Alternate high-molecule arrangements are known as "island in a sea" type composite fibers. The ultrathin fibers obtained by dividing them or removing one component therefrom are used for the production of a variety of artificial leathers, waterproof high-density textiles and knittings, raised textiles, tricots, filters, high-grade strings, reinforced fibers, and silky textiles and knittings, and for other beneficial purposes. Their films are usable as image guide when put one upon another, polarizing plate, high-grade light reflecting road signs, and applied to optical and other many uses. So far, nevertheless, no process has been presented for easily manufacturing alternate high-molecule arrangement fibers and films.
Conventional processes and systems for obtaining alternate high-molecule arrangement fibers are proposed in Patent Gazette Nos. 18369/1969, 13208/1969 and 26723/1972. The former process and systems are very useful because of the high ratios of the island components and the accurate arrangement of the islands as well as the highly-steady spinning and much-high controllability thereof, but defective in that their cost is unavoidably raised because the hole of the nozzles cannot be multiplied although the island components are extremely increased in quantity.
On the other hand, Patent Gazette Nos. 3505/1969, 889/1969 and 19604/1968, U.S. Pat. Nos. 3,051,453, and others present the spinning processes wherein the alternate-layer or similar flows of fluids A and B are made (former: ABABABAB. . .) and passed through a sand layer or metal or cloth gauge for their disturbing and splitting so that the components in large quantity (generally above 50%--this slightly varies in accordance with the differences of viscosity, boundary tension, etc.) surround those in small quantity, both having a dispersion-nondispersion relationship like polymer blend spinnings, by which the spinnings obtained have a fairly-regular arrangement of the components thanks to the spinning holes.
Because the cross-section of the mixed polymer stream varies at every moment, the above-mentioned methods have serious defects: (1) the spinning is not stable, (2) the discharged polymer must be cooled rapidly with a strong flow of cooling air, (3) it is impossible to take up the discharged polymer at high speed, (4) the rapidly cooled fiber possesses inferior physical properties making it impossible to draw and (5) drippings of the discharged polymer sometimes interfere with the spinning process because the randomly mixed polymer has poor fiber forming properties. These are commercially fatal defects because the resulting fiber does not have a high island ratio, the cross-section of every fiber varies, each fiber possesses different physical properties and the spinning process is not stable.
Several patents, for instance Japanese Patent Publication No. 15530/72, disclose spinning methods and apparatuses in which many paths are incorporated for polymer mixing. However, many disadvantages must be overcome if these methods and apparatuses are used. For example, all polymer components have a laminar structure, each polymer component is distributed nonuniformly throughout the fiber, i.e., the cross section of the fiber is not fixed and varies along the fiber axis, the quality of every fiber varies and the island ratio cannot be controlled.
USPTO Backgrounds
USPTO Backgrounds