Twin screw extruders kneading blocks

K. Funatsu, S.-I. Kihara, M. Miyazaki, S. Katsuki, and T. Kajiguara, 3-D Numerical Analysis on the Mixing Performance for Assemblies with Filled Zone of Right-handed and Left-handed Double-flighted Screws and Kneading Blocks in Twin-screw Extruders, Polym. Eng. Sci., 42, 707-723 (2002). 

Corotating twin-screw extruder Experimental work. Samples were scooped directly from the venting ports located between the melting and kneading block sections, as well as after the latter section. After melting, the dispersed phase consisted of fibers and droplets, both with diameters already below 10 pm. The kneading section (independently of Its construction) further reduced the drop diameter by a factor of ten Huneault et al. 1995b, 1996... 

Table 7.1 Main characteristics of conveying elements and kneading blocks of twin-screw extruders ((a) and (b) should not be directly compared) [44].

Figure 7.14 Flow visualization for a highly viscous silicone oil along the mixing zone of a twin-screw extruder (a) orthogonal kneading block (90°) (b) kneading block with negative staggering (—30°C), plus left-handed element [146].

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