Emulsion quality

The common raw materials of particleboard are wood, adhesive, and wax emulsion. High quality particleboard at the optimum production rate demands continuous monitoring of the wood material to determine when adjustments should be made in the process or the adhesive. Monitoring of the adhesive and wax emulsion quality is a critical, but often ignored, factor in particleboard manufacture. 

The three major companies follow different policies in matters of raw materials. Fuji Photo film, which has no links with the chemical industry, buys 80 percent of its supplies outside, while Eastman Kodak and Agfa-Gevaert supply half their needs through their own production. They all produce their most sensitive organic derivatives, which are kept secret since they form the basis of emulsion quality. 

Another aspect of the transportation of heavy-oil-in-water emulsions, especially for short-distance pipelines, is the presence of sand particles. In situ solids concentration and emulsion quality can be measured with various sampling devices. However, serious errors in measuring both parameters arise from improper sampling. 

Emulsion Quality. The quality of an emulsion is defined as the volume fraction (or percent) of the dispersed phase in the emulsion. The quality of emulsions strongly affects their rheology. Several studies have been reported for the relationship of isothermal shear stress to shear rate for emulsions of different qualities. OAV emulsions having qualities less than 0.5 (or 50%) exhibit Newtonian behavior, and those having higher qualities exhibit non-Newtonian behavior (9, 16, 25),... 

Figure 5. Cartesian plot of Newtonian and non-Newtonian behavior of flow of OfW macroemulsions through porous media, (t is emulsion quality.) (Reproduced with permission from reference 25. Copyright 1979 Society of Petroleum...

Figure 9 from Uzoigwe and Marsden (26) shows a plot of apparent viscosity versus emulsion quality. This graph shows that apparent viscosities increase sharply with quality particularly at low shear rates. It also shows the Newtonian behavior at low qualities and non-Newtonian behavior at high qualities. 

Figure 7. Apparent viscosity vs. shear rate at various emulsion qualities (Fj. (Reproduced with permission from reference 26. Copyright 1970 Society of Petroleum Engineers.)...

Bock, T.K. Lucks, J.-S. Kleinbudde, P. Muller, R.H. Muller, B.W. High pressure homogenization of parenteral fat emulsions—influence of process parameters on emulsion quality. Eur. J. Pharm. Biopharm. 1994, 40 (3), 157-160. 

Bitumen is a colloidal dispersion of high-molecular-weight polar asphaltenes in lower-molecular-weight relatively non-polar hydrocarbons. Asphaltenes can associate strongly and this leads to difficulties in emulsification. One solution is to add cationic surfactants, so-called peptizing agents, which help disperse the asphaltenes and improve the emulsion quality. Bitumen... 

An alternative description of emulsion quality uses the specific surface area A (surface area of all emulsion droplets per unit volume of emulsion),... 

Redmond et al. [60] gave an example of an experimental factorial design to study the infiuence of composition and process parameters on the emulsion quality. They used the cream composition given in Table 4. They also draw up a fractional factorial designed experiment contemplating the following variables (Tables 5 and 6) in order to determine whether or not a continuous making could be used ... 

Fig. 15.47 High-pressure chamber for visual observation of the emulsion quality after the static mixer...

Fig. 15.48 Emulsion quality after the static mixer at 353 K and 5.2 MPa and different concentrations of the dispersed phase...

Images of the emulsion quality are presented in the following Fig. 15.48. The left... 

The production of solid emulsion powders was successfully carried out. Powders consisting of tristearin and water concentrations of up to 35 wt% were produced without using an emulsifier with particles sizes in the range of 10 pm were produced. It was observed that the supercritical fluid can act as an emulsifier to lower the interfacial tension between the dispersed and continuous phase. A visual investigation of the emulsion quality showed improvement of the latter with increasing turbulence in the static mixer. It was observed however that the structure of the produced emulsion will be most probably affected by the nozzle flow. Ongoing experiments where a variation of the saturation pressure, nozzle diameter, and viscosity ratio should help link the droplet sizes to dimensionless numbers and determine the optimal parameters for the encapsulation process. 

Skin surface moisture Stratum corneum hydration Cutaneous pH, epicutaneous emulsion quality Corneometry pHmetry, evaporimetry EC, DD, TC EC, DD, TC... 

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