Several preparations for rendering textile and other inflammable fabrics incombustible and practically fireproof have been recently introduced by Martin and Tessier, of Paris. The compositions are said to be of an inexpensive nature, and capable of rendering incombustible all kinds of readily inflammable substances, such as woven and other fabrics of cotton and other fibrous materials, paper, printed or otherwise, including bills of exchange and other securities, woodwork, theatrical scenery, straw, etc.
(1) The first composition, which may be applied to all kinds of fabrics, without deteriorating them in any way, consists of sulphate of ammonia (pure), 8 lb.; carbonate of ammonia, 2..5 lb.; boracio acid, 3 lb.; borax (pure), 1.7 lb.; starch, 2 lb.; water, 100 lb. It is simply necessary to steep the fabrics in a hot solution composed as above until they have become thoroughly impregnated, after which they are drained and dried sufficiently to enable them to be ironed or pressed like ordinary starched goods.
(2) A second composition, to be used for theatrical scenery (or the mounted but unpainted canvas to be used for this purpose) and also for woodwork, furniture, door and window frames, etc, is to be applied hot with a brush like ordinary paint. It is composed of boracic acid, 5 lb.; hydrochlorate of ammonia or sal-ammoniac, 15 lb.; potash felspar, 5 lb.; gelatine, 1.5 lb.; size, 50 lb.; water, 100 lb.; to which is added a sufficient quantity of a suitable calcareous substance to give the composition sufficient body or consistency.
(3) A third composition, to be used for coarse canvas or sailcloth, cordage, straw, and wood, is applied by immersing the articles therein or by imbibition, and consists of boracic acid, 6 lb.; hydrochlorate of ammonia or sal-ammoniac, 15 lb.; borax (pure), 3 lb.; water, 100 lb.
(4) A fourth composition, applicable to all kinds of paper, whether printed tr not, including securities, books etc, is formed of sulphate of ammonia (pure), 8 lb.; boracic acid, 3 lb.; borax, 1.7 lb.y water, 100 lb.
The solution is to be placed in a vat heated to 122° F. (50° C.) at the end of the paper-making machine, and the paper as it leaves the machine is passed through the solution in this vat, so as to be completely impregnated therewith, after which it is dried upon a warm cylinder and then wound on a reel. If the paper be in sheets or printed, it is simply immersed in the above heated solution, spread out to dry, and afterwards pressed to restore the glaze destroyed by the moisture. The above compositions ensure a degree of incombustibility without precedent as regards the preservation of the materials to which they are applied. The proportions of the several ingredients are given as examples only, and may be varied as found necessary in practice.
(5) The ' Manufacturers' Review ' translates from Hager the following directions for preparing a starch paste, impregnation with which renders a fabric incombustible: - 10 lb. calcined and pulverized bones are treated with 50 lb. hot water, to which 6 lb. concentrated sulphuric acid are gradually added. The mixture is well stirred, and left to stand 2 days in a warm spot, being stirred from time to time; 100 lb. distilled water are then added, and the liquid filtered. 5 lb. sulphate of magnesia (Epsom salts) are dissolved in 15 lb. distilled water, the solution is added to the first, and caustic ammonia is added till the liquid smells of it. The precipitate is thrown on a linen filter, pressed, dried in a moderately warm place, and rubbed to a very fine powder. Of this powder, 2 lb. are mixed with exactly 1 lb. tungstate of soda, 6 lb. wheat-starch, and a little indigo blue to impart a bluish tint to the powder. In order to use this powder, it is stirred up with about twice its weight of cold water, and enough hot water is then added to produce a gelatinous liquid, in which the fabrics that are to be rendered incombustible are steeped.
(6) An old recipe for rendering cotton goods uninflammable is to add to the starch-size 15 lb. borax for every 1000 lb. size.
(7) To render ladies' clothing uninflammable it has been proposed that the materials should be sized with starch containing ammonia sulphate, a mixture of phosphoric and boracic acid, or in some cases tungstate of soda. Professor Gintl, in a recent report on the " dressings " for textile fabrics sent to the late Vienna Exhibition, observes that a considerable amount of ignorance appears to prevail amongst manufacturers in the choice of the substances employed. In very many instances the dressing is not as harmless to the colours of the material as it professes to be, neither does the latter gain the requisite degree of uninflammability. His experiments have led him to recommend ammonia alum and hyposulphite of soda, both of them very cheap, as suitable substances for the purpose. (Neue Ge-werbe Zeitung.)
(8) The French Societ d'Encourage-ment pourl'Industrie Nationale awarded a sum of l000f. to Martin for his preparations, which have been variously tested by a committee of the society. The report briefly is that Martin's mixtures render tissues and the superficial parts of wood uninflammable, that they do not alter the tissues or colours on them, and that staffs so rendered uninflammable retain this property after having been exposed several months, either in a stove at 97° F. (36° C), or or on the stage of a theatre. Martin's preparations are said to have been used with success for decorations in the Theatre des Varices and the Theatre des Nouveautes, and at the Theatre du Chitelet, in the Venus Noire for rendering uninflammable the masts of vessels in which a Are is simulated every night by means of oakum wrapped round the masts. Martin has also been charged to render uninflammable the large sheets employed for covering goods at night in the magasins of the Louvre.
(9) The Abbe Maurau proposes to render textile fabrics of various kinds uninflammable, without affecting their colour, suppleness, strength, or wearing qualities, by treating them with a preparation of borax, sulphate of soda, and boracic acid, combined in suitable proportions. (Revue Indust.)
(10) Tremaux states that a more or less concentrated solution of sulphate of potassium and alum applied to textile fabrics prevents them from flaming (not .from burning without flame) when a light is applied to them, and is in this respect as good a preservative as is to be met with. (Comptes Bendus.)
(11) In consequence of the fire at the Vienna Ring Theatre, the question of rendering tissues incombustible has again been ventilated, and fresh trials have been made in Berlin with apparently new substances. On closer examination, however, it was found that these substances have been used from time to time, and that a large number of similar trials was made about 50 years ago. Gay-Lussac proposed to saturate tissues with ammonium carbonate. Chevalier used this salt in conjunction with borax. Fuchs recommends the use of sodium silicate (soluble glass). Versmann and Oppenheim employed ammonium phosphate alone, and with sal-ammoniac, ammonium sulphate, and sodium tungstate. Abel impregnated tissues with lead silicate, first soaking them in lead acetate, and then immersing in a solution of sodium silicate, and rinsing. The following solutions have been successfully applied for rendering tissues incombustible: - (a) A mixture of sodium tungstate solution of 25° Tw. and 3 per cent, sodium phosphate; (6) 6 lb. alum, 2 lb. borax, 1 lb. sodium tungstate, 1 lb. dextrine dissolved in soap water; (c) 5 lb. alum, 5 lb. ammonium phosphate, 100 lb. water; (d) 3 lb. borax, 2 1/4 lb.
Epsom salts, 20 lb. water; (e) 8 lb. ammo* nium sulphate, 2 1/2 lb. ammonium carbonate, 3 lb. boracic acid, 2 lb. borax, 2 lb. starch, 100 lb. water. (Indust. Blat.)
(12) Hosemann takes a solution of calcium chloride at 22° to 49° Tw., or in its place, aluminium or magnesium chlorides. He adds hydrochloric acid in the proportion of 1 lb. acid to 75 or 100 lb. of the solution, and stirs into the liquid 10 to 30 lb. potato starch. The liquid is heated to boiling, and 5 lb. steatite, previously stirred up in 1 gal. water, is added. While continuing the heating and agitation there are added 1 lb. ammonia sulphate dissolved in 1/2 gal. water, 3 lb. potash silicate dissolved in 30 lb. water, and lastly 5 lb. soda or lime bisulphite. The stirring and heating are maintained for 1/2 hour after the addition of all the materials. Thus is formed a whitish gelatinous mass, which may be used like starch or dressing. Articles saturated or coated with this mixture are uninflammable. A more simple composition may be obtained by adding potato starch to a solution of calcium chloride at 49° Tw., and heating to 167° F. (75° C.); having well stirred and continued to heat, 1 or 2 per cent, of soluble silicate of potash is added, and the liquid, which is alkaline, is neutralized by addition of an acid or acid salt. (Mon. Prod. Chim.}.