Paper

Name:
Paper
Detailed information:
A semisynthetic product made by chemically processing cellulosic fibers. A wide variety of sources have been used for specialty papers (flax, bagasse, esparto, straw, papyrus, bamboo, jute, and others), but by far the largest quantity is made from softwoods (coniferous trees), such as spruce, hemlock, pine, etc.; some is also made from such hardwoods as poplar, oak, etc., as well as from synthetic fibers. Papermaking technology involves the following basic steps: (1) chipping or other subdivision of the logs (see Groundwood); (2) manufacture of chemical or semichemical pulp by digestion in acidic or alkaline solutions, which separates the cellulose from the lignin (see Pulp, Paper); (3) beating the pulp to break down the fibers and permit proper bonding when the sheet is formed; (4) addition of starches, resins, clays, and pigments to the liquid stock (or “furnish”); (5) formation of the sheet continuously on a fourdrinier machine, where the water is screened out and the sheet dried by passing over a series of heated drums; (6) high-speed calendering for brightness and finish; (7) coating either by machine application or (for heavy finishes) by brushes. Further information can be obtained from the Technical Association of the Pulp and Paper Industry or from the Institute of Paper Chemistry, Appleton, WI.See Appendix II for history of the industry.