| 摘要 |
Artificial straw, ribbons, or like products of flattened cross-section, produced by coalescing a number of yarns or filaments as described in Specifications 328,312, [Class 2 (ii), Cellulose &c.], 354,233, 368,738, and 371,428 or otherwise, are subjected to severe bending so that they are split lengthwise to form a number of finer straws associated together. Splitting may be effected after the straw is fully set after coalescing or while it is in a slightly solvent-softened condition. The material to be coalesced may be in the form of twisted or untwisted fine filaments of, say, 2 to 25 denier, and the filaments may be in the form of artificial bristles of, say, 50 to 1000 denier or more, or may be in the form of artificial straw. Thermoplastic derivatives of cellulose may be employed and may be cellulose acetate or other derivatives, examples of which are given in Specification 354,233, and any suitable coalescing liquid of the required solvent or restricted solvent power may be used, examples of which are given in the same Specification. The splitting process may be effected continuously with the coalescing process, and excess solvent is preferably driven off by drying the straw as it emerges from the coalescing apparatus. If the split straws are required to be closely associated the straw may be severely twisted by apparatus such as ring, flyer, or cap spinning-apparatus, or if close association is not desired and a substantially twistless product is desired the straw may be passed through a tortuous path, for example through a fine slot and then immediately through another at right-angles. Ornamental effects, such as are produced by differential colour effects or differential lustre may be obtained by associating yarns of non-thermoplastic material with yarns of thermoplastic material, and metallized effects may be produced by similarly associating fine metal bands, such as are used in making tinsel, or metallized yarns or threads as described in Specification 354,233. Colouring, either continuous or intermittent, may be effected by applying dyestuff, which may be in the form of a solution as described in Specification 313,451, [Class 2 (ii), Cellulose &c.], while the filaments are passing through the pressure rollers or at any other suitable stage in the manufacture. Lustrous, metallic or opaque effects or waterproof properties may be imparted by treating the material as described in Specifications 328,312 and 354,233. |
