Compounding mixing time

Quantitative eomparisons of aromatic reactivities were made by using the competitive method with solutions of nitronium tetrafluoroborate in sulpholan, and a concentration of aromatic compounds 10 times that of the salt. To achieve this condition considerable proportions of the aromatic compoimds were added to the medium, thus depriving the sulpholan of its role as true solvent thus, in the nitration of the alkyl- and halogeno-benzenes, the description of the experimental method shows that about 50-60 cm of mixed aromatic compounds were dissolved in a total of 130 cm of sulpholan. 

SBR mbber compounds are prepared in two stages the nonproductive and the productive phases. In the nonproductive phase the compound ingredients are mixed, usually in internal mixers (Banbury). The mixing time is usually short and the compound temperature is in the 160—195°C range. 

A similar experiment was conducted using N-299 carbon black. In this case the premastication was limited to 3 min of mixing time. The average batch temperature measured after this mixing operation was 309°F. Each experiment was performed in duplicate the average of two mixes is shown in Figure 16.6. The viscosity of the final control compound was similar to that of the premasticated mbber. 

Unload the compound when temperature reaches 150°C or mixing time 150 s is reached... 

The dump temperature of the compound was varied by changing the mixer s rotor speed and fill factor while keeping the other mixing conditions and the mixing time constant. Under the assumption that the final dump temperature is the main parameter influencing the degree of the sUanization reaction, the effect of the presence of ZnO on the dynamic and mechanical properties of the compound was investigated. ZnO was either added on the two-roll mill or in the mixer. 

It is well known that the cycle time of the mixing process in an industrial-sized internal mixer is limited by the increase of the compound temperamre. For example, typical mixing times on a 400 L tangential mixer with four wing rotors is of the order 200 s as can be derived from Figure 35.2. Especially during the last mixing phase the temperature increase of the compound is approximately l°C/s. 

In the processing of mbber compounds (mixing, rewarmings, calendering, extrusion) heat history is a term used to indicate the total heat which has been received by the compound, particularly the temperatures reached by the mbber and the time it has been held at these temperatures. See Scorching. 

The simultaneous addition of the elastomers and all the compounding ingredients to an internal mixer at the beginning of the mixing cycle. A saving in mixing time is claimed but dispersion may be adversely affected. 

Comparative ED Relative binding useful for highly bound compounds. Mixing plasma types can influence binding properties. Time to reach equilibrium can exceed 24 h. [38, 39]... 

The use of dielectric constant has been suggested as a processability measure95. It was found that for carbon black filled compounds the dielectric constant decreased with mixing time to reach a steady level which was deemed to indicate when sufficient mixing had taken place. 

Silver is one of the basic elements that make up our planet. Silver is rare, but occurs naturally in the environment as a soft, "silver" colored metal. Because silver is an element, there are no man-made sources of silver. People make jewelry, silverware, electronic equipment, and dental fillings with silver in its metallic form. It also occurs in powdery white (silver nitrate and silver chloride) or dark-gray to black compounds (silver sulfide and silver oxide). Silver could be found at hazardous waste sites in the form of these compounds mixed with soil and/or water. Therefore, these silver compounds will be the main topic of this profile. Throughout the profile the various silver compounds will at times be referred to simply as silver. 

Fig. 14 Aliphatic/aromatic region of NOESY spectrum of a mixture of tubulin, EpoA, and bac-catin III with concentrations of 12 pM, 0.6 mM, and 0.6 mM, respectively. The spectrum was acquired on a 900-MHz spectrometer equipped with a cryoprobe with a mixing time of 70 ms. The blue and green peaks are intramolecular transferred NOE peaks of EpoA and baccatin, respectively. The red peaks represent the interligand transferred NOEs mediated by the protein protons. The numbering of the atoms corresponds to that shown in the compound structures for EpoA (E) and baccatin (B). B-m, B-o, and B-p indicate the protons in the meta, ortho, and para positions of the benzene ring of baccatin, respectively. (Reprinted with permission from [75]. Copyright 2005 Wiley-VCH Verlag GmbH Co. KGaA, Weinheim)...

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