Flake type particles

Flake type Particle size distribution Application Optical appearance... 

The most common type of machines used to produce flake-type particles are the cylinder type and the rotating disc type. The cylinder type has knives mounted either on the exterior of the cylinder similar to a planer or on the interior of a hollow cylinder. For the rotating disc type, the knives are mounted on the face of the disc at various angles. The knife angle and spacing influence the nature of the flake obtained. 

Boards exhibiting excellent dimensional stability and internal bonds vie re produced using 3 and % NO, Once again it appears that splinter-type particles rather than flakes give highest internal bonds. Densities of all boards reported ranged from 0 73 to 0.78, Molar ratios of furfuryl alcohol to formaldehyde used vieve approximately 3 2. 

The flat vibrating screen used had to be partially blocked to avoid air leaking into the air classifier. The effective screening area was 2.1 x 2.4 m and apparently easily blocked by the feed of flake-like particles, at least judging from the relationship found between feedrate, F (short tons/h) and recovery of material <6.4 mm, 0 < R < 1, which was R = 0.64/F0 1 2. The results indicate that a screen at some point can remove a significant quantity of ash-forming material but that the type of screen used in the preparation of the fuel described here was improper. 

Figure 4. Optical properties of aluminum pigments as a function of particles size distribution and flake type. ME - metallic...

Ni powder is characterized by cauliflower-like type particles in ammoniacal electrolytes, while in citrate electrolytes the flakes of the maximum size of about 50 pm covered with nodules of mainly flat surfaces were detected. On some particles the formation of a second zone of dendrites (beginning with the formation of small crystals) could be detected. The Fe powder particles of the size of about 200 pm also contain nodules of flat surfaces, but they are characterized by the presence of cone-shaped cavities. In the case of Co powder, generally two types of particles were detected... 

Moving-bed percolation systems are used for extraction from many types of ceUular particles such as seeds, beans, and peanuts (see Nuts). In most of these cases organic solvents are used to extract the oils from the particles. Pre-treatment of the seed or nut is usually necessary to increase the number of ceUs exposed to the solvent by increasing the specific surface by flaking or rolling. The oil-rich solvent (or misceUa) solution often contains a small proportion of fine particles which must be removed, as weU as the oil separated from the solvent after leaching. 

Lost circulation materials are flake, fiber, or granular-shaped particles. Each type is sold individually, often in two or more size grades, or two or more materials of different shapes may be sold as a blend (133—136). Materials of different shapes and sizes are often blended into the mud at the well site. 

Type I Mg powder shall consist of shavings, turnings, flakes, plates or any combination of these which meets the granulation requirement. Type II Mg powder shall consist of oblong chip-like particles with rounded edges. Type III Mg powder shall consist of granular or spheroidal particles... 

A composite material is defined as a material consisting of two or more distinct constituents or phases, which are insoluble in one another. The main types of reinforcement are particles, discontinuous fibers, continuous fibers (or filaments) and flakes. 

Fluid loss additives such as solid particles and water-thickening polymers may be added to the drilling mud to reduce fluid loss from the well bore to the formation. Insoluble and partially soluble fluid loss additives include bentonite and other clays, starch from various sources, crushed walnut hulls, lignite treated with caustic or amines, resins of various types, gilsonite, benzoic acid flakes, and carefully sized particles of calcium borate, sodium borate, and mica. Soluble fluid loss additives include carboxymethyl cellulose (CMC), low molecular weight hydroxyethyl cellulose (HEC), carboxy-methYlhydroxyethyl cellulose (CMHEC), and sodium acrylate. A large number of water-soluble vinyl copolymers and terpolymers have been described as fluid loss additives for drilling and completion fluids in the patent literature. However, relatively few appear to be used in field operations. 

Figure 2 shows the SEM image of the flake at a magnification of 350 x, as it was mounted on the conductive carbon tape. If there is a polymeric film covering the sample, the SEM will only show the surface topography of the film, not the structure residing below the polymeric film. EDS was conducted on two areas on the sample as indicated in Figure 2. The EDS analysis was conducted in square spot mode, approximately 1 pm by 1 pm in size. The elemental results are shown in Table 2. Based on these data sets it is apparent that the Type A defect is an iron-rich particle. Based on the lack of chromium or nickel the Type A defect is a particle of steel, not stainless steel.

Colloids are classified according to the phases of the substances involved (Table 15.10). A colloid that is a suspension of solids in a liquid is called a sol, and a suspension of one liquid in another is called an emulsion. For example, muddy water is a sol in which tiny flakes of clay are dispersed in water mayonnaise is an emulsion in which small droplets of water are suspended in vegetable oil. Photographic emulsions also contain solid colloidal particles of light-sensitive materials such as silver bromide. Foams are suspensions of a gas in a liquid or solid. Foam rubber, Styrofoam, soapsuds, and aerogels are foams. Zeolites (Box 13.4) are a type of solid foam in which the openings in the solid are comparable in size to molecules. 

Clusters consist of from five to several hundred spherical particles attached to each other in a similar fashion to a bunch of grapes. They occur infrequently and appear to be a product of high power or high velocity. Flakes of smokeless powder are few in number and are occasionally seen in promptly collected residue. Unlike the other three types of particles, which are inorganic in nature, the flakes are organic although sometimes spherical particles are embedded in their surface. They range in size from about 50 to 1,000 pm. Clusters and powder flakes are rarely seen in casework as they are... 

During the troubles in Northern Ireland only indoor-type fireworks could be purchased without a special license. Analysis of particles originating from the use of indoor-type fireworks showed only a few spherical particles the majority was large irregularly shaped flakes. The elements aluminum, barium, chlorine, chromium, iron, potassium, sulfur, and antimony were detected, all of which were at a major level. 

Bentonite is a colloidal clay that is both hydrophilic and organophilic. It is waterswelling with some types of clay absorbing as much as 5 times their own weight in water. It is used in emulsions, adhesives, and sealants. It is a gritty, abrasive white particle filler. A macroscopic particle of bentonite is composed of many thousands of stacked and/or overlapped submicroscopic flakes. 

Electrically conductive adhesives owe their conductivity as well as their high cost to the incorporation of high loadings of metal powders or other special fillers of the types shown in Table 9.8. If enough metal particles are added to form a network within the polymer matrix, electrons can flow across the particle contact points, making the mixture electrically conductive. Virtually all high-performance conductive products today are based on flake or powdered silver. Silver offers an advantage in conductivity stability that cannot... 

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