The process has only the incidental interest in connection with our main subject, that it employs chiefly the 'chemical' pulps or celluloses as raw materials. The industrial future of the application must, of course, be largely determined by costs of production, as the directions of application in the weaving industries will be limited by the necessarily inferior grade of tensile strength belonging to these products and the degree by which this is lowered on complete wetting. All these questions have been duly weighed by those engaged in this interesting development, and the conclusion of those qualified to judge is that the new industry has vindicated for itself a permanent position.
II. The Chemical Derivatives of Cellulose, in their industrial aspects, have come to occupy a profoundly important position in the world's affairs. In the way of any essential alteration of the perspective from that obtaining in 1895 we have nothing to chronicle. No new derivatives of industrial importance have been added in that period; but certain new methods incidental to the preparation of well-known compounds or for converting them into more generally available forms have been introduced, and these are contributing to the rapid expansion of the 'artificial' cellulose industries.
Of the cellulose esters the nitrates are still the only group in industrial use. There uses for explosives have attained immense proportions, and their applications for structural purposes are continually on the increase. The manufacture of smokeless powders on the one hand, and of celluloid and xylonite (both in the form of films and solid aggregates) on the other, has taken no new departure. The industry in 'artificial silks' or 'lustra-celluloses,' by the collodion processes also, whilst presenting features of unusual interest attaching to rapid expansion, has been barren of contribution of fundamental scientific or technical importance. The tetracetate is now manufactured on the large scale, but the product has yet to make its market.
The process of mercerising cotton yarns and cloth has been developed to an industry of colossal dimensions, and the growth has been especially rapid during the last five years. Significant of the technical progress in these two industries, with their common aim of appreciating cellulose in the scale of textiles by approximating its external properties in those of silk, is the appearance of a monograph of the technology of each, notices of which have been previously given (pp. 22-26).
There is little doubt, however, that the question of the future industry in the various forms of cellulose, thread, film, structureless powder or solid aggregate, obtainable by artificial means, mainly turns upon cost of production. Irrespective of cost, there would, no doubt, be a market for all these products, based upon such of their properties or effects as are indispensable and not otherwise obtainable. As an illustration, we may cite the extraordinary selling prices of 40-50 fr. per kilo, for the 'artificial silks' (collodion process) which ruled some three years ago; and we may note that for a special application of viscose the dissolved cellulose is paid for at the rate of 10s. per lb. These facts are certainly worthy of mention, and should be borne in mind as an index of some special features of modern manufacturing industry. But with a material like cellulose rendered available in a new shape the question which always arises more prominently than that of limited uses at high prices is that of consumption on the extensive scale which marks the older and well-known products. That question is rapidly solving itself in this country as regards the 'artificial silks.' There is at present a limited market at 9s.-10s. per lb., a price which on the one side excludes extensive consumption, and on the other practically bars manufacture in this country by any of the collodion systems. It will appear from a very elementary calculation of what we may call the theoretical costs that the above selling price would not have a remunerative margin. The theoretical costs are made up of
| Raw materials[14] | Cotton. Nitrating acid. Ether-alcohol (solvent). Denitrating chemicals. |
| Labour | (a) Nitrating and preparing collodion. Denitrating and bleaching. (b) Textile operations. Spinning. Winding and twisting. Rewinding. |
| Power | Making, filtering, and distributing collodion. Driving textile machinery. |
Added to which are the costs of expert management and supervision and general establishment expenses. It is evident that raw materials make up a large fraction of the total cost; also that a very large item is the waste work of converting the cellulose into nitrate, only to remove the nitric groups so soon as the cellulose is obtained as thread.
It is clear that the aqueous solutions of cellulose have a double advantage in this respect—not only do they readily yield an approximately pure cellulose as a direct product of regeneration or decomposition, but the first cost of the solution is very much less. With these newer products, therefore, the spinning problem enters on a new phase of struggle. It is certain that at selling prices at or about 5s. to 7s., very large markets will be open to the product or products. The two processes which are or may be able to fulfil this demand are those based (1) on cuprammonium solutions of cellulose, (2) on the sulphocarbonate or viscose. As regards first cost of the solution the latter has a large advantage. One ton of wood pulp (at 12l.) can certainly be obtained in solution in a condition ready for spinning at a total cost (materials) of less than 30l. The cuprammonium process, so far as 'outside' information goes, requires for production of the solution (1) cotton as raw material, (2) ammonia (calc. as concentrated aqueous) equal to 1-1/2 times its weight, and (3) metallic copper 25 p.ct. of its weight; and the costs are approximately 100l. per ton. It is obvious that the materials are recoverable from the precipitating-bath, but at a certain added cost. We have no statements as to the proportion recoverable nor the costs incurred, and we are therefore unable to measure the total net cost of the regenerated cellulose by this process. It is certainly much less than by the collodion processes. As to the textile quality of the thread, the product has not yet been on a sufficiently wide selling basis for that to have been determined. There are a great many factors which enter here. Not merely the external characters of lustre, softness, and translucency, but the all-important quality of uniformity of thread. The collodion-spinning is a process still very defective in this respect, and the defect is no doubt referable to the difficulty of securing absolute physical invariability of the collodion. It is to be regretted, in the interests of scientific development, that none of the technologists who have published investigations of these processes have entered into the discussion of the fundamental factors of the spinning processes; we are, therefore, unable at this stage to discuss these elements of a full comparison in greater detail. We cannot, for this reason, say how far the cuprammonium process diverges in point of control from the standard of the collodion processes. Of the 'viscose' product we have a more intimate knowledge, and it certainly reaches a higher general standard than the older and now well-known artificial silks. The process is also sufficiently developed to enable the total costs of production to be estimated at a figure less than one-half that of the 'collodion' processes. This would assure to this system an entrée in this country, and a basis of expansion limited only by the ordinary laws of supply and demand.
This prospect is opened up precisely at the moment when, for various reasons connected both with the difficulties of manufacture and the narrowing of the margin of profit, the proprietors of the two systems of collodion-spinning have decided to abandon all idea of manufacturing by these systems in this country.[15] We leave the discussion of the industrial problem at this point.