Dispersive mixing ability

A category of processing referred to as instantizing can use a combination of recrystallization or a hardening binder as described previously, but may also make use of the fluidized bed s mixing abilities. A surfactant can be uniformly distributed in a bed of powders and improve the dispersibility without altering particle size. A possible disadvantage of this technique is that surfactants may impart some taste to the product. 

In immiscible polymer blends, one polymer is dispersed in the form of domains in the continuous phase of the other. The degree of dispersion depends upon the mixing ability of the polymers, which decreases with an increase in concentration of the other polymer in the blend. Therefore, the quantity of domains and the degree of dispersion in PVC/CPE blends determine the progress of the degradatimi. The evolved HCl partially lags in the bulk sample, due to inefficient diffusion and, consequentially, has a catalytic effect on dehydorchlorination at low level of dehydrochlorination, as well as on the secondary reactions of polyene residues (Mahmood and Quadeer 1994). 

Tannin chemistry is complex and tannin blends (composed of singletree species tannins mixed together) offer a number of useful water treatment functions. Apart from oxygen-scavenging abilities, they act as passivating agents, film-formers, sequestrants, and polymeric sludge dispersants (for more details, see Section 10.3). 

FIG. 25 Lime soap dispersing ability of linear alkylbenzenesulfonate-a-olefmsulfonate (LABS-AOS) mixed surfactant system. LSDA, lime soap dispersion ability. (From Ref. 3.)... 

Although the full history of this screw is unknown, the mixing pins appeared to have been added to the screw after the screw failed to mix and homogenize the extrudate. Pin mixers have been retrofitted to screws for many years as a way to improve the distributive mixing for an extruder. Here the pin mixers would distribute the solid polymer fragments evenly in the extrudate, hut the mixers lacked the ability to trap and disperse them. Pin mixers were clearly the wrong type of mixer to use for this application. Instead, a dispersive mixer such as a Maddock-style mixer would be preferred see Section 8.5.1. 

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