Single-screw extruders are mainly used for forming processes, but can also be used for modification of polymers. It should be noted that the three-stage screw formed by the conventional thread has a limited mixing ability, and if it is used for the filling modification, it is difficult to obtain a filler-modified material having a high mixing quality. Therefore, the single screw used for the mixing operation has a mixing section such as a barrier section, a BM section, a wavy section, a pin section, and the like. These components have good dispersion and mixing properties, and some have good distribution and mixing performance.
In general, the dispersive mixing element should be placed upstream of the distributed mixing element. This arrangement is more likely to produce a lower material temperature at the inlet of the dispersive mixing element, while the material temperature at the inlet of the distributed mixing element is due to material passing. Viscous heat generation and higher in dispersive mixing elements. The low feed temperature at the inlet of the dispersive mixing element will increase the dispersion mixing, while the high feed temperature in the distributed mixing element will improve the distributed mixing.
The dispersion and distribution mixing performance of the barrier section, the wavy section and the BM section are good. However, the wavy section is likely to cause fluctuations in the discharge, so it is preferable to add a barrier section downstream. The pin screw that only sets the pin on the screw has the main function of shunting, increasing the interface, and distributing and mixing. If it is used for dispersive mixing, it is difficult to open the solid phase agglomerate because there is no high shear zone. However, if the screw and the inner wall of the barrel are equipped with pins, the mixing effect can be greatly improved. After the inner wall of the barrel and the screw are staggered at the same time, when the material passes through this section, the flow condition is greatly different from that of the pin screw.
(1) The pin on the screw is shunted, and the pin on the barrel is also shunted.
(2) There is a large relative speed between the screw pin and the barrel pin, the direction of the relative speed being perpendicular to the direction of the material flowing axially through the pin spacing, which is particularly advantageous for mixing according to the mixing theory. Moreover, this relative speed shearing of the stream is high frequency, intermittent pulse shearing, which is also very advantageous for mixing. Due to the small gap between the screw pin and the barrel pin, the relative speed in the gap is high and the material is subject to high shear.
(3) There is a small gap and a high relative speed between the top of the pin and the surface of the screw and the surface of the barrel, so that the material is also highly sheared at these locations. It has been proved that the turbo-crush head pin screw has good mixing characteristics and can be used for filling modification.
Acid Dyes
An acid dye is a dye which is a salt of a sulfuric, carboxylic or phenolic organic acid. The salts are often sodium or ammonium salts. Acid dyes are typically soluble in water and possess affinity for amphoteric fibers while lacking direct dyes' affinity for cellulose fibers. When dyeing, ionic bonding with fiber cationic sites accounts for fixation of colored anions in the dyed material. Acids are added to dyeing baths to increase the number of protonated amino-groups in fibers.
Some acid dyes are used as food colorants.
Acid Dyes
Acid Orange,Acid Black 194,Acid Black 210,Acid Dyes Acid Red
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