August, 1926
INDUSTRIAI, AND ENGINEERING CHEMISTRY
By this method the water-soluble barium salt is converted to barium sulfate by the sulfuric acid and then the excess acid is neutralized with known strength sodium hydroxide. Results by this method check duplicate gravimetric determinations within 0.4 per cent. Phenolphthalein is used as indicator because the end point is sharper and more easily seen than with methyl orange. T h e 0.5 cc. added to the actual consumption represents the difference between the end points of phenolphthalein and methyl orange. The solution of sulfuric acid is standardized against sodium carbonate using methyl orange as an indicator.
829
Calculation of Factor HgS04 B a s +Bas04 H2S 98.08 169.43 - = 43 1.7274 98.08 1 cc. H2SOa = 0.04 gram B a s We want - = O4 0 02316 1 7274 Therefore, 1 cc. HISO4 should contain 0.02316 gram in order that we may calculate percentage of BaS by multiplying (CC. Plus 0.5) by 2.
++
+
Of course, other strengths of acid may be used, but for rapid control work the above strength simplifies calculations.
The Advance of Rayon’ By Otto Wilson WASHINGTON, D. C. MUNSEY BUILDING,
OR the chemist-economist few things are of more engrossing interest than to watch how, day by day, the great world of business swings more and more round (the laboratory as a center. One after another the industries .founded on a utilization of natural products are yielding place to the synthetics. Among the latest children of chemistry .to challenge the long-established prder is the new material which modern science has presented to the textile world, the fiber heretofore known as artificial silk but no%- christened by Americans “rayon.” For thousands of years wool, cotton, silk, and flax, the “big four” of the textile industry, provided the civilized and semicivilized world with clothing. Yet already, in an existence of only forty years, the new filament has sprung to a position ahead of one of them, and now occupies fourth place among the world’s great fibers. It has outstripped silk, and is looking ahead to the time when it will rival even linen and wool. In these rushing modern times we have grown used to the spectacle of gigantic industries springing up overnight. The rayon industry, in the suddenness with which it has appeared and the size it has attained, can claim kinship with that of the motor car, the motion picture, and the radio, and in one sense even takes precedence over them in that it serves one of the basic needs of the human race. The father of the rayon industry is generally conceded to be the French chemist, Count de Chardonnet, who introduced the first practicable process for spinning a cellulose thread in 1884 and exhibited manufactures from it a t the Paris Exposition in 1889. He lived to see his discovery blossom into one of the world’s great industries, his death occurring in 1924. For the first sixteen years following de Chardonnet’s announcement the history of the laboratory-born fiber was largely one of experimentation in a search for improved methods. But a t about the beginning of the present century three new processes were perfected and put in operation, and it is from that time that the commercial life of the synthetic textile really dates. Progress a t first was not rapid. At the outbreak of the World War the total world production was only about 26,000,000 pounds, and during the war years it did not increase spectacularly. Only in the last eight or nine years has it gone forward with great strides. Following is the statistical trail of its progress since the “outbreakof the war:
F
1
Received June 30, 1926.
World Production of Rayon Pounds
1914 1918 1919 1920 1921
26,000,000 35,000,000 40,000,000 50,000,000
1922 1923 1924 1925=
Pounds
79 738 000 97:OOO:OOO 141,414,000 186,000,000
65,000,000
” Estimated. For the current year the estimate is for an output of about 245,000,000 pounds. This compares with an estimated world production of l , O ~ , O O O , O O O pounds of flax, 86,000,000 pounds of silk, 2,900,000,000pounds of wool, and 13,000,000,000 pounds of cotton. These figures are for the raw fiber, however. When they are reduced to a poundage of yarn or thread, the proper basis of comparison, rayon is seen to be not only far ahead of silk, but within hailing distance of linen and wool. I n the United States the production of rayon practically dates from 1912, when the first plant to be devoted exclusively to its manufacture was opened by the Viscose Company. Development was rapid, especially following the war, and this country is now the leading producer and consumer. American units have increased their output year by year, but they have never quite caught up with the advancing demand, and we have been obliged to draw on foreign sources to fill out our requirements. This phenomenal advance in this country and the world has been attended by the usual accompaniments of rapidly rising industries-the leaping forward in price of industrial stocks, an atmosphere of excited optimism, and confident forecasts of still more startling expansion which could hardly be realized. There are, indeed, a t the present moment many warning voices in the air advising caution. It is said that new production is outstripping demand, that the market will be overstocked, that many of the newly organized companies will find rough going. These statements may or may not be borne out by future developments. But even if they are proved sound the fact remains that if certain admitted defects of rayon textiles can be removed it would probably be hard to set a limit to the possible demand. Four distinct processes are at present being followed in the commercial production of artificial fibers. All of them start with cellulose and end up with a yarn of fine luster, but the chemical and mechanical steps in between, and the qualities of the resulting product, are different. 1-The original nitrocellulose process, invented in 1884 and still followed in the production of “Chardonnet” silks, involves
the nitration of cottoii linter to form a nitrocellulose, which i s then dissolved in a solution of alcohol and ether. This viscous solution is then passed through fine glass tubes. The solvent evaporates on striking the air, leaving a fine filament, which is twisted into threads, wound into skeins, and denitrated. 2-In the cupramnzonizlm process either cotton linter 01 wood pulp is dissolved in a copper-ammonium solution and forced through fine orifices into the form of threads, which src coagulated by sulfuric acid, twisted, wound on bobbins, and washed i n n chemical bath. 3-The viscose process, by which three-fourths of the world production of rayon is made, starts with either cotton or wood pulp (spruce is commonly used), which is cooked with steam and pressed into sheets. These are soaked in a solution of caustic soda, pressed, and shredded to a form known as "alkali
The acetate and the other artificial fibers have certain ellrecognized virtues and defects. Particnlarly in tho case of the fabrics of pure rayon the great objection is that they lose much of their strength when wet. This strength returns when they dry out, hut if they are carelessly handled before they dry they are liable to be stretched out of shape. The proper laundering of articles made from this material is thus a matter of some care, and manufacturers in their advertising are constantly trying to educate the public to the same watchfulness in urashing and drying rayon as it has become accustomed to exercise in cleaning silk. Another objection to some rayon yarns and fabrics is that they take dyes unevenly. In a recent article Harold Hibbert, professor of chemistry in McGill University and an authority on cellulose chemistry, summarizes the objections to the new fiber.
ing agents, etc., can-any one of them compare with cotton. espeaally with a mercenzed fine cotton yarn In the ease of rayon the entire efforts of the manufacturer are concentrated u ~ o nthe oroductmn of a matenal wh& wtll have maximum s&engtb and elasticity when wet, a i d wiii possess uniform dyeing properties, and it may be boldly asserted that neither problem has yet been satisfactorily solved.*
The Weaver's Loem
Offsetting these defects many virtues are claimed for rayon. Strong bleatching compounds will not turn it yellow, as they sometimes do silk. Neither very hot nor very cold water permanently injures rayon iabrics. Whatever its treatment or age, its chief attraction, the luster, always remains. Colors are as fast or faster than those of silk. Some manufacturers claim that, with care in washing, rayon textiles have been found to be as durable as cotton or silk. In the research lahnratories of the larger rayon companies chemists are earnestly seeking means to remove the objections to rayon, and particularly to give the wet fabric more strength. Through the Bureau of Standards the Government has interested itself in these effort&,and that Bureau is now conducting experiments along these lines, as recoinut conference of research workers from the
n in this country were for braids and hen hosiery of that material became popular, and for a while half the total production found an outlet in hosiery manufacture. Since the war sweaters and other knit goods for outer wear have ahsorbed large amounts of rayon, in some years more than one-fourth of the entire production. At present the tendency is increasing to use i t with other fibers, weaving a bright rayon pattern into a cloth o u t by the three foregoing processes; and its manufacturers madeof other material. insist that it is not to be classified either as "rayon" or "artiIn 1925, according to one computation, 20 per cent of the ficial silk." but is a scoarate textile fiber entirelv. It is made lrom either cotton or wood pulp by treatment Gith acetic an- rayon used in this country went into hosiery, 10 per cent was hydride, precipitation of celltilose acetate in water, wlution of the used in knit outerwear, 18 per cent for mixing with silk, precipitate in a solvent, and the forcing of this solution through holes to form filameuts, as with the other processes. The re- 21 per cent for mixing with cotton, 15 per cent in underwear, sultinx fiber is made into so-called "acetate" yam, which is S per cent in braids, 2 per cent in upholstery goods, 1 per cent in woolen goods, 2 per cent in plush, and 3 per cent for miscellaneous uses. Although, as noted, the output. of this country exceeds that place the nitrocelluloseprocess in the future. of any other, its manufacture has been taken up with enThe unique mechanical device necessary for the manufac- thusiasm by all the industrial countries. Taken as a whole, ture of rayon by any method corresponds to the spinneret Rurope produces about two-thirds of the world supply. of the silkworm and is now known bv that name. It consists The following table-distributed by the Textile Division of the U. S. Deuartment of Commerce, which gives the estimates of a n excelient British authority-shows the comparatir-e with hnlei! in i t thmiwh whirh the e n l i d o n ig nT&d Tho& Output Of each producing country for 19% and 1925: cellulose " After standinn and oxidmix for several hours this
I\.
iuguat, IYLti
n usrmr. A .I o E.VGIKEERIXG cm.ms2w -
World Rayon Production 1924
Umfed stater Italy Bngland G'XnihW
France
BdglUm Switieiland
Ponndr 39 ow mu
is~4sn'oon
23,947,000
23 672 nnn
192.5 Poundr
~4,ino.ono~ 2s:ooo:m 30 000 nno
1d333:~nn
Netherlands Austrls Poland Clecho&i.iovAkia Japan HunRary
220 oon iidcno 88,000
5patri
5wedm XOssla T ~ A 14i,414,4on L
I s~i.484.nno
As noted below thii estimate is Slightly high the recently announced l i ~ e ui a the n u r w oi the census brmg zi.bon,oon P ~ ~ W for I S ism
In the Tiuted States many coinpaincs hale aiid another been formed Ioi the production of rayon, but iherc iiai e been a laige iiuiuber of failures The requi for successful operation aie rather exacting, includi technical shill and plrntiiul capital. It is said to b iiecessnry to capitalize a new plant at several million as rayon is not In any seiise t industry. About twenty-five companies for rayon production ni the Un t s e h c are operating and only \-isrose Company, with h e d q
from 36,153000 pounds in 1923 to 51,792,000 pounds last year. For the current year estimates of pioductiou are from 74,000,000 to 80,000,ooO pounds, comparing ulth the above figures for 1923 and 1925 and with 39,000,000 pounds in I924 and 23,500,000 pounds iu 1922. In four years, therefore, the output has almost quadrupled. In spite of a 45 per cent duty, imports of foteigu yariis have bern bringing the price of the domestic ploduct down. I n 19222, imports were 2,088,000 pounds and in 1923,3,906,000 pounds American hrms then cut prices, aud imports dropped to 1,711,000pounds in 1'321. But last )'ear, IU spite of the big increase 111 American output, our plants were unable to meett],e Goniug denland, and our purchases of foielgn yam5, tiireads, and filaments rose to 7,000,000 pounds. I n June, 1926, hmeiican firms announced a fuither cut of 20 per cent in prices to meet this competition from abroad. Among f o r e p countnes England and Geiinauy wcre the ,but in 1925 Italy forged to the front the largest producer outside of the tdul waterpowcr and low-priced labor ing that country forward. All the comhe busmess in Italy use the viscose process, es the cuprammoniuin and one wlucli men ulose process not being represented. the Sma Viscosa, mth headquarters capacity of nearly 20,000,000 pounds ing to mise that amount to 30,000,000
uses the nitrocellulose process in its plant a t H snd will have an estimated 1926 production of so pounds The Industrial Film Corporation, n
credited with 70
and one which uses t
531
W a x Crystallization' A Preliminary Report
