Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
  • D01F8/02—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from cellulose, cellulose derivatives, or proteins
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof

Definitions

• Coextrusion of two different materials to form a side-by-side bicomponent fiber has been done extensively, primarily to develop a crimped product.
• U.S. Patent No. 2,439,813, Kulp discloses such a product, where both components are viscose of different contractivity due to different aging times and different concentrations of cellulose, carbon disulfide, or sodium hydroxide.
• Sheath core structures have also been formed, again usually for crimping purposes.
• U.S. Patent No. 3,458,615, Bragaw discloses a coextrusion of two streams in the molten state and any orientation to be developed will be induced downstream from the die.
• the Bragaw patent is directed to the production of light guides where a well controlled smooth interface is critical to maintaining internal reflection of the light passing through the core and reflected off the surface.
• U.S. Patent No. 2,932,079, Dietzch discloses a sheath core structure which must contain at least two cores of different materials and a
• U.S. Patent No. 2,989,798, Bannerman is also involved in the production of a sheath core fiber in which both layers are polyamides.
• the core polyamide is hosen or modified to be more dye receptive.
• U.S. Patent No. 2,063,180, Meyer involves a coextrusion process in which an inner stream consisting of a volatile solvent carrying a coloring substance passes through a wick and is subsequently covered by a viscose solution. During spinning the volatile solvent diffuses through the forming rayon leaving behind only the coloring substance.
• the inner core would not exist as a discrete region since the dye would form a gradient into the rayon.
• the invention involves creation of a sheath core fiber comprising an inner core of an oriented thermoplastic material, such as nylon, polyester, acrylic, and olefin, and any other oriented thermoplastic material, and a sheath made of a nonthermoplastic material, such as rayon, or regenerated protein and any other appropriate nonthermoplastic material.
• an oriented thermoplastic material such as nylon, polyester, acrylic, and olefin, and any other oriented thermoplastic material
• a sheath made of a nonthermoplastic material, such as rayon, or regenerated protein and any other appropriate nonthermoplastic material.
• FIG. 1 is a schematic diagram of the method of producing the fiber of this invention.
• Fig. 2 is a perspective view of a single fiber.
• Fig. 3 is a scanning electron micrograph of a fiber produced by this invention at a magnification of 1250X.
• the core material 10 is introduced into the chamber 11, which is provided with a die 12 at its lower end.
• ⁇ U9STITUTE SHEET material is introduced through member 13 by gravity or pressure flow into the chamber 11.
• the fiber solution contact region is designed to be sufficient to insure that the core 10 is thoroughly coated with the sheath- forming material prior to entering the die 12.
• the relative amount of solution coated onto the core fiber is controlled by die opening geometry, solution rheological properties, and drag and pressure driven flow.
• the combined sheath core fiber 14 exits the die 12 and enters the acid bath 15 where the sheath material is coagulated.
• Fig. 2 is a scanning electron micrograph of the sheath core fiber shown in Fig. 2 at a magnification of 1250x, reveals dimples that are not elongated indicating lack of orientation of the surface and the enhanced surface area. Both of these properties contribute high sorptivity and thus comfort and dyeability.
• the core fiber was nylon 66 and was 20 microns in diameter.
• the die opening was approximately 800 microns and the resultant rayon skin thickness was one micron.
• the line speed of 100 feet per minute was used with a commercial concentration spinning bath consisting of nine weight percent sulfuric acid and 13 weight percent of sodium sulfate. Much higher line speeds, of course, can be used and different die openings and/or a higher pressure head may also be used.
• the resulting fibers maintain essentially the bulk mechanical properties of the nylon core and have the dyeability of rayon.
• rayon fibers typically are formed from a solution containing about seven percent cellulose in a sodium xanthate form and seven percent alkali. An acceptable viscosity for spinning is achieved by ripening the viscose solution for four to five days. The fibers are formed by extruding thin filaments of this solution from a spinning bath in which the cellulose is regenerated from its xanthate form and coagulated. This is performed under tension and orientation develops in the rayon fiber, the level of which is controlled by the tension, cellulose source and character, and the spinning bath concentration and temperature.
• the sheath material since the core material carries the tensile load, the sheath material develops very low, if any, orientation, as opposed to normal rayon fibers that are spun under tension to develop strength relating to orientation. This enables surface dimpling which results in an enhanced surface area contributing to higher sorptivity and greater dyeability. Furthermore, since the core material carries the tensile load, the acid bath, as shown ' in Fig. 1, can be spaced from the face of the die and thus precious metal faced dies are not needed in practicing this invention. In addition, since this process does not require the viscose solution to be able to be drawn into a fiber, a broader class of viscose solutions may be used.
• core material 10 has been shown as a single monofilament, it should be kept in mind that, contemplated within the scope of this invention are multiple filament bundles, such as yarns, which may also be used as core material.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Multicomponent Fibers (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Materials For Medical Uses (AREA)

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• 1986
  • 1986-07-08 KR KR1019870700193A patent/KR930012186B1/ko not_active IP Right Cessation
  • 1986-07-08 EP EP86904673A patent/EP0229172B1/de not_active Expired - Lifetime
  • 1986-07-08 AT AT86904673T patent/ATE75788T1/de active
  • 1986-07-08 WO PCT/US1986/001473 patent/WO1987000561A1/en active IP Right Grant
  • 1986-07-08 JP JP61503952A patent/JPS63500109A/ja active Pending
  • 1986-07-08 DE DE8686904673T patent/DE3685208D1/de not_active Expired - Fee Related

Patent Citations (2)

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