to about 85 percent. To make up the loss, new soda ash or sodium sulphate is added.

Semichemical pulp.

Semichemical pulp is produced by mechanical means after the wood has been partially digested in solvents of less than usual strength. Most of the domestic semichemical pulp is produced from chestnut wood in connection with the extraction of tannin and is used in the making of corrugating board.

Drying and storing.

Pulp, both mechanical and chemical, after leaving the grinders or the digesters must be screened and washed to remove dirt, undigested chips, and other foreign matter. The screened stock consists of fiber suspended in water in the proportions of less than 1 percent air-dry fiber to more than 99 percent water. While the pulp is usually of still lower consistency when fed to the paper machine, for handling or storing it must be thickened. Following the screening it is thickened to "slush pulp" by deckering or dewatering to a consistency of 5 to 6 percent air-dry fiber. In integrated pulp and paper operations, it is pumped in slush form directly to the paper mill. This is the least costly form of pulp suitable for conversion into paper. Slush pulp, however, is not thick or dry enough to hold together in handling, and can only be moved by pumping or by the use of containers.

For commercial transportation of pulp or for storage it is necessary to extract sufficient water to permit collecting the fibers into sheets dry enough to hold together in handling. The pulp may be converted to wet laps, or into sheets or rolls, or dried and shredded. For lapped pulp, the pulp is passed through a wet machine or wet press where, by pressure and suction, it is concentrated to a consistency of from 30 to 45 percent air-dry fiber. The pulp is collected on a roller in several successive layers which are compacted into a sheet, which the operator cuts from the roll and folds or laps, hence the name "lapped." These laps may be loosely stacked for storage or for shipment, or they may be compressed and baled. In the latter case, the pulp will range from 50 to 60 percent air-dry fiber. Dried pulp is pulp from which nearly all water has been removed by a drying machine utilizing compression and heat. Pulp is usually dried on a machine similar to paper machines in which pulp is formed into a sheet and passed over numerous heated rollers which evaporate the moisture. As delivered from the machine, the pulp is in sheets of uniform size, or in a continuous roll. Some dried pulp is shredded and packed in bales. Such pulp passes through a wet press resembling that used for lapped pulp. It is delivered from the press in a continuous sheet which is shredded or macerated by revolving cutters. The macerated pulp is dried on a continuous moving wire or screen which carries it through a heated chamber or oven.

Pulp is marketed and measured on an air-dry basis. Air-dry means 90 percent absolutely dry or oven-dry fiber and 10 percent moisture. Dry pulp may be more or less than 100 percent air-dry, but the price and volume are based on the air-dry fiber content. European pulp shipped to the United States is usually approximately air-dry. The same is true of pulp shipped from the West coast of the United States. Canadian pulp is usually shipped with a greater moisture content.

Throughout this report quantities of pulp are expressed in air-dry weight unless otherwise noted.

WORLD PRODUCTION AND CONSUMPTION OF WOOD PULP

There is some production of wood pulp in many countries, but substantial contributions to the total world production are confined to a much smaller number of which the most important in the order named are the United States, Canada, Sweden, Germany, Finland, and Norway. All these countries have large supplies of timber suitable for the manufacture of wood pulp, but some of them, particularly the United States and Germany, manufacture substantial quantities of pulp from imported wood. The Soviet Union also has large supplies of pulp timber, and in recent years its production of pulp has increased rapidly, but the country still has only a small pulp industry relative to its pulpwood resources. The substantial quantities of pulpwood exported by the Soviet Union provide part of the raw materials for the pulp industries of several other countries.

The production of paper and of various kinds of board, in which the bulk of the world production of pulp is used, is distributed among countries more nearly in accordance with their respective requirements of such products than is pulp production. All important industrial countries and certain countries not highly industrialized have substantial paper industries utilizing imported pulp where domestic supplies are lacking or inadequate. However, some types of paper, particularly newsprint and some kinds of kraft wrapping paper, are manufactured principally in integrated pulp-paper mills, and thus the production of such papers is mainly in countries producing the pulp.

Thus there is substantial international trade in all three commodities pulpwood, wood pulp, and paper. The movement of pulpwood is mainly between countries in close proximity, as from Canada to the United States, or from Finland, Hungary, and Czechoslovakia to Germany. Some pulpwood has, however, moved as far as from the Soviet Union to the United States and from Canada to the United Kingdom, Norway, and Sweden.

International trade in wood pulp is extensive. All the important pulp-producing countries export substantial quantities, particularly of chemical pulps, for use of the paper industries of countries deficient in pulp production. Some countries also import considerable quantities of high-grade pulp for the manufacture of rayon and other synthetic textiles and cellulose compounds. The United States, which is the world's largest producer of pulp, imports much larger quantities of pulp than it exports and imports more, in fact, than any other country. Great Britain, France, Italy, Japan, and Germany, in the order named, are the next most important markets for the pulp of other countries. Sweden, Finland, Norway, Canada, and Germany, in the order named, are the leading exporters of wood pulp.

In paper, also, there is a large international trade, particularly in newsprint and such other papers as are usually produced in paper mills integrated with pulp mills. The exports of pulp as such by certain countries, therefore, fail to indicate the full extent of the depend-ence of their pulp industries on foreign markets. Canada especially is a large exporter of newsprint paper, and Sweden, Finland, and Germany also have considerable export trade in it. Similarly, the imports of pulp of certain countries fail to indicate the full extent of their dependence on foreign supplies of pulp. The United States, for instance, is a large importer of newsprint as well as of wood pulp. The United Kingdom and many other countries are also markets of considerable importance for the paper industries of other countries.

In 1934 the world production of all kinds of wood pulp is estimated to have amounted to about 20,000,000 short tons. United States production was then about 22 percent of the world total; Canada accounted for about 18 percent; Sweden, 16 percent; Germany, Finland, and Norway, about 11, 9, and 5 percent, respectively; the remaining 19 percent was supplied by about 20 countries, of which the largest producers were the Soviet Union and Japan, each with between 31⁄2 and 4 percent of world production. Most of the countries not named that produce wood pulp, except Newfoundland, are in Europe.

The general trend of pulp production over a long period of years has been upward in practically all producing countries, and though in most countries there was a decided recession after 1929, the last few years have witnessed marked increase. Already, by 1934, world production was probably about 5 percent greater than in 1929 and 40 to 45 percent greater than in 1925. However, among the more important producers, the United States, Canada, and Germany produced less in 1934 than in 1929. In all the other countries named in the preceding paragraph, and in most of the less important producing countries, pulp production had by 1934 surpassed the predepression levels. By 1936 the same was true of the United States and Canada also.

The percentages of world production accounted for by the United States and Canada have been declining over a number of years. In 1925 the United States produced about 28 percent of the world total and Canada about 20 percent, as against 22 and 18 percent, respectively, in 1934. Germany also, which in 1925 produced about 12 percent, has failed to maintain that share of world production. Among the countries whose production has expanded rapidly in recent years, Finland shows the greatest increase. The output of that country has almost tripled since 1925. Production in the Soviet Union shows an even greater percentage increase, but production in that country in 1925 was only about one-sixth of that of Finland.

World capacity of wood-pulp mills.

The world capacity of wood-pulp mills is estimated at about 26 million tons annually, considering 310 days as a full year for the operation of such mills. This estimate is subject to a wide margin of error, complete data not being available for any of the countries concerned and only very fragmentary information for some of them. It is clear, however, that in recent years there has been considerable unused capacity. Some pulp mills are not economically located with respect to sufficient supplies of pulpwood to permit the full utilization of their capacity. New mill capacity is now being developed in more favorable locations, and it is likely that part of the existing capacity not being utilized in the older areas will in time be abandoned.

The United States and Canada each had pulp-mill_capacity of about 2 million tons in excess of production in 1934. In that year production in these two countries was probably about 70 and 65 percent, respectively, of capacity. For the world as a whole, production was not at that time as far short of capacity as in the United States and Canada. The operating ratios for almost all countries were probably higher in 1936 than in 1934.

Of more significance perhaps to the future of the pulp industry in the various countries than the capacity of existing mills are the conditions of pulpwood supplies. However, the potential pulp-producing capacities of different countries as limited by present and future

supplies of pulpwood are not capable of estimation even where data on forest resources are available. The timber that may be cut during any short period of time depends not so much on the rate of growth as on public and private policies of forest utilization. Over a longer period of time, the volume of wood available will be greatly affected by reforestation programs. At the present time, in several countries, elaborate programs of control of forest utilization, conservation, and reforestation are being formulated, and in several other countries existing policies are undergoing revision.

Moreover, the volume of wood that may be used for pulp depends to some extent on intensity of the demand for lumber or other timber products in relation to that for wood pulp. In general, probably the stronger the demand for lumber of the species principally used in the production of wood pulp, the smaller would be the supplies available for pulp. However, in some areas considerable supplies of pulpwood are derived as a byproduct from lumber production. In such areas a considerable wood-pulp industry might be sustained on the basis of sawmill and forest waste.

UNITED STATES PRODUCTION, IMPORTS, AND EXPORTS OF WOOD
PULP
GENERAL

Nearly all of the large production of wood pulp in the United States is consumed domestically. Exports have at no time exceeded 4 percent of the domestic output. The paper and other important but smaller consuming industries in the United States use, in addition to the bulk of domestic production, imported pulp in amounts equal to about 30 percent of total domestic consumption.

Table 1 shows for the period 1919 to 1936 the domestic production, imports, and exports of wood pulp (all kinds combined) by quantity and value. Statistics are not available showing the actual consumption of pulp, but the apparent consumption for each year obtained by deducting the figures for exports from the sum of those for domestic production and imports would not vary substantially from the actual annual consumption of the country.

Consumption and production in 1935 were higher than in any prior year, and consumption in 1936 exceeded that in 1935 by more than 1 million tons, while production also increased by nearly 700,000 tons. Prior to 1935 consumption had been highest in 1929, but between then and 1932 both production and imports declined sharply. Imports recovered in 1933 when they were greater than in any prior year; in fact, the volume of imports in 1933 was not exceeded until 1936. Production recovered steadily after 1932, but did not exceed the 1929 output until 1935. The share of domestic consumption of pulp supplied by imports rose from about 22 percent in the 5-year period immediately following the war to about 29 percent in the next 5-year period, since which time there has been no material change in the ratio, which was 29.5 percent in 1936.

The changes in the ratio of imports to domestic production have been slightly different from those in their ratio to consumption, since exports, though still small, have increased sharply. This ratio averaged 40 percent from 1924 to 1928, 39.1 percent in 1935, and 40.5 percent in 1936.

Wood-pulp production by concerns for their own use is only indirectly affected by imports. However, there are large imports of products made from wood pulp, principally newsprint paper, which also compete with the domestic pulp and paper industry, and such imports probably impinge more directly on some concerns producing pulp for use in their own converting operations than do imports of pulp itself. The extent of the foreign competition with the domestic pulp industry, resulting from imports of both pulp and further advanced products, is discussed later in this report. (See Pulp Requirements of the United States, p. 59.)

TABLE 1.-Wood pulp: Summary of production, imports, exports, and apparent consumption 1

Source: Production, Bureau of Census (except 1936). Figures for 1936, sulphite, sulphate, ground wood, from United States Pulp Producers Association; soda pulp, from Soda Pulp Manufacturers Association; miscellaneous grades and off quality from monthly reports of United States Pulp Producers Association; imports and exports from Foreign Commerce and Navigation of the United States.

Table 2 shows for the period 1929 to 1936 United States production, imports, exports, and apparent consumption of the various kinds of wood pulp by quantity, value, and unit value. The unit values give a rough idea of price trends and of the relative prices of different kinds of pulp. In comparing the unit values of imports with those of domestic production, however, it should be borne in mind that the unit values of imports are those of the pulp in the country of exportation and are therefore exclusive of costs of transportation to the United States. The unit values of domestic production shown, on the other hand, are those of the pulp at the producing mills in this country, which are in many cases at or near the points of large domestic paper production.

As used in table 2, consumption refers to the utilization of pulp itself in the United States in the production of paper and other products. If this country's consumption of wood pulp were taken to mean