Triple-shaft mixer to the rescue After a long development period, the HTI team was close to success, but needed a mixer that could create the membrane material and meet consis- tency and cost-efficiency goals. The multistep process first requires aggressive cellulose grinding, fol- lowed by continued dispersion and dissolution as numerous other ingre- dients are added to a casting solution.We knew that a single-shaftmixer ӗ even one equipped with multiple disperser blades could not handle the job. So, my first impulse was to test a dual-shaft mixer,ה says Steve Peterson, P.E., and senior project...

CP CP ,April, p. 31).With a dual-shaft mixer, the initial phase producedӑgel balls that resisted wetting out and dispersion,Ҕ Peterson says. But with the triple-shaft mixer ӗ thanks to the intense shear that the rotor/stator mixer applies the gel balls dissipate very quickly. At that point in the cycle, we turn off the high-shear mixer and proceed with only the high-speed disperser and the anchor agitator.ה The batch was complete in two hours, compared with the six-hour cycle that a dual-shaft mixer required.Today, HTI operates with a 40-gal. VersaMix in full-scale production, while a 2-gal....