Another important element in the making of rayon is water. The viscose process requires I oo to 2oogal. of pure soft water to make one pound of yarn, while the acetate process requires about I,000gal. per pound of yarn. The availability of such a supply of soft water free from chemical impurities is one of the controlling factors in the selection of a site for a rayon manu facturing plant.
Growth of Rayon Production.—The growth of the rayon indus try since its beginning is traced in Table I. In the nearly so years covered by these data, rayon has passed through the experimental stage to become a major textile fibre, surpassed in production only by cotton. World production of the major textile fibres for the year 1938 was as follows (in pounds) : cotton 13,600,000,000; wool (scoured basis) 2,220,000,000; rayon 1,948,000,00o, and silk 78,000,000.
Rayon filament yarn is now a well-established fibre, though its use continues to increase, as shown by Table II. The rapid rate of growth in rayon production in the past decade is primarily due to the newer product, rayon staple fibre, the production of which is given in Table III for selected years. Not only did staple fibre receive the benefit of all previous technical developments in the filament yarn division of the industry in rapidly attain ing satisfactory quality and proper adaptation to new uses for it, but the growth of the industry has had government encourage ment and protection in many countries. The fact that the rayon staple fibre industry has made rapid strides in the United States and Great Britain proves that it is able to advance on its own merits in free competition with other fibres. But the national istic countries, Italy, Germany, and Japan, finding rayon staple fibre a great asset in establishing textile self-sufficiency and in conserving foreign exchange for the purchase of other raw materials which they lacked, have encouraged its manufacture both for home consumption and for export to other countries. Under this stimulus, rayon staple fibre production increased at times as much as I so% to 200% a year.
These three nationalistic countries have also led the way in rayon consumption, as may be seen in Table IV. Consumption, as shown in this table, is assumed to be the sum of production and imports of rayon items, less exports of rayon. The high per
capita consumption rates for Germany, Japan, and Italy are in part due to the mandatory use, in these countries, of a mixture of rayon staple fibre in the manufacture of cotton and woollen goods for home consumption.
United States Industry.—Rayon yarn production in the United States was first begun on a commercial scale in 1911 and rapidly increased until, in 1919, the United States became the foremost rayon producing country in the world. Except for the one year 1937, when Japan surpassed her, the United States has continued to be the leading producer of rayon filament yarn, although Japan and Germany, with their tremendous staple fibre output, have taken first position in total rayon production.
The first commercial production of rayon in the United States was by the viscose process. In 1921 the nitrocellulose process was introduced, followed by the acetate process in 1925, and the cuprammonium in 1927 (the nitrocellulose process was discon tinued in 1934). The United States filament yarn and staple fibre production figures are given in Tables II and III. Of the 1939 production of filament yarn in the United States 30% was by the acetate process and 70% by the viscose and cuprammonium processes.
The prices of rayon filament yarn and staple fibre have been steadily decreasing, although the quality of the product continues to improve, both of these tendencies being a result of the pro gressive improvement in the technique of rayon manufacture. For example, the price of 1 so-denier viscose yarn (a representa tive quotation) at 53 cents per pound in 1939 showed a decrease of 91% from the high point of $6 per pound in 192o. Accompany ing this downward trend has been a tendency to decrease the price premiums (a) for the acetate and cuprammonium yarns as com pared with viscose yarn, (b) for finer deniers as compared with coarser deniers, (c) for multifilament yarns as compared with standard yarns, and (d) for special packaging (such as coning) as compared with standard skeins. Extra charges are no longer made either for semi- or fully-delustred yarn.