2002) p. 681.
G. Akay, V. J. Price and S. Y. Chan, Flow Induced Phase Inversion in the Intensive Agglomeration/Microencapsulation of Powders, in Recent Advances in Particle Technology, IChemE CD-Rom, 1998.
G. Akay, in “Encyclopaedia of Fluid Mechanics,” edited by N. P. Cheremisinoff (Gulf Publishing, Houston, 1986) Vol. 1, p. 1155.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Akay, G., Tong, L. Process intensification in particle technology: Intensive granulation mechanism and granule characteristics. Journal of Materials Science 38, 3169–3181 (2003). https://doi.org/10.1023/A:1025109231638
Issue Date:
DOI: https://doi.org/10.1023/A:1025109231638