Patent GB-191322826-A (GB)
IPC: B29C48/91
Granted: 1900-01-01
Abstract: 22,826. Borzykowski, B. Oct. 9. Apparatus for making films.-Films or strips containing or prepared from solutions of nitrocellulose, viscose, acetyl-cellulose. ammoniacalcopper cellulose, casein, fibrin, and maisin, and in the form of imitation textile goods of lace-like, perforated, or open-work character are produced by applying the viscous solution as a thin layer to a smooth surface-cylinder, disk, or endlessband-which is then brought against an engraved roll, which pressing into the layer, produces an open-work pattern corresponding to the engraving; the latter is made wider and deeper than the width and thickness desired in the finished product in order to compensate for subsequent shrinkage. In the initial solution the cellulose &c. may be in a completely-dissolved condition, or it may be partly dissolved so as to form a gelatinous mass, as by the use of a limited quantity of solvent; and to the solution may be added powdered glass or coloured fibres, or iron powder if the goods are to be metallized by subsequent immersion in a copper salt solution; and by the use of a mixture of initial materials; one for example, the fibrin, may be subsequently dissolved out or removed so as to give a product that is porous, soft to the touch, and dyes readily. Other effects may be produced by applying to the strip, during manufacture, coloured fibres suspended in liquid, or liquid gum, talc, or powdered metals. In a suitable apparatus, cellulose &c. solution is delivered as a thin layer from a spreading.apparatus 1, Fig. 1, on to a rotating cylinder 3 against which is pressed an engraved roll 2, and which is immersed in a bath 5 of hardening-liquid: side cheeks 4 obviate lateral escape of the viscous layer. After passage through the bath. the strip, now sufficiently hardened. is detached from the cylinder, is led between rolls 6, and is then passed through tanks containing suitable precipitating, acidifying, and washing liquids, and is finally wound on a spool 17. After removal of the strip, the surface of the cylinder 3 is cleaned by washing liquor supplied to a box 20, the edges of which act as a stripper or scraper, and is subsequently dried by a heated roll 23. On to. the engraved roll is sprayed, as from a pipe 18, suitable hardening liquid which produces a superficial setting of the surface of the viscous layer and prevents any tendency for the strip to adhere to the engraving; superfluous liquid is removed by a scraper 19. The strip may, however, be allowed to adhere to the engraved roll 2<1>, as shown in Fig. 2, and to travel some distance thereon; in this case the strip after leaving the roll 2<1> travels over an endless band 27, and is finally piled in a tank 28, in which it remains without the necessity for further handling during the subsequent washing, bleaching, dyeing, &c. operations; after the final washing, the strip is treated with magnesium chloride solution or with glycerine or like solutions such as those which contain softening-substances such as fatty acid soap, and is finally dried under tension between wet bands or on pin blocks or pin rollers. The engraved roll 2<1> may run at the same peripheral speed as the cylinder 3<1>, or at a greater or lesser speed, so as to produce a rubbing effecton the surface of the strip, and the roll may be arranged to produce simultaneously a number of strips of material, for which purpose it may be in sections which are assembled on the shaft and interchanged as desired. By mounting the roll 2<1> in adjustable bearings so that it may be raised somewhat from the cylinder, goods with a pattern in relief may be produced. When used for producing perforated goods, a revolving brush 24 may be applied to the underside of the strip while it is still on the engraved roll 2<1>, to remove any portions of the layer not completely pressed out and still adhering to the material. To prevent the material being too hard at the thicker portions, the grooves for the thicker threads on the engraved roll may be subdivided at intervals by longitudinal ribs.