Mixing enhancers, extruders

FIG. 18-48 Mixing enhancers for single-screw extruders a) Maddock (straight), (h) Maddock (tapered), (c) pineapple, (d) gear, (e) pin,... 

Mixing in single screw extruders. Mixing caused by the cross-channel flow component can be further enhanced by introducing pins in the flow channel. These pins can either sit on the screw as shown in Fig. 3.29 [9] or on the barrel as shown in Fig. 3.30 [15]. 

T. Brouwer, D. B. Todd, and L. P. B. M. Janssen, Flow Characteristics of Screws and Special Mixing Enhancers in a Co-rotating Twin Screw Extruder, Int. Polym. Process., 18, 26 (2002). 

Figure 3.13 Mixing enhancers for single-screw extruders [20]. (a) Pineapple, (b) Dulmage, (c) Saxton, (d) pin, and (e) cavity transfer.

Brouwer T, Todd DB et al (2002) Flow characteristics of screws and special mixing enhancers in a co-rotating twin screw extruder. Int Polym Process 17(l) 26-32 Carpenter J, Katayama D et al (2009) Measurement of Tg in lyophilized protein and protein exdpient mixtures by dynamic mechanical analysis. J Therm Anal Calorim 95 881-884 Chiang P-C, Ran Y et al (2012) Evaluation of drug load and polymer by using a 96-well plate vacuum dry system for amorphous solid dispersion drug delivery. AAPS Pharm Sci Tech 13(2) 713-722 Chokshi RJ, Sandhu HK et al (2005) Characterization of physico-mechanical properties of in-domethadn and polymers to assess their suitability for hot-melt extrusion process as a means to manufacture sohd dispersion/solution. J Pharm Sci 94(11) 2463-2474... 

Compounding Screws m Atypical screw-extruder device which make use of mixing enhancements such as barriers, flutes, waves, pins, or cavities to overcome the... 

Figure 16-24 Mixing enhancers for single-screw extruders.

Figure 16-38 Mixing enhancers for intermeshing co-rotating twin-screw extruders.

Fig. 23. Screw sections for enhancing distributive mixing in single-screw extruders (a) Dul-madge mixer, (b) Saxton mixer, (c) pin mixer, (d) pineapple mixer, (e) cavity transfer mixer, (f) slotted screw flight, (g) Kenics and Ross ISG static mixers [148]...

The efficiency of compounding extruders may be enhanced in a number of ways, and twin-screw units are designed also for special purposes. Mixing elements in a variety of forms (reversed flights, kneading discs, pins, etc.) may... 

Conventional poly(vinyl chloride) (PVC) batch preparation in which the dry materials are blended in a heated mixer and then cooled in a cooler mixer, was compared with the double batching preparation process. In this process, twice the required additives are added to the PVC, blended in the hot mixer, and the balance of the PVC then added to the mixed materials in the cooler mixer. This reduces the overall energy requirements. Rigid PVC for pipe manufacture was processed by both methods, and assessed by studying the rheological and physical properties and extrudability. Material of acceptable quality and pipe to the required standards were produced by the double batching process, with enhanced productivity and cost savings on power and labour. 4 refs. INDIA... 

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