Paper Making - Raw Materials
( Originally Published 1920 )
PAPER has been defined as "an aqueous deposit of cellulose," and while this is incomplete as a catalogue of the materials composing a sheet of modern paper, it is an excellent epitome of the foundation of paper-making. Minute cellulose fibers, derivatives of various raw materials, are deposited upon a wire cloth by the passage of a volume of water in which they have been suspended. The pulpy film thus formed becomes a sheet of paper, after the expulsion and evaporation of the water which served as a medium for their deposit.
The minute fibers composing this hypothetical sheet of paper may have been isolated from one of several sources of raw materials in present commercial use, or the sheet may be composed of a mixture of different fibers, all more or less pure cellulose, in accordance with the preliminary treatment each has undergone.
The principal sources from which American paper fibers are derived are cotton and linen rags, hemp, jute, wood, straw; and waste papers.
Previous to the year 1840, the sources were limited to rags. These are almost wholly composed of pure cellulose fibers, which give up their non-cellulose concomitants with slight resistance. The more severe chemical treatments necessary for the isolation of cellulose fibers, from wood, for example, half of which is non-cellulose in structure, were unknown to early paper-makers, and only became possible after the discovery of bleaching-powder by Tennant, and the manufacture of soda by Le Blanc.
Although experiments in search of suitable substitutes for rags began to be made in the eighteenth century, it was Keller's invention of ground wood in 1840, Routledge's work on esparto grass and wood with a soda process in 1854, and our own fellow countryman Tilghmann's patent of the sulphite process in 1866, from which we may date the beginnings of the now extensive use of materials other than cotton and linen wastes.
The accompanying table, taken from the United States Statistics of Manufacture for 1909, gives an illuminating indication of the rapid growth of our paper industry, and also shows the remarkable increase in the use of wood celluloses.
It may be observed that the percentage of increase in the use of wood-pulp of all kinds for the decade 1899-1909 was 111.6, and of rags, 50. Approximately four and one-quarter millions tons of paper were produced in 1909.
A further investigation as to the species of woods used shows that, while spruce is still the most important, contributing nearly 60 per cent, other woods are being increasingly used.
Another noteworthy fact is the mighty increase in imports of wood-pulps, which jumped from 33,319 tons in 1899 to 307,122 tons in 1909, an amount equal to 12 per cent of all that is used in the United States.
The high point of importation of chemical wood-pulp was reached in 1914, when approximately 3,600,000 tons came in from Europe and 92,000 from Canada. In January 1916 owing to the war, imports for the month from Europe dropped from an average of 30,694 tons to 12,985 tons, while Canadian pulp increased from an average of 7,654 to an actual importation for the month of 28,833 tons.
Although the use of wood now so heavily overshadows that of rags that it almost seems as though the latter were being slowly abandoned, this is of course only relatively true, their consumption being actually greater than ever. The mere cost of the rags in 1909 was slightly in excess of the total value of all paper products recorded in the United States Census for 1850, a circumstance which leads us to wonder at the timely discoveries which made wood cellulose available.
It is evident, however, that to some extent paper history is already beginning to repeat itself. The visible supplies of wood are markedly less, as evidenced by their increasing costs, and we are forced to a much more active attitude than one of mere speculation as to what new sources may become available to supply our demand for paper, which has lately been increasing in the value of the annual products by almost 11 per cent.
In the decade from 1899 to 1909 shown by government statistics, book-paper advanced 104 per cent in quantity, but 120 per cent in value; writing-paper, 88 per cent in quantity, but 104 per cent in value; wrapping-paper, 43 per cent in quantity and 72 per cent in value. It is true that rising wages account in part for these changes in value, but above and behind all this stands the inexorable law of supply and demand.
The discrepancies between the percentages of increase in production and value serve to emphasize the increasing difficulties in obtaining raw material. That sprucewood is being consumed in this country faster than it is grown, is indicated by the recourse to less-favored species, as well as by the steadily increasing imports, both of pulpwood and wood-pulp. This situation emphasises the great importance of conserving waste papers, in spite of the fact that 21.4 per cent of the fiber used in 1909 in the United States were derived from waste papers. Vast quantities may readily be saved which now go to waste, as was definitely proved by England's experience during the war, when the imports of pulp were shut off and immediate substitutes had to be found.
This is a matter demanding the attention not only of printers, but of municipalities and nations. It offers an immediate source of relief from the drain on our forests and is hence a most practical form of conservation. Further-more as demonstrated by the city of Cleveland the revenue from collecting waste papers assists substantially in off-setting the cost of the collection of municipal wastes.