Paper raw materials

The pulp produced by the kraft process is widely used throughout the paper and board industries. Unbleached kraft is used for grocery sacks, wrapping papers, raw material packaging, and linerboard for corrugated boxes. Bleached kraft pulps are used for printing and writing papers, sanitary tissue, and bleached paperboard. 

Insulation Boa.rd. The panel products known as insulation board were the earliest commodity products made from fibers or particles in the composite panel area. These are fiber-base products with a density less than 500 kg/m. Early U.S. patents were obtained in 1915 and production began soon thereafter. The initial production used wood fiber as a raw material, but later products were made of recycled paper, bagasse (sugar cane residue), and straw. Schematics of the two major processes still ia use are shown ia Figure 4. 

Reinforcement. PVA fiber in the form of short cut chips having a length of several millimeters to several tens of millimeters is widely used as raw material for paper and for reinforcing plastics, cement, and the like, and has been acquiring more and more significance. 

Most of the commercial tree plantations that produce wood for captive use as a raw material in manufacturing operations use a portion as fuel. Examples of short-rotation plantations are Hsted in Table 38 (127). Paper companies in the southeastern United States are reported to have short-rotation plantings also, eg, Weyerhaeuser, James River Corp., Buckeye Cellulose, and Lykes Brothers, but the intensity of maintenance is not known (127). 

L. E. Swabb, Jr., G. K. Vick, and T. Aczel, "The Liquefaction of SoHd Carbonaceous Matedals," paper presented at The World Conference on Future Sources of Organic Raw Materials, Toronto, Can., July 10, 1978. 

Fumaric acid occurs naturally in many plants and is named after Fumaria officinalis, a climbing aimual plant, from which it was first isolated. It is also known as (E)-2-butenedioic acid, aHomaleic acid, boletic acid, Hchenic acid, or /n j -l,2-ethylenedicarboxylic acid. It is used as a food acidulant and as a raw material in the manufacture of unsaturated polyester resins, quick-setting inks, furniture lacquers, paper sizing chemicals, and aspartic acid [56-84-8]. 

The type of paperboard used by the carton industry is boxboard. Boxboard may be categorized, based on the raw material, as combination or soHd boxboard. Combination boxboard, of which there are many grades, normally is made on a multicylinder paper machine using a substantial percentage of waste paper with virgin pulp. SoHd boxboard usually is made on a Fourdrinier paper machine using only virgin pulp and it is bleached or coated. 

Some hquid defoamers are preemulsified relatives of paste defoamers. In addition to the fatty components mentioned above, kerosene [8008-20-6] or an organic cosolvent such as 2-propanol have been used to enhance stabiUty of the oil—water emulsion and the solubiUty of the defoamer s active ingredients. These cosolvents are used less frequently as concerns increase about volatile organic emissions (VOCs) from the paper machine. Additionally, the use of ultrapure mineral oil in defoamers has become commonplace. Concern about the creation of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF) in the pulping process has led to the discovery of unchlorinated precursor molecules, especially in recycled mineral oil and other organic cosolvents used in defoamer formulations (28). In 1995 the mineral oil that is used is essentially free of dibenzodioxin and dibenzofuran. In addition, owing to both the concern about these oils and the fluctuating cost of raw materials, the trend in paper machine defoamers is toward water-based defoamers (29). 

The defoamer formulations mentioned so far consist of fairly inexpensive raw materials, but several more cosdy defoaming materials have come into use in paper mills. Hydrophobicized siUca particles are useful in some emulsion formulations. SiUcone solutions and emulsions are very effective in eliminating foam in paper machine water systems. The siUca- or siUcone-based defoamers have higher activity, which somewhat compensates for the higher cost, but care must be taken to prevent ovemse. 

Other industries that are traditionally located close to the source of raw materials include the steel (qv) industry, located close to iron ore the flour industry, close to wheat fields the meat-packing industry, close to gracing land for catde pulp and paper, close to forests and the mining industry, close to mines. The inorganic industry, including salts, ash, borax, and gypsum, has always been located near the source of the needed raw material. 

The future for amino resins and plastics seems secure because they can provide quaHties that are not easily obtained in other ways. New developments will probably be in the areas of more highly specialized materials for treating textiles, paper, etc, and for use with other resins in the formulation of surface coatings, where a small amount of an amino resin can significantly increase the value of a more basic material. Additionally, since amino resins contain a large proportion of nitrogen, a widely abundant element, they may be in a better position to compete with other plastics as raw materials based on carbon compounds become more costly. 

Many large chemical companies produce amino resins and the raw materials needed, ie, formaldehyde, urea, and melamine. Some companies may buy raw materials to produce amino resins for use in their own products, such as plywood, chipboard, paper, textiles, or paints, and may also find it profitable to market these resins to smaller companies. The technology is highly developed and sales must be supported by adequate technical service to select the correct resin and see that it is appHed under the best conditions. 

M. J. Kocurek and C. F. B. Stevens, "Properties of Fibrous Raw Materials and Their Preparation," Pulp and Paper Manufacture, 3rd ed., Vol. 1, TAPPI Press, Atlanta, Ga., 1983. 

The principle uses of Na2S04 are in the manufacture of paper, soaps, and detergents. These accounted for 65% of U.S. consumption from 1990 to 1995, representing a significant shift from 1980 when paper production alone consumed 67%. Pulp (qv) and paper consume only 25% (2). The kraft paper process uses a mixture of sodium sulfide and sodium hydroxide to digest wood chips. Both the sulfide and hydroxide are generated, starting with sodium sulfate as the raw material. 

Titanium raw-material utilization can be broken down as illustrated in Figure 9. About 4% of the titanium mined is used as metal, 94% is used as pigment-grade Ti02, and 2% as ore-grade mtile for fluxes and ceramics. In 1995, the estimated U.S. Ti02 pigment production was valued at 2.6 biUion and was produced by five companies at 11 plants in nine states. About 47% was used in paint, 18% in plastics, 24% in paper, and 18% in other misceUaneous appHcations (56). 

Vinyl compares favorably to other packaging materials. In 1992, a lifecycle assessment comparison of specific packages made from glass, paperboard, paper, and selected plastics concluded that vinyl was the material that has the lowest production energy and carbon dioxide emissions, as well as the lowest fossil fuel and raw material requirements of the plastics studied (169). Vinyl saves more than 34 million Btu per 1000 pounds manufactured compared to the highest energy-consuming plastic (170). 

The principal chemical iadustry based on wood is pulp and paper. In 1995, 114.5 x 10 metric tons of wood were converted iato - 60 x 10 metric tons of fiber products ranging from newsptint to pure cellulose ia the United States (1,76). Pure cellulose is the raw material for a number of products, eg, rayon, cellulose acetate film base, cellulose nitrate explosives, cellophane, celluloid, carboxymethylceUulose, and chemically modified ceUulosic material. 

Industrial uses make up most of the market for cyanamide. Calcium cyanamide is used directly for steel nitridation (34) and to some extent for desulfurization (36) (see Steel). Cyanamide is used to produce cationic starch (36) and calcium cyanide. Cyanamide is, of course, the raw material for dicyandiamide and melamine. New uses include intermediates for pesticides, detergents (37), medicines such as antihistamines, hypertension, sedatives, contraceptives, etc (38), the photography industry (39), as an additive for fuels and lubricants, as a paper preservative, and as a cement additive. 

As with textiles the principal reasons for the coloring paper are for aesthetic appearance and utihtarian purposes. Aesthetic appearance includes colored background for printed material, colored writing papers, colored household products to harmonize with interior decor, and many other diverse uses dictated by individual tastes. Utihtarian purposes include identification of multicopy forms, identification of manufacturer or marketer of specific materials or products, opaqueness or hiding power of packaged material, or to control consistency of paper manufactured from various colored raw materials. 

Lacl<. of markets. The implementation of pollution-prevention processes and the production of environmentally friendly products will be of no avail if markets do not exist for such goods. As an example, the recychng of newspaper in the United States has resulted in an overabundance of waste paper without markets prepared to take advantage of this raw material. 

A steady reduction in the cost of basic plastics raw materials relative to the cost of such traditional materials as leather, paper, metals and ceramics. 

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