Classifications

• • 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
• • 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
  • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
  • D01D10/02—Heat treatment
• • 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
  • D01D5/08—Melt spinning methods
  • D01D5/082—Melt spinning methods of mixed yarn
• • 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
  • D01D5/22—Formation of filaments, threads, or the like with a crimped or curled structure; with a special structure to simulate wool
• • 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
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters
• • 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
  • D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
  • D01F8/12—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyamide as constituent
• • 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
  • D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
  • D01F8/14—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyester as constituent
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
  • D02G1/18—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by combining fibres, filaments, or yarns, having different shrinkage characteristics
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch

Definitions

• This invention concerns improvements in, and t relating to, polyester fine filaments and their 5 manufacture and use.
• polyester fibers have generally been supplied to the textile industry for use in fabrics and garments with the object of more or less
• polyester filaments have been available commercially in a range of dpf similar to that of natural silk, i.e. of the order of 1 dpf, and even in subdeniers, i.e., less than about 1 dpf, despite the increased cost.
• subdeniers i.e., less than about 1 dpf
• X 30 and handling techniques could not be used for such fine filaments.
• three approaches are discussed for making microfibers; namely, 1) conventional spinning to fine deniers, 2) splitting bicomponent fibers (of higher deniers) , and 3) dissolving away a component from bicomponent fibers of higher denier.
• the 2nd and 3rd approaches involve bicomponent spinning to form filaments first of higher denier, and processing such spun higher denier filaments to obtain the filaments of reduced denier; such processing techniques are not the subject of the present invention.
• the present invention is concerned with the preparation of fine filaments by a novel direct spinning/winding process, in contrast with a process of first spinning and winding up bicomponent filaments of higher denier which then must be further processed to obtain the reduced fine denier filaments that are desired for use in textiles.
• Another 2-stage possibility of manufacturing filaments of reduced denier is to spin filaments of greater than one denier, and then, draw the filaments after the spinning operation, but this possibility has important disadvantages that have been discussed in the art; on the one hand, there are practical limitations to the amount of draw that can be effected; there are also product disadvantages in the properties of drawn yarns, as contrasted with direct spin-oriented yarns; and the cost of such processing (i.e., drawing) has to be considered, especially when the drawing is performed as a separate operation, after first packaging the spun filaments, such as single yarn or warp drawing.
• Such drawing proposals may have involved conventional drawing techniques, or may have involved other techniques, e.g., aerodynamic effects or reheating the filaments after they have been solidified, but still advancing under sufficient tension to draw (sometimes referred to as space-drawing, if performed without godets of differential speeds) .
• Some direct spinning processes that have been proposed have relied on use of specific polymer compositions, for instance specific viscosities, that have disadvantages, so it would be ⁇ tJ 5 desirable to use a process that does not require use of special viscosities or other special compositional aspects.
• filaments of the invention are "spin-oriented", the significance of which is
• the art discloses fundamental differences in fine structure and properties between filaments that are spin-oriented, indicating orientation of the polyester molecules obtained from the (high speed) spinning, and drawn filaments, indicating orientation derived from drawing of the filaments as an entirely separate process, after winding the spun filaments, or even as a continuous process, before winding, but after cooling the melt to form solid filaments before drawing such filaments.
• An object of the present invention is to provide fine filaments that have the characteristics of being spin-oriented, because of the advantageous properties that are provided by this characteristic.
• spin-oriented polyester fine filaments especially suitable for use as direct-use textile yarns, without need for additional draw or heat treatments, in critically dyed flat woven and knit fabrics; for use as feed yarns for air-jet texturing and stuffer-box crimping, wherein no draw is required; and may be uniformly cold drawn, if desired, to prepare warp yarns of higher shrinkage with dye uniformity suitable for critically dyed end-uses;
• mixed filament yarns wherein the fine filaments are of this invention; and especially mixed filament yarns, wherein, all filaments are of this invention, but differ in denier, cross-section, and/or shrinkage potential.
• the polyester polymer is selected to have a relative viscosity (LRV) in the range of about 13 to about 23, a zero-shear melting point (T ⁇ 0 ) in the range of about 240°C to about 265°C, and a glass transition temperature (Tg) in the range of about 40°C to about 80°C;
• LDV relative viscosity
• T ⁇ 0 zero-shear melting point
• Tg glass transition temperature
• said polyester is melted and heated to a temperature (Tp) in the range of about 25°C to about 55°C, preferably in the range of about 30°C to about 50°C, above the apparent polymer melting point (Tt ⁇ ) a ;
• the resulting melt is filtered sufficiently rapidly that the residence time (t r ) at polymer melt temperature (Tp) is less than about 4 minutes;
• the filtered melt is extruded through a spinneret capillary at a mass flow rate (w) in the range about 0.07 to about 0.7 grams per minute (g/min) , and the capillary is selected to have a cross-sectional area (A c ) in the range about 125xl0" 6 cm 2 (19.4 mils 2 ) to about 1250xl0 ⁇ 6 cm 2 (194 mils 2 ) preferably in the range of about 125xl0 ⁇ 6 cm 2 (19.4 mils 2 ) to about 750xl0" 6 cm 2 (116.3 mils 2 ) and a length (L) and diameter (DRND) such that the (L/Dpjjo)-ratio is at least about 1.25 and preferably less than about 6, and especially less than about 4;
• V withdrawal speed in the range of about 2 to about 6 kilometers per minute (km/min) , preferably in the range of about 2 to about 5 km/min, and especially in the range of about 2.5 to about 5 km/min;
• Polyester fine filaments of denier per filament about 1 or less, preferably in the range of about 0.8 to about 0.2 dpf, wherein, said polyester is characterized by having a relative viscosity (LRV) in the range of about 13 to about 23, a zero-shear polymer melting point (TM°) in the range of about 240°C to about 265°C, and a glass-transition temperature (Tg) in the range of about 40°C to about 80°C; and said fine filaments are further characterized by:
• a tenacity-at-7%-elongation (T7) in the range of about 0.5 to about 1.75 g/d, and such that the [ (Tg) n /T7]-ratio is of at least about (5/T7) and preferably at least about (6/T7) ; wherein, (T ⁇ ) n * s tne tenacity-at-break normalized to a reference LRV of 20.8 and % delusterant (such as i ⁇ 2) of 0%;
• Spin-oriented fine filaments especially suitable for use as draw eed yarns (DFY) , characterized by a boil-off shrinkage (S) at least about 12%, an elongation-at-break (E ⁇ ) in the range about 80% to about 160%, a tenacity-at-7%-elongation (T7) in the range about 0.5 to about 1 g/d.
• S boil-off shrinkage
• E ⁇ elongation-at-break
• T7 tenacity-at-7%-elongation
• a tenacity-at-7%-elongation (T7) of at least about 1 g/d such that the [ (Tg) n /T7]-ratio is at least about (5/T7) ; preferably at least about (6/T7) , wherein, (T ⁇ ) n is the tenacity-at-break normalized to a reference LRV of 20.8 and percent delusterant (such as Ti ⁇ 2) of 0%; and an elongation-at-break (Eg) in the range of about 15% to about 55%;
• a post-yield modulus (M py ) , preferably in the range about 5 to about 25 g/d;
• Bulked spin-oriented polyester fine filaments of denier after boil-off shrinkage, dpf (ABO),in the range of about 1 to about 0.2 dpf, preferably 0.8 to about 0.2 dpf, wherein, said bulked filaments are further characterized by a boil-off shrinkage (S) and dry heat shrinkage (DHS) in the range 2% to about 12%, an elongation-at-break (Eg) in the of range about 15% to about 55%, a tenacity-at-7%-elongation (T7) at least about 1 g/d, and preferably with a post-yield modulus (Mpy) in the range about 5 to about 25 g/d and a relative disperse dye rate (RDDR) , normalized to 1 dpf, of at least about 0.1.
• S boil-off shrinkage
• DHS dry heat shrinkage
• Eg elongation-at-break
• T7 tenacity-at-7%-elongation
• Mixed filament yarns wherein the fine filaments are of this invention; and especially mixed filament yarns, wherein, all filaments are of this invention, but differ in denier, cross-section, and/or shrinkage potential.
• Preferred such spin-oriented, bulked and drawn flat filaments are capable of being dyed with cationic dyestuffs, on account of containing in the range of about 1 to about 3 mole % of ethylene-5-M- sulfo-isophthalate structural units, where M is an alkali metal cation, such sodium or lithium.
• Especially preferred such spin-oriented, bulked, and drawn flat filaments capable of being disperse dyed uniformly under atmospheric conditions without carriers are characterized by a dynamic loss modulus peak temperature TfE' ⁇ ax) of less than about 115°C, preferably less than about 110°C; and are of polyester polymer, essentially poly(ethylene terephthalate) , composed of first alternating hydrocarbolenedioxy structural units A, [-O-C2H4-O-] , and hydrocarbolenedicarbonyl structural units B, [-C(0)-CgH4-C(0)-] , modified with minor amounts of other hydrocarbolenedioxy structural units A and/or hydrocarbolenedicarbonyl structural units B, that are different from the first structural units, such as to provide a polyester polymer with a zero- shear melting point (TJI°) in the range about 240°C to about 265°C and a glass-transition temperature (Tg) in the range of about 40 ⁇ C to about 80°C.
• the filaments of the present invention may be nonround for enhanced tactile and visual aesthetics, and comfort, where said nonround filaments have a shape factor (SF) at least about 1.25, wherein the shape factor (SF) is defined by the ratio of the measured filament parameter (PJJ) and the calculated parameter ( P RND) for a round filament of equivalent cross- sectional area.
• Hollow filaments may be spun via post- coalescence from segmented spinneret capillary orifices to provide lighter weight fabrics with greater bulk and filament bending modulus for improved fabric drape.
• FIG. 1 is a graphical representation of spinline velocity (V) plotted versus distance (x) where the spin speed increases from the velocity at extrusion (V 0 ) to the final (withdrawal) velocity after having completed attenuation (typically measured downstream at the point of convergence, V c ) ; wherein, the apparent internal spinline stress ( ⁇ a ) is taken as being proportional to the product of the spinline viscosity at the neck point (»?)N , (i.e., herein found to be approximately proportional to about the ratio LRV/Tp 6 , where Tp is expressed in °C),and the velocity gradient at the neck point (dV/dx) , (herein found to be approximately proportional to about V 2 /dpf, especially over the spin speed range of about 2 to 4 km/min and proportional to about V 3 / 2 /dpf at higher spin speeds, e.g., in the range of about 4 to 6 km/min) .
• the spin line temperature is also plot
• FIG. 2 is a graphical representation of the birefringence ( ⁇ n ) of the spin-oriented filaments versus the apparent internal spinline stress ( ⁇ ) a ; wherein the slope is referred to as the "stress-optical coefficient, SOC" and Lines A, B, and C have SOC values of 0.75, 0.71, and 0.645 (g/d)" 1 , respectively; with an average SOC of about 0.7; and wherein Lines A and C are typical relationships found in literature for 2GT polyester.
• the values of the apparent internal spinline stress ( ⁇ a ) agree well with values found in literature.
• FIG. 3 is a graphical representation of the tenacity-at-7%-elongation (T7) of the spin-oriented filaments versus the apparent internal spinline stress ( ⁇ a ) .
• T7 apparent internal spinline stress
• the near linear relationship of birefringence ( ⁇ n ) and T7 versus the apparent internal spinline stress ( ⁇ a ) permits the use of T7 as a useful parameter being representative of the filament average orientation.
• Birefringence ( ⁇ n ) is typically very difficult structural parameter to measure for fine filaments with deniers less than 1.
• the process of the invention is described by the enclosed region ADLI with region ADHE (II) preferred for preparing direct-use filaments and region EHLI (I) preferred for preparing draw feed yarns.
• regions BCGF and FGKI are represented by regions BCGF and FGKI.
• FIG. 5 is a representative Instron load- extension curve showing the graphical calculation of the "secant" post-yield modulus (M p y) calculated from the tenacity-at-7%-elongation (T7) , denoted by point C, and from the tenacity-at-20%-elongation ( 20) denoted by point A, and defined by the expression
• FIG. 6 is a graphical representation of the secant M py (tan ⁇ in FIG. 5) versus birefringence ( ⁇ n ) of spin-oriented filaments.
• M p y post-yield modulus
• FIG. 7 is a graphical representation of the Relative Disperse Dye Rate (RDDR) , as normalized to 1 dpf, versus the average filament birefringence ( ⁇ n ) .
• RDDR Relative Disperse Dye Rate
• FIG. 8 is a graphical representation of the filament amorphous free-volume of the fiber (Vf am , as defined herein after) , versus the peak temperature of the fiber dynamic loss modulus, T(E" max ), taken herein as a measure of the glass transition temperature which is typically 20°C to about 50°C above the Tg of the polymer.
• T(E" max) the peak temperature of the fiber dynamic loss modulus
• a decreasing T(E"max) value corresponds to greater amorphous free-volume (Vf am ) , and hence to improved dyeability, as measured herein by a Relative Disperse Dye Rate (RDDR) value (normalized to 1 dpf) of at least about 0.1.
• RDDR Relative Disperse Dye Rate
• FIG. 9 is a graphical representation of the filament density (p) versus birefringence ( ⁇ n ) ; wherein the diagonal lines represent combinations of density (p) and ( ⁇ n ) of increasing fractional amorphous orientation (f a ) , used in the calculation of the free- volume Vf am depicted in FIG. 8.
• FIG. 10 is a representative Differential Scanning Calorimetry (DSC) spectrum showing the thermal transitions corresponding to the glass-transition temperature (Tg) , onset of "cold" crystallization T CC (DSC) and the zero-shear melting point TJJ of the fiber, which is higher than the zero-shear melting point T M ° of the polymer due to the effect of orientation and crystallinity of the fiber melting point.
• TJJ° glass-transition temperature
• T JJ° the zero-shear melting point
• FIG. 11 is a representative shrinkage tension (ST)-temperature spectrum for the spin-oriented fine polymer filaments of the invention showing the maximum shrinkage tension ST( max ) , peak temperature T(ST max ) and the preferred "heat set" temperature T se t below which heat setting does not appreciably adversely affect dye ability.
• FIG. 13 is a graphical representation of the preferred values for the tenacity-at-break (Tg) n , normalized for the affects of LRV and percent delusterant (such as Ti ⁇ 2) , plotted as the (Tg) n /T7- ratio versus the reciprocal of the T7 (i.e., versus I/T7) ; wherein.
• FIG. 13 is a graphical representation of the preferred values for the tenacity-at-break (Tg) n , normalized for the affects of LRV and percent delusterant (such as Ti ⁇ 2) , plotted as the (Tg) n /T7- ratio versus the reciprocal of the T7 (i.e., versus I/T7) ; wherein. Curve A: [( g) n
• the slope "n" from a ln-ln plot is found to be about negative 0.7 (-0.7); that is, the tenacity- at-7%-elongation (T7) is found to vary proportionally to (V 2 /dpf) and to [(#c) (Dref/Dsprt) 2 r 0 - 7 ; that is, the tenacity-at-7%-elongation (T7) decreases approximately linearly with an increase in the filament extrusion density to the power of plus 0.7 (+0.7); and thereby the filament extrusion density may be used to as a process parameter to spin finer denier filaments at higher spinning speeds (V) .
• the polyester polymer used for preparing spin-oriented filaments of the invention is selected to have a relative viscosity (LRV) in the range about 13 to about 23, a zero-shear melting point (TJJ°) in the range about 240°C to about 265°C; and a glass- transition temperature (Tg) in the range about 40 ⁇ C to about 80°C (wherein T ⁇ 0 and Tg are measured from the second DSC heating cycle under nitrogen gas at a heating rate of 20°C per minute) .
• LRV relative viscosity
• TJJ° zero-shear melting point
• Tg glass- transition temperature
• the said polyester polymer is a linear condensation polymer composed of alternating A and B structural units, where, A is a hydrocarbolenedioxy unit of the form [-O-R'-O-] and B is a hydrocarbolenedicarbonyl unit of the form [-C(0)-R"-C(0)-], wherein, R* is primarily [-C2H4-] , as in the ethylenedioxy (glycol) unit [-O-C2H2-O-3 , and R" is primarily [-C5H4-], as in the 1,4-benzenedicarbonyl unit [-C(0)-C5H4-C(0)-] , such to provide, for example, at least about 85 percent of the recurring structural units as ethylene terephthalate, C-0-C 2 H 4 -0-C(0)-C 6 H 4 -C(O)-] .
• Suitable poly(ethylene terephthalate) herein denoted as PET or 2GT, based polymer may be formed by the DMT-process as described by H. Ludwig in his book “Polyester Fibers, Chemistry and Technology", John Wiley and Sons Limited (1971) , and by the TPA-process as described in Edging U. S. Patent No. 4,110,316.
• copolyesters in which, for example, up to about 15 percent of the hydrocarbolenedioxy and/or hydrocarbolenedicarbonyl units are replaced with different hydrocarbolenedioxy and hydrocarbolenedicarbonyl units to provide enhanced low temperature disperse dyeability, comfort, and aesthetic properties.
• Suitable replacement units may be found in Most U. S. Patent No. 4,444,710 (Example VI), Pacofsky U. S. Patent No. 3,748,844 (Col. 4), and Hancock, et al. U. S. Patent No. 4,639,347 (Col. 3).
• the polyester polymer may also be modified with ionic dye sites, such as ethylene-5-M-sulfo- isophthalate residues, where M is an alkali metal cation, such as sodium or lithium; for example, in the range of 1 to about 3 mole percent ethylene-5-sodium- sulfo-isophthalate residues may be added to provide dyeability of the polyester filaments with cationic dyestuffs, as disclosed by Griffing and Remington U. S. Patent No. 3,018,272, Hagewood etal in U. S. Patent No. 4,929,698, Duncan and Scrivener U. S. Patent No.
• DEG diethylene glycol
• a process for preparing spin-oriented polyester filaments having a fineness for example, in the range of about 1 to about 0.2 denier per filament (dpf), preferably in the range about 0.8 to about 0.2 denier per filament (dpf) ;
• T M )a tT M ° + 2X10-4(L/DRHoJGa], where L is the length of the capillary and D ND is the capillary diameter for a round capillary, or for a non ⁇ round capillary, wherein, for a non-round capillary, D ND ( cm ) i the calculated equivalent diameter of a round capillary of equal cross-section area A c (cm 2 ) ; and G a (sec -1 ) is the apparent capillary shear rate defined, herein after;
• the free-volume (Vp,cm 3 ) of the filter cavity (filled with the inert filtration medium) is experimentally determined by standard liquid displacement techniques using a low surface tension liquid, such as ethanol.
• the residence time t r decreases with increasing filament denier, withdrawal speed (V) and number of filaments (#c) P er filter cavity, and decreases with a reduction in the filter cavity free-volume (Vp) .
• the cavity free-volume (Vp) may be decreased by altering the pack cavity dimensions and by utilizing inert material which provides sufficient filtration capabilities with less free-volume.
• the number of filaments (i.e, capillaries) per filter cavity (# c ) may be increased for a given yarn count by extruding more than one multifilament bundle from a single filter cavity, that is, spinning a larger number of filaments and then splitting (herein, called multi-ending) the filament bundle into smaller filament bundles of desired yarn denier, preferably by using metered finish tip separator guides positioned between about 50 cm to about (50+90dpf ⁇ )cm;
• the filtered polymer melt is extruded through a spinneret capillary at a mass flow rate (w) in the range of about 0.07 to about 0.7 grams per minute (g/min) and the capillary is selected to have a cross-sectional area, A c - (T/4)DRJJD 2 in the range of about 125xl0 ⁇ 6 cm 2 (19.4 mils 2 ) to about I250xl0 -6 cm 2 (194 mils 2 ), preferably in the range of about 125X10"" 6 cm 2 (19.4 mils 2 ) to about 750xl0"” 6 cm 2 (116 mils 2 ), and a length (L) and diameter (DRJJD) such that the L/DRN D - ratio is in the range of about 1.25 to about 6, preferably in the range of about 1.25 to about 4; wherein,
• G a (sec-1) [(32/60T) (W/P)/DRN D 3 ],
• w is the capillary mass flow rate (g/min)
• p is the polyester melt density (taken as 1.2195 g/cm 3 )
• D RND is tne capillary diameter (defined herein before) in centimeters (cm) ;
• ⁇ a an apparent spinline strain in the range of about 5.7 to about 7.6, preferably in the range of about 6 to about 7.3
• the apparent spinline strain ⁇ a is defined as the natural logarithm (In) of the spinline extension ratio (ER) , and ER is the ratio of the withdrawal speed (V) and the capillary extrusion speed (V 0 ) ; that is, for DRJJ Q in centimeters, ⁇ a is given by:
• an apparent internal spinline stress ( ⁇ a ) in the range of about 0.045 to about 0.195 g/d, preferably in the range of about 0.045 to about 0.105 g/d for preparing spin-oriented filaments, especially suitable for draw feed yarns (DFY) , characterized with tenacity-at-7%-elongation (T7) values in the range of about 0.5 to about 1 g/d, and preferably an apparent internal spinline stress ( ⁇ a ) in the range of about 0.105 to about 0.195 g/d for preparing spin-oriented filaments especially suitable for direct-use yarns (DUY) , characterized by tenacity-at-7%-elongation (T7) in the range of about 1 to about 1.75 g/d; wherein, the apparent internal spinline stress ( ⁇ a ) is defined herein by the product of the apparent viscosity of the attenuating melt ( ⁇ m ) and the spinline velocity gradient (dV/dx)
• k has an approximate value of 10 -2 (Pm/SOC) , where p m is the density of the spin-oriented filaments (e.g., in the range of about 1.345 to about 1.385 g/cm 3 , that is about 1.36 g/cm 3 ) and SOC is the "stress-optical coefficient" for the polyester polymer (e.g., about 0.7 in reciprocal g/d for 2GT homopolymer) ; TR is the polymer reference temperature defined by (TJJ° + 40°C) where TJI 0 is the zero-shear (DSC) polymer melting point; Tp is the polymer melt spin temperature, °C; V is the withdrawal speed expressed in km/min; # c is the number of filaments
• LRV is the measured polymer (lab) viscosity and LRV20.8 i the corresponding reference LRV-value (where LRV is defined herein after) of the polyester polymer having the same zero-shear "Newtonian" melt viscosity (r, 0 ) at 295°C as that of 2GT homopolymer having an LRV-value of 20.8 (e.g., cationic-dyeable polyester of 15 LRV is found to have a melt viscosity as indicated by capillary pressure drop in the range of 2GT homopolymer of about 20 LRV and thereby a preferred reference LRV for such modified polymers is about 15.5 and is determined experimentally from standard capillary pressure drop measurements) ;
• V withdrawal speed
• V the surface speed of the first driven roll
• the retractive forces from aerodynamic drag are reduced by relaxing the spinline between the first driven roll and the windup roll by overfeeding in the range of about 0.5 to about 5%, without the application of heat (except for use of heated interlace jet fluid (such as heated air or water-saturated air) for preventing finish deposits forming on the interlace jet surfaces as described by Harris in U. S. Patent No. 4,932,109.
• polyester fine filaments of this invention are manufactured by a simplified direct spin- orientation (SDSO) process which does not incorporate drawing or heat treatment, and therein provides a preferred balance of shrinkage and dyeability behavior making the polyester fine filaments of the invention especially suitable for replacement of natural continuous filaments, such as silk.
• SDSO direct spin- orientation
• fine filaments with excellent mechanical quality and uniformity are made; such that the fine filaments, having shrinkages less than about 12%, may be used in multifilament direct-use yarns (DUY) and processed without forming broken filaments in high speed weaving and knitting; and filaments, having shrinkages preferably greater than about 12%, may be used in multifilament draw-feed yarns (DFY) in high speed textile draw processes, such as friction-twist texturing, air-jet texturing, stuffer-box crimping and warp-drawing, without forming broken filaments.
• DY multifilament direct-use yarns
• DFY multifilament draw-feed yarns
• the fine filaments of this invention are characterized by having excellent mechanical quality permitting yarns made from these filaments to be used in high speed textile processes, such as draw false- twist and air-jet texturing, warp drawing, draw gear Z .
• the filaments of this invention are further characterized by having excellent denier uniformity (as defined herein by along-end denier spread, DS) permitting use in critically dyed fabrics.
• the filaments of this invention may be used as filaments in draw feed yarns (and tows) , preferably filaments having boil-off shrinkage (S) and dry heat shrinkage (DHS) greater than about 12% are especially suitable for draw feed yarns; and filaments of this invention, having shrinkages less than about 12%, are especially suitable flat untextured multifilament yarns, and as yarns for such texturing processes as air-jet texturing, gear crimping, and stuffer-box crimping, wherein, no draw need be taken, and the flat and textured filaments of this invention may be cut into staple fibers and flock; but the filaments with shrinkages less than about 12% may be uniformly cold drawn as described by Knox and Noe in U. S. Patent No. 5,066,447.
• polyester fine filaments of about 1 dpf or less, preferably less than about 0.8 dpf, especially less than about 0.6 dpf, and greater than about 0.2 dpf; wherein said polyester is of relative viscosity (LRV) in the range of about 13 to about 23, with a zero-shear polymer melt temperature (TJJ°) in the range of about 240°C to about 265°C, and polymer glass transition temperature (Tg) in the range of about 40°C to about 80°C; and said filaments are further characterized by:
• a maximum shrinkage tension, (ST max ) between about 0.05 and about 0.2 g/d, with the peak temperature of maximum shrinkage tension, T(ST max ) , between about (Tg+5°C) and about (Tg+30°C) ; i.e.. between about 75°C and about 100 ⁇ C for poly(ethylene terephthalate) with a polymer Tg of about 70°C;
• Spin-oriented fine filaments are further characterized by: (a) boil-off shrinkage (S) and dry heat shrinkage (DHS) between in the range of about 2% to about 12%, preferably in the range of about 6% to about 12% for woven and preferably in the range of about 2% to about 6% for knits, such that the filament denier after boil-off, dpf(ABO) - dpf(BBO)x[ (100/(100-S) ] , is in the range of about 1 to about 0.2 dpf, preferably in the range of about 0.8 to about 0.2 dpf, and especially in the range of about 0.6 to about 0.2 dpf;
• S boil-off shrinkage
• DHS dry heat shrinkage
• T cc an onset of cold crystallization, T cc (DCS) , of less than about 105°C, as measured by differential scanning calorimetry (DSC) at a heating rate of 20°C per minute;
• the shrinkage (S) of said drawn filaments may be reduced, if desired, without significant loss in dyeability provided that the post heat set temperature (T se t) i less than about the temperature at which the shrinkage tension undergoes no significant further reduction with increasing temperature; that is, it is preferred to maintain T se t less than about the temperature at which the onset of rapid (re)- crystallization begins.
• the maximum value for T se t is herein, defined as the temperature, at which the slope, [d(ST)/dT], of a shrinkage tension versus temperature spectrum abruptly decreases in value (becoming less negative) - see FIG. 11.
• boil-off shrinkages S
• DHS dry heat shrinkages
• T(E"max) a dynamic loss modulus peak temperature, T(E"max) less than about 115°C; and preferably less than about 110 ⁇ C;
• Bulky fine filament yarns are provided by passing the fine filament yarns of this invention through a bulking process, such as air-jet 5 texturing, false-twist texturing, stuffer-box and gear crimping; wherein, said bulky filaments are characterized by having individual filament deniers (after shrinkage) less than about 1, preferably less than about 0.8, with boil-off shrinkage (S) and dry 0 heat shrinkage (DHS) less than about 12% and characterized by a T(E" max ) of less than about 115°C, preferably less than about 110 ⁇ C, and a RDDR of at least about 0.1, and preferably at least about 0.15.
• a bulking process such as air-jet 5 texturing, false-twist texturing, stuffer-box and gear crimping; wherein, said bulky filaments are characterized by having individual filament deniers (after shrinkage) less than about 1, preferably less than about 0.8, with boil-off shrinkage (S) and dry 0 heat shrinkage (DHS
• Especially preferred filaments for use in 5 direct-use yarns are also characterized by:
• Vf /am an amorphous free-volume (Vf /am ) of at least about 0.5xl0 6 cubic angstroms (A 3 ), preferably at least about lxlO 6 A 3 , where Vf am is defined herein by (CS) 3 [(1-X V )/X V )] [(l-f a )/f a ], providing a dynamic loss modulus peak temperature, T(E" max ), less than about 115°C, and preferably less than about 110°C;
• an atmospheric relative disperse dye rate normalized to 1 dpf, of at least about 0.1, and preferably at least about 0.15.
• Poly(ethylene terephthalate) having a polymer LRV in the range of about 13 to about 23 (which corresponds to an [17] in the range of about 0.5 to about 0.7), preferably in the range of about 13 to about 18 for ionically modified polyesters, and in the range of about 18 to about 23 for nonionically modified polyesters, a zero-shear melting point (T ⁇ 0 ) in the range of about 240 ⁇ C to about 265°C, and a glass- transition temperature (Tg) in the range of about 40°C to about 80°C, and containing minor amounts of delusterants and surface friction modifiers (e.g., Ti ⁇ 2 and Si ⁇ 2) , is melted at a polymer temperature Tp (°C) and filtered through inert medium for a residence (hold-up) time (t r , min) and then extruded through spinneret capillaries of diameter (DRN Q ) with length (L) at a capillary mass flow rate w [ (
• filaments of most of the examples herein were spun from spinnerets having a filament density per extrusion surface area in the range of typically about 2.5 to about 13, while it was possible to spin and quench filament bundles with a extrusion filament density as high as about 25 provided capillary hole pattern (filament array) was optimized for the type of quench (i.e., radial vs.
• extrusion filament density is defined by the ratio of the number of filaments (# c ) divided by the extrusion surface area (A 0 ),(i.e., # C /A 0 ,cm"" ) , into a "shroud” which protects the freshly extruded filaments from direct quench air for a distance at least about 2 cm and not greater than about (12dpf ⁇ ,cm) ; and then carefully cooled to a temperature less than about polymer Tg, preferably by radially directed air having a temperature T (herein about 22°C) less than about the polymer Tg (herein T a was about 70°C for 2GT homopolymer) and of linear velocity V a (m/min) in the range of about 10 to about 30 m/min.
• Suitable spinning apparatus used are essentially as that described in ⁇ . S. Patent Nos.
• the along-end denier spread (DS) and draw tension variation (DTV) were minimized by balancing the values for the delay quench length (L ⁇ Q) , the quench air temperature (T a ) , the quench air flow rate (V a ) , and the convergence length (L c ) , while selecting Tp for spinning continuity.
• Tp polymer spin temperature
• Tp but less than about [ (T ⁇ ) a + 55°C] usually increases spinning continuity and mechanical quality (i.e., T ⁇ , g/d), but usually decreases along- end uniformity and increases shrinkage.
• incipient shear-induced molecular ordering e.g., lower chain entropy and possible incipient "nucleation" of the polymer melt occurs, especially for polymer melt filtered prior to extrusion for residence times (t r ) greater than about 4 minutes, wherein this molecular ordering (possible incipient nucleation) is believed to increase the apparent polymer melting point from the zero-shear value (TJI°) to an apparent value (Tjj) a .
• This has the effect of reducing the spin temperature differential, Tp-(T M ) a .
• the bulk polymer temperature Tp needs to be further increased as given by the amount defined by the expression: 2xl0"" 4 (L/D RND )G a , °C, for the selected values of L, D RND' and G a .
• the apparent internal spinline stress ( ⁇ a ) at the "neck- point" is controlled in the range of about 0.045 to about 0.195 g/d while controlling the melt extension strain ⁇ a in the range of about 5.7 to about 7.6.
• the attenuated and cooled filaments are converged into a multifilament bundle and withdrawn at a spinning speed (V, km/min) as defined by the surface speed of the first driven roll.
• the external spinline tension arising from frictional surfaces (and air drag) is removed prior to packaging by slightly over feeding the spinline between the first driven roll and the windup, usually between about 0.5% and 5%. Finish is applied at the point of convergence and interlace is provided, preferably after the first driven roll.
• the values for finish-on-yarn (weight, %) and degree of filament entanglement (RPC) are selected to meet end-use processing needs.
• Polyester fine filaments of the invention are of good mechanical quality and uniformity having a linear density less than about of that of natural worm silk, but greater than that of spider silk, that is between about 1 and about 0.2 denier per filament, and having the capability of being uniformly dyed without use of high temperatures and chemical dye assists; that is, more akin to that of natural silks.
• the fine denier filament yarns may be treated with caustic in spin finish (according to the invention as taught by
• Fine filaments of lower shrinkage may be obtained, if desired, by incorporating chain branching agents, on the order of about 0.1 mole percent, as described in part in Knox U. S. Patent No. 4,156,071, MacLean U. S. Patent No. 4,092,229, and Reese in U. S. Patents Nos. 4,883,032, 4,996,740, and 5,034,174; and/or increasing polymer viscosity by about +0.5 to about +1.0 LRV units.
• the fine filament yarns of this invention are suitable for warp drawing, air jet texturing, false- twist texturing, gear crimping, and stuffer-box crimping, for example; and the low shrinkage filament yarns may be used as direct-use flat textile yarns and a feed yarns for air-jet texturing and stuffer-box crimping wherein no draw is need be taken.
• the filaments (and tows made therefrom) may also be crimped (if desired) and cut into staple and flock.
• the fabrics made from these improved yarns may be surface treated by conventional sanding and brushing to give suede-like tactility.
• the filament surface frictional characteristics may be changed by selection of cross- section, delusterant, and through such treatments as alkali-etching.
• the improved combination of filament strength and uniformity makes these filaments, especially suited for end-use processes that require fine filament yarns without broken filaments (and filament breakage) and uniform dyeing with critical dyes.
• the fine denier filament polyester yarns of the invention are especially suitable for making of high-end density moisture-barrier fabrics, such as rainwear and medical garments.
• the surface of the knit and woven fabrics can be napped (brushed or sanded) .
• the filaments may be treated (preferably in fabric form) with conventional alkali procedures.
• the fine filament yarns especially those capable of being cationic dyeable, may also be used as covering yarns of elastomeric treatments yarns (and strips) , preferably by air entanglement as described by Strachan in U. S. Patent No. 3,940,917.
• the fine filaments of the invention may be co-mingled on-line in spinning or off-line with higher denier polyester (or nylon) filaments to provide for cross- dyed effects and/or mixed shrinkage post-bulkable potential, where the bulk may be developed off-line, such as over feeding in presence of heat while beaming/slashing or in fabric form, such as in the dye bath.
• the degree of interlace and type/amount of finish applied during spinning is selected based on the textile processing needs and final desired yarn/fabric aesthetics.
• Yarns of 100 and 300 filaments of nominal 0.5 dpf were spun from poly(ethylene terephthalate) of 19 LRV (corresponding to about 0.60 [ ⁇ ] ) and containing 0.3 weight percent of Ti ⁇ 2-
• the 300-filament yarns were spun using spinnerets of varying construction; e.g.
• T ⁇ The normalized values for T ⁇ (denoted herein by (T ⁇ ) n ) are defined by the product the measured tenacity-at-break (T ⁇ ) and the factor (20.8/LRV) 0 - 75 (l-X) -4 which for these yarns is about 1.057; thereby, the normalized break tenacities (T ⁇ )n are about 6% higher when compared to reference LRV and % Ti0 2 of 20.8 and 0%, respectively.
• the fine filament yarns of this example were capable of being dyed to deep shades at atmospheric conditions (100°C) without use of dye carriers as given by an Relative Disperse Dye rate (RDDR)-value (normalized to a 1 dpf) of about 0.16 versus an RDDR- value of 0.055 for a conventional fully drawn yarn.
• RDDR Relative Disperse Dye rate
• the 300-filament yarn bundle into 2,3 or 4 individual bundles of 150, 100, and 75-filament yarn bundles, respectively, preferably by use of metered finish tip separating guides at the exit of the radial quench chamber. Multi-ending permits a higher mass flow rate (w) through the filter pack cavity and thereby reducing the residence time (t r ) in the pack cavity per threadline.
• Fine filaments were spun from poly(ethylene terephthalate) of nominal 20.8 LRV (about 0.65 [ ⁇ ]) and containing 0.1 weight percent Ti ⁇ 2 at a withdrawal speed (V) of 4000 ypm (3.66 km/min) using a radial quench apparatus, essentially as described in Example I, except for having a delay "shroud" length (LDQ) of about 2.25 inches (5.72 cm).
• LDQ delay "shroud" length
• Example III 68-and 136-(unplied and plied) filament yarns were spun, essentially according to Example I, except convergence was by a metered finish tip as described in U. S. Patent No. 4,926,661 for Examples III-l through III-9 and III-ll through 111-25.
• Example 111-10 used a metering finish roll surface to converge the filaments as described in Examples I and II. Other process details are summarized in Tables I and II.
• the filaments of Example III-l through III-5 and 111-12 through 111-15 have ⁇ 7-values greater than about 1 g/d making them especially suitable for use as filaments in direct-use textile filament yarns and as feed yarns in air-jet textured, wherein no draw is taken; and, if desired, can be drawn uniformly without heat (cold) in warp drawing (and air-jet texturing) as described in Knox and Noe U. S. Patent No. 5,066,447.
• the filaments of 111-6,7, and 111-16 through 111-25 with T 7 -values less than about 1 g/d are especially suitable as filaments in draw feed yarns (DFY) , such as draw false-twist texturing (FTT) and draw air-jet texturing (AJT) or as draw feed yarns in warp drawing.
• DTY draw feed yarns
• FTT draw false-twist texturing
• AJT draw air-jet texturing
• Example III-4 had a spinning continuity of 0.39 breaks per 1000 lbs. (0.86 per 1000 kg) which is equivalent to about 9.5 breaks per 10 9 meters.
• the yarns of Example III-4 were wound with about 10 cm interlace (as measured by the rapid pin count procedure described in U. S. Patent No. 3,290,932) for air-jet texturing on a Barmag FK6T-80 without drawing and wound with about 5-7 RPC interlace for direct-use as a flat textile yarn in wovens and warp knits.
• Example III-6 and 7 were drawn without broken filaments at 1.44X and 1.7X, respectively, to give drawn 35 denier 68-filament yarns.
• Example III-6 is preferred versus III-7 since the spinning productivity (spun denier x spin speed) of III-6 is about 25% greater than Example III-7.
• Yarns of Example III-6 were successfully cold warp drawn using a 1.44X draw-ratio.
• Residence times (t r ) less than about 4 minutes for high L/DRN capillary spinnerets are found to be necessary to spin without having to use high "input" polymer temperatures (Tp) .
• Tp polymer temperatures
• Example IX for a more detailed discussion about the spinning with high shear capillary spinnerets.
• 136- filament yarns were spun using 136-9x36 mil (0.229x0.916 mm, 0.0229x0.0916 cm) capillaries per spinneret, and thereby reducing the filtration residence time (t r ) by 50%, to provide yarns with good mechanical quality.
• the high filament count yarns are especially suitable for draw air-jet texturing (AJT) and for false-twist texturing (FTT) , wherein, a straight draw-texturing machine configuration is preferred.
• Yarns from Examples 111-19,22,24 and 25 were used for preparing warp drawn flat yarns of nominal 0.5 dpf as described in Example XII.
• Example 111-10 The structural properties of th.j filaments of Example 111-10 are representative of spin-oriented filaments of this invention having shrinkages less than 6%.
• LRV about 0.66 [7j]
• LRV about 0.66 [7j]
• LDQ length of the delay "shroud”
• the filament bundles were converged by a metered finish tip at 43 inches (109 cm) from the face of the spinneret.
• Tables III and IV Other process details are summarized in Tables III and IV.
• Increasing weight percent Ti ⁇ 2 is observed to decrease the tenacity-at- break (T13) of these fine filaments.
• the amount of Ti ⁇ 2 is usually varied between about 0.035% for minimum yarn-to-metal and yarn-to-yarn frictional needs and less than about 1.5%, more typically less than about 1% for desired mechanical quality and visual aesthetics.
• Poly(ethylene terephthalate) of nominal 21.1 LRV (about 0.655 [ ⁇ ] ) and containing 0.3 weight percent Ti0 2 was spun using apparatus similar to Example IV.
• Examples V-l through V-4, IV-9 and IV-10 use 12x50 mil (0.305x1.270 mm, 0.0305x0.127 cm) spinneret capillaries.
• Examples V-5, 7, 8, and 11 through 13 use 9x36 mil (0.229x0.914 mm, 0.0229x0.0914 cm) spinneret capillaries, and Example V-6 uses 6x18 mil (0.152x0.457 mm, 0.0152x0.0457 cm) spinneret capillaries to spin 100-filament 85 denier feed yarns for warp draw and draw air-jet texturing (AJT) .
• the length of delay quench (LDQ) was increased from 2-5/8 inches (6.7 cm) to 4-5/8 inches (11.7 cm) in EX. V-8 and V-10.
• L D Q Increasing the length of delay (L D Q) , increased along- end non uniformity 4X and interfilament denier non uniformity, as measured optically from yarn bundle cross-sections, by 2X.
• the delay length (L Q) is less than about (12dpf%)cm, good uniformity may be obtained.
• Examples V- 11 through V-13 have tenacity-at-7%-elongation (T7) values less than about 1 g/d making them especially suitable as draw feed yarns even though the shrinkages of the undrawn yarns were less than 12%.
• T7 tenacity-at-7%-elongation
• Example VI Example V-13 was repeated at 3300 ypm (3.02 km/min) for varying spun deniers, delay quench lengths (LDQ) , spinning temperatures (Tp) , and convergence guide lengths (L Q ) .
• Example VI-2 with a denier spread (DS) of 3.8% was successfully drawn 1.35X to give a drawn 0.3 dpf 100-filament yarn with a 2.3% denier spread, tenacity of 4.4 g/d. Eg of 32.5% and a boil-off shrinkage(S) of 6.3%.
• DS denier spread
• S boil-off shrinkage
• Fine trilobal filaments were spun from poly(ethylene terephthalate) of nominal 21 LRV (about 0.65 [77] containing 0.035 weight percent Ti0 2 using spinnerets with 9x36 mil (0.229x0.914 mm, 0.0229x0.0914 cm) and 12x50 mil (0.305x1.270 mm, 0.0305x0.127 cm) metering capillaries and a Y-shaped exit orifices of area (A c ) of about 197 mils 2 (1.27 mm 2 , 0.0127 cm 2 ), which corresponds to a DRJJD of about 15.9 mils (0.40 mm, 0.04 cm) with an L/DJ ⁇ JD of about 1.5 (as essentially as described in Examples 45-47 of U.
• the 9x36 mil metering capillaries provided better mechanical quality and along-end denier uniformity than the 12x50 mil metering capillaries.
• the 100-filament yarns could be drawn without forming broken filaments to nominal 50 denier, or about 0.5 dpf.
• Poly(ethylene terephthalate) polymer modified with about 2 mole % of ethylene 5-sodium-sulfo isophthate having a nominal LRV of about 15.3 was spun using a laminar cross-flow quench apparatus with a 2.2 inches (5.6 cm) delay, essentially as described in U. S. Patent No. 4,529,638, and converging the filament bundle at about 43-inches (109 cm) with metered finish tip guides.
• the lower LRV is usually preferred for ionically modified polyesters because the ionic sites act as cross linking agents and provide higher melt viscosity.
• the 15 LRV used, herein, had a melt viscosity about that of a 20 LRV homopolymer.
• LRV LRV
• viscosity builders such as tetra-ethyl silicate (as described in Mead and Reese, U. S. Patent No. 3,335,211). It is generally preferred to spin ionically modified polyesters with LRV in the range of about 13 to about 18 and nonionically modified polyesters with LRV in the range of about 18 to about 23. Withdrawal speeds were increased from 2400 ypm (2.2 km/min) to 3000 ypm (2.74 km/min) . As expected the cationic copolymer yarns had lower Tg-values based on their lower LRV.
• the lower LRV is preferred for filaments yarns used in napped and brushed fabrics and for tows to be cut into flock.
• the as-spun yarns could be drawn without breaking filaments to about 50 denier 100-filament yarns.
• the cationically modified polyester had a RDDR value of 0.225 versus 0.125 for the 2GT homopolymer spun under similar conditions.
• Example IV LRV (about 0.67 [ ⁇ ]) and containing 0.3 weight percent Ti ⁇ 2 was spun using apparatus similar to Example IV with a air flow rate of about 30 m/min.
• Examples IX-1 through IX-3 use 12x50 mil (0.305x1.270 mm, 0.0305x0.127 cm) spinneret capillaries;
• Examples IX-4 through IX-8 use 9x36 mil (0.229x0.914 mm, 0.0229x0.0914 cm) spinneret capillaries; and .
• Examples IX-9 through IX-11 use 6x18 mil (0.152x0.457 mm, 0.0152x0.0457 cm) spinneret capillaries to spin nominal 50 denier 100-filament low-shrinkage yarns suitable as direct-use textile yarns for warp knits and wovens and as feed yarns for air-jet and stuffer-box texturing wherein no draw is required.
• Poly(ethylene terephthalate) of nominal 21.9 LRV (about 0.67 [ ⁇ ] ) and containing 0.3 weight percent Ti ⁇ 2 was spun using apparatus similar to Example IV with an air flow rate varied from about 11 to about 30 m/min.
• Examples X-l through X-9 use 12x50 mil
• spinneret capillaries and Examples X-10 through X-16 use 9x36 mil (0.229x0.914 mm, 0.0229x0.0914 cm) spinneret capillaries to spin nominal 70 denier 100-filament low- shrinkage yarns with T7-values greater than about l g/d, making these especially suitable as direct-use textile yarns for warp knits and wovens and as feed yarns for air-jet and stuffer-box texturing wherein no draw is required. It was observed that mechanical quality improved with higher polymer temperatures, and lower air flow rates.
• the fine filament feed yarns of Example V-ll, 12, and 13 were uniformly drawn cold and at 155°C at 1.45X, 1.5X, and 1.55X draw-ratios, respectively, to give nominal 50 denier 100-filament drawn yarns that can be used as flat textile yarns.
• the drawn fine filament yarns have excellent mechanical quality and along-end denier uniformity with boil-off shrinkages (S) less than about 6%.
• S boil-off shrinkages
• the cold drawn yarns had slightly less shrinkage than the hot drawn yarns and also were slightly more uniform. With less interlace levels and a different finish, these yarns may be cold drawn air-jet textured, consistent with the teachings of Knox and Noe in U. S. Patent No. 5,066,447.
• These fine filament spun yarns could also be used as feed yarns for draw air-jet/stuffer-box/friction-twist texturing. Warp draw process and product details are summarized in Table VII.
• Examples 111-20 through 25 were repeated by varying spin speed and spun denier to provide draw feed yarns capable of being drawn to provide 35 denier 68- filament yarns.
• Nominal 50 to 60 denier as-spun yarns with excellent mechanical quality and denier uniformity were drawn cold and heat set at 160°C to 180°C to obtain low shrinkage filaments of nominal 0.5 dpf yarns without loss in mechanical quality and along-end denier uniformity.
• Spin process and product details are summarized in Tables IV and V, and the corresponding draw process and product details are summarized in Table VII.
• Example XIII the ability to obtain high T 7 fine filament yarns was explored.
• Spinning apparatus similar to that in Example X was used.
• Poly(ethylene terephthalate) of nominal 20.8 LRV (0.65 [ij]) containing 0.3 weight percent Ti ⁇ 2 was extruded through 9x36 mil (0.229x0.914 mm, 0.0229x0.0914 cm) spinneret capillaries and cooled using a radial quench apparatus as described in Example I, except for having a delay length LDQ of about 2.25 inches (5.7 cm).
• the cooled filaments were converged into yarn bundles at a convergence length (L c ) of about 32 inches (81.3 cm) from the face of the spinneret by use of metered finish tip guides.
• the withdrawal speed (V) was varied from 4500 ypm (4.12 km/min) to 5300 ypm (4.85 km/min) to provide 68 and 100-filament direct-use textile yarns with T ⁇ -values between about 1 and 1.5 g/d.
• the process and product details are summarized in Table VI.
• the tensiles of Example XIII were inferior due to use of lower polymer melt temperature (Tp) and higher quench air flow rates (V a ) than in Example X.
• a 91 denier 100-filament yarn made according to Example IV was air-jet textured using a Barmag FK6T80 at 300 km/min; wherein, the as-spun yarns were drawn cold (about 40 ⁇ C) at 1.0X, 1.1X, 1.2X, and 1.32X draw-ratios and sequentially air-jet textured using a conventional air-jet at 125 lbs./in 2 (8.8 kg/cm 2 ) to provide bulky yarns with filament deniers between about 0.7 and 0.9 (before boil-off shrinkage) and between about 0.77 and 0.94 dpf (after boil-off shrinkage).
• the denier of the textured filament yarn showed an increase in yarn denier of about 11% due to bulk (e.g., filament loops), where the ratio (denier) AJT /(denier)FLAT is preferably greater than about 1.1); however, the filament denier showed no increase in denier.
• Example XIV-l and 2 were uniformly cold partially drawn, as defined herein, by providing a RDR of at least about 1.4X in the drawn yarn.
• Example XIV-5 through 8 68-filament yarns were sequentially draw cold and air-jet textured. The shrinkage increased with draw ratio, providing a route to higher shrinkage AJT yarns.
• Table VIII The process and product data for Example XIV is given in Table VIII.
• Co-mingling (plying) 2 or more cold drawn AJT yarn textile yarns wherein at least one AJT yarn has been heat set to shrinkages less than about 3%, and a second AJT yarn has not been heatset, so has significantly higher shrinkage, provides a simplified route to a mixed shrinkage yarn.
• Similar mixed shrinkage AJT yarns may be provided with the lower shrinkage component provided by alternate techniques, for instance by hot drawing, with or without heat setting.
• mixed shrinkage AJT yarns may be provided by co-mingling 2 or more drawn filament bundles wherein both bundles are drawn by cold drawing, without post heat treatment, but the bundles are cold drawn to different elongations, preferably by about 10% or more.
• the resulting mixed shrinkage drawn yarn may be AJT to provide a mixed shrinkage textured (bulked) yarn.
• Incorporating filaments of different deniers and/or cross-sections may also be used to reduce filament-to-filament packing and thereby improve tactile aesthetics and comfort.
• Unique dyeability effects may be obtained by co-mingling drawn filaments of differing polymer modifications, such as homopolymer dyeable with disperse dyes and ionic copolymers dyeable with cationic dyes.
• AJT process and product details are summarized in Table VIII.
• Example XV yarns were spun for use as draw feed yarns (DFY)in false twist texturing (FTT) .
• Example XV-1 a nominal 58 denier 68-filament yarn was textured at 500 m/min on a L900 PU machine with a 1.707 D/Y-ratio at a 1.628X draw to provide 68-filament textured yarns of nominal 37 denier (0.54 dpf) with a tenacity (T) of 4.1 g/d, an elongation-at-break (Eg) of 26.8%, a tenacity-at-7%-elongation (T 7 ) of 2.19 g/d, and an initial modulus (M) of 44.6 g/d.
• T tenacity
• Eg elongation-at-break
• T 7 tenacity-at-7%-elongation
• M initial modulus
• Example XV- 2 a nominal 118 denier 200-filament draw feed yarn was prepared for false twist texturing, as in Example XV-1, except with a D/Y-ratio of 1.59 at a 1.461X draw-ratio to provide 200-filament textured yarns of 83.5 nominal denier (0.42 dpf) with a tenacity (T) of about 3.25 g/d and an elongation-at-break (Eg) of about 23.9%.
• the 200-filament yarns were also successfully "partially" warp drawn as per the teachings of Knox and Noe in U. S. Patent No.
• Example XV-3 a nominal 38 denier 100- filament yarn was prepared for use as a draw feed yarn in false-twist texturing and in warp drawing.
• the process operability for Example XV-3 was better with 6x18 mil (0.152x0.457 mm) capillaries than with 9x36 mil (0.229x0.914 mm) capillaries.
• the yarns of Example XV-3 were warp drawn over a range of conditions in Example XVIII to provide 0.22 to 0.27 dpf 100-filament yarns for wovens and knit fabrics.
• Example XVI 21.2 LRV polyester polymer containing 0.035 weight percent Ti ⁇ 2 was extruded at 285°C through 9x36 mil (0.229 x 0.914 mm) metering capillaries with a four-diamond-shaped corrugated ribbon cross-section exiting orifice of area .318 mils 2 (0.205 mm 2 ).
• the 80 denier 100-filament bundles were quenched using radial quench apparatus similar to that used in Example III having a delay length of 2.9 cm and converged by a metered finish tip applicator at 109 cm from the face of the spinneret and withdrawn at a spin speed of 2350 ypm (2.15 km/min).
• DS along-end denier spread
• Eg average elongation-at-break
• T ⁇ average tenacity-at-break
• T B -values are a consequence of the corrugated filament cross-sectional shape and such filaments may be used in processes, such as false-twist texturing (FTT) and air-jet texturing (AJT) where filament fracture is desired to give even finer filaments (i.e., even less than about 0.2 dpf) for a more spun-like aesthetics.
• FTT false-twist texturing
• AJT air-jet texturing
• Example XVII nominal 43 denier 50- filaments with a concentric void of about 16-17% were spun at 3500 ypm (3.2 km/min) and at 4500 ypm (4.12 km/min) .
• the hollow filaments were formed by post- coalescence of nominal 21.2 LRV polymer at 290°C using segmented capillary orifices with 15x72 mil (0.381x1.829 mm) metering capillaries as essentially described by Champaneria etal in U. S. Patent No. 3,745,061, Farley and Barker in Br. Patent No. 1,106,263, Hodge in U. S. Patent No. 3,924,988 ( Figure 1), Most in U. S. Patent No.
• the void content is found to increase with extrusion void area ( ⁇ ID 2 /4) , mass flow rate, polymer melt viscosity (i.e., proportional to LRV/Tp) and with increasing withdrawal speed (V) and the above process parameters are selected to obtain at least about 10% and preferably at least about 15% void content (VC) .
• the fine hollow filaments were quenched using radial quench apparatus fitted with a short delay shroud as described in Example XVI, except air flow was reduced to about 16 m/min and converged via a metered finish tip applicator at a distance less than about 140 cm.
• the yarns spun at 3.2 km/min had tenacity/elongation/modulus of about 3 gpd/90%/45 gpd. respectively and a tenacity-at-7%-elongation (T7) of about 0.88 g/d.
• Yarns spun at 4.115 km/min had tenacity/elongation/modulus of about 2.65 gpd/46%/64 gpd, respectively, and a tenacity-at-7%-elongation (T7) of about 1.5 g/d.
• Yarns spun at 3.2 and 4.12 km/min had boil-off shrinkage (S) values between about 3-5%.
• Example XVIII the spun yarns of Example XV-3 were drawn over a range of draw-ratios from 1.4X to 1.7X to provide drawn filament yarns of deniers 26.6 to 22.2, respectively; with tenacities increasing from 4.38 g/d to 5.61 g/d and elongations-at-break (E ⁇ ) decreasing from 36.6% to 15.8% with increasing draw- ratio. All the draw yarns had boil-off shrinkages (S) of about 4%. See Table VIII for process and product summery.
• Example XIX-1 and XIX-2 200-filament and 168-filament yarns (feed yarns from Example XV-3 and 4, repsectively) of nominal 0.5 dpf were spun at 4400 ypm (4.02 km/min) for use as direct-use flat yarns in woven and knit fabrics. These yarns can also be air-jet textured (AJT) without draw to provide low-shrinkage AJT yarns of nominal 3% shrinkage.
• AJT air-jet textured
• Example XX mixed filament yarns were prepared by co-spinning sub denier filaments of the invention with higher denier filaments, such as the low shrinkage filaments as described by Knox in U. S. Patent No. 4,156,071 and/or the high shrinkage filaments described by Piazza and Reese in U. S. Patent No. 3,772,872 to provide the potential for mixed- shrinkage (e.g., post-bulking in fabric) such as in the case when the low shrinkage filaments of this invention are combined with the high shrinkage ilaments of Piazza and Reese.
• higher denier filaments such as the low shrinkage filaments as described by Knox in U. S. Patent No. 4,156,071 and/or the high shrinkage filaments described by Piazza and Reese in U. S. Patent No. 3,772,872 to provide the potential for mixed- shrinkage (e.g., post-bulking in fabric) such as in the case when the low shrinkage filaments of this invention are combined with the high shrinkage
• On-line thermal treatment by use of a heated tube or a steam jet, wherein essentially no reduction in filament denier takes place (i.e., no space drawing) of mixed dpf low shrinkage filament yarns, such as those prepared by co-spinning filaments of this invention with those as described by Knox in U. S. Patent No. 4,156,071, provides a route to unique mixed shrinkage post-bulkable filament yarns wherein the shrinkage of the sub denier filaments of this invention remain essentially unchanged while the shrinkage of the higher denier filaments (e.g., 2-4 dpf) is increased from initial boil-off shrinkage (S) of less than about 6-10% to greater than 10%, typically about 15-35%.
• S initial boil-off shrinkage
• the mixed shrinkage yarns prepared with the mentioned intermediate heat treatment differ from those obtained by combining the low shrinkage filaments of this invention with the higher shrinkage filaments of Piazza and Reese in that the heat treated high shrinkage filaments have significantly improved shrinkage tension (e.g., at least about 0.15 g/d) which permits development of the bulk from the mixed- shrinkage even in very tightly constructed woven fabrics.
• shrinkage power The combination of high shrinkage and high shrinkage tension (herein called shrinkage power) was heretofore only obtained, for example, by fully drawing conventional LOY/MOY/POY followed by no or low temperature annealing.
• the sub denier filaments of the invention migrate to the surface on mixed shrinkage and provide a soft luxurious tactile aesthetics even in the most tightly constructed fabrics.
• the heat treatment is typically carried out after the filaments are fully attenuated and quenched to below their glass transition temperature and in a manner that the increase in tension during the heat treatment is of the magnitude equal to that of the observed increase in shrinkage tension by said heat treatment.
• Example XXII 50 denier 68-filament undrawn flat textile yarns were uniformly cold drawn and heat treated at 160, 170, and 180°C to provide nominal 36 denier 50 filament drawn yarns of about 4-5% boil-off shrinkage (S) with a T7 of about 3.5 g/d, a tenacity of about 4.5 g/d with an elongation-at-break (E ⁇ ) of about 27%.
• the drawn yarns have a percent Uster of about 2.1-2.4% and may be used for critically dyed fabrics.
• the fine denier filaments of this invention may be used to cover elastomeric yarns (and tapes) by high speed air-jet entanglement as taught by Strachan in U. S. Patent No. 3,940,917.
• Polyester fine filaments prepared from polymer modified for cationic dyeability are especially suitable for elastomeric yarns, such as Lycra® to prevent "bleeding" of the dyestuff from the elastomeric yarns, such as observed for Lycra® covered with homopolymer polyester dyed with nonionic disperse dyes.
• the direct-use filaments of this invention are preferred (and those with increased shrinkage, shrinkage tension, and shrinkage power as described in Example XX are especially preferred) for air-entanglement covering and permit the covered elastomeric yarns to be dyed under atmospheric conditions without the use of carriers, e.g., similar to the dye bath conditions to dye nylon filament covered elastomeric yarns (except for being dyed with anionic acid dyes) .
• Some example fabrics made from the yarns of the invention are: 1) a medical barrier fabric constructed with a low shrinkage 70 denier 100-filament direct-use flat yarn filling and a 70 denier 34- filament conventional warp drawn POY in the warp and woven on a high speed water-jet loom at 420 picks per minute to give a plain weave fabric of 164 ends per inch in the warp and 92 picks per inch in the fill; 2) a lounge wear satin constructed using the above 70 denier 100-filament direct-use yarn in the warp and combining it with a 60 denier 100-filament false twist textured fill to provide a satin with 172 ends per inch in the warp and 100 picks per inch in the fill; and 3) a crepe de chines fabric constructed with the above 70 denier 100-filament direct-use yarn in the warp and a 2-ply 60 denier 100-filament false twist textured yarn in the fill.
• T M Zero-shear polymer melting point (°C)
• T M Apparent melting point of polymer
• EX.-ITEM 1-8 1-9 5- 1 5-2 5-3 5-1 5-5 5-6 5-7 5-8 5- 5-10 5-11 5-12 5-13 6- 1 6-2 6-3 6-1 6-5 6-6

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• 1992
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