PAPER-MAKING PLANTS. Figs. The farmer is not called on to grow crops for the purpose of supplying the raw materials used for making paper. The cutting of timber and the sale of straw for this purpose have been incidental to other farm work, filling in the gaps between more profitable work. But conditions are chang ing: the wild growths and the wastes of other industries heretofore used are supplied at con stantly increasing cost, and the time is now come when the farm may be called on to contribute more largely to these supplies, both with its waste materials and with its crops.
Paper can be made from any fibrous vegetable material. The materials commonly used, how ever, are not numerous, and are obtained from flax, cotton, hemp, esparto, manila, jute, woods, straws of cereals, Sunn hemp, rhea, China grass or ramie, New Zealand hemp, coconut fiber, adansonia, agave, and bark of the paper mulberry. Other ma terials which are used to a certain extent, or for various reasons may be considered promising, are bamboo, sugar-cane and corn-stalks. There is also a long list of cultivated and wild grasses, rushes of all kinds, reeds, banana fiber, barks of trees, com mon broom and heather, tobacco- and cotton-stalks, beet-pulp waste, peat, and many miscellaneous materials from which small quantities of paper have been made experimentally.
The woods most used are spruce, poplar, hem lock, cottonwood, balsam and pine. A number of others are now being employed in the manufacture of paper, possibly not in sufficient quantity to require individual mention, but enough to indicate that, as the necessity arises, many other woods will also be used for this purpose. Indeed, there is every reason to suppose that, with proper modifica tions in methods of handling and treating, most of the woods will make paper. Fig. 728 shows a pulp mill with its accompanying log pond.
Of the standard paper-making plants, cotton, flax, hemp. straws and woods are the only ones produced commercially in the United States. Sugar-cane, corn-stalks, cotton- and tobacco-stalks are produced in large quantities, and vigorous efforts are being made to produce paper from them on a commercial scale.
The best paper-making materials—those that make paper of the highest quality and greatest value—are wastes, derived chiefly from the textile industries, which from their form or condition are of little value for any other purpose. Cotton, flax, hemp, jute and ramie fiber come to the paper-maker in the form of rags or as waste, and as old bagging, canvas, rope cordage and oakum. The coarse fiber from the end of jute stalks is cut off, baled and sold to the paper-maker as "jute butts." Waste paper, new and old, is an important material, which is used in making all grades of paper. Wood, esparto and bamboo are the chief materials now used which are not the wastes of other industries.
All plants are made up of certain definite chemi cal constituents, among which are fats, tannins, lignin, pectose, coloring matters, sugar, starch and cellulose, and, when treated with certain chemicals, according to established methods, a more or less pure cellulose is obtained ; and it is on the amount, fibrous nature, softness and pliability of this cellu lose that the paper-making value of the plant chiefly depends.
Classification of materials.
With regard to the quality and value of the paper produced, the chief materials may be classi fied in four general groups : (1) Cellulose from cotton, flax, hemp and ramie ; (2) cellulose from jute, manila and chemical wood ; (3) cellulose from esparto and straws ; (4) ground wood. From the consideration of the nature and the percentage of cellulose in the materials they are classified as, (a) simple cellulose : cotton, containing 91 per cent of cellulose ; (b) pecto-cellulose : flax, cellulose 82 per cent ; hemp, cellulose 77 per cent ; ramie, cellu lose 76 per cent ; Sunn hemp, cellulose 80 per cent ; manila, cellulose 64 per cent ; bamboo, cellulose 50 per cent ; sugar-cane, cellulose 50 per cent ; straw, cellulose 46 per cent ; esparto, cellulose 48 per cent ; adansonia, cellulose 49 per cent ; (c) ligno cellulose: New Zealand hemp, cellulose 86 per cent ; jute, cellulose 64 per cent ; pine, cellulose 67 per cent ; poplar, cellulose 53 per cent.