Mixing procedure

Mixing. Ethylene—acrylic elastomers are processed in the same manner as other elastomers. An internal mixer is used for large-scale production and a mbber mill for smaller scales. In either case, it is important to keep the compound as cool as possible and to avoid overmixing. Ethylene—acryflc elastomers require no breakdown period prior to addition of ingredients. Mixing cycles for a one-pass mix are short, typically 2.5—3.5 min. When compounds are mixed on a mbber mill, care should be taken to add the processing aids as soon as possible, after the polymer has been banded on the mill. Normal mill mixing procedures are followed otherwise. 

The non-fibrous components are first mixed together and the fibrous materials are then added. The properties of components are critically dependent on the mixing procedures since these will affect dispersion and fibre degradation. 

The general practice is to deliver the oil-base mud ready mixed to the rig, although some oil-base muds can be prepared at the rig. In the latter case, the most important principles are (1) to ensure that ample energy in the form of shear is applied to the fluid, and (2) to strictly follow a definite order of mixing. The following mixing procedure is recommended ... 

An important breakthrough in that respect was the use of soHd-phase organic synthesis (SPOS) where the attachment of the substrate to an insoluble support allowed for easy workup (filtration) and for rapid generation of products via split-mix procedures [1,2]. An important subsequent development consisted of the immobihzation of reagents, scavengers and catalysts. This technique, coined polymer-assisted solution phase chemistry (PASP), allowed solution phase synthesis of compoimds, yet still enjoying the bene-... 

Blend System (A/B) Blend Ratio Filler Loading (phr) Mixing Procedure Cb/C,... 

Rubber compounds were made using A1 and A2 shown in Table 17.2 and using a model tire recipe shown in Table 17.4. The ingredients listed in Table 17.4 are in grams per 100 g of rubber (PHR). The mixing procedure used for the samples presented in Table 17.5. Both cured and un-cured compounds were tested and the mechanical testing results are shown in Table 17.6. 

The compounds were mixed in three steps The first two steps were done in an internal mixer with a mixing chamber volume of 390 mL. The mixing procedures employed in the first two steps are indicated in Table 29.2. The starting temperamre was 50°C and the cooling water was kept at a constant temperature of 50°C. The rotor speed was 100 rpm and the fill factor 66%. After every mixing step the compound was sheeted out on a 100-mL two-roll mill. The third mixing step was done on the same two-roll mill. The accelerators and sulfur were added during this step. 

FIGURE 35.7 Masterbatch mixing procedure (straight mixing). 

Mixing Procedures on Kobe Steel s BB270 Mixer with 4WH Mark II Rotors... 

Generally radical acceptors or oxidation catalysts, which effectively remove free radicals formed during milling and mixing procedures. Inter-macromolecular action leads to reduction of the entanglements between polymer molecules. Chemically activated zinc soaps. 

Approach ii is applicable to all thermoplastic polymers and offers considerable practical advantage since reactively modified polymers can be readily produced by normal commercial high-shear mixing procedures at no additional cost. 

To measure the influence of the mixing procedure on the sedimentation and turbidity (1) the stirrer speed, vR rpm, (2) the time of polymer addition, tz[min], and (3) the time of stirring after addition of the polymer, tN[min], were varied. Two polymer coverages, 0 0.2 and 6 1.0, at three pH-values, pH A.7, pH 3.2 and pH 2.3 (the latter is close to the isoelectric point) were selected for the stability measurements. Fig. 2 shows the dependence of the three stability characterizing parameters T(l )Ere ... 

The variation of the mixing procedure at pH 2 3 implies that the critical concentration of the polymer necessary for flocculation is independent of the mixing parameters. This behaviour differentiates the flocculation behaviour of precipitated silica from that of pyrogenic silica at pH 7. However, it should be remembered that at low pH values the flocculation of pyrogenic silica is also independent of mixing conditions. 

The CpFe(C0)p 2"Y adducts are prepared in the same way but with heating at 1+0°C under vacuum when the dry mixing procedure is used. 

Step 5 If the lacquer is of the desired quality then the mixing vessel is moved to a filling station, starts with docking and is then emptied. The mixing vessels are treated as occupied until the mixing procedure has finished and the lacquers are considered as having the desired quality. 

Type of mixing Mixing procedure Shaking/ sonication... 

FIGURE I Retention times of two analytes using various mobile preparations vs. pump blend. Note that procedures A and D are almost equivalent while column B or C (using volumetric flasks) yields retention times which are either too high or too low depending on whether methanol or water is filled first.This phenomenon is caused by the negative volume of mixing. Procedure A is recommended for all mobile phase preparation. 

Equations 3.121 and 3.122 distinguish the bulk Gibbs free energy of the mixture ( mixture) from the Gibbs free energy term involved in the mixing procedure... 

Selected entries from Methods in Enzymology [vol, page(s)] Enzyme-substrate complex formation, 64, 53 data analysis, 64, 56, 57 extensions of technique, 64, 57-59 as evidence for occurrence of intermediate, 64, 47-59 kinetic equation, 64, 49-52 limitations, 64, 57-59 mixing procedure, 64, 53-56 reaction condition, 64, 56, 57 termination, 64, 56, 57. 

---