US3748844A - Polyester yarn - Google Patents

Polyester yarn Download PDF

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US3748844A
US3748844A US00168953A US3748844DA US3748844A US 3748844 A US3748844 A US 3748844A US 00168953 A US00168953 A US 00168953A US 3748844D A US3748844D A US 3748844DA US 3748844 A US3748844 A US 3748844A
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yarn
yarns
fabric
percent
shrinkage
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E Pacofsky
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EIDP Inc
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EI Du Pont de Nemours and Co
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    • 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
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/78—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products
    • D01F6/84—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products from copolyesters
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S57/00—Textiles: spinning, twisting, and twining
    • Y10S57/908—Jet interlaced or intermingled

Definitions

  • 2,783,609 and 2,852,906 describe a textured yarn which is characterized by filament convolutions and which provides fabrics with improved bulk and tactile aesthetics.
  • Steam or hot air can be used in a jet bulking apparatus to provide, under proper conditions, a stable crimped yarn which does not require twist to hold the filament convolutions in place.
  • a yarn with a highly desirable stable crimp having a random, threedimensional, curvilinear, extensible configuration is described by Breen et al. in U.S. Pat. No. 3,186,155 and an improved process for preparing such yarns is described by Scott in U.S. Pat. No. 3,143,784.
  • One method of improving warp knit fabrics utilizes a low shrinkage yarn fed to the top (front) bar of a knitting machine in combination with a high shrinkage yarn fed to the bottom (back) bar of the machine. Subsequent heating of the fabric causes the two yarns to shrink different amounts, which results in improved fabric covering power. Bulk, however, is not significantly improved.
  • the present invention provides a novel continuous multifilament polyester yarn eminently suitable for use in the preparation of improved apparel, particularly knitwear.
  • the yarn provided is prepared by an economical process, exhibits good processibility on knitting machines, and is capable of giving fabrics having excellent bulk and handle when used in combination with ordinary commercially available polyester yarns.
  • the excellent processibility in knitting is in large measure due to the fact that the yarns are essentially crimpfree, and develop little or no crimp upon heating. In view of this lack of significant crimp, it is quite surprising that excellent bulk and tactile aesthetics are developed when fabrics containing these yarns are heated.
  • the improved multifilament yarn of the present invention is an assembly of low-shrinkage, continuous filaments which are substantially free of crimp.
  • the yarn consists of synthetic linear condensation polyester and is characterized by having an orientation, as measured by sonic velocity, of 1.9 to 3.0 kilometers per second, an X-ray crystallinity value of 16 to 35 percent, and a single shrinkage-tension peak at a temperature lower than 100C.
  • the preferred yarns of the invention have a boil-off shrinkage of 1 to 10 percent and a sonic velocity value between 2.0 and 2.5 kilometers per second.
  • the shrinkage-tension peak is determined for temperatures between 60 and 200C. Preferably, this peak is at a temperature between and 100C. and the peak tension is less than about 0.06 gram per denier.
  • Particularly good fabric bulk is obtained with yarns consisting essentially of ethylene terephthalate polyester, which may be modified slightly as illustrated in Example II for basic dyeability.
  • the novel yarn of the invention is prepared by a simple, low-cost manufacturing process characterized by a critical combination of spinning, drawing, and relaxing conditions not previously disclosed for polyester yarns.
  • the process comprises melt-spinning a synthetic linear terephthalate polyester into filaments; quenching the filaments and combining them into a multifilament strand; drawing the multifilament strand at a temperature above C. between feed rolls and draw rolls; heating the drawn strand in a substantially tensionless state in a plasticizing medium to cause it to shrink in the longitudinal direction; and then cooling and winding the strand.
  • the process is characterized by the use of a low draw ratio within the range of about 2:1 to 3:1 to provide a drawn multifilament strand having a sonic velocity value within the range of 1.9-3.0 km./sec., and by the control of temperatures in and following the drawing process at a level to produce a boil-off shrinkage in the drawn yarn within the range of 7-20 percent, and further by control of the exposure time and temperature of the plasticizing medium in the shrinkage step to allow a shrinkage of 7-20 percent to occur without the formation of crimp to provide filaments having a crystallinity value that does not exceed 35 percent.
  • the shrinkage step is carried out in a low-turbulence, heated gas stream, preferably air or steam, within a jet enclosure.
  • a suitable maximum machine draw ratio for the drawing step may be calculated from the expression D.R. 4.S/(1 0.0006V,) where V, is spinning speed (i.e., feed roll speed) in yards per minute.
  • yarns of very low orientation tend to become brittle when crystallized, so that fabrics prepared from such yarns, i.e., yarns having a sonic velocity below about 1.9 kilometers per second, would be relatively useless in ordinary commercial usage.
  • yarns having a crystallinity value above about 35 percent are too crystalline to develop the desired bulk by ordinary fabric finishing treatments; and yarns having a crystallinity below about 16 percent would be so amorphous as to shrink excessively upon heating, which would lead to unacceptable commercial fabrics.
  • a unique feature of the yarns of the present invention is the presence of a low-temperature peak (below 100C.) in the tension-temperature spectrum.
  • the yarns of the invention are low-shrinkage yarns in the sense that the normally measured boil-off shrinkage falls in the range of l to percent.
  • the yarns of this invention are useful in many types of fabrics, but offer an outstanding improvement in properties in warp knit fabrics. Unusually good results are obtained, as illustrated more fully in the examples, in warp knit fabrics using bar-on-bar construction when the yarns of the invention are used in combination with conventional commercial yarns. In such fabrics, best results are obtained with the yarn of this invention on the top (front) bar. In addition to bar-on-bar constructions, excellent results may also be obtained by combining the yarns of the invention with ordinary commercial yarns by twisting or by intermingling filaments to form a unitary yarn for fabric preparation.
  • the yarns of the invention are free of significant crimp and that fabric bulk is observed only after the fabric has been constructed and heated to a temperature of about 100C. or above. Such heating takes place during normal fabric finishing procedures, as when the fabric is scoured, dyed, or heat-set on a tenter frame.
  • fabrics prepared from the yarns of the invention possess excellent dyeability characteristics and show better color yield, improved color clarity and better print definition in comparison with both ordinary and set-textured polyester yarns.
  • FIGS. 1 and 2 are front and back views, respectively, of a warp-knit tricot fabric having a 2-3, 1-0 stitch on the front bar and a 1-0, 1-2 stitch on the back bar. In both figures, the front bar yarn is shown darker than the back bar yarn.
  • novel yarns of the present invention are composed of a synthetic linear condensation terephthalate polyester of the type described in U.S. Pat. Nos. 2,465,319 and 2,901 ,466.
  • the yarn is composed of a glycol terephthalate polyester which is a linear polyester in which at least about percent of the recurring structural units are glycol terephthalate units,
  • G is a glycol residue.
  • copolyesters in which up to 15 percent of the terephthalate is re-' placed by a dicarboxylate of a hydrocarbon free from ethylenic unsaturation, or by a metallic salt of sulfoisophthalic acid.
  • Typical copolyesters are formed by replacing up to about 15 mol percent of the terephthalic acid or derivative thereof with another dicarboxylic acid or ester-forming derivative thereof, such as adipic acid, dimethylsebacate, isophthalic acid, hexahydroterephthalic acid, or sodium 3 ,5- dicarbomethoxybenzene-sulfonate.
  • glycols are ethylene glycol and hexahydro-p-xylylene glycol.
  • Glycol terephthalate linear polyesters can readily be prepared in the oriented, relatively amorphous or noncrystalline form useful in preparing the yarns of the invention.
  • the yarns of this invention are composed of polymer of fiber-forming molecular weight, and have an intrinsic viscosity of at least about 0.3. Intrinsic viscosity is defined by the expression:
  • a convenient solvent for use in the measurement of intrinsic viscosity of polyethylene terephthalate is a mixture of trifluoroacetic acid and methylene chloride in a volume ratio of 1:3.
  • degree of polymerization is also indicated by RV which is the relative viscosity of a polymer solution at a nominal concentration of percent.
  • RV refers to the ratio of the viscosity of a 10 percent solution (2.15 grams polymer in 200 milliliters solvent) of the polymer in a solvent to the viscosity of the solvent per se measured in the same units at 25C.
  • the solvent used for the measurement of relative viscosity in the examples is Fomal, a mixture of ten parts phenol and seven parts 2,4,6-trichlorophenol (parts by weight).
  • a relative viscosity of 25 corresponds roughly to an intrinsic viscosity of 0.64
  • a relative viscosity of 30 corresponds roughly to an intrinsic viscosity of 0.70.
  • the yarns of this invention are composed of filaments having a molecular orientation such that the measured values of sonic velocity fall between 1.9 and 3.0 kilometers per second, and preferably between 2.0 and 2.5 km./sec.
  • the term sonic velocity is a polymer structural parameter related to molecular orientation along the fiber axis with higher values of sonic velocity indicating a higher degree of orientation.
  • Sonic velocity (C) is related to the modulus of elasticity (E) by the formula E 1 1.3 C where E is in grams per denier and C is in kilometers per second. Sonic velocity relationships and test procedures are described by Charch & Moseley in the Textile Research Journal, Volume 29, page 525 (July, 1959).
  • sonic velocity in kilometers per second, is measured by passing a sound wave having a frequency of about 10,000 cycles per second through the polymer structure for a known distance using apparatus known in the art.
  • Sonic velocity is used as a measure of orientation in preference to birefringence because birefringence is difiicult to measure with precision in the range of concern (generally greater than 0.10), and is difficult to measure for filaments of non-round cross-section. Also, because birefringence measurements are made on very short segments of a filament, an excessive number of measurements is required to give a reasonable, average birefringence value unless highly uniform filaments are under observation.
  • the crystallinity of the terephthalate polyester making up the filaments of the present invention can be obtained by X-ray diffraction techniques.
  • X-ray crystallinity as reported in the examples, is as follows: a bundle of parallel filaments of 0.020 inch (0.05 cm.) thickness is mounted with the fiber axis perpendicular to a beam of nickel-filtered Cu X-rays generated at 50 kilovolts and milliamperes and collimated through 0.020 inch (0.05 cm.) pin holes.
  • the diffraction pattern is photographed in Ilford G X-ray film at a sampleto-form distance of 5 centimeters using an exposure time sufficient to give an optical density on the developed film of about 1.0 at the 010 diffraction maximum.
  • the exposed film is developed for 3 minutes at 68C. in Du Pont X-Ray Developer prepared as recommended by the manufacturer.
  • the film is rinsed 30 seconds in 3 percent acetic acid stop bath, fixed for 6 minutes in Du Pont X-Ray Fixer and l-lardener, rinsed for at least ont hour in running water and dried at room temperature.
  • the optical density of the film is scanned along the equator using a Knorr-Alpers micorphotometer (Leeds & Northrop Model 6700 Pl, A2 assembly), set at a plate travel rate of 5 millimeters per minute and a chart speed of 2 inches per minute (5.08 cm. per minute).
  • the resulting curve exhibits 3 peaks, corresponding to the scattering from the 010, 110, and diffraction plates, which represent the principal scattering from glycol-terephthalate linear polyester crystallites.
  • a straight line is drawn underneath the 010 peak and tangent to the curve on either side of the 010 peak.
  • a perpendicular line is then dropped from the highest point of the 010 peak to the 100 percent transmission axis.
  • the height of the point of intersection between this perpendicular line and the line tangent to the curve is then designated as I representing the intensity (log. l/transmission) of the amorphous background.
  • the height of the highest point of the 010 peak itself is designated as 1,. Crystallinity is then calculated from the following formula:
  • the yarns of this invention are composed of filaments having an X-ray crystallinity between 16 and 35 percent measured by the above procedure.
  • An alternative method of measuring X-ray crystallinity which gives results in conformance with those given by the above method utilizes a Norelco X-ray diffraction unit (North American Philips Co., Inc., New York) fitted with a wide-angle diffractometer and a scintillation counter.
  • a high-intensity copper-target tube is used at a voltage of 40 kilovolts and a beam current of 40 milliamperes.
  • the X-ray beam is collimated with 0.5 divergence slits, 0.006 inch receiving slits and 05 scatter slits.
  • a nickel filter is placed before the receiving slit to provide monochromatic radiation, and pulse-height discrimination is also used according to the manufacturers directions.
  • a parallel array of fibers is mounted in the reflecting mode, and equatorial scattering is recorded at a scanning rate of 1 per minute (in 20 units) and recorded as intensity (counts per second) vs. the scattering angle, 20.
  • the resulting curve is equivalent to the densitometer curve obtained in the first-described method (above), counts-per-second being proportional to (log. lltransmission), and the fiber crystallinity is calculated from the curve by the same procedure.
  • shrinkage tension refers to the retractive force exhibited by a yarn when heated.
  • the shrinkage tension of terephthalate polyester filaments usually changes appreciably with the temperature to which the filaments are heated. In the temperature range 60-200 C., the yarns of the present invention show a single peak in the tension-temperature spectrum, and this peak appears at a temperature below 100c. The value of the peak shrinkage tension is less than about 0.06 gpd for the preferred yarns of the invention.
  • Shrinkage tension is measured by mounting a looped specimen of yarn between lnvar hooks in a small oven provided with a means of heating and a means of indicating temperature.
  • One hook is attached to a strain gauge and the other is fixed at a distance which gives a taut loop (minimum measurable tension). Heat is applied to the oven to raise the temperature at a rate of about 30C. per minute. The temperature and the tension are measured simultaneously and plotted on a graph of tension versus temperature to provide a convenient read-out of the temperature of peak tension. Measurements of this type are described by Weidner in Chemiefasern 10, 751 (1968).
  • the yarns of this invention are composed of continuous filaments essentially free from individual filament twist.
  • filament twist is easily observed by examination under a microscope.
  • the methods for observing twist in round filaments involve microscopic examination of filaments illuminatee by plane-polarized light.
  • For round filaments containing significant quantities of Ti0 filament twist may be observed by using the techniques described by Astle- Fletcher, Journal of the Textile Institute, Vol. 48, T-l 2- 8-132 (1957) and by Woods, Journal of the Textile Institute, Vol. 55, T-243-250 (1964).
  • EXAMPLE 1 Polyethylene terephthalate continuous filament spinning and drawing procedures using a spinning speed (feed roll speed) of 1485 ypm (1358 mpm), and single-stage drawn in a steam jet similar to that described by Pitzl in U.S. Pat. No. 3,452,132 using steam at a temperature of 160C. and a pressure of psig.
  • test yarns (coded B, C, and D) are prepared by this general process using the specific conditions listed in Table 1. Examination of the test yarns reveals that they are free of significant crimp and give no indication of individual filament twist.
  • a conventional yarn (A) is melt spun in the same fashion as above but drawn in an aqueous bath of the general type described by Dusenbury in U.S. Pat. No. 3,091,805 using a temperature of 9192C. and a draw ratio of 2.4, with the draw roll heated to C. No hot relaxing jet is used.
  • a second conventional yarn (E) is a commercially available dull (2% TiO polyethylene terephthalate 27-filament yarn having a total denier of 40, a tenacity of 4.27 gpd, a break elongation of 27.6 percent, and a boil-off shrinkage of 8 percent.
  • This yarn is characterized by a sonic velocity of 3.81 km./sec., an X-ray crystallinity of 28 percent, and a shrinkage-tension peak at C.
  • test and comparison yarns are used to knit tricot fabrics in yarn combinations shown in Table II.
  • Greige fabric construction parameters are adjusted to give the same finished fabric construction for all samples.
  • the fabrics are finished by subjecting them to a relaxed scour, in which they are heated from room temperature to the boil and then held 20-30 minutes at the boil, using an aqueous solution of 0.5 gmJliter of a suitable wetting agent such as Duponol RA (sodium salt of a modified alcohol sulfate) or Alkanol HCS and 0.5 gm./liter tetrasodium pyrophosphate. After rinsing, the fabric is heatset on a pin tenter for 60 seconds at C. under sufficient tension to provide 48 X 48 wales and courses per inch (19 X 19 per cm.). Properties of the finished fabrics are listed in Table II.
  • 1050100 2-3, 1 2-3, 1.0 2-3, 1-0 2-3, 111 2-3, H) 2-3, 1-0 2-3, H) Back bar ..1-0, 1 1-0, 1-2 1-0, 1--2 1 -0, 12 10, 1-2 10, 12 1-0, 1 2 Runners (111.):
  • Fabric 10 is knit with a 4-6 percent boil-olfshrinkage yarn on the front bar and a 14 percent boiltemperature of 92C., where drawing occurs, and then on to draw rolls moving at a surface speed of 2998 ypm (2740 mpm). Other process details are shown in Table III.
  • the 40-denier/27-filament yarn is coded control yarn 2.
  • a copolymer of polyethylene terephthalate containing 2 mol. percent S-(sodiumsulfo)-isophthalate in the 50 molecule and having a relative viscosity of 20.5 is melt is heat-Set a P Enter for Seconds at spun into a l4-filament yarn in which all filaments have under sufficient tension to provide the wale and course a trilobal cross-section.
  • test yarn 3 The yarn is designated test yarn 3, Table V.
  • control yarn (4) is prepared as above, with the draw yarn bypassing the relaxing jet and proceeding directly to the windup. Process details are shown in the table.
  • Jersey tricot fabrics are knit utilizing the test copolymer yarns (3) and control copolymer yarns (4) in the front bar with the conventional 40-27 yarn described in Table 111 as a common back bar yarn as specified in Table VI. These fabrics are scoured for 30 minutes at the boil in an aqueous solution of 0.5 gmJliter Duponol D and 0.5 gm./liter tetrasodium pyrophosphate, rinsed, centrifuged and dried. The dried fabric is heat-set on a pin tenter frame for 60 seconds at 190C. to the Wale and course counts given in Table VI. Fabric bulk data measured under the three compressive loadings of 3, 40, and 239 gmJcm.
  • Example 1 that used in Example 1) which is supplied with steam at a temperature of 160C. and a pressure of 50 psig. (3.4 atm.).
  • the yarn proceeds from the jet to and around draw rolls heated to 101C. and operating at a peripheral speed of 3005 ypm. (2747 mpm).
  • the draw ratio is 2.09 X, and the residence time on the hot draw roll is 0.43 second.
  • the drawn 38 denier yarn is wound up at 3010 ypm. (2752 mpm). A skein of this yarn is then allowed to relax for 10 minutes in water at a temperature of 66C. A shrinkage of 5.0 percent is noted.
  • the shrinkage tension of the yarn as a function of temperature is measured and the yarn is found to have a shrinkage tension peak at 95C., and maximum shrinkage tension of 0.027 gpd.
  • X-ray measurements indicate 23 percent crystallinity and sonic velocity measurements give a value of 2.52 kilometers/sec. measured under a tension of 0.7 grams per denier.
  • the yarn is substantially free of crimp, and examination under a microscope between crossed polarizers gives no indication of individual filament twist.
  • Jersey tricot fabric is knitted using the above described yarn, designated test yarn 7, as a front bar yarn in combination with a back bar of conventional yarn 2 (Table 111).
  • This tricot fabric is finished according to the procedure specified in Example 111 and compared to a control tritot fabric (cf., Table IV) having front and back bar yarns of the conventional yarn 2 which is similarly finished.
  • Fabric data given in Table V11 shows that the tricot fabric containing yarn of this invention has appreciably greater bulk. Upon subjective evaluation of the fabrics, the preferred spun-like handle of the test yarn tricot is clearly evident.
  • Front bar (Table v s 4 Yams Back bar (Table III) 2 2 Fr nt Bar 7 2 titch: Back Bar (Table 111) 2 2 Front bar 2-3, 1-0 2-3, l-O S i h R g g 1 Front Bar 24, l() 24, l-() l forit 152.. 65 64 Back Back barn u: 44 4:; Rune Ratio (mm back).-- 1.41 1. 49 Front Bar 62 62 Fabric in. per rack... s 3 Back Bar 44 44 Finished count (w.p.l 48-50 47-69 Ratio (Front/Back) 1.41 1.41 gg fi z ggf) 1 0 Fabric in.
  • the yam has a boil-off shrinkage of 40.6 percent.
  • a skein prepared from this yarn is relaxed 10 minutes in 80C. water during which time it shrinks 11.4 percent.
  • the skein is dried and backwound.
  • the 71-denier yarn has a crystallinity of 18 percent, a sonic velocity of 2.24 km./sec., a peak shrinkage tension of 0.035 gpd at 80C. and exhibits a boil-off shrinkage of 5.6 percent.
  • the yarn is designated test yarn 8.
  • a tricot fabric is prepared with the above-described yarn as a front bar yarn in combination with the conventional yarn 2 (Table III) in the back bar.
  • the fabric is relax scoured, dried, and heat-set as described in Example III.
  • Fabric properties are given in Table VIII.
  • the test yarn is found to impart an appreciable amount of bulk, as well as improved tactile aesthetics, to the tricot fabric.
  • EXAMPLE V For comparison with the excellent improvement in bulk shown by the yarns of this invention'in Example I, a typical prior art fabric, as illustrated by Kasey in US. Pat. No. 3,041,861, is prepared from conventional polyester yarns.
  • a warp knit bar-on-bar fabric is prepared from two yarns possessing a large difference in shrinkability. This fabric is then compared directly with a fabric knit from a single yarn (i.e., all the same shrinkage) under similar conditions.
  • the yarns are prepared as follows: polyethylene terephthalate having an RV of 30 and containing 2.0 weight percent TiO is spun at about 308C. through a spinneret having 54 Y-shaped orifices.
  • the trilobal filaments are quenched with a crossflow stream of air at 125 cfm and 70F, then passed around a feed-roll assembly (four wraps) maintained at 933 ypm (852 mPm), through an aqueous finish bath at 92C. and onto a set of draw rolls (13 A wraps) running at a surface speed of 2998 ypm (2741 mpm), and then to a dual windup at 2900 ypm (2862 mpm) to maintain a threadline tension of 15 grams.
  • the draw ratio is 3.2:] and the draw rolls are held at 140C.
  • Two ends of 40-denier 27-filament yarn, coded x1 are obtained having representative properties of 4.0 gpd tenacity, 24 percent break elongation, 1 29 gpd initial modulus and a boil-off shrinkage (BOS) of 4-6 percent.
  • Representative samples of these yarns have an SV of 3.22, an X-ray crystallinity of 45 percent and a shrinkage tension peak at 180C.
  • a high shrinkage 40-27 polyethylene terephthalate yarn is prepared using the above procedure with the exception that the draw rolls are maintained at a temperat0re of 94C.
  • Representative properties of this yarn, coded X2 are 3.7 gpd tenacity, 30 percent break elongation, 145 gpd initial modulus, a boil-off shrinkage of about 14 percent, an SV of 3.92 km./sec., an
  • the normal shrinkage 40-27 polyethylene terephthalate yarn described in Example I as yarn A is used in both bars to make a tricot control fabric (Fabric No. 47, Table II).
  • the yarns are prepared for knitting by backwinding onto cones and then transferring the yarns to 7 inch 18 cm.) section beams for knitting on a 28 gauge tricot machine. Knitting and fabric details are summarized in Table IX.
  • the knitting conditions of the fabric containing the low-shrinkagelhigh-shrinkage yarn combination are adjusted to give a greige fabric which achieves the desired fabric weight under low tension finishing conditions. Finishing conditions, i.e., relaxed scour followed by heat setting at dry width, are such that maximum available bulk can be developed. It is found that under these optimum conditions only a marginal improvement in fabric bulk is obtained with the mixed-shrinkage fabric over the second fabric prepared from yarns having no difference in shrinkage.
  • the advantages of the yarns of the invention are realized primarily in warp knit fabrics, such as tricot, it is appreciated that the yarns are also useful in preparing weft knits such as fullfashioned and circular knits and also woven fabrics such as taffeta, twill, oxford, satin, and basket Weaves. Warp knit fabrics are particularly useful in mens shirts, womens dresswear, uniforms, blouses and intimate apparel.
  • EXAMPLE VII Polyethylene terephthalate containing 2 weight percent TiO is melt spun to give a 14-filament strand in which all filaments have a trilobal cross section.
  • the quenched strand is passed over a feed roll operating at a surface speed of 1271 yards per minute (1162 meters per minute), then through a jet enclosure supplied With steam at a temperature of 190C. at a pressure of 50 psig. (3.4 atm.), and then around draw rolls operating at a surface speed of 3060 ypm (2798 mpm).
  • the draw ratio is 2.4: l
  • the draw rolls are enclosed in a box heated with circulating air maintained at a temperature of 92-93C.
  • the drawn yarn proceeding from the enclosed draw rolls passes through a relaxing" (shrinkage) jet enclosure supplied with air at a pressure of 55 psig (3.7 atm.) and a temperature of 290C, then around a change-of-direction roll to a driven letdown roll assembly running at a surface speed of 2600 ypm (2377 mprn), and then to a windup operating at 2643 ypm (2417 mpm).
  • the percent overfeed to the relaxing jet, based on letdown roll speed is 17.3 percent.
  • the percent net overfeed, based on windup speed is 15.5 percent.
  • the relaxed yarn which is wound up in the abovedescribed process has the properties listed in Table XI.
  • test yarn (VIIl prepared by the process described above is knit into a tricot fabric as the front-bar yarn along with a commercial polyester yarn (T-57) similar to Yarn E in Table lb in the back bar.
  • the greige knit fabric is given a finishing treatment similar to that described for knit fabric in Example I.
  • Fabric construction parameters and finished fabric properties are summarized in Table XII along with similar parameters and properties for a comparison fabric knit with the conventional yarn in both the front bar and back bar.
  • the improved bulk and spunlike handle of the test fabric are readily apparent.
  • EXAMPLE VIII Following the general procedure of Example I, polyethylene terephthalate containing 2 weight percent of TiO, is melt-spun through a 14-hole spinneret to give a yarn in which all filaments have a trilobal cross section. The quenched, undrawn yarn passes over a feed roll rotating with a surface speed of 960 ypm (878 mpm), through a jet enclosure supplied with steam at a temperature of C. and a pressure of 50 psig (3.4 atm.), and then over draw rolls operating at a surface seed of 3010 ypm (2752) mpm). The draw ratio is 3.14:1. The draw rolls are enclosed in a box heated with circulating air at a temperature of 78C.
  • a yarn as defined in claim 1 wherein the peak tension at said peak is less than about 0.06 grams per denier.
  • a yarn as defined in claim 1 composed of ethylene terephthalate polyester.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Artificial Filaments (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
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Application Number Title Priority Date Filing Date
US00168953A Expired - Lifetime US3748844A (en) 1971-08-04 1971-08-04 Polyester yarn

Country Status (9)

Country Link
US (1) US3748844A (OSRAM)
BE (1) BE787120A (OSRAM)
CA (1) CA985469A (OSRAM)
DE (1) DE2238499A1 (OSRAM)
FR (1) FR2148234B1 (OSRAM)
GB (1) GB1402765A (OSRAM)
IT (1) IT963717B (OSRAM)
LU (1) LU65847A1 (OSRAM)
NL (1) NL7210741A (OSRAM)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307152A (en) * 1977-12-12 1981-12-22 Akzona Incorporated Hydrophilic polyester fiber and process for making same
US4426516A (en) 1981-03-31 1984-01-17 Asahi Kasei Kogyo Kabushiki Kaisha Polyester fiber dyeable under normal pressure
US4600644A (en) * 1982-06-10 1986-07-15 Monsanto Company Polyester yarn, self-texturing in fabric form
US4819458A (en) * 1982-09-30 1989-04-11 Allied-Signal Inc. Heat shrunk fabrics provided from ultra-high tenacity and modulus fibers and methods for producing same
US4876774A (en) * 1982-09-30 1989-10-31 Allied-Signal Inc. Method for preparing heat set fabrics
US4929698A (en) * 1988-06-14 1990-05-29 E. I. Du Pont De Nemours And Company New polyester yarns having pleasing aesthetics
US4933427A (en) * 1989-03-03 1990-06-12 E. I. Du Pont De Nemours And Company New heather yarns having pleasing aesthetics
US5061422A (en) * 1988-06-14 1991-10-29 E. I. Du Pont De Nemours And Company Process for preparing polyester feed yarns
US5204041A (en) * 1988-10-28 1993-04-20 Teijin Limited Method of making ultra-fine polyester fibers
US5645936A (en) * 1986-01-30 1997-07-08 E. I. Du Pont De Nemours And Company Continuous filaments, yarns, and tows
US6020578A (en) * 1994-09-29 2000-02-01 A.U.A. Putz Gesellschaft Mbh & Co. Kg Electric heating element and method for preparing the same
US20110059288A1 (en) * 2009-09-04 2011-03-10 Shavel Jonathan G Flannel sheeting fabric for use in home textiles

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3069836A (en) * 1958-08-01 1962-12-25 Du Pont Yarn relaxation process using fluid jets
US3199281A (en) * 1961-09-27 1965-08-10 Du Pont Composite polyester yarn of differentially shrinkable continuous filaments
US3261071A (en) * 1965-05-25 1966-07-19 Du Pont Yarn treating jet
US3303169A (en) * 1962-01-18 1967-02-07 Du Pont High-modulus, high-tenacity, lowshrinkage polyamide yarn
US3421194A (en) * 1967-10-24 1969-01-14 Du Pont Process for treating a filamentary strand
US3423809A (en) * 1967-11-15 1969-01-28 Du Pont Process for forming differential shrinkage bulked yarn
US3452130A (en) * 1967-02-02 1969-06-24 Du Pont Jet initiated drawing process
US3452131A (en) * 1967-06-27 1969-06-24 Du Pont Process for stretching filaments
US3662440A (en) * 1970-08-17 1972-05-16 Du Pont Process for controlling yarn tension and threadline stability during high speed heat treating of the yarn

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3069836A (en) * 1958-08-01 1962-12-25 Du Pont Yarn relaxation process using fluid jets
US3199281A (en) * 1961-09-27 1965-08-10 Du Pont Composite polyester yarn of differentially shrinkable continuous filaments
US3303169A (en) * 1962-01-18 1967-02-07 Du Pont High-modulus, high-tenacity, lowshrinkage polyamide yarn
US3261071A (en) * 1965-05-25 1966-07-19 Du Pont Yarn treating jet
US3452130A (en) * 1967-02-02 1969-06-24 Du Pont Jet initiated drawing process
US3452131A (en) * 1967-06-27 1969-06-24 Du Pont Process for stretching filaments
US3421194A (en) * 1967-10-24 1969-01-14 Du Pont Process for treating a filamentary strand
US3423809A (en) * 1967-11-15 1969-01-28 Du Pont Process for forming differential shrinkage bulked yarn
US3662440A (en) * 1970-08-17 1972-05-16 Du Pont Process for controlling yarn tension and threadline stability during high speed heat treating of the yarn

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307152A (en) * 1977-12-12 1981-12-22 Akzona Incorporated Hydrophilic polyester fiber and process for making same
US4426516A (en) 1981-03-31 1984-01-17 Asahi Kasei Kogyo Kabushiki Kaisha Polyester fiber dyeable under normal pressure
US4600644A (en) * 1982-06-10 1986-07-15 Monsanto Company Polyester yarn, self-texturing in fabric form
US4819458A (en) * 1982-09-30 1989-04-11 Allied-Signal Inc. Heat shrunk fabrics provided from ultra-high tenacity and modulus fibers and methods for producing same
US4876774A (en) * 1982-09-30 1989-10-31 Allied-Signal Inc. Method for preparing heat set fabrics
US5645936A (en) * 1986-01-30 1997-07-08 E. I. Du Pont De Nemours And Company Continuous filaments, yarns, and tows
US4929698A (en) * 1988-06-14 1990-05-29 E. I. Du Pont De Nemours And Company New polyester yarns having pleasing aesthetics
US5061422A (en) * 1988-06-14 1991-10-29 E. I. Du Pont De Nemours And Company Process for preparing polyester feed yarns
US5204041A (en) * 1988-10-28 1993-04-20 Teijin Limited Method of making ultra-fine polyester fibers
US4933427A (en) * 1989-03-03 1990-06-12 E. I. Du Pont De Nemours And Company New heather yarns having pleasing aesthetics
US6020578A (en) * 1994-09-29 2000-02-01 A.U.A. Putz Gesellschaft Mbh & Co. Kg Electric heating element and method for preparing the same
US20110059288A1 (en) * 2009-09-04 2011-03-10 Shavel Jonathan G Flannel sheeting fabric for use in home textiles

Also Published As

Publication number Publication date
LU65847A1 (OSRAM) 1973-01-15
FR2148234A1 (OSRAM) 1973-03-11
CA985469A (en) 1976-03-16
DE2238499A1 (de) 1973-02-15
IT963717B (it) 1974-01-21
NL7210741A (OSRAM) 1973-02-06
BE787120A (fr) 1972-12-01
GB1402765A (en) 1975-08-13
FR2148234B1 (OSRAM) 1976-08-13

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