Alexander Watt

MATERIALS USED IN PAPER-MAKING.

Raw Materials.—Rags.—Disinfecting Machine.—Straw.—Esparto Grass.—Wood.—Bamboo.—Paper Mulberry.

In former days the only materials employed for the manufacture of paper were linen and cotton rags, flax and hemp waste, and some few other fibre-yielding materials. The reduction of the excise duty, however, from 3d. to 1½d. per lb., which took effect in the first year of Her Majesty's reign—namely, in 1837—created a greatly increased demand for paper, and caused much anxiety amongst manufacturers lest the supply of rags should prove inadequate to their requirements. Again, in the year 1861 the excise duty was totally abolished, from which period an enormously increased demand for paper, and consequently paper material, was created by the establishment of a vast number of daily and weekly papers and journals in all parts of the kingdom, besides reprints of standard and other works in a cheap form, the copyright of which had expired. It is not too much to say, that unless other materials than those employed before the repeal of the paper duty had been discovered, the abolition of the impost would have proved but of little service to the public at large. Beneficent Nature, however, has gradually, but surely and amply, supplied our needs through the instrumentality of man's restless activity and perseverance.

The following list comprises many of the substances from which cellulose, or vegetable fibre, can be separated for the purposes of paper-making with advantage; but the vegetable kingdom furnishes in addition a vast number of plants and vegetables which may also be used with the same object. We have seen voluminous lists of fibre-yielding materials which have been suggested as suitable for paper-making, but since the greater portion of them are never likely to be applied to such a purpose, we consider the time wasted in proposing them. It is true that the stalks of the cabbage tribe, for example, would be available for the sake of their fibre, but we should imagine that no grower of ordinary intelligence would deprive his ground of the nourishment such waste is capable of returning to the soil, by its employment as manure, to furnish a material for paper-making. Again, we have seen blackberries, and even the pollen (!) of plants included in a list of paper materials, but fortunately the manufacturer is never likely to be reduced to such extremities as to be compelled to use materials of this nature.

Raw Materials.

Rags.—Linen and cotton rags are imported into Great Britain from almost all the countries of Europe, and even from the distant states of South America, British South Africa, and Australasia. The greater proportion, however, come from Germany. The rags collected in England chiefly pass through the hands of wholesale merchants established in London, Liverpool, Manchester, and Bristol, and these are sorted to a certain extent before they are sent to the paper-mills. By this rough sorting, which does not include either cleansing or disinfecting, certain kinds of rags which would be useless to the paper-maker are separated and sold as manure. Woollen rags are not usually mixed with cotton rags, but are generally kept apart to be converted into "shoddy." The importance of disinfecting rags before they pass through the hands of the workpeople employed at the paper-mills cannot be over-estimated, and it is the duty of every Government to see that this is effectually carried out, not only at such times when cholera and other epidemics are known to be rife in certain countries from which rags may be imported, but at all times, since there is no greater source of danger to the health of communities than in the diffusion of old linen and cotton garments, or pieces, which are largely contributed by the dwellers in the slums of crowded cities.

Respecting the disinfecting of rags, Davis[11] thus explains the precautions taken in the United States to guard against the dangers of infection from rags coming from foreign or other sources. "When cholera, or other infectious or contagious diseases exist in foreign countries, or in portions of the United States, the health officers in charge of the various quarantines in this country require that rags from countries and districts in which such diseases are prevalent shall be thoroughly disinfected before they are allowed to pass their stations. Rags shipped to London, Hull, Liverpool, Italian, or other ports, and re-shipped from such ports to the United States, are usually subjected to the same rule as if shipped direct from the ports of the country in which such diseases prevail. It is usually requisite that the disinfection shall be made at the storehouse in the port of shipment, by boiling the rags several hours under a proper degree of pressure, or in a tightly-closed vessel, or disinfected with sulphurous acid, which is evolved by burning at least two pounds of roll sulphur to every ten cubic feet of room space, the apartment being kept closed for several hours after the rags are thus treated. Disinfection by boiling the rags is usually considered to be the best method. In the case of rags imported from India, Egypt, Spain, and other foreign countries where cholera is liable to become epidemic, it is especially desirable that some efficient, rapid, and thorough process of disinfecting should be devised. In order to meet the quarantine requirements, it must be thorough and certain in its action, and in order that the lives of the workmen and of others in the vicinity may not be endangered by the liberating of active disease-germs, or exposure of decaying and deleterious matters, and that the delay, trouble, and exposure of unbaling and rebaling may be avoided, it must be capable of use upon the rags while in the bale, and of doing its work rapidly when so used."

Disinfecting Machine.—To facilitate the disinfecting of rags while in the bale, Messrs. Parker and Blackman devised a machine, for which they obtained a patent in 1884, from which the following abstract is taken.

Formerly rags and other fibrous materials were disinfected by being subjected to germ-destroying gases or liquids in enclosed chambers, but in order to render the disinfecting process effectual, it was found necessary to treat the material in a loose or separated state, no successful method having been adopted for disinfecting the materials while in the bale. "This unbaling and loosening or spreading of the undisinfected material is absolutely unsafe and dangerous to the workmen, or to those in the vicinity, because of the consequent setting free of the disease germs, and the exposing of any decaying or deleterious matters which may be held in the material while it is compressed in the bale. The unbaling and necessary rebaling of the material for transportation also involves much trouble and expense and loss of time. Large and cumbrous apparatus is also necessary to treat large quantities of material loosened or opened out as heretofore."

It is specially necessary that rags coming from Egypt and other foreign countries should be thoroughly disinfected by some rapid and effectual means, which, while not endangering the health of workmen employed in this somewhat hazardous task, will fully meet all quarantine requirements. The apparatus devised by Messrs. Parker and Blackman,[12] an abridged description of which is given below, will probably accomplish this much-desired object.

In the illustration, Fig. 1, A is the disinfecting chamber. At one end is an opening A¹, and a door B, hinged at its lower edge and adapted to be swung up, so as to close the opening tightly. For supporting and carrying the bale C of material to be placed in the chamber is a carriage C¹, consisting of a platform supported upon wheels or castors c c. While the carriage is wholly within the chamber A, as shown in Fig. 2, these wheels rest upon the false bottom B²; when the carriage is rolled back and out of the chamber, as shown in Fig. 1, they roll upon the upper face of door B swung down. The carriage is provided with a clamping device D to hold the bale firmly and immovably. To cause the carriage to move into and out of the chamber, the inventors provide upon the under side of the platform a fixed sleeve E, interiorly threaded to fit the screw E¹, journalled at one end near the opening in the chamber end in a stationary block E² fixed upon the false bottom B². From this end the screw extends along under the carriage through the screw sleeve and to the other end of the chamber. A collar e² on the screw bears against the inner end of this journal-bearing, and upon the end of the shank e bearing against the other end of the journal is fixed a pinion F, which is to be driven in either direction as desired. Above this journal-bearing is a series of similar bearings (five being shown), G G, passing through the wall of the chamber. Of these the middle one is in a line with the centre of the bale, supported and held on the carriage. The others are arranged at the corners of a square. Journalled in these bearings are the hollow shanks H H of the hollow screws I I pointed at I¹ I¹. Each screw is perforated, i i, between the threads i¹ i¹ from the fixed collar K K. Upon the tubular shanks H H of the screws are fixed the gear-wheels L L. At a short distance from the end of the chamber, A is the hollow chamber or receptacle M, into which is to be forced the disinfectant liquid or gas. The tubular shanks H H of the screws project through the wall M, passing through stuffing-boxes m m, and their bores communicate with the interior of the chamber, the shank of the middle screw being continued through the opposite wall and a stuffing-box, its solid or projecting end being provided with two fixed pulleys, N N, and a loose pulley O. When a gaseous disinfectant is used, it can be forced by any desired means through the pipe S into the chamber. Where a liquid disinfectant is used, an elevated tank R containing the fluid may be used. As most fibrous materials, and especially rags, are baled so as to be in layers, it is preferable so to place the bale upon the carriage that the perforated screws may penetrate the material at right angles to the layers by which the gas or liquid issuing through the holes in the screws passes in all directions throughout the mass within the bale.

In the upper part of chamber A are perforated shelves V V, upon which, if desired, the material can be spread out and subjected to disinfecting gas or vapour. On the top of the chamber is a tank W nearly filled with disinfecting liquid. A passage W¹ extends from upper part of the chamber up into the tank above the level of the liquid therein, and is then carried at its end down below the surface of the liquid. At its other end the tank is provided at its top with a discharge opening X and a suitable pipe X¹, forming a continuation of the opening; by this means all foul and deleterious vapours or gases passing out of the closed chamber A through the passage W must pass through the disinfecting liquid in the tank before escaping through the opening X and stack X¹ into the air, and are thus rendered harmless.

When a sufficient amount of the disinfectant has been forced into and through the bale, the disinfectant is turned off, and cold dry air can be forced through chamber M, and out through the nozzles and bale, whereby the material within the bale becomes cooled and dried, and all the foul air from the chamber A driven out, so that it may be opened and entered with safety. Any suitable disinfectant may be used with this apparatus, as, for example, sulphurous acid, in gas or solution, superheated steam, carbolic acid, or any solution or vapour containing chlorine.

Straw.—Very large quantities of this material are used in the manufacture of paper, but more especially for newspapers, the straw from wheat and oats being mostly employed. Although the percentage of cellulose in straw is about equal to that of esparto, the severe treatment it requires to effectually remove the silicious coating by which the fibre is protected, and to render the knots amenable to the action of the bleach, greatly reduces the yield of finished pulp. Many processes have been introduced for the treatment of straw for paper-making, but the most successful of them appear to be modifications of a process introduced in 1853 by MM. Coupier and Mellier.

Esparto Grass.—This important fibrous material is largely imported from Algeria, Spain, and other countries, and constitutes one of the most valuable fibre-yielding materials with which the manufacturer has to deal. Some idea of the amount of esparto and other fibres which find their way to our shores may be gleaned from the fact that while the import of cotton and linen rags in the year 1884 was 36,233 tons, of the value of £487,866, that of esparto and other fibres amounted to 184,005 tons, of the value of £1,125,553.

Wood.—As a paper-making material, the fibre obtained from various kinds of wood now holds an important position, since the sources of supply are practically inexhaustible. The first practical process for manufacturing pulp from wood fibre was perfected and introduced by the author's father, the late Mr. Charles Watt, who, in conjunction with Mr. H. Burgess, obtained a patent for the invention on August 19th, 1853. The process was afterwards publicly exhibited at a small works on the Regent's Canal, when the Earl of Derby (then Lord Stanley), many scientific men and representatives of the press, were present, and expressed themselves well satisfied with its success. Specimens of the wood paper, including a copy of the Weekly Times printed thereon, were exhibited, as also some water-colour drawings which had been produced upon paper made from wood pulp. Failing to get the process taken up in England, an American patent was applied for and obtained in 1854, which was subsequently purchased; but with the exception of an instalment, the purchase-money was never paid to the inventor! Thus the process "got" into other hands, the original inventor alone being unbenefited by it.

It has been repeatedly stated,[13] no doubt unwittingly, that a person named Houghton first introduced the wood paper process into this country; but considering that his patent was not obtained until 1857, or four years after the process above referred to was patented and publicly exhibited in England, it will be seen that the statement is absolutely without foundation. The first knowledge Mr. Houghton received concerning wood as a paper-making material was from the author's father, and he (Mr. Houghton), in conjunction with Mr. Burgess, introduced the Watt and Burgess process into America in the year 1854. These are the facts.

Bamboo (Bambusa vulgaris).—The leaves and fresh-cut stems of this plant are used for paper material, but require to pass through a preliminary process of crushing, which is effected by suitable rolls, the second series of crushing rolls being grooved or channelled to split or divide the material, after which the stems are cut to suitable lengths for boiling.

Paper Mulberry (Broussonetia papyrifera).—The inner bark of this tree, and also some other basts, have long been used by the Japanese and Chinese in the manufacture of paper of great strength, but of extreme delicacy.