# US 5,701,644 A · Method for producing self-crimping polymer bi-component fibers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,701,644 A - Document ID: US5701644A - Status: Granted - Kind: A - Application number: 08/642,960 - Filed: 1996-05-06 - Granted: 1997-12-30 - Earliest claimed: 1995-05-11 - Assignees: EMS-Inventa AG - Inventors: Werner Kaegi; Werner Stibal; Gunther Schaech; Rainer Straub; Gerhard Schmidt - Web page: https://patentgrep.com/patent/US5701644A ## CPC - D21H 15/10: Composite fibres - D01F 8/12: with at least one polyamide as constituent - D01F 8/14: with at least one polyester as constituent - D02G 1/18: by combining fibres, filaments, or yarns, having different shrinkage characteristics {(D02G1/004 takes precedence)} - D02J 1/22: Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch (stretch spinning D01D5/12) - D21H 13/24: Polyesters - D21H 13/26: Polyamides; Polyimides - D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR - D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS - D02G: CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS - D02J: FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE (curling or crimping D02G; by treatment with liquids, gases or vapours D06B; finishing other than by liquid treatment, of yarns in warp or sheet form D06C; for chemical matters, see D06L, D06M, D06P, D06Q; treatment during rope-making, apparatus for treating ropes auxiliary to rope-making D07B) ## Abstract A method for self-crimping of S/S bi-component fibers on a fiber line includes the steps of main drawing, post-drawing on a cold drawing unit, water application in the tensed state and relaxation at the dryer inlet in the compact closed state, which results in fibers with a novel .OMEGA.-shaped crimping structure. ## Claims ### Claim 1 In a method for producing self-crimped bi-component fibers from a tow of bi-component fibers which have been side-by-side spun from bi-component material, comprising drawing said tow to provide a drawn tow; optionally finishing said drawn tow; then relaxing the drawn and optionally finished tow to provide a relaxed tow; drying and heat setting said, relaxed tow to provide a heat-set tow; and optionally cutting said heat-set tow; the improvement further comprising post-drawing said drawn tow prior to said optional finishing and said relaxing said post-drawing being carried out in a hot and dry state on a cold drawing unit; after said post-drawing with said tow being in a tensed state, prior to said relaxing, providing said post-drawn tow with a water coating of between 10 and 30 weight percent, measured prior to relaxation, to provide a water-coated tow; carrying out said drying of said water-coated tow in a dryer having an inlet; and carrying out said relaxing of said water-coated tow at the inlet of said dryer while said water-coated tow is in a compact, closed state to provide bi-component fibers having two-dimensional .OMEGA.-crimped bows. ### Claim 2 (depends on 1) A method in accordance with claim 1, wherein a drawing ratio of maximally 1:100 is used forsaid post-drawing. ### Claim 3 (depends on 1) A method in accordance with claim 1, wherein a drawing ratio of between 1:005 and 1:050 is used for post- drawing. ### Claim 4 (depends on 1) A method in accordance with claim 1, wherein finishing is performed by immersion or roller finishing. ### Claim 5 (depends on 1) A method in accordance with claim 1 wherein said optional finishing is carried out and comprises applying a silicon finish to said post-drawn tow. ### Claim 6 (depends on 1) A method in accordance with claim 1, wherein said water coating is 15 to 20 weight %. ### Claim 7 (depends on 1) A method in accordance with claim 1, wherein said bi-component fiber comprises two related polymers-selected from the group consisting of PA 6/PA 66, PET/PBT, PE/PP, PET/co-PET. ### Claim 8 (depends on 7) A method in accordance with claim 7, wherein said bi-component fiber is PET/co-PET. ### Claim 9 (depends on 8) A method in accordance with claim 8, wherein said co-PET comprises 4-12 mol % of randomly distributed .OMEGA.-caprolactone. ### Claim 10 (depends on 2) A method in accordance with claim 2, wherein said water coating is 15 to 20 weight %. ### Claim 11 (depends on 1) Endless or cut self-crimped bi-component fibers comprising at least 30% of two-dimensional .OMEGA.-crimped bows, producible according to the method of claim 1. ### Claim 12 (depends on 11) Endless or cut self-crimped bi-component fibers according to claim 11 comprising at least 60% of said two-dimensional .OMEGA.-crimped bows. ### Claim 13 (depends on 2) Endless or cut self-crimped bi-component fibers comprising at least 30% of two-dimensional .OMEGA.-crimped bows, producible according to the method of claim 2. ### Claim 14 (depends on 13) Endless or cut self-crimped bi-component fibers according to claim 13 comprising at least 60% of said two-dimensional .OMEGA.-crimped bows. ### Claim 15 (depends on 10) Endless or cut self-crimped bi-component fibers comprising at least 30% of two-dimensional .OMEGA.-crimped bows, producible according to the method of claim 10. ### Claim 16 (depends on 15) Endless or cut self-crimped bi-component fibers according to claim 15 comprising at least 60% of said two-dimensional .OMEGA.-crimped bows. ### Claim 17 A method for producing self-crimped polymer bi-component fibers having at least partially two-dimensionally .OMEGA.-crimped bows from spun self-crimpable bi-component fibers in a fiber tow, comprising drawing said tow on a device comprising plural hot drawing rollers to provide a drawn tow; post-drawing said drawn tow on a cold drawing unit to produce a post-drawn tow; applying a water coating of between 10 and 30 weight percent to said post-drawn tow and to provide a water-coated tow; relaxing said water-coated tow at an inlet of a dryer to provide a relaxed tow; drying and heat setting said relaxed tow to provide a heat-set tow; and optionally cutting said heat-set tow.