Fluidity foaming

The properties and densities of the mixtures and their resultant syntactic foams not only depend on the binder/filler ratio but also on the microspheres themselves, their size, sphericity, polydispersity, apparent and bulk density, the thickness and uniformity of their shells. Thus, at a given binder/filler ratio, the fluidity of a mixture depends on the size of the microspheres (Fig. 2) and the apparent density depends on their bulk density (Fig. 3)l). As the bulk density of the microspheres increases (the filler particles become larger), the final strength of the material decreases3 76>. 

ABSTRACT In gypsum board xoduction. the amount of water required for a stucco slurry with a suitable fluidity is considerably greater than the amount necessary for hydration of the stucco. Since excess water must be removed by drying, it is advantageous, from an energy point of view, to reduce the consistency or water demand of stucco. Constant board density is maintained thereby through increased addition of foam. 

The effect of the gas on mechanical properties depends on the paradox of closed- versus open-cell construction. In a closed-cell foam, mechanical deformation compresses the gas, so the gas contributes to rigidity and strength of the plastic product. In an open-cell foam, on the other hand, the fluidity of air permits it to rush out when the foam is deformed and to rush back when the deformation is released therefore, the foam contributes to the softness, flexibility, and resilience of the plastic product. 

Softness, flexibility, and "rubberiness," particularly in opencell foams. These properties are due to the negligible modulus and high fluidity of the gas phase. 

Resilience and recovery from both slow and impact deformation, primarily in open-cell foams, again because of the fluidity of air as it rushes back into the foam after the deforming force is released. 

Triacylglycerols Source of fatty acids Affect neutral lipid droplet fluidity in foam cells Liquid crystalline — liquid neutral transformation of foam cell droplets... 

The plastics of interest are mainly PP. In theory, these polymers are easier to sort because they are the only ones which float alongside polyethylene (PE) and foams, wood and other pollutants. Fairly rapidly, we devised simple solutions to eliminate a large proportion of the foam and wood. A simple sorting process to yield only PP without PE seemed far more complicated industrially. Based on the same principle as is used for vehicle fenders with PP/PE copolymers, we envisaged retaining this mix of PP and PE, but rendering them compatible to obtain a PP/PE compound similar to a copolymer in terms of shock resistance, fluidity and injectability. 

Abstract. The stability of suspensions/emulsions is under consideration. Traditionally consideration of colloidal systems is based on inclusion only Van-der-Waals (or dispersion) and electrostatic components, which is refereed to as DLVO (Derjaguin-Landau-Verwey-Overbeek) theory. It is shown that not only DLVO components but also other types of the inter-particle forces may play an important role in the stability and colloidal systems. Those contributions are due to hydrodynamic interactions, hydration and hydrophobic forces, steric and depletion forced, oscillatory structural forces. The hydrodynamic and colloidal interactions between drops and bubbles emulsions and foams are even more complex (as compared to that of suspensions of solid particles) due to the fluidity and deformability of those colloidal objects. The latter two features and thin film formation between the colliding particles have a great impact on the hydrodynamic interactions, the magnitude of the disjoining pressure and on the dynamic and thermodynamic stability of such colloidal systems. 

In Chapter 17, we discuss rheological properties, in particular viscosity and elasticity, of colloidal systems. These properties are at the basis of quality characteristics such as strength, pliancy, fluidity, texture, and other mechanical properties of various materials and products. In addition to bulk rheology, rheological features of interfaces are discussed. Interfacial rheological behavior is crucial for the existence of deformable dispersed particles in emulsions and foams. Emulsions and foams, notably their formation and stabilization, are considered in more detail in Chapter 18. 

Silicone polyethers are important nonionic surfactants that are also used in cosmetics and household chemistry. However, their most important application is the manufacture of polyurethane foams, both rigid and flexible ones. There are no substitutes for them and their role eonsists in the facilitation of mixing of foam components. They prevent from the formation of large bubbles, facilitate the control of fluidity of liquid mixture (that expands due to the bubble growth), and they enable accurate control of time and degree of foam opening. 

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