Static foam test

The first method is quite difficult to reproduce due to the strong influence on the results that small contaminations or vibrations can have. The latter two are also difficult to reproduce since the foam generation and collapse is not always uniform, yet these methods are very commonly used. The dynamic foam tests are most suitable for evanescent foams since their lifetimes are transient. For more stable foams the static foam tests are more commonly used. 

In either the dynamic or static foam tests, but especially the static tests, one should bear in mind the many changes in a foam that may occur over time, including gas diffusion and changing bubble size distribution. 

The foaming capability and foam stability obtained from sparkling wines is usually tested by a dynamic foam stability method, as discussed in Section 2.6.2. Because these foams are evanescent and not really very stable, at least compared with the foams found in other industries, dynamic rather than static foam tests are the most suitable. In one version of the dynamic foam test, the Mosalux method, the foam heights are automatically measured using infrared beams and sensors [848],... 

A method for assessing foam stability in which one measures the rate of collapse of a (static) column of foam that has been generated by allowing a certain quantity of foaming solution to fall a specified distance into a separate volume of the same solution contained in a vessel. This technique is ASTM method D1173-53. See also Static Foam Test. 

Spotting Agent Static Foam Test Static Mixer... 

Surfactants with low foamability were found to be poor candidates for mobility control. In general, anionic surfactants appear superior in the static foam tests. Sulfate esters of ethyoxylated linear alcohols were slightly better than the other classes of surfactants. Most sulfonates do not appear compatible with even small amounts of calcium and, therefore, produce very little foam at the temperatures used, 75-120 F. 

Static foam tests can even measure for specific shear rate regimes ... 

In the static foam test, it is also usually fairly easy to measure the volume of bulk hquid that has separated after a specified interval. The separated volume, expressed as a percentage of the original volume of liquid foamed, is termed the foam number. 

The atmospheric static foam test method (Borchardt et al., 1988) was used in order to determine comparative performance of the neutralized VA/AA surfactant. In a 25-ml graduated cylinder, 10 ml of 0.5wt% surfactant in brine (1.5X, which contained 15.57 wt% NaCl and 1.14 wt% CaCl2), and 3 ml crude oil were mixed by vertical shaking, and the foam volume measured vs time. Two kinds of crude oil were used a heavy one and a light one. 

Table 5.2.1 shows the results of the static foaming test in comparison with literature values. 

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