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
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/24—Formation of filaments, threads, or the like with a hollow structure; Spinnerette packs therefor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
  • Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
  • Y10T428/264—Up to 3 mils
  • Y10T428/265—1 mil or less
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2967—Synthetic resin or polymer
  • Y10T428/2969—Polyamide, polyimide or polyester
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2973—Particular cross section
  • Y10T428/2975—Tubular or cellular

Definitions

• the present invention relates to a multifilament textile yarn whose filaments or strands have a hollow section, a method of manufacturing this hollow yarn, and the textile surfaces obtained with such a yarn.
• It relates more particularly to the manufacture of multifilament yarns comprising hollow filaments obtained by melt spinning of a polyamide composition.
• the spinning speed is very low compared to the speeds of current industrial processes which are often greater than 3000 m / min.
• the drawing step is often integrated into the spinning, without intermediate recovery of the filaments.
• One of the aims of the present invention is to provide a multifilament textile yarn whose strands have a hollow section obtained by a spinning or spinning-drawing process which has the advantages of current industrial processes for spinning filaments with a full section, namely productivity. and regularity of the properties of the yarn by using a VR polyamide similar to that of the polyamides used in the manufacture of textile yarns.
• the invention provides a multifilament textile yarn of polyamide with a strand count of less than 10 dtex, and the strands of which have a hollow section comprising a central empty surface representing at least 5% of the total surface of the cross section of said cross-section.
• strand characterized in that the wire has a USTER coefficient (U%) of less than 3% and a number of strands with a section in the form of an arc of a circle less than 30% of the total number of strands with a hollow section.
• U% USTER coefficient
• hollow section strand must be understood all the strands or filaments obtained from a die hole in the form of an arc of a circle as will be described below.
• the hollow strands are those whose cross section is in the form of a closed or open crown.
• the multifilament yarn has a U% of less than 2%, preferably less than 1%.
• the number of filaments in the shape of an arc of a circle is advantageously less than 20% of the total number of filaments with a hollow section, preferably less than 10%.
• U% or USTER coefficient is representative of the regularity of a continuous thread. Thus, this coefficient is determined by measuring the variations in the titer of a continuous thread on a USTER device (Zellweger).
• the wire maintained under a certain voltage passes at a constant speed between the plates of a capacitor, the variation of the dielectric element formed by the wire due to the variation in mass of the wire causes a variation in capacitance of the capacitor. which is translated into thread title irregularity.
• a graph representing the irregularities of the titer or variation in mass along the wire is drawn, the coefficient USTER (U%) representing the average variation in mass expressed in% of average mass.
• the percentage of empty surface in the section of the filaments or strands is greater than 10%, preferably greater than 15% of the cross section of each strand.
• this value is between 15 and 50%.
• the multifilament yarn is obtained by spinning from a die of a polyamide-based composition having a relative viscosity VR greater than 40 and preferably between 40 and 55, advantageously between 40 and 50.
• the relative viscosity VR of the polyamide is determined on an 8.4% solution of polymer in formic acid.
• the polyamide suitable for the invention is chosen from the group advantageously comprising polyamide 6, polyamide 66, mixtures of polyamides comprising at least 80% by weight of polyamide 66 or polyamide 6, copolyamides comprising at least 80% by number polyamide 66 or polyamide 6 units.
• the yarn of the invention has excellent regularity, and the absence of open filaments or of section in the form of an arc of a circle, that is to say which have not coalesced at the outlet of the die, avoids the problems of breakage and jamming in downstream treatments of the yarn such as texturing, dyeing, weaving or knitting, for example, as well as irregularities on textile surfaces.
• the invention also relates to a process for manufacturing a multifilament yarn having the characteristics indicated above.
• the method of manufacturing a polyamide multifilament yarn comprising filaments of hollow section consists in extruding a polyamide composition through at least one die comprising several die holes to form filaments or strands, to be made to converge at the at least part of said strands at a point distant from the die to form said multifilament thread, then return said thread on a spool characterized in that each die hole is constituted by a slot in the form of an arc of a circle whose ends are distant by a length at most equal to 5 times the average width of said slit opening at the exit face of the die, with cooling of the filaments at the exit of the die and with a wire winding speed greater than 3000 m / min., preferably greater than 3500 m / min.
• the width of the slot forming a die hole on the exit surface of the die is advantageously between 0.05 mm and 0.12 mm.
• the ends of the circular arc forming each die hole are symmetrical over at least 5% of the total length of said circular arc, preferably over at least 15% of this total length.
• the dies are produced according to the usual techniques such as by electroerosion
• the density of holes on a die is between 0.25 hole / cm 2 and 3 holes / cm 2 .
• the wire leaving the die is cooled.
• the distance between the start of cooling and the outlet of the die is as short as possible technologically.
• cooling immediately at the outlet of the die can be difficult to implement since it can cause polymer deposits on the surface of the die which result in breakage of the filaments.
• the cooling is obtained by a cooling fluid chosen from the group comprising air, a non-oxidizing gas, or an inert gas such as nitrogen.
• this fluid is not saturated with water vapor.
• the cooling fluid is air or an inert gas.
• the processes for treating the yarns thus formed are those usually used for the manufacture of polyamide textile yarns.
• sizes to improve the surface lubrication, modify the hydrophilic or hydrophobic properties thereof can be applied.
• these wires are subjected to either a cold or a hot drawing, in the presence of steam or not.
• This stretching is generally integrated into the spinning process, that is to say carried out before the rewinding.
• the threads can also be drawn in a drawing process independent of the spinning, by taking up the returned thread. It is also possible to intertwine the filaments to improve the cohesion of the wire. This intermingling is often carried out before stretching, but can be done during or after it.
• the polyamide yarn can then be relaxed before rewinding on a spool.
• the multifilament yarns of the invention can be subjected to crimping, texturing according to the field of use.
• these threads can be used as flat thread, twisted thread or texture, in weaving processes as warp thread or weft thread, for example.
• the yarns of the invention are also used for the manufacture of knitted surfaces.
• Such textile surfaces woven or knitted with at least one thread of the invention are also objects of the invention.
• FIG. 1 represents a schematic view of the shape of a die hole according to the present invention.
• the yarns according to the invention are obtained by spinning a composition comprising a polyamide PA 66 with a relative viscosity VR equal to 49 and a mattifying agent consisting of titanium oxide at a weight concentration of 0.3%.
• This composition is fed into a conventional spinning device comprising a die suitable for spinning hollow wire.
• the die comprises 40 die holes (hole density equal to 0.8 hole / cm 2 ) having a profile 1 in an arc of an outside diameter equal to 1.5 mm.
• the ends 1a, 1b of the arc of a circle are separated by a distance e equal to 0.15 mm.
• the width I of the slot is regular in the example illustrated and is equal to 0.08 mm. However, this width can be different over the length of the slit without departing from the scope of the invention and while respecting the characteristic of symmetry of the end parts of the slit as defined above.
• the spinning conditions are as follows: - pressure: 250 bar
• the bundle of filaments is cooled at the outlet of the die by a flow of cooling fluid supplied in a direction substantially perpendicular to the direction of travel of the bundle.
• This feed is arranged at a distance of 30 mm from the outlet surface of the die.
• the cooling fluid is air at a temperature of 22 ° C.
• the flow of cooling fluid is supplied at a speed which does not cause disturbance in the movement of the bundle of filaments.
• the filaments are then converged at a point 130 cm from the outlet of the die.
• a sizing composition is deposited on the yarn thus formed according to conventional methods and devices.
• the wire is then returned on a spool at a winding speed equal to 4500 m / min.
• the yarn obtained has a total titer of 165 dtex and comprises 40 filaments (thread title
• FIG. 2 representing a cross-sectional view of the wire obtained shows the hollow section in the form of a crown of the filaments.
• the void percentage is more than 15%.
• the number of filaments having a section in the form of an arc of a circle, that is to say the ends of which have not coalesced at the outlet of the die is equal to zero in the example illustrated.
• the characteristics of the wire obtained are as follows:
• a fabric was produced with threads obtained by the process described above and of title 165F40.
• the fabric is made on a lance loom and is subjected to a calendar.
• the yarns according to the invention are obtained by spinning in an Integrated Stretching Spinning process, of a composition comprising a polyamide PA 6 of relative viscosity VR equal to 50 and a matting agent consisting of titanium oxide at a weight concentration 0.4%.
• This composition is fed into a conventional spinning device comprising a die suitable for spinning hollow wire identical to that used in Example 1, but comprising 20 holes per die.
• the spinning conditions are as follows: - pressure: 220 bar
• the bundle of filaments is cooled at the outlet of the die by a flow of cooling fluid supplied in a direction substantially perpendicular to the direction of travel of the bundle.
• This feed is placed at a distance of 40 mm from the outlet surface of the die.
• the cooling fluid is air at a temperature of 20 ° C.
• the flow of cooling fluid is supplied at a speed which does not cause disturbance in the movement of the bundle of filaments.
• the filaments are then converged at a point 130 cm from the outlet of the die.
• a sizing composition is deposited on the yarn thus formed according to conventional methods and devices.
• the wire is then wound up on a spool at a winding speed equal to
• the yarn obtained has a total titer of 78 dtex and includes 20 filaments (thread title
• the wire obtained has a percentage of void greater than 15%.
• the number of filaments having a cross-sectional shape, ie the ends of which have not coalesced at the outlet of the die is equal to zero.
• the characteristics of the wire obtained are as follows:

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Woven Fabrics (AREA)
• Knitting Of Fabric (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 1997
  • 1997-12-29 FR FR9716833A patent/FR2773178B1/fr not_active Expired - Fee Related
• 1998
  • 1998-12-23 RU RU2000120193/04A patent/RU2194102C2/ru active
  • 1998-12-23 ES ES98963617T patent/ES2164469T3/es not_active Expired - Lifetime
  • 1998-12-23 DE DE69802841T patent/DE69802841T2/de not_active Expired - Fee Related
  • 1998-12-23 WO PCT/FR1998/002857 patent/WO1999034040A1/fr not_active Ceased
  • 1998-12-23 EP EP98963617A patent/EP1044293B1/de not_active Expired - Lifetime
  • 1998-12-23 KR KR1020007007318A patent/KR100361197B1/ko not_active Expired - Fee Related
  • 1998-12-23 PL PL98341523A patent/PL186839B1/pl not_active IP Right Cessation
  • 1998-12-23 AU AU18823/99A patent/AU1882399A/en not_active Abandoned
  • 1998-12-23 CN CNB988133504A patent/CN1193119C/zh not_active Expired - Fee Related
  • 1998-12-23 AT AT98963617T patent/ATE210211T1/de not_active IP Right Cessation
  • 1998-12-23 DK DK98963617T patent/DK1044293T3/da active
  • 1998-12-23 CA CA002316819A patent/CA2316819C/fr not_active Expired - Fee Related
  • 1998-12-23 BR BR9814531-2A patent/BR9814531A/pt not_active IP Right Cessation
  • 1998-12-23 PT PT98963617T patent/PT1044293E/pt unknown
  • 1998-12-23 JP JP2000526685A patent/JP3920571B2/ja not_active Expired - Fee Related
  • 1998-12-23 US US09/582,649 patent/US6565972B1/en not_active Expired - Fee Related
  • 1998-12-23 SK SK989-2000A patent/SK285172B6/sk not_active IP Right Cessation
• 2004
  • 2004-01-23 JP JP2004015643A patent/JP2004150009A/ja active Pending

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