Double kneading disc

Figure 2.11 also shows the normal double-flighted kneading disc, also with Erdmenger s commentary. The practical limit for double-flighted elements is shown in Fig. 2.12 with a small tip angle and large product volume (see Section 2.2.1). 

Figure 2.11 Double-flighted kneading discs operation of blunted lens-shaped discs...

Figure 5.15 Example of double-flighted kneading discs...

Erdmenger s patent for single-flighted and double-flighted self-cleaning kneading discs is considered to be the basic patent of the twin screw extruder. The patent describes the eccentric disc as well as the traditional profiles. 

Interestingly, double-flighted kneading discs are described long before Erdmengers time. 

Figure 6.16 Erdmenger s single- and double-tipped kneading disc block machine [107].

Another special mixing section was described by Loomans [118] of Baker Perkins in a 1967 patent application. This is shown in Figure 6.20. These are essentially double-zipped kneading disc blocks with a 90° staggering angle. 

Kneading is a double-disc screw, that is, an eccentric disc mounted on two shafts rotating in the same direction, the screws are water cooled. Feeding of kneader is continuous. I he water is thus separated from the material. 

---