Fluid binders

There is a practical maximum concentration of amorphous silica that can be dispersed in the aqueous silicate solution. It is often desirable to incorporate as high a concentration of amorphous silica as possible, yet still have a workable fluid binder to apply to the sand. If the proportion of amorphous silica to soluble silicate is too low, than the shake-out will be adversely affected. On the other hand, if the ratio of amorphous silica to soluble silicate is too high, the mixture will be too viscous and must be thinned with water. Also, there will not be enough binder to fill the spaces between the amorphous silica particles in the bond, and it will be weak. In generally, the higher the content of amorphous silica relative to sodium or potassium silicate, the weaker the initial bond as set by carbon dioxide. Conversely, the more silicate in the binder, the higher will be the initial and retained strengths. 

After the filling step, the mixer is closed (rectangular punch visible top center in Fig. 4a and the homogenization of the ceramic-polymer mixture starts. As the powder particles are progressively separated from one another and dispersed in the fluid binder, the viscosity of the mixture, and hence the recorded torque, drop as shown in Fig. 4b. When the torque reaches a steady state plateau, no additional mixing takes place, and the mixing time necessary to obtain a homogeneous material is defined as the time required to reach this steady state. 

Uses Antistat, binder, emulsion stabilizer, film-former, vise, control agent, thickener, suspending agent, stabilizer, slip agent, flocculant in cosmetics mineral flotation depressant textile auxiliaries vise, builder for oil-well workover/completion fluids binder, surfactant, lubricant, plasticizer in ceramics dry str. and formation aid in mfg. of paper/paperboard in contact with aq.ffatty foods... 

As mentioned earlier, there are a number of other substances whose use can be characterized as occasional or, in some particular cases, also entirely intentional. Concerning fairly liquid binders, one can choose among (iv) aliphatic and cyclic hydrocarbons [7, 38—41] and (v) organic ethers and esters (e.g., tricresyl phosphate and dioctyl phthalate [57]). Thicker but still fluid binders can be some (vi) aromatic hydrocarbons [39, 51, 52] and (vii) highly viscous polysilox-anes (such as sihcone fluids with > 20 000 [56]). Their advantage is a more compact carbon paste mixture, but its manual preparation may be less comfortable [16]. 

An aqueous fluid binder is applied to the layer of the dry particulate material in a predetermined pattern to cause binding in the areas to which the binder is apphed,... 

Small, complex-shaped glass articles such as thread guides for the textile industry and television gun mounts for the electronics industry are made by the multiform process. The dry-milled powder is mixed with an inorganic binder and a fluid vehicle, and then atomi2ed by a spray dryer into small, dried agglomerates of glass powder and binder with good flow characteristics. They are subsequently pressed to the desired shape and fired. 

Although a number of low temperature processes have been studied, only a few have been used commercially. These have been limited in the types of coal that are acceptable, and the by-products are less valuable than those obtained from high temperature processing. The Disco process is used in the United States to supply a limited amount of fuel to meet requirements of smoke ordinances. The British CoaUte and Rexco processes produced substantial amounts of domestic smokeless fuel. Development of fluid-bed methods of carbonizing finer coal at ca 400°C has been studied in the United Kingdom. A reactive char is briquetted without a binder to produce a premium open-fire smokeless fuel. 

The drop distribution and spray rate of binder fluid have a major influence on wetting. Generally, finer drops wiU enhance wetting as well as the distribution of binding fluid. The more important question, however, is how large may the drops be or how high of a spray rate is... 

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