Foamability stability

Shan et al. (2000) reported that flaxseed gum had good foamability, stability, emulsibility, and salt resistance, and that flaxseed gum has the... 

Foamability of phosphoric acid esters in aqueous solutions is in general only moderate, with the acid phosphates showing a better stability against water hardness than the alkali or amine salts. 

The excellent foamability of the quaternary blend also relates to the microstructure. All selected quaternary blend systems revealed a PPE/PS matrix phase able to stabilize the formed cells, as a result of the higher glass transition temperature and viscosity compared to the dispersed SAN. 

Ten aspects of the Maillard reaction will be considered in this chapter the effect on a,, on pH, on redox potential, on solubility, on texture, on foamability and foam stability, on emulsifying power, on volatile formation on storage, on binding of volatiles, and on other functionalities. The third of these has received by far the most attention and this is reflected here. 

It can be considered from the scheme that one has to distinguish between the foam kinetics, i.e. the rate of generation of foam under well defined conditions (air input and mechanical treatment) and the stability and lifetime of a foam once generated. The foam kinetics is also sometimes termed foamability in the literature. These quantities can be related to interfacial parameters such as dynamic surface tension, i.e. the non-equilibrium surface tension of a newly generated surface, interfacial rheology, dynamic surface elasticity and interfacial potential. In the case of the presence of oily droplets (e.g. an antifoam, a... 

The systems are listed In the decreasing ease of formulating foamable systems which will yield foams of the proper stability for foam processing of textiles. While completely non-aqueous foamable systems have been used to apply finishes under laboratory conditions, none have yet been developed that can be handled In a finishing plant environment. Since "100% solids" systems represent the ultimate In energy savings, efforts In this area are continuing. 

The foamable compositions are designed so that the foam can be easily collapsed after being applied to the fabric. The degree of stability and ease of collapse of the foam are dictated by function and application mode of the finish (Table III). 

Thus foamable systems for printing normally contain, In addition to the foaming agent, an additive to stabilize the foam. 

A foamable formulation for continuous dyeing requires less stability In the foamed state. The foam Is generated continuously at a rate equal to Its consumption on the dye range. The foam must be sufficiently stable to survive during the application step. 

For the plant trials which will be subsequently discussed, a 7% solids durable press, fabric stabilization conventional finish and a 14% solids foamable counterpart were applied to polyester/cotton fabrics of various weights. 

In protein-stabihzed foams, protein flexibility is critical to the molecule functionality in stabilizing interfaces (Hailing 1981 Lemeste et al. 1990). This has important consequences in the development and stability of dairy foams and emulsions, where the heat treatment received by the material can define its foamability and dispersion properties. A symbiotic effect between native and denatured proteins on the emulsifying properties of whey proteins isolate blends has been observed by (Britten et al. 

Early researchers turned to foamability or foaminess" measurements to screen surfactants for flow experiments (51). In one variation of this test, a long, vertical glass cylinder with a frit at the bottom was filled with the test solution, and gas was forced through the frit. The height of foam formed in the column was then measured, or, the foam was collected and the amount of liquid in the foam determined (51). In his screening of some 200 materials, Raza measured interfacial tensions of aqueous solutions with respect to air and to oil, and the foamability and foam stability in the absence and presence of oil. The latter experiment consisted simply of shaking the solution in a test tube and measuring the volume of foam at various times (60). 

A foamable compound is produced by compounding the obtained prepolymer mixture with a physical blowing agent, a foam stabilizer, and further additives (e.g., adhesion promoters, catalysts, etc.). 

The global scale which is the consumer one deals with the liquid foamability, the foam expansion and stability. 

The valuable component of cheese whey is not the lactose but the whey proteins, primarily lactalbumin. The amino acid profile of these proteins is superior nutritionally to casein and is equal to or better than whole egg protein. The heat-denatured form of these proteins has been manufactured for many years usually by heating the cheese whey to precipitate the proteins. The product was tan colored and completely insoluble. With the advent of UF, these proteins could be recovered, concentrated and demineralized athermally. The result was a "whey protein concentrate" (WPC) with improved solubility and other functional properties (emulsification, foamability, water binding, gelation and cloud stability). 

For the evaluation of the foamability of a surfactant the bulk concentration is used at which the relative rate of foam collapse is equal to 50% of its formation (cw °). The cw ° values determined from foam formation isotherms of a number of products are given in Table 6.1. As it is seen, typical representatives of anionics (sodium dodecyl sulphate), cationics (cetyl trimethyl ammonium bromide) and nonionics (ethoxylated alkylphenols) give bubble foams at very low concentrations, and the foam stability of ionic surfactants does not differ much from that of nonionics. For anionics, the highest concentrations are required for soaps of higher carboxylic acids. 

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