Foams industrial applications

Generation Spontaneous generation of gas bubbles within a homogeneous liquid is theoreticaUy impossible (Bikerman, Foams Theoiy and Industrial Applications, Reinhold, New York, 1953, p. 10). The appearance of a bubble requires a gas nucleus as avoid in the liquid. The nucleus may be in the form of a small bubble or of a solid carrying adsorbed gas, examples of the latter being dust particles, boiling chips, and a solid wall. A void can result from cavitation, mechan-ic ly or acoustically induced. Blander and Katz [AlChE J., 21, 833 (1975)] have thoroughly reviewed bubble nucleation in liquids. 

Zero-ODP alternatives are the substitutes of choice in many foam-manufacturing applications. However, the use of HCFCs is sometimes necessary in order to meet some product specifications. The viability of liquid hydro fluorocarbon (HFC) isomers in this industry remains to be proved, and hydrocarbon alternatives need to be better qualified, as well. 

The most important industrial application of alkanesulfonates is the generation of the appropriate emulsions for polymerizing vinyl monomers, e.g., vinyl-chloride or styrene. Other uses are as textile and leather auxiliaries, formulating aids for plant protection agents, and fire-extinguishing foams. 

Over the last few decades, the use of radiation sources for industrial applications has been widespread. The areas of radiation applications are as follows (i) Wires and cables (ii) heat shrinkable tubes and films (iii) polymeric foam (iv) coating on wooden panels (v) coating on thin film-video/audio tapes (vi) printing and lithography (vii) degradation of polymers (viii) irradiation of diamonds (ix) vulcanization of mbber and rubber latex (x) grain irradiation. 

Likewise, the practical food foreman knows that by following certain manufacturer s recommendations and certain processing conditions in his plant, he is able to produce stabilized foam products to the satisfaction of his superiors and the public, most of the time yet when problems of instability and poor shelf life of the finished product are brought to his attention and all simple adjustments fail to produce a satisfactory result, he must turn to the food or colloid chemist for the theory and industrial application of foams. 

Bikerman, J. J., Foams, Theory and Industry Applications, Reinhold, New York,... 

Cationic surfactants show a high affinity for negatively charged surfaces making them suitable for industrial applications and as components for consumer products where they are used as disinfectants, foam depressants, and first and foremost as textile softeners [23], Due to the possible formation of ion-pair associates they are usually not formulated together with anionic surfactants. 

Diverse foam structure applications In foam rubber, foamed polymers, shaving foams, milk shakes, and whipped creams, slowly draining thin liquid films (TLF) are needed. Accordingly, the rate of drainage is the most important factor in such industrial foam applications. 

As it turned out, CFCs were ideal for the purpose. The members of this chemical family are nonflammable, noncorrosive, nontoxic, odorless, and very stable. Within a short period, they became widely popular for a variety of industrial applications. In addition to their applications in refrigeration systems, they became popular as aerosol propellants, cleansing agents for electrical and electronic components, and foaming agents in the manufacture... 

While the potentials and challenges of foaming multiphase blends were demonstrated for some reference systems, this knowledge now needs to be transferred to other systems and processes, in order to establish general guidelines for foaming polymer blends, all finally aiming at the development of industrial applications and market products. 

Beside the development of new strategies for controlling cellular structure, the potential of foamed blend systems needs to be transferred into industrial applications. As demonstrated, blending allows one to reduce the cell size and to increase the cell density, beneficial for thermal insulation applications, while the mechanical or barrier properties can be improved via multiphase cell walls. 

Polyurethanes are part of a very versatile group of materials that find uses in a wide range of applications, both domestic and industrial. Polyurethanes are widely used in many applications such as paints and lacquers, foam mattresses, medical implants, and industrial applications such as rollers, electrical encapsulation, engineering components, shoe soles, seals, and in the mining industry. 

The wide range of practical and industrial applications of emulsions, foams, and surfactants in particular, has led to the adoption of a wide range of technical terms, some quite specific to particular industries. This chapter provides brief explanations for about 500 significant terms in the science and engineering of industrial emulsions, foams, and suspensions. In addition, cross-references for selected synonyms, abbreviations, and closely-related terms are included. 

Ferch, H. Leonhardt, W. Foam Control in Detergent Products in Defoaming Theory and Industrial Applications, Garrett, P.R. (Ed.), Marcel Dekker New York, 1993, pp. 221-268. 

The applications of, or problems caused by emulsions, foams, and suspensions in industry area are quite diverse and have great practical importance. The different industrial application settings share some important common themes as well. Colloidal dispersions can be found, may require treatment, or may be applied to advantage throughout most, if not all, of the process industries. In each case the nature, properties, or even the presence or absence of these dispersions can determine both the economic and technical successes of the industrial process concerned. In this book, a wide range of application areas are summarized. 

The Dow Chemical Company, Castor Oil, Inc., and the USD A Western Regional Research Center are collaborating to develop the castor plant as a suitable oilseed for specialty oils that can be converted into lubricants, coatings, foams, adhesives, and engineering thermoplastics. Castor oil already contains ricinoleic acid, a fatty acid used in many industrial applications, but project partners hope to produce other industrially desirable fatty acids within the castor bean. 

The role of surfactants in stabilization/destabilization of foam (air/liquid dispersions) is similar to that for emulsions. This is due to the fact that foam stability/instability is determined by the surface forces operative in liquid films between air bubbles. In many industrial applications, it is essential to stabilize foams against collapse, e.g., with many food products, foam in beer, fire-fighting foam, and polyurethane foams that are used for furniture and insulation. In other applications, it is essential to have an effective way of breaking the foam, e.g., in distillation... 

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