Twin screw granulation

Twin-Screw Granulation Twin-Screw Wet Granulation... 

Dhenge RM, Cartwright JJ, Hounslow MJ, Salman AD Twin screw granulation steps in granule growth, Int J Pharm 438 20-32, 2012. 

In another case where the twin-screw extruder was used, the rubber and plastic were melt mixed with all ingredients in a similar manner as described in blend compositions for static vulcanizations. The product was then dumped, cooled, and granulated. The premixed granules were then fed into a twin-screw extruder where a very narrow temperature profile was maintained with a relative high compression (2 1), and the screw speed was adjusted depending on the final torque and the flow behavior of the extruded stock. The stock was cured by shear force and temperature enforced by the twin-screw extruder. The dynamically crosslinked blend was taken out in the form of a strip or solid rod to determine the... 

API material characterization before manufacturing for potential impact assessment. Process understanding and evaluation of specialized technologies [twin-screw wet granulation (TSWG), extrusion, solid dispersion, etc.] for long-term resolution... 

Lindberg, N O., Turfvesson, C., and Olbjer, L. Extrusion of an effervescent granulation with a twin screw extrudeDrug Dev. Ind. Pharm., 13(1987), 1891-1913. 

The third type of compounding device is the extruder. Next to its use for fabrication (which will be dealt with in 11.4.2), it is applied as a mixer. In essence, it is a screw pump, in which the mass to be mixed is transported in a heated cylinder by a screw, or, with twin-screw extruders, by two parallel screws. During this transport melting and intensive mixing take place. At the end of the screw the blend is pressed through a number of openings and cooled down in most cases the strands thus obtained are on-line cut into granules. 

Granular starch and copolymers of ethylene and acrylic esters and alkyl(meth)acr-ylates or vinylacetate are produced as master batches for the production of mulch films, geotextiles and molded articles.146 The polar copolymers act as compatibilizers by lowering the interfacial energy between starch and the polyolefin and eliminate the need to coat granules. Processing via a vented twin-screw extruder also eliminates the need for anhydrous starch. 

Anhydrous citric acid and NaHCOs were granulated with ethanol in a twin-screw extruder at powder flow rates of 60-90 kg/h in a continuous processJ The air suspension coating-reacting technique also is used in the production of effervescent granulates. 

Miyagawa, Y. Sato, H. Okabe, T. Nishiyama, T. Miyajima, M. Sunada, H. In vivo performance of wax matrix granules prepared by a twin-screw compounding extruder. Drug Dev. Ind. Pharm. 1999, 25, 429-435. 

Granulation consists of steps granulation (I) of lumpy material which returns to the mixing unit and back to granulation and to a twin-screw extruder. 

Granulate I passes to tlie blending unit and then to granulation unit H. I he material is dried and sitaped in the extrusion plant with a twin-screw extrusion extruder with two shafts rotating in the same direction. 

There are systems, which provide a dedicated mixing system. The use of mixing within a co-rotating twin-screw extruder system is described by Kleinebudde et al. (13). This system also claims the ability to be able to adjust the water content to the appropriate level and because it acts as both mixer and extruder, reduces the number of items of equipment required. This system is not widely employed in screen extruder systems, which without careful formulation can generate considerable heat that could be detrimental to heat sensitive formulations. Hellen et al. (14) describe the use of a granulator (Nica M6L, Nica systems AB, Molndat, Sweden) that functions with a high speed turbine to mix the powder with the water prior to extrusion. 

N.-O. Lindberg, C. Tufvesson, and L. Olbjer, Extrusion of an effervescent granulation with a twin screw extruder. Baker Perkins MPF50D, Proc. 6th Int. Conf. Pharm. Tech. (APGI), 187-209 (1996). 

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