Large particles

We consider the motion of a large particle in a fluid composed of lighter, smaller particles. We also suppose that the mean free path of the particles in the fluid, X, is much smaller than a characteristic size, R, of the large particle. The analysis of the motion of the large particle is based upon a method due to Langevin. Consider the equation of motion of the large particle. We write it in the fonn... 

Crushing and grinding uses mechanical force to break larger particles into smaller ones. A variety of tools are used depending on the particle s size and hardness. Large particles are crushed using jaw crushers capable of reducing particles to diameters of a few millimeters. Ball mills, disk mills, and mortars and pestles are used to further reduce particle size. 

Distribution of radiation for (a) Rayleigh scattering and (b) large-particle scattering. 

Using the original Hc2/r values, recalculate M using the various refractive index gradients. On the basis of self-consistency, estimate the molecular weight of this polymer and select the best value of dn/dc2 in each solvent. Criticize or defend the following proposition Since the extension of the Debye theory to large particles requires that the difference between n for solute and solvent be small, this difference should routinely be minimized for best results. 

This equation indicates that, for small particles, viscosity is the dorninant gas property and that for large particles density is more important. Both equations neglect interparticle forces. 

There are two principal PVC resins for producing vinyl foams suspension resin and dispersion resin. The suspension resin is prepared by suspension polymerization with a relatively large particle size in the 30—250 p.m range and the dispersion resin is prepared by emulsion polymerization with a fine particle size in the 0.2—2 p.m range (245). The latter is used in the manufacture of vinyl plastisols which can be fused without the appHcation of pressure. In addition, plastisol blending resins, which are fine particle size suspension resins, can be used as a partial replacement for the dispersion resin in a plastisol system to reduce the resin costs. 

In an aqueous system with large particles weU-separated by a distance, s, (D and 5 > t ) the electrostatic repulsion energy between two identical charged spheres may be approximated (1) ... 

Cleaners are most efficient on relatively large particles, 80—300 pm in diameter (see Fig. 1). Flat toner ink particles can fragment during processing, therefore it is probably best to locate mechanical cleaners early in the sequence of office paper deinking unit operations (40). 

Parallel Plate Viscometer. In parallel plate viscometers (164) the gap width usually is larger and can be varied freely. This is an advantage when measuring suspensions or dispersions with large particles or with a tendency to fly out of the gap. The wide gap means that there is less sensitivity to... 

Channel blacks such as the old EPC and MPC grades are acidic to neutral and can vary from having Httie effect to having a slight retardation in cure rate. The pH-neutral large-particle size MT thermal black generally has Httie effect on cure rate. 

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