The seventh part of the invention consists in an improved combination of materials for producing a porous and spongy gutta-percha, fit for stuffing or forming the seats of chairs, cushions, mattresses, saddles, horse-collars, railway carriage-buffers, and other like articles, similar to that described in the specification before alluded to; and in the application of the said improved combination of materials to the rendering of caoutchouc and jintawan similarly porous and spongy. The patentee takes 40 parts of gutta-percha, India-rubber or jintawan (moistened when a very light product is desired, with oil of turpentine, naptha, bi-sulphuret of carbon, or other proper solvent), 6 parts of hydrosulphuret of lime, sulphuret of antimony, or any other analogous sulphuret, 10 parts of carbonate of ammonia, carbonate of lime, or other substance that is either volatile or capable of yielding a volatile product, and one part of sulphur. He mixes these materials together in a masticator, and then subjects them to a high degree of heat, observing the same conditions in respect thereof, which are set forth in the specifications alluded to; except only that the heat may be pushed with advantage several degrees higher, say to from 260 to 300°.
The ninth part of the invention consists in producing by the combination of gutta-percha, caoutchouc and jintawan, with other materials, a fabric of a permanent lustre, resembling that of japanned goods, and in giving the like lustre to articles made of any of these materials in a sulphuretted state. The patentee takes the gutta-percha, caoutchouc, or jintawan after it has been sulphuretted, and either before or after it has been made into an article of use, and brushes it over with a solution of resin in boiling oil; he then places it for from two to five hours in a chamber heated to from 75 to 100° Fahrenheit; and afterwards polishes it by the means and in the manner usually adopted by Japanners. In some instances coloring matters are mixed with the Japanning materials, which are to be applied by blocks, cylinders, or rollers, in the usual way of floor cloth printing.
RE-VULCANIZATION.
Patent dated December 30th, 1847, for “Improvement in the Treating and Manufacture of Gutta-percha, or any of the varieties of Caoutchouc.” Patentees, Thomas Hancock, of Stoke Newington, and Reuben Phillips, of Islington, chemists. Specifications enrolled June 30, 1847.
The patentees state that their improvements consist in the dissolving of gutta-percha, or any of the varieties of caoutchouc, or of reducing any of them to a soft, pulpy, and gelatinous state after they have undergone the process of “vulcanization or conversion;” also in preparing or treating unvulcanized, or unconverted solutions of any of these substances, so as to bring them into a vulcanized or converted state; and, lastly, in the moulds employed in the manufacture of articles therefrom. The term “vulcanized” or “converted” are used to designate certain processes by which these substances are rendered less liable to be injuriously affected by exposure to comparatively high temperatures, and which were described, the first in the specification of a patent granted to Mr. Thomas Hancock,[[2]] November 21, 1843, and the record in that of a patent granted to Mr. Alexander Parker,[[3]] August 25, 1846.
[2]. See London Mechanics Magazine, vol. xlii. pp. 112 and 150.
[3]. See London Mechanics Magazine, vol. xlv. p. 400.
The patentees desire to be understood, that when employing the term gutta-percha, or any of the varieties of caoutchouc, as referring to all those substances known to the Indians, or natives of the country where they are produced, under the names of saiknah, gutta-tuban, gutta-percha, jintawan, dollah, &c., in this country of bottle, root, sheet, scrap, India-rubber, &c. In operating upon any of these materials, which have previously undergone the vulcanizing or converting process, it is preferred to use the cuttings or waste of them, as being an economical application of what would otherwise be useless. These cuttings or waste, are first submitted to the action of rollers, or other suitable machinery for reducing them to shreds, and then boiled in oil of turpentine until reduced to the requisite consistency. Other solvents may be employed, such as coal, naptha, &c., but in that case, in order that the solvents may attain to a degree of temperature sufficiently high to dissolve the material, close vessels must be employed, for which reason, oil of turpentine is preferred.
No fixed rule, it is stated, can be given for the guidance of the workman to enable him to determine the relative proportion of the material to the solvent, the time for conducting the operation, or the degree of temperature, on account of the varieties of the material, and the degree of vulcanization or conversion to which it has been subjected; for these and other details he must rely upon his own intelligence, and the result of actual experience.
The rule which the patentees, however, state that they have found to be the best, under ordinary circumstances, it is to just cover the material when prepared and placed in the vessel with the solvent, and then to add about one-third more, and maintain the mixture at the boiling point of oil of turpentine, for about from 15 to 30 minutes. The consistency of the mixture may subsequently be increased or diminished by evaporating, or by the addition of oil of turpentine, coal, naptha, or other solvent. When the material has been rendered hard or horny by vulcanization or conversion, the time necessary to dissolve it or reduce it to a soft pulpy state would be so long, as to render the preceding process worthless.