Flow agents

USP-grade anhydrous magnesium carbonate is used as a flavor impression intensification vehicle in the processed food industry (see Flavors and spices). Basic magnesium carbonates are used as free flowing agents in the manufacture of table salt, as a hulking agent in powder and tablet pharmaceutical formulations, as an antacid, and in a variety of personal care products (see Pharmaceuticals). 

When a sample of ca 100 g has been obtained, a representative sample for use in size characterization equipment must then be taken. Some of the more modem methods of size characterization require as Htde as 1 mg of powder, thus obtaining a representative sample can be quite difficult. If the powder flows weU and does not contain too many fines, a device known as the spinning riffler (Fig. 4c) can be used. A spinning riffler consists of a series of cups that rotate under the powder supply. The time of one rotation divided into the time of total powder flow should be as large a number as possible. Although this device has been shown to be very efficient, problems can be encountered on very small (1 mg) samples, and the powder must be processed several times. Moreover, in order to avoid cross-contamination, cleanup after each of the sampling processes can be quite difficult. Furthermore, if the powder is cohesive and does not flow weU, the equipment is not easy to use. A siUca flow agent can be added to the powder to enable the powder to flow... 

For free-flow agents, water-insoluble, finely divided adsorbents such as sodium siUcoalurninate, tricalcium phosphate, calcium siUcate, magnesium carbonate, and siUcon dioxide are used. Concentrations between 0.5 and 2% are typically added to table salt and some industrial grades of salt for use in apphcations where caking may occur. 

The actual name dry scrubbing was first publicized by Teller [U.S. Patent no. 3,721,066 (1973)]. He worked both with classical Army-type soda-lime and with his patented water-activated form of the alkaline feldspar nepheline syenite as a flow agent and feedstock sorbent for HF and SO9 in hot, sticky fumes from glass melting furnaces. He claimed capture of more than 99 percent of 180 ppm HF and SO9 for more than 20 hours in a packed bed of 200 X 325 mesh hydrated nephehne syenite at 42,000/hr. 

The first area covers low volumetric flow rates, and entrance pressures below Pcr. This sector of two-phase flow in the molding machine is characterized by a complex non-linear dependence of reduced pressure on reduced volumetric flow rate. The structure of foam plastics obtained in this way was called shell structure by the authors in [20, 21] — the extrudate contains huge shell bubbles which are comparable to its section. As CBA concentration increases, or medium volumetric flow rate is increased at low CBA concentration, small bubbles materialize in the melt around the shell bubbles, and the structure becomes shell-bubble . Increase of the volumetric flow rate and the concentration of flowing agent neutralizes the difference in bubble size their lateral dimensions become smaller than their longitudinal ones. 

Agents have also been micropulverized, encapsulated, or treated with flowing agents such as silica aerogel to facilitate their dispersal and increase their persistency. Color and other physical properties of the agent may be affected by these additives. 

Free energy of micellization, 24 130 Free enzyme-catalyzed reactions ionic liquids in, 26 897-898 Free fatty acids, 70 802-804, 825-826 removal of, 70 807 as soap bar additives, 22 742-743 Free-flow agents, in sodium chloride (salt), 22 808... 

Additives Defoamers, thickeners, coalescing agents, flowing agents, driers, biocides, etc. 

Here the melt solidifies into an amorphous structure which is broken into small rod shaped pieces by mechanical agitation. The flavor pieces are recovered by centrifugation, dried under a vacuum, mixed with a free flowing agent and packaged for sale. The product of this process contains 8-20% flavor load and is exceptionally stable to deterioration by oxidation. 

The extrusion into a cold isopropanol bath, recovery by centrifugation, drying in a vacuum oven, addition of a free flowing agent and packaging are essentially unchanged from the recommendations of Swisher ( 3). 

The meta-orientation of the two methoxyl groups does, however, greatly increase the susceptibility of the aromatic ring to electrophilic attack. This is one of the three possible meta-dimethoxy substituted amphetamines, and it is the best studied one in the pursuit of potential radio-halogen substituted brain blood-flow agents. This strategy is discussed under 1DNNA the other two meta-compounds are discussed under 3,4-DMA. 

The additives used for lacquer manufacture are composed of processing aids like hardening accelerators, flow agents, crosslinking agents and others like plasticisers, fillers and if necessary pigments. 

Function pH control neutralizer anticaking agent free-flowing agent firming agent. 

Function Anticaking and free-flowing agent bulking agent stabilizer and thickener surface-finishing agent. 

Sample Preparation for Evaporated Salt Transfer 10.0 g of sample into a 400-mL beaker, and dissolve in 100 mL of water. If free-flowing agents are present, filter and rinse quantitatively. Dilute the solution or filtrate to 200 mL with water. 

The pelletizing process is illustrated by the flowchart in Figure 14.8. The pellets can be prepared from press cake or pigment powder. In some processes temporary flow agents are added, which will evaporate. 

Antifoam agents Flow agents Suspension agents... 

In this case it is more effective to minimize the friction between the inside surface of the tube and the composition by painting a lubricant like paraffin on the surface or by adding about 1% of a flow agent, e g calciiun orthophosphate(s R Lancaster Fireworks p 32(l972)), to the composition. 

To improve the flowability of powders and granulations, a small amount of a flow agent, or glidant, is... 

Chemicals optical chemicals and plastics, silica free-flow agents, chlor-alkali and phosgene derivatives. 

---