Materials Handbook 15th ed - G. Brady_ H. Clauser_ J. Vaccari (McGraw-Hill_ 2002) Episode 5 pot

but may be colored by impurities to cream, gray, pink, green, or black. For furnace linings it is calcined, but for fluxing it is simply crushed. The raw dolomite, marketed by Basic Refractories, Inc., for open-hearth steel making, is washed crushed stone in 0.625-in (1.6-cm) size. When calcinated at a temperature of about 3100°F (1704°C), dolomite breaks down to MgO and CaO, and it is limited to about 3000°F (1649°C) as a refractory. Calcined dolomite used in Germany as a water-filter material under the name of magno masse is in grain sizes 0.02 to 0.2 in (0.5 to 5.0 mm). Dolomite for the production of magnesia, some of which is cut as building mar- ble, contains 10 to 20% magnesia, 27 to 33 lime, 1 to 12 alumina, 40 to 46 carbonic acid, 1 to 5 silica, and 0 to 3 iron oxide. The dolomite found in huge deposits in Oklahoma contains 30.7% CaO, 21.3 MgO, and only very small amounts of silica, alumina, and iron oxide. For the production of magnesium metal, calcined dolomite and ferrosilicon are brought to a high temperature in a vacuum, and the magnesium is driven off as a vapor. In the ceramic indus- try, dolomite is sometimes called bitter spar and rhombic spar. Isostatic pressing and sintering a mixture of like amounts of dolomite and synthesized zirconia plus 0.5% by weight lithium fluo- ride yields a ceramic having a melting point of 3722°F (2050°C) and 30 to 60% porosity that may be useful as a catalyst carrier for treat- ing vehicle emissions. Developed by the National Industrial Research Institute of Nagoya in Japan, porosity is controlled by varying the sintering temperature between 1832 and 2552°F (1000 and 1400°C). Nanoceramics of this composition could be used for high-temperature filters. DOUGLAS FIR. The wood of the tree Pseudotsuga taxifolia, of the northwestern United States and British Columbia. It is sometimes called Oregon pine, Douglas pine, Douglas spruce, red fir, fir, yellow fir, and Puget Sound pine. The wood of young trees with wide growth rings is reddish brown and is the type called red fir, though the true red fir is from the large tree Abies magnifica of California and Oregon, the lumber of which is called golden fir, and the wood of which is used also for paper pulp. The wood of older trees of slower growth with narrow rings is usually yellowish brown and is called yellow fir. Both woods may come from the same tree. The narrow-ringed wood is stronger and heavier. Douglas fir averages below longleaf pine in weight, strength, and toughness, but above loblolly pine in strength and toughness, though below it in weight. The grain is even and close, with resinous pores less pronounced than in pitch pine. It is a softwood and is fairly durable. The density is 34 lb/ft 3 (545 kg/m 3 ). The compressive strength perpendicular to the grain is 1,300 lb/in 2 (9 MPa); the shear- ing strength parallel to the grain is 810 lb/in 2 (5.5 MPa). 320 DOUGLAS FIR Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses Douglas fir is used for general construction and millwork, plywood, boxes, flooring, and where large timbers are required. It is also used for pulping and yields kraft paper of high folding endurance but low bursting strength. The fibers are large. The trees grow to great heights, the average being 80 to 100 ft (24 to 30 m). The stand is esti- mated at more than 450 billion bd ft (1 billion m 3 ), or about one-fourth of all timber in the United States. Douglas fir bark contains from 7.6 to 18.3% of a catechol tannin, the bark of young trees yielding the higher percentages. It is suitable for tanning heavy leathers and yields a pliable, light-colored leather. Silvacon 383, of Weyerhaeuser Co., is Douglas fir bark in flaky, corklike granules used in flooring and acoustical tile. Silvacon 490 is the bark as a reddish powder used in dusting powders and paints. Silvacon 508 is hard, spindle- shaped small fibers from the tissue of the bark, used as a filler for plastics and in asphalt and fibrous paints. Douglas-fir bark wax is a hard, glossy wax extracted from the bark of the Douglas fir and is a partial replacement for carnauba wax. A ton of bark yields 150 lb (68 kg) of wax by solvent extraction with 150 lb (68 kg) of tannin and 10 lb (4.5 kg) of quercetin as by-products. DRIERS. Materials used for increasing the rapidity of the drying of paints and varnishes. The chief function of driers is to absorb oxygen from the air and transfer it to the oil, thus accelerating its drying to a flexible film. They are in reality catalyzers. Excessive use of driers will destroy the toughness of the film and cause the paint to crack. Solutions of driers are called liquid driers; it is in this form that paint driers are most used. Certain oils, such as tung oil, have inherent drying properties and are classified as drying oils but not as driers. Driers may be oxides of metals, but the most common driers are metallic salts of organic acids. Manganese acetate, (CH 3 COO) 2 Mn и 4H 2 O, is a common paint drier. It is a pinkish, crys- talline powder soluble in water and in alcohol and is used in strengths of 6, 9, or 12% metal. Sugar of lead, used as a drier, is lead acetate, Pb(CH 3 COO) 2 и 3H 2 O, a white, cyrstalline powder with a faint acetic acid odor, also used as a mordant in textile printing. It is known as plumbous acetate and Goulard’s powder. Lead oleate, Pb(C 18 H 33 O 2 ) 2 , is a drier made by the action of a lead salt on oleic acid. It is used for thickening lubricants. Lead linoleate, Pb(C 18 H 31 O 2 ) 2 , is a drier made by adding litharge to linseed oil and heating. Lead and manganese compounds together act more effec- tively as driers than either alone. Lead resinate adds toughness of film as well as drying power. Because of antilead laws, this metal is being replaced by zinc, cobalt, calcium, and zirconium compounds. Zinar is a zinc resinate with 5.6% zinc content. Cobalt octoate, which has about 12% cobalt in combination with hexoic acid, is used DRIERS 321 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses as a drier. Cobalt driers are twice as rapid in drying power as man- ganese driers, but too rapid drying often makes a wrinkled film which is desirable for some finishes but not for others. Naphthenate driers are metallic salts made with naphthenic acids instead of fatty-oil acids. They are usually more soluble in paint solvents, and since the naphthenic acids can be separated into a wide range of molecular weights by distillation, a wider variety of charac- teristics can be obtained. Sodium naphthenate, with 8.6% metal content, and potassium naphthenate, with 13.1%, are powders that are good bodying agents and emulsifiers as well as driers. Tin naph- thenate, with 20% tin, may be added to lubricating oils as an antioxi- dant. Mercuric naphthenate, with 29% mercury, retards the growth of bacteria and mold when added to finishes. Barium naph- thenate, with 22.6% barium, has binding and hardening properties and is used in adhesives and in linoleum. Uversols are naphthenic acid salts of aluminum, calcium, cobalt, lead, manganese, or zinc, in liquid form for use as paint driers, wetting agents, and catalysts. Octoic driers, of Witco Corp., are metallic salts made with ethylhex- oic acid, and the metal content is lower than that of driers made with naphthenic acids. They are light in color, have no odor, and have high solubility. The Octasols are ethylhexoic acid metal salts. Drying agents for resin coatings and inks may act by oxidation or other chemical reaction. Sulfur dichloride, S 2 Cl 2 , speeds the drying action of coatings and inks formulated with alkyd, urea, or melamine resins, and such inks dry almost instantly. DRILL ROD. Tool-steel round rod made to a close degree of accuracy, generally not over or under 0.0005 in (0.0127 mm) the diameter size, and usually polished. It is employed for making drills, taps, reamers, punches, or for dowel pins, shafts, and rollers. Some mills also fur- nish square rods to the same accuracy under the name of drill rod. Common drill rod is of high-carbon steel hardened by quenching in water or in oil. The usual commercial sizes are from 1.5 in (3.8 cm) in diameter down to No. 80, which is 0.0135 in (0.343 cm) in diameter. The usual lengths are 1 to 3 ft (0.3 to 0.9 m). The sizes are by the standard of drill gages, with about 200 different diameters. The car- bon content is usually from 0.90 to 1.05%, with 0.25 to 0.50 man- ganese, 0.10 to 0.50 silicon, and a maximum of 0.04 phosphorus or sulfur. It also comes in high carbon with from 1.50 to 1.65% carbon and 0.15 to 0.35 manganese. Drill rod can be obtained regularly in high-speed steels and in special alloy steels for dowel pins. Needle wire is round tool-steel wire used for making needles, awls, and latch pins. It comes in coils, in diameters varying by gage sizes from 0.010 to 0.105 in (0.025 to 0.267 cm). Needle tubing for surgical instru- 322 DRILL ROD Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses ments and radon implanters is stainless-steel tubing 0.014 to 0.203 in (0.036 to 0.516 cm) in diameter in 6-ft (1.8-m) lengths. Hypodermic tubing is hard-drawn stainless-steel tubing 0.008 to 0.120 in (0.020 to 0.304 cm) in outside diameter, with wall thicknesses from 0.004 to 0.012 in (0.010 to 0.304 cm), in 2-ft (0.6-m) lengths, with a fine finish. Capillary tubing is also stainless steel, but comes in lengths to 200 ft (61 m), with outside diameters from 0.060 to 0.125 in (0.152 to 0.318 cm). The inside bore can be had in various diameters from 0.006 to 0.025 in (0.015 to 0.064 cm) for the 0.060-in (0.152-cm) tubing and from 0.010 to 0.024 in (0.025 to 0.061 cm) for the 0.125-in (0.318-cm) tubing. Stud steel is an English name for round bar steel made to close limits and hardened and descaled, used for heavy pins and studs. Pin bar is small-diameter rod of case-hardened steel used for dowel pins. Drill steel, for mine and quarry drills, comes in standard rounds, octagons, squares, and cruciform bars, solid or hollow, usually in carbon steel. DRYING OILS. Vegetable oils which are easily oxidized by exposure to air and thus suitable for producing a film in paints and varnishes, known as paint oils. The use of drying oils as the sole or main binder in alkyd coatings is steadily decreasing with the advent of water- based latex paints. Currently, it is limited to solvent-thinned exterior house paints and some metal paints. The oils are also used in oleo- resinous varnishes and in the manufacture of synthetic resins for coating binders, epoxy ester resins, and oil-modified urethane resins. Small amounts are used in printing inks, linoleum, putty and caulk- ing compounds, core oils, and hardboard. The best drying oils are those which contain the higher proportions of unsaturated acids, in which oxidation causes polymerization of the molecules. The drying of an oleoresinous varnish takes place in two stages. First, the reducer or solvent evaporates, leaving a continuous film composed of gums and drying oil. The drying oil is then oxidized by exposure, leaving a tough, hard skin. This oxidation is hastened by driers, but the drying oil itself is responsible for the film. The drying power of oils is mea- sured by their iodine value, as their power of absorbing oxygen from the air is directly proportional to their power of absorbing iodine. Drying oils have typical iodine values about 140, semidry oils above 120, and nondrying oils are below 120. Linseed oil is the most com- mon of the drying oils, though tung oil and oiticica oil are faster in drying action. Linseed oil alone will take about 7 days to dry, but can be quickened to a few hours by the addition of driers. Linseed oil and other oils may be altered chemically to increase the drying power. Conjugated oils are oils that have been altered catalytically by nickel, platinum, palladium, or carbon to give conjugated double DRYING OILS 323 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses bonds in place of isolated double bonds in the molecules of the fatty acids. Conjulinol is a drying oil of this class made from linseed oil. The iodine value is 180, and the drying time is greatly reduced. Normally, soybean oil is not classed as a drying oil although it may be blended with drying oils for paint use. But by chemical alteration and, lately, by mixing with synthetic resins, it can be given good dry- ing power. Conjusoy is a drying oil made by conjugation of soybean oil. The iodine value is 128, and the drying time is about half that of boiled linseed oil. Castor oil, which has poor drying properties, is dehydrated to form a good drying oil. Other methods are used to alter oils to increase the drying power, notably polymerization of the linoleic and some other acids in the oils; or oils may be fractionated and reblended to increase the percentage of acids that produce drying qualities. The Admerols, of the Archer-Daniels-Midland Co., comprise a series of drying oils made by treating linseed or soybean oil with butadiene, styrene, or pentaerythritol. Kel-X-L oil, of Spencer-Kellogg, is a modified linseed oil with an iodine value up to 170, used as a substitute for tung oil in quick-drying varnishes. Kellin, of the same company, is a quick-drying blended oil with a linseed-oil base, while Kellsoy is a similar oil with a soybean-oil base. Cykelin, of the same company, is a quick-drying oil made by treating linseed oil with cyclopentadiene, (CH:CH) 2 и CH 2 , a low-boiling liquid obtained from coal tar or from cracking petroleum. Cykelsoy is another drying oil made by treating soybean oil with cyclopentadiene. Dorscolene is a drying oil made from fractionated and blended fish oils. The German substitute drying oil known as Resinol was a liquid obtained by the distillation of the heavy frac- tions of the benzolated oils derived from scrubbing coke-oven gas. Resigum is the final residue in the distillation of tar-oil benzol which has been washed with sulfuric acid, caustic soda, and water. It con- tains a maximum naphthalene content of 5%. It is miscible with resins or copals, and with vegetable oils, and makes a good paint without other drying oils. Synthetic drying oil is glycerol allyl ether derived from propylene gas obtained in cracking petroleum. C oil is a heavy, sticky liquid with a butadiene base. In paints it gives high adhesion to metals and masonry and produces a smooth, hard, glossy coating with good chemical resistance. Although the great volume of drying oils is produced from linseed, soybean, tung, oiticica, castor, and fish oils, many other oils have dry- ing properties and are used in varying quantities. N’gart oil is from the seed nuts of a climbing plant of Africa and is equal in drying power to linseed oil. Lallemantia oil, obtained from the seeds of Lallemantia iberica, of southeastern Europe and Asia, resembles lin- seed oil in physical properties. Isano oil, obtained from the kernel of 324 DRYING OILS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses the nut of Ongokea klaineana of tropical Africa, is a pale-yellow vis- cous oil that has little drying power, but when heat-treated sets up an exothermic action to produce a varnish oil. Anda-assu oil, also used in Brazil for paints, is from the seeds of the plant Joannesia princeps. The seeds yield 22% of a clear yellow oil with an iodine value of 142 which is bodied by heating. Manketti oil is a varnish oil with about two-thirds the drying power of linseed oil. It is a light-yellow viscous oil from the seed nuts of the tree Ricinodendron rautanenii, of south- west Africa. Chia-seed oil is a clear amber-colored oil extracted from the seeds of the plant Salvia hispanica of Mexico. It has a higher drying value than linseed oil. The seeds yield about 30% oil, which contains 39% linolenic acid, 45 linoleic, 5 palmitic, 2.7 stearic, with some arachidic, oleic, and myristic acids. The specific gravity is 0.936, iodine value 192, and acid value 1.4. The seeds scatter easily from the pods and are difficult to collect. DUCK. A strong, heavy cotton fabric employed for sails, awnings, tents, heavy bags, shoe uppers, machine coverings, and where a heavy and durable fabric is needed. It is woven plain, but with two threads together in the warp. It is made in various weights and is designated by the weight in ounces per running yard 22 in (0.6 m) wide. It is marketed unbleached, bleached, or dyed in colors, and there are about 30 specific types with name designations usually for particular uses such as sailcloth. When woven with a colored stripe, it is called awning duck. Russian duck is a fine variety of linen duck. Large quantities of cotton duck are used for making lami- nated plastics and for plastic-coated fabrics, and it is then simply designated by the weight. Belt duck, for impregnated conveyor and transmission belts, is made in loosely woven, soft ducks and in hard-woven, fine-yarn hard fabric. The weights run from 28 to 36 oz (0.80 to 1.02 kg). Conveyor belting for foodstuff plants is usually of plastic fabric for cleanliness. Transilon, of Extremultus, Inc., is a belting of good strength and flexibility to operate over small- diameter rollers. It is made of nylon fabric faced on both sides with polyvinyl chloride sheet. It may have a variety of surface finishes such as tetrafluoroethylene. Hose duck, for rubber hose, is a soft-woven fabric of plied yarns not finer than No. 8, made in weights from 10 to 24 oz (0.28 to 0.68 kg). The grade of duck known as elevator duck for conveyor belts is a hard-woven 36-oz (1.02-kg) fabric. Plied-yarn duck is used for army tents instead of flat duck as it does not tear easily and does not require sizing before weaving. Canvas is duck of more open weave. The term is used loosely in the United States to designate heavy duck used for DUCK 325 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses tarpaulins, bags, sails, and tents. But more properly it is a heavy duck of square mesh weave more permeable than ordinary duck, such as the canvas used for paintings and for embroidery work. The word duck is from the Flemish doeck, meaning cloth, originally a heavy linen fabric. The word canvas is from the Latin cannabis, originally a coarse, heavy hempen cloth for tents. Osnaburg cloth is a heavy, coarse, plain- woven fabric used for wrapping and bailing and for inside sacks for burlap flour bags. It is made from lower grades of short-staple cotton and from waste. In colored checks and stripes it is used for awnings. Drill is a stout, twilled cotton fabric used for linings and where a strong fabric lighter than duck is required. It differs from duck also in that it has a warp-flush weave that brings more warp than filling to the face of the cloth. It comes unbleached, bleached, or piece-dyed, or it may be yarn-dyed. It is made in various weights and is designated in ounces per yard, the same as duck. Tan-colored drill is called khaki. Denim is a heavy, twill-woven, warp-flush fabric usually lighter in weight than drill. The warp is yarn-dyed. The filling is made with one black and one white yarn. It is much used for workers’ clothing, and the light weights for sportswear are called jean. Denim is also used industrially where a tough fabric is needed. Art denim, in plain colors or woven with small figures, is used for upholstery. DYESTUFFS. Materials, also called colorants, used to color textiles, paper, leather, wood, or other products. They may be either natural or artificial. Many chemicals will stain and color other materials, but a product is not considered a dye unless it will impart a distinct color of some permanence to textiles. The natural dyestuffs may be mineral, animal, or vegetable, but the artificial dyes are derived mainly from coal-tar bases. Almost all naturally extracted dyes have been replaced by synthetic counterparts for commercial use; an exception is log- wood, a Central American tree extract, known as natural black 1, CI 75290. Tyrian purple, from various Mediterranean snails, was in ancient times the most noted of the animal dyestuffs. Cochineal and kermes are other animal dyes. One of the earliest metallic or mineral dyestuffs was called iron buff. It was made by allowing pieces of iron to stand in a solution of vinegar to corrode. Fabrics that had been dipped in this solution were rinsed in a solution of wood ashes. Mineral dyes now include ocher, chrome yellow, and Prussian blue. Vegetable dyes may be water solutions of woods, barks, leaves, fruits, or flowers. The buff and brown textile colors of early New England were made by boiling fresh green butternuts in water, while a dark-red dye was made by boiling the common red beet in water. The yellow to red colors known by the Algonquin name of puccoon were from the orange-red juice of the root of the bloodroot, a peren- 326 DYESTUFFS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses nial of the poppy family. Vegetable dyes now include brazilwood, bar- wood, sappanwood, fustic, logwood, madder, henna, saffron, annatto, indigo, and alkanet. The camphire of the ancients mentioned in the Bible and Koran was a reddish-orange dyestuff made by grinding to a paste the red, sweet-scented spikes of the small cypress tree Lawsonia inermis, of Egypt and the Near East. It was used by Eastern and Roman women to stain fingernails, and is now used under the name henna for dyeing leather and hair. It gives various shades from yellowish to red or brown. Argol, a brilliant red used extensively until replaced by synthetic dyes, is from the orchilla, a lichen found in the Canaries and Near East. It was used to produce the brilliant colors of the medieval Florentine cloth. Chinese green, buckthorn bark, or lokao is the powdered bark of the buck- thorns, Rhamorus globosa and R. utilis, of China and Russia. It is used in dyeing silk and cotton. Weld, from the plant Reseda luteola of Europe, produces a very bright-yellow color with an alum mordant. With indigo it produces green. Woad is the dried fermented leaves of the plant Isatis tinctoria of Europe. It gives a blue color, but is now little cultivated. Ecolor dyes, of Allegro Natural Dyes, are derived from plants, such as the Maclura pomifera (Bodark tree) and the insect, cochineal. No heavy metals are required as mordants to pre- treat fibers to accept the dyes, and no toxics or solvents, other than water, are used in dyeing. More than 100 colors exist for cotton fibers. Synthetic dyes are mostly coal-tar or aniline colors. They are more intense, brighter, faster, and generally cheaper than natural dyestuffs. The dyes are complex chemicals, but they usually contain characteris- tic groups of atoms so that the color or change in color can be pre- dicted. The Colour Index (CI) from the U.K.’s Society of Dyers and Colourists is a new system for classifying dyes. It assigns a number defining the chemical class while a generic name identifies the appli- cation; in industry, the trade name is also appended. Benzene-azo-m- phenylenediamine hydrochloride is sold as Chrysoidine Y and classified as Azo or Basic Dye, CI 11270, Basic Orange 2. The Colour Index recognizes 26 types of dyes by chemical classification. The azo dyes, with an и N:N и linkage, constitute about half of the production and are produced by diazotization of primary arylamines, followed by reaction with aromatic amines, phenols, and enolizable ketones. Azobenzene, C 6 H 5 и N:N и H 5 C 6 , is made from nitrobenzene and is in crystalline red plates melting at 154°F (68°C). This may be converted to hydrazobenzene, C 6 H 5 NHNHC 6 H 5 , a solid of camphor- like odor melting at 268°F (131°C). Substituted azo dyes constitute a class containing OH and NH groups, made by coupling amines or phenols with the salts. The azo dyes are in general poisonous, but are sometimes used in restricted quantities to color foodstuffs. Some are DYESTUFFS 327 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses poisonous in contact with skin, such as xylyazonaphthol and the sodium salt of sulfophenylazo, designated by the Food and Drug Administration as red No. 32 and orange No. 1, and proscribed for use in coloring lipstick and oranges. Three other important classes are anthraquinone dyes, indigoid dyes, and thioindigoid dyes, the latter being sulfur dyes. The sul- fur dyes may be made by treating the organic compounds with sodium sulfide. They are fast to washing and to light, but the range of color is limited, and their use is generally limited to fibers where a strongly alkaline bath is tolerable. Some of the synthetic dyes will color animal fibers well and not veg- etable fibers, or vice versa, while some will color all fibers. As a result, it is possible to divide the bulk of the dyes into six classes, including azoic dyes. The direct dyes can be dyed directly, while others require a mordant. Some are permanent, or fast, while others are water-soluble and will fade when the fabric is washed, or some may not be light-fast and will fade when exposed to light. Direct dyes usu- ally have a weak OH bond between the nitrogen in the dye and the fiber, usually cotton. In reactive dyes, the dye reacts with the fiber to produce both an OH and an oxygen linkage, the chlorine combining with the hydroxyl to form a strong ether linkage. Such dyes are fast and very brilliant and are used for cotton, rayon, and nylon. Acid dyes contain a carboxylic or sulfonic acid group and operate best in an acid bath. They are used for drying protein fibers, such as wool, silk, and nylon, and sometimes for leather and paper. They are usually azo, triaryl methane, or anthroquinone complexes. Basic dyes are com- monly amino and substituted amino compounds, such as triaryl methane or xanthenes. They are used for dyeing cotton with a mor- dant. Vat dyes are insoluble and are applied in the soluble colorless form and then reduced or oxidized to color. They usually have an anthraquinone or indanthrene structure and are solubilized by the reducing agent, a hydroxyl group, OH, diffusing into the fiber where it is fixed. The best known example is indigo, the dye synonymous with the color of bluejeans, which has become one of the most important colorants because of the popularity of denim garments. Originally derived from plants, synthetic indigo dye now dominates the market. Synthesis, first commercialized by BASF of Germany more than 100 years ago, uses aniline formaldehyde and sodium cyanide as the raw materials. The process generates toxic wastewater. A biosynthesis process, of Genecor International, Inc., however, is said to be environ- mentally benign. Pioneered by Amgen, Inc., and the University of Texas, it uses no petrochemical feedstocks, and biomass is the only waste product. Genecor produces recombinant Escherichia coli bacte- ria, which contain an enzyme capable of converting indole to indigo. Indole is a naturally occurring by-product of an enzyme within E. coli. 328 DYESTUFFS Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses Bifunctional reactive dyes, such as the Sumifix Supra line of Sumitomo, of Japan, combine several reactive groups in a single mol- ecule. Each group compensates for the other during changing process conditions, improving color fixation and reproducibility. The Levafix line, of Miles Inc., combines vinyl sulfone, monofluorotriazine, and fluorochloropyrimidine to increase color fixation rates to 75 to 90% and higher in contrast with the 50 to 70% rates typical of conventional reac- tive dyes. Cibacron C bifunctional reactives, of Ciba Geigy, are said to provide color fixation rates of 95%. Increasing the fixation rate reduces the amount of dye discharged in textile wastewater. To reduce sulfur effluents in nonreactive sulfur dyes, Sandozol RDT, of Sandoz Chemical Corp., contains nonsulfide-reducing agents, which cut sulfide consumption in half. Color carriers, used to aid adherence of dyes to synthetic fibers, are usually chemicals that act as swelling agents to open the fiber structure, such as phenylphenol, benzoic acid, or dichlorobenzoic acid. Ketosol 75, of Union Carbide, is 75% methylphenyl carbinol and 25 acetophenone. Monochlorobenzene, used as a color carrier for Dacron fiber, acts to promote a concentrated layer of dye solution around the fiber. Ring-dyed fiber is a synthetic fiber not receptive to dyes that has been passed through a bath of a receptive plastic before dyeing. The dye then adheres to the coated surface and encases the fiber. EBONY. A hard, black wood valued for parts subject to great wear, and for ornamental inlaying. It is the wood of various species of trees of the ebony family, Ebenaceae, although the name is also applied to some woods of the genus Dalbergia, family Leguminosae. Black ebony, from the tree Diospyros dendo of West Africa, and ebony, from the tree D. melanoxylos, of India, are the true ebonies. Black ebony has a black heartwood with brownish-white sapwood. It is next to lignum vitae in hardness and has a fine, open grain and a density of 78 lb/ft 3 (1,250 kg/m 3 ). It is used for inlaying, piano keys, and turnery. The ebony of India is also extremely hard, with a fine, even grain. The heartwood is black with brownish streaks. Marblewood, or Andaman marblewood, is an ebony from the tree D. kurzii of India and the Andaman Islands. The wood is black with yellowish stripes. It has a close, firm texture, is hard, takes a fine polish, and has a density of 65 lb/ft 3 (1,041 kg/m 3 ). Marble ebony is another species from Malagasy. The ebony from Japan, called kaki, is from the tree D. kaki. It has a black color streaked with gray, yellow, and brown. The grain is close and even, and the wood is very hard, but the density is less than that of African ebony. Ebony wood is shipped in short billets and is graded according to the color and the source, as Niger, Macassar, or Cameroon. Green ebony is a name sometimes given to the cocoswood of the West Indies. Artificial ebony, formerly composed of asphaltic EBONY 329 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Materials, Their Properties and Uses [...]... gold-silver, gold-copper, gold-silver-platinum, gold-silver-nickel, and gold-copper-platinum-silver, are more commonly used Platinum and palladium are also used for contacts but, again, in alloy form more than as pure metals Among the most common ones are platinum-iridium, platinu ruthenium, platinum palladium-ruthenium, palladium-ruthenium, palladium-copper, and palladium-silver A palladium-silver-platinum-gold... 77°F ( 25 C), viscosity is about 3 ,50 0 cP, one-fourth that of Epon 828 It also has a glass transition temperature of 50 0°F (260°C), which is high for a low-viscosity resin PR -5 0 0, of 3M, is a one-part compound that can resist temperatures up to 350 °F (177°C) Reinforced with 50 % glass fiber, it is used for resin-transfer-molded vent louvers of auxiliary power units on large commercial aircraft FR-4 is... resistivity, 58 3 (970), of the pure metals, followed by tantalum, 81 (1 35) ; platinum, 64 (106); nickel, 48 (80); and tungsten, 33 (55 ) The radio alloys are in the 30 to 180 (50 to 300) range, the manganins 228 to 289 (380 to 480), the constantans 2 95 to 300 (490 to 50 0), and most of the nickel-chromium-aluminum, iron-chromium-aluminum, and various other alloys are in the 610 to 872 (1,0 15 to 1, 450 ) range... composed basically of silicone and oxygen atoms There are four major elastomer composition groups In terms of application, silicone elastomers can be divided roughly into the following types: general-purpose, low-temperature, high-temperture, low-compression-set, high-tensile–high-tear, fluid-resistant, and room-temperature vulcanizing All silicone elastomers are high-performance, high-price materials. .. highest, and most of the alloys are intermediate Tensile strength and ductility also range widely depending on the alloy or metal Maximum operating temperatures in air for the commonly used resistance-heating alloys range from 1700°F (927°C) for 43 .5 Fe– 35 Ni–20 Cr–1 .5 Si alloy to 250 5°F (1374°C) for 72 .5 Fe–22 Cr 5. 5 Al For platinum, this temperature is 2 750 °F ( 151 0°C) The refractory metals are suitable... developed by the National Bureau of Standards, called Therlo, contains 85% copper, 9 .5 manganese, and 5. 5 aluminum Fecraloy has 15% chromium, 5 aluminum, and the balance iron It is for temperatures to 1400°F (760°C) Sparkaloy is a spark-plug wire and is a manganese-nickel Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies... electrical-resistance alloys: (1) radio alloys, which contain 78 to 98% copper with the balance nickel; (2) manganins, 87% copper and 13 manganese or 83 to 85 copper, 10 to 13 manganese, and 4 nickel; (3) constantans, 55 to 57 % copper and 43 to 45 nickel; (4) nickel-chromium-aluminum alloys, 72 to 75% nickel, 20 chromium, 3 aluminum, and either 5 manganese or 2 copper, iron, or manganese; (5) iron-chromium-aluminum... one-component epoxy resins, named Arnox, was developed by General Electric Co Suitable for compression, transfer, injection molding, filament winding, and pultrusion, they cure rapidly at temperatures of 250 to 350 °F (121 to 177°C) The compression and transfer-molding grade is a black, mineral-filled compound The injection-molding grade is a pelletized glass-fiber-reinforced compound with a shelf life... for 70 h at 392°F (200°C) 9 to 45% , and the continuous-use temperature 0 to 392°F (Ϫ17.8 to 200°C) The properties of Fluorel II, a VF2-TFE-propylene elastomer, are within these ranges except for density [0. 058 lb/in3 (16 05 kg/m3)] Aflas, a 3M dipolymer of TFE and propylene with 57 % fluorine, has a density of 0. 056 lb/in3 ( 155 0 kg/m3) and a service temperature range of 35 to 392°F (2 to 200°C) Depending... parts per million per degree Fahrenheit (Celsius) range from ±10 to ± 15 at 59 to 113°F ( 15 to 45 C) for the manganins to +6,000 at 68 to 95 F (20 to 35 C) for pure nickel Thermoelectric potentials versus copper in the ␮V/°F range from Ϫ43 to 77 to 221°F ( 25 to 1 05 C) for the 57 copper–43 nickel constantan to +12.2 at 32 to 167°F (0 to 75 C) for pure iron The refractory metals have the lowest coefficients . divided roughly into the following types: general-purpose, low-temperature, high-temperture, low-compression-set, high-tensile–high-tear, fluid-resistant, and room-temperature vulcanizing. All. to give conjugated double DRYING OILS 323 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights. Many have continuous-use service temperatures as high as ELASTOMERS 3 35 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill