These plants are cultivated in the West Indies, Mexico, Yucatan, Central America and Venezuela. The fibers are separated from the leaf by scraping. The ultimate fibers are 1 to 6 mm. long, white, lustrous and stiff. The material reaches the paper mill in the form of cordage and old bagging and is suitable for making strong wrapping paper. [See Fiber plants.] Spruce (Picea nigra, P. alba and P. rubra). Conif: enc. Fig. 731. [See Fig. 465.] Spruce is particularly suitable for the produc tion of sulfite pulp made by cooking the wood with a sulfite liquor, and is still the chief source of this pulp. The bark is always removed before making the wood into pulp. Spruce is native in Canada, northern United States and in the mountains as far south as North Carolina. It is also found in northern Europe and Asia. The fibers are 1.5 to 2.5 mm. long and .035 mm. in diameter. The yield of paper is about 50 per cent. It is largely used in combina tion with other materials for making lithograph, book and other printing papers, and for writing papers. Unbleached, it is also largely used with other materials for making wrapping paper. So-called manilas often consist almost entirely of unbleached spruce fiber.
Straws of cereals. Graminece.
Until the introduction of wood, rye- and wheat straws were largely used in the production of news paper material and other cheap printing paper. Straw is still used in small quantities, even in high grade to impart to them stiffness and hard ness, but is used chiefly for strawboard, which is made in large quantities almost exclusively in the Ohio valley. Barley-, rye-, wheat- and oat-straw fibers are .1 to .5 mm. long and .0125 to .024 mm. in diameter. Rice-straw fibers are .88 mm. long and .0025 mm. in diameter. The yield of paper is about 42 per cent. Of strawboard the yield is about 80 per cent. Rice-straw is not used to any extent, but experimental work indicates that it makes a paper similar to that from other straws and that it is just as suitable for the making of strawboard.
The high percentage of silica which it contains (which reduces the quantity of soda recovered) operates against its use for paper-making. Immense quantities of straw are wasted annually. [See articles on the cereal grains.] Sunn hemp (Crotalaria juncea). Leguntinosee. Fig. 396.
This is cultivated for its fiber in India and the Sunda islands. It is used chiefly in the form of old rope and bagging for strong wrapping papers. The fibers are 7 to 8 mm. long and .03 mm. in diameter. [See Fiber plants.] Waste paper.
In printing there is considerable waste of paper, due to the tearing of the paper on the presses, to soiling, and to trimming and cutting to desired sizes. Magazines, advertising matter, books and newspapers, after serving their purpose, are col lected and returned to the paper-mill, to be again used in making such kinds of paper as they may be suitable for. The quantity of waste paper thus used is very large and might well be much greater.
Literature.
Handbuch der Papierfabrication,Mierzmski,Wein, 1886 ; Manufacture of Paper, Davis, Philadelphia, 1886 ; Chemistry of Paper Making, Griffin & Little, New York, 1894 ; Treatise on Paper Making, Hoff man, New York, 1895 ; Vegetable Fibers, Bulletin of Miscellaneous Information, Additional Series III, Royal Gardens, Kew, 1898 ; Paper Making, Cross & Bevan, London, 1900; Industrial Organic Chem istry, Sadtler, Philadelphia, 1900 ; Die Rohstoffe der Pflanzenreiches, Wiesner, Leipzig, 1900 ; The Art of Paper Making, Watts, London, 1901; Papier Priifung, Hertzberg, Berlin, 1902; Cellulose, Cross & Bevan, London, 1903 ; Textile Fibers, Mathews, New I ork, 1904: IIandbuch der Papier Runde, Klemm, Leipzig, 1904 ; Die Cellulose Fabrikation, Schubert, Berlin, 1911G; An Elementary Manual of Paper Technology, Sindall, London, 190G; Philip pine Fibers and Fibrous Substances, Richmond, Philippine Journal of Science, i., 433, 190G.