Fillers and pigments

Industrial Fillers. Whiting is widely used ia paints as a filler and pigment extender. A high refiective white color is a requisite for paint. Both ultrafine and relatively coarse carbonate fillers ate iacorporated ia mbber products. The latter type of a nominal 0.074 mm (200 mesh) size is for iaexpensive mbber products. 

Though functionally and chemically similar, fillers and pigments ate distinguished from one another in that fillers are added at the wet end of the paper machine, and serve to fill the sheet pigments are added at the size press and serve to alter the surface of the sheet. The most common fillers are mineral pigments, eg, clay, titanium dioxide [13463-67-7] calcium carbonate, siUca [7631-86-9], hydrated alumina [21645-51 -2], and talc [14807-96-6]. 

Model plasters are manufactured from select finishing plasters with special emphasis on a clean, white color. Setting-time control agents, setting-expansion control additives, fillers, and pigments may be added. 

Study waxes ie, waxes for carving, are useflil in the study and modeling of tooth forms and the teaching of anatomical detail. Carving wax compositions include paraffin, ceresin, ozokerite, camauba wax, montan waxes, and Acrawax C. Fillers and pigments may be added. 

Each of these additives plays an important role in either the processing or service life of the finished goods. In addition, fillers and pigments are two larger scale additives that play an important role in product economics and aesthetics. 

The term plastisol is used to describe a vinyl dispersion that contains no volatile thin-ners or diluents. Plastisols often contain stabilizers, fillers, and pigments, along with the essential dispersion plastics and the liquid plasticizer. All ingredients exhibit very low volatility under processing and use conditions. Plastisols can be made into thick fused sections with no concern for solvent or water blistering, as with solution or latex systems, so they are described as being 100 percent solids. 

Many fillers and pigments are cationic at acidic pH and thus can be deposited on to negatively charged cellulose fibres relatively... 

The substances listed in Table 28 correspond to the basic structure of elastomeric closures. The other components in rubber formulations are curing or vulcanizing agents, accelerators, activators, antidegradants, plasticizers, fillers, and pigments. The most common additives used to compound rubber for the pharmaceutical industry are listed in Table 29. The amount of each component may vary from rubber to rubber, and, depending on the component, the amount can reach more than 50% of the total mass of a formulation. While accelerators are used in amounts of around 1%, fillers may make up more than 50% of the formulation mass. 

Besides their two main uses as reinforcing fillers and pigments, small amounts of carbon blacks are used by the electrical industry to manufacture dry cells, electrodes, and carbon brushes. Special blacks are used to give plastics antistatic or electrical conduction properties. Another application is the UV stabilization of polyolefins [4.31]. 

The first step in processing is usually powder mixing in a high speed, intensive mixer. PVC resin, stabilizers, plasticizers, lubricants, processing aids, fillers, and pigments are added to the powder blend for distributive mixing. 

Fluorosilicones can be compounded by the addition of mineral fillers and pigments. Fillers for such compounds are most commonly silicas (silicon dioxide), because they are compatible with the elastomeric silicon-oxygen backbone and thermally very stable. They range in surface areas from 0.54 to 400 m2/g and average particle size from 100 to 6 nm. Because of these properties, they offer a great deal of flexibility in reinforcement. Thus, cured compounds can have Durometer A hardness from 40 to 80. Other fillers commonly used in fluorosilicones are calcium carbonate, titanium dioxide, and zinc oxide. 

Magnesium silicate is used as a filler and pigment in dispersive paints. 

Size exclusion chromatography in the main uses conventional liquid chromatographic equipment. In most cases the polymer in solution can be injected directly onto the chromatograph, however in the case of formulated polymers which contain inorganic fillers and pigments some prior sample separation will be needed. 

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