US3858387A - Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof - Google Patents

Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof Download PDF

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US3858387A
US3858387A US375941A US37594173A US3858387A US 3858387 A US3858387 A US 3858387A US 375941 A US375941 A US 375941A US 37594173 A US37594173 A US 37594173A US 3858387 A US3858387 A US 3858387A
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yarn
per inch
percent
texturing
ratio
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Janardhana B Baliga
Robert L Dainton
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EIDP Inc
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EI Du Pont de Nemours and Co
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Priority to US375941A priority Critical patent/US3858387A/en
Priority to FR7422833A priority patent/FR2236032B1/fr
Priority to ZA00744206A priority patent/ZA744206B/xx
Priority to JP49074391A priority patent/JPS5036727A/ja
Priority to GB2913974A priority patent/GB1471688A/en
Priority to AR254511A priority patent/AR202560A1/es
Priority to CA203,772A priority patent/CA1040403A/en
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    • 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
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
    • D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
    • D—TEXTILES; PAPER
    • 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
    • D02G1/02—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist
    • D02G1/0206—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist by false-twisting
    • D02G1/0213—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist by false-twisting after drawing the yarn on the same machine
    • 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
    • D02G1/02—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist
    • D02G1/0206—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist by false-twisting
    • D02G1/022—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist by false-twisting while simultaneously drawing the yarn

Definitions

  • the textured product is [58] Field 011 Search 57/140 R, 34 HS, 157 TS; strong, has a low yarn-on-yarn friction and high values 264/168,290; 161/172,173;260/78 R,78 A, for crimps per inch, crimp elongation and ratio of 78 S crimps per inch to turns per inch. Triclinic X-ray diffraction patterns show a marked increase in the [56] References Cited tit-crystalline form during texturing.
  • the polyamide yarns of commerce are of 6-6 nylon (polyhexamethyleneadipamide) or 6-nylon (from A-amino-caproic acid or caprolactam). Only minor amounts of yarns are manufactured from other polyamides, such as ones having branched chains or aromatic groups in the chains.
  • a vast number of other polyamides are possible, but previous extensive research had not found any as desirable as 66 nylon for textile yarn, even among the linear aliphatic polyamides most closely related to 66 nylon. It is surprising, therefore, to find that one can be prepared to have properties superior to 6-6 nylon yarn, particularly for textile uses where texturing is important to provide bulk, softness and stretch in fabrics.
  • the present invention provides a polyamide feed yarn for drawing and texturing into products which are superior to comparable 6-6 nylon yarn for textile uses.
  • the invention also provides a draw-texturing process for providing improved crimp properties.
  • An improved textured yarn is provided which has tenacity and modulus properties at least equivalent to comparable 6-6 nylon yarn under normal conditions and is less sensitive to humidity, which has improved ratios of crimp to turns per inch of twist liveliness for better processibility when knitting, and which can be knitted into more powerful stretch fabrics having better recovery from stretching.
  • the polyamide feed yarn of this invention has a break tenacity of at least 6.5 grams per denier and a yarn-nyarn coefficient of friction'of less than 0.50 which is free from stick-slip behavior when tested as described Subsequently.
  • the polyamide consists essentially of polyhexamethylenedodecanedioamide of 30 to 70 relative viscosity having a triclinic crystallite cell structure characterized by a crystal perfection index of less than 50 percent with substantial freedom from the a-crystalline form.
  • the yarn is preferably an undrawn yarn suitable for drawing at a draw ratio of 3.5X to 4.5X when the yarn is textured. However, the yarn can be partially drawn or fully drawn prior to the the texturing opera tion. Yarn which has been drawn to have a break elongation of about 30 to 40 percent is usually used in conventional texturing operations.
  • undrawn feed yarn of 30 to 70 relative viscosity polyhexamethylenedodecanedioamide, having a triclinic crystallite cell structure characterized by a crystal perfection index of less than 50 percent with substantial freedom from the a-crystalline form is draw-textured at an applied twist of I70 to 200 turns per inch and a texturing temperature of 150 to 200C.
  • the draw-texturing can be performed in three ways. In the tandem process, drawing is completed in a separated draw zone and the drawn yarn is immediately fed into a false-twist texturing zone. In the simultaneous process, drawing is accomplished in the false-twist texturing zone. In the third proces, part of the drawing is accomplished in a separate draw zone and drawing is completed in the falsetwist texturing zone.
  • Textured polyamide yarn is readily produced which has a break tenacity of at least 6.5 grams per denier, a yarn-on-yarn coefficient of friction of less than 0.50, free from stick-slip behavior, about 45 to crimps per inch (restrained), a crimp elongation of at least 40 percent and a ratio of crimps per inch (restrained) to turns per inch (off pirn) of at least 1.6; the polyamide consisting of polyhexamethylenedodecanedioamide of 30 to relative viscosity having a triclinic cell structure characterized by a crystal perfection index of at least percent and a ratio of a/B crystalline forms of at least 1.0.
  • the excellent crimp properties obtained are believed to be due, at least in part, to the change in triclinic cell structure which occurs during texturing. Accordingly, the feed yarn is produced under conditions which provide a crystal perfection index of less than 50 percent and substantial freedom from the a-crystalline form, and heating of the feed yarn prior to the drawtexturing operation is avoided.
  • FIGS. 1 and 2 are schematic representations of pre ferred apparatus for practicing the draw-texturing process.
  • FIG. 1 illustrates a coupled drawing and texturing operation and
  • FIG. 2 illustrates simultaneous drawtexturing operation.
  • FIG. 3 is a side view of a friction-twist device for imparting twist to yarn during draw-texturing. Orientation relative to yarn travel is indicated.
  • FIGS. 1 and 2 represent single positions of a drawtwister rngdified to both cold-draw and false-twist texture a drawable nylon feed yarn. Corresponding parts are identically numbered.
  • Drawable feed yarn 12 is preferably completely undrawn and fed directly from its partially shown spin bobbin 10. Via creel pigtail guide 14, creel snub guide 16, and traverse guide 18, yarn 12 is led to and partly around cott roll 20 before passing through the nip between cott roll 20 and driven feed roll 22.
  • Draw roll 26 is driven and comprises two sections: (1) minor step 30 serving as a first drawing stage, and (2) major step 28 serving as a second drawing stage. Separator roll 32 is also provided, as is well understood. From feed roll 22, yarn 12 first passes about draw pin 24 and then to several wraps around minor step 30 and separator roll 32. Because the peripheral velocity of minor step 30 is greater than that of feed roll 22, yarn 12 becomes drawn.
  • Yarn 12 next passes in contact with hot plate 34 (or other known heating means) which is sized and operated to produce a predetermined yarn-temperature at its outlet. False-twisting occurs on passage of yarn 12 through rotating friction-tube twister 36 (described more fully hereinafter). Via guide 38, yarn 12 takes several wraps around major step 28 and separator roll 32, whereby further drawing occurs, since major step 28 and minor step 30 have different diameters, but rotate at the same angular velocity. Passing through balloon guide 40, the false-twist textured yarn is wound on pirn 42 using a conventional ring and traveler (not shown).
  • This treatment is labeled underfeed.
  • a 4 percent underfeed is used for Examples 3 and C; i.e., the diameter of major step 28 is 4 percent greater than that of minor step 30.
  • a nip roll (not shown) bears against yarn 12 on minor step 30 at the point where yarn 12 tangentially departs toward heater 34.
  • a special case of the above-described underfeed process is one in which major step 28 and minor step 30 have the same diameter. In this case, all the drawing occurs between feed roll 22 and minor step 30. All the texturing occurs without any further drawing in the travel from minor step 30 to major step 28.
  • This percent underfeed is herein labeled tandem to designate serial coupling, but complete separation of the drawing and false-twisting operations.
  • FIG. 2 A third variation is represented by FIG. 2. It differs from the above-described arrangements, as follows:
  • yarn 12 initially bypasses draw roll 44 via guides 46. It is then heated by hot plate 34, false-twisted via twister 36, and directed via guide 38 to several wraps around draw roll 44 and its separator roll 32. It is packaged as before. Thus, all the drawing and all the false-twisting occur in the same zone. This variation is labeled simultaneous.
  • knit-deknit texturing, gear crimping, and the like are effective for texturing yarns of this invention.
  • Twister 36 is basically an electric motor 50 having hollow rotor 52. Fitted onto each end of rotor 52 is a ring-like bushing 54 having its inner surfaces 56 outwardly flared. At least a portion of the yarn-contacting surfaces of bushings 54 has a high coefficient of friction with the running yarn.
  • Yarn 12 enters twister 36 via guide 58 positioned to provide a preselected entrance angle, [3, with respect to the center line (axis of rotation). Likewise, on exit, yarn 12 travels over guide 60 positioned to provide exit angle 7. Ordinarily, for most satisfactory performance, the center line of twister 36 is at angle a with respect to the horizontal.
  • the yarn of this invention melts at about 125C.
  • the heat-setting temperature is also lower than that of 66 nylon, which is an advantage in high speed texturing processes because heat-setting temperatures can be reached more quickly. This means that the same texturing equipment can be operated at higher speeds or a simpler heating device can be used.
  • the initial tensile modulus is about the same as that of 66 nylon at room temperature, but decreases much more rapidly at elevated temperatures. At 150C. it is only about onefourth that of 66 nylon. The resistance to applied torque is correspondingly reduced, so the yarn of this invention textures more readily and becomes more highly crimped than does 66 nylon in comparable processes.
  • the yarn of this invention is quite strong. In order to avoid confusion when comparing yarns which have been drawn to different extents or have been drawtextured under different conditions, tenacities given herein are calculated from stress in grams and denier at the instant of yarn failure. This break tenacity" is at least 6.5 grams per denier for yarns of the present in vention, and preferred embodiments have break tenac ities of at least 8.0 gpd.
  • Textured nylon yarns are frequently used for knitting ladies stretch sheer hosiery. High shape recovery after stretching is an important property. Much experience with 6--6 nylon stretch hosiery has taught that the higher is the degree of crimp of the yarns, the lower is the recovery. This is believed due to difficulty yarn portions have in sliding past other yarn portions as recovery forces approach zero. Surprisingly, the textured yarn of the present invention exhibits recoveries at least equivalent to 66 nylon even though its level of crimp is distinctly higher.
  • the improved crimp properties can be regenerated by a simple heat treatment after a fabric is prepared.
  • drawing and colddrawing are used interchangeably herein. They describe sufficient stretching of a yarn in its solid state (i.e., usually between room temperature and about 100C.) to result in a permanent reduction in denier.
  • draw-ratio When a yarn is fed into a zone at one linear velocity and removed from the zone at a higher linear velocity, the draw-ratio (DR) is the ratio of the higher to the lower of the linear velocities.
  • Relative Viscosity is the ratio of viscosities at 25 1': 005C. of a solution of nylon and the solvent alone.
  • the solvent is percent by weight formic acid (10 percent water), and the solution is formed from 5.500 gm. of dry 66 nylon in 50 ml. (25C.) of 90 percent formic acid.
  • the solvent is 50 percent by weight phenol and 50 percent by weight 98 percent formic acid.
  • a solution of 3.700 gm. of polymer in 50 ml. (25C.) of the solvent is employed.
  • Denier is the weight in grams of 9,000 meters of a yarn. It is ordinarily calculated from the weight of a known shorter length.
  • Tensile Testing Tensile determinations referred to herein include tenacity, break tenacity, elongation, initial modulus, and work recovery. These are all calculated from measurements on the trace of a recording stress/strain analyzer. Sample length is inches, and elongation is at the rate of 60 percent per minute.
  • packaged yarn is equilibrated for at least 24 hours in the test atmosphere at 72 percent RH and 25C.
  • Tenacity (T) is the force in grams per denier where the force in grams is that indicated at the point of tensile failure and denier is that obtained for the initial sample before elongation.
  • T Break tenacity
  • Elongation is expressed as the percentage increase in length of a yarn beyond its unstretched initial length.
  • Break elongation is elongation at tensile failure.
  • Modulus is expressed in grams per denier and is a measure at any point on the stress/strain curve of the change in stress (gm/denier) per unit increase in elongation (fractional, unitless).
  • Initial modulus as shown in Table I is calculated from the measured stress in grams per denier at precisely the point where 1,425 percent elongation of the structural elements has occurred (following straightening of crimp). The measured stress is divided by 1.425 and multiplied by 100 to obtain the listed initial moduli.
  • Applied twist is the amount of twist accumulated along a yarn at the time twist is heat-set in the yarn.
  • a spring-loaded device is used to take a sample of the traveling yarn just upstream of the false-twister (rotating friction-tube of spindle, etc.). The sampling device clamps two locations on a twisted length about 1.5 inches apart and simultaneously cuts the yarn just outside both clamped places. The number of twists per inch (tpi) of this twisted sample is counted under a microscope.
  • Twists per inch of product are measures of twist-liveliness in yarns after being packaged at least a week.
  • the packaged yarn is equilibrated for at least 24 hours at 72 percent RH and 25C.
  • a sample about 24 inches long is carefully removed by unwinding the package (notover its end) while preventing development of twist and without stretching the yarn.
  • the sample is then doubled without allowing any twisting, and taped at the joined ends to form a loop.
  • the loop is pulled very gently until there are no twist kinks in any filament. With the loop suspended at one end, twist of one leg around the other is permitted in small increments working from the bottom to the supported end.
  • TPI off-pirn The number of rotations at one end required to eliminate any twisting of the legs of the loop about one another, divided by 10, is labeled TPI off-pirn.
  • Another sample is identically prepared, except that, just before mounting it in the twist counter, it is steamed to fully develop any latent twist. Steaming is for 2 minutes in saturated steam at atmospheric pressure. The value calculated as above is labeled TPl-steamed.
  • CPI-restrained is measured as follows:
  • Crimp elongation (C.E.).
  • a 630-denier skein of test yarn is prepared while preventing any twisting. (This denier is twice the number of loops of yarn in the skein times the denier of a single yarn).
  • the skein is hung from the top pin of a skein-testing board, and from its bottom is hung a weighted hook.
  • the skein-testing board is a vertically supported board having (1) the above-mentioned pin, (2) an attached skein-length scale, and (3) two vertical rods parallel to, l-inch from either side of, and all along the length of the suspended skein.
  • the weighted bottom hook has fine laterally extending pins, 21 pair extending to each side and spaced apart just enough that one goes before and the other behind the respectivevertical rods. This prevents rotation of the skein.
  • Weight is added to the bottom hook until a total of 3.15 gm. (5mg./denier) is suspended.
  • the skein which had been wound under 0.1- gm./denier tension, is not relaxed until the 3.15 gm. weight is in place.
  • Atmospheric steam is directed onto the skein until no more shortening in length occurs.
  • the unextended length (L,,) is read from the attached scale. Then another 206.64 gm. is added to the hook. After 30 seconds, extended length (L is read.
  • Hose Power and Recovery hose to be submitted to this test should be plain-stitch, circular-knit hose of customary degrees of stretch. Results are relatively insensitive to the number of stitches per course, to the number of courses, and (with less leeway) to tensions employed during knitting, assuming the latter are customary ones. To assure obtaining comparable results each time, the circular-knitting machine preferably has 400 needles and knits 1,780 total courses.
  • Selected yarn tensions during knitting are such that, after subjecting the knitted hose to boiling water for 30 minutes and drying, the Jones Stretch is measured at 13.0 i 1.0 inches at the knee (4 inches below the shadow welt for hose, or 4 inches below the junction of panty and leg portions for pantyhose), and at l 1.0 i 1.0 at the ankle (2 inches above the heel).
  • the Jones Tester is a commonly-used test device which has its own built-in indicator for Jones Stretch in inches, which is manufactured by Jones Machine Company of Burlington, North Carolina, and which is as described in US. Pat. No. 2,706,402 to Gaither M. Jones, Sr.
  • Hose power and recovery are measured as follows: The boiled-off test hose is laid onto a table and carefully flattened and straightened without any stretching. The unstretched initial length (L of the completely relaxed hose is measured from the toe to the junction of the leg and welt portions (if pantyhose, measure to the junction of the leg and panty portions). A bulldog clamp (less than 100 gm. and preferably about 40 gm.) is fastened at each end of L and the hose is supported by the clamp at the welt end. A 100 gm. weight is added to the toe clamp and, after 30 seconds, a new length (L,) is measured. This last step is repeated until the weight added in 100 gm. increments totals 1,000 gm.
  • Yarn-on-yarn coefficient of friction is a measure of the ease with which filaments slip by each other.
  • About 700 yards of yarn are wound uniformly along a 2% inch portion of a cylinder 2 inches in diameter, using a winding tension of about 5 grams.
  • the cylinder is mounted for rotation about its central axis.
  • a 12-inch length of the same yarn is laid over the cylinder so that it rests on the wrapped yarn and is parallel to the turns thereof.
  • a 30-gram weight is attached to one end and the other end is attached to a strain gauge.
  • the cylinder is then rotated at least 180 at a peripheral speed of 0.0016 cm./second so that the strain gauge is under tension.
  • the tension is recorded continuously by an automatic device on a plot of force in grams vs. time.
  • the textured 6-12 nylon yarns of this invention' are particularly suited to the knitting of stretch fabrics and especially well to knitting ladies sheer stretch hosiery.
  • the hose power developed i.e., greater than about 500 gm.
  • the hose recovery is at least equivalent.
  • transparency, clarity, and luster are desired, they are readily provided at heretofore unobtainable levels by simply omitting delusterant from the polymer.
  • High initial modulus, low degree of moisture sensitivity, and low coefficient of yarn-on-yarn friction combine to provide a new level of dimensional stability in nylon stretch fabric.
  • EXAMPLES A 26 percent by weight aqueous solution of the salt if dodecanedioic acid (DDA) and hexamethylene diamine (HMD) is prepared in a mixing tank filled to the desired level by simultaneously charging 1.00 lb./min. of solid DDA, 1.26 1b./min of a 40 percent by weight aqueous solution of HMD, and 3.54 lb./min. of water. This solution is maintained at 44 i 2C. and finally adjusted to pH 7.60 i 0.04 by incremental addition of whichever ingredient is required. At this point, any desired antioxidants and/or antifoam agents are added, as is also a small amount of acetic acid for molecular weight control.
  • DDA dodecanedioic acid
  • HMD hexamethylene diamine
  • the initial salt solution is then evaporated to about percent by weight salt in an evaporator heated with steam at 300 psig. (21.1 kg./cm. gauge). Vapor temperature at this point is 141C.
  • Polymerization is then carried out in an autoclave in four stages. in the first stage, pressure increases from to 250 pounds per square inch absolute (psia.) (10.5 to 17.6 kg./cm while temperature increases to C. Constant pressure of 265 psia. (17.6 kg./cm. is maintained in the second stage until temperature reaches 227.9C. Pressure is reduced to 14.8 psia. (1.04 kg./cm. in the third stage while temperature rises to 237C.
  • polymerization is completed by maintaining the 14.8 psia. (1.04 kg./cm. pressure until temperature reaches 254C. Delustrant, if desired, is added between the first and second stages. Finally, the molten 6-12 nylon is extruded under pressure of inert gas, quenched with water, and cut into flake for subsequent use.
  • the polymer flake has a relative viscosity (RV) of.27.
  • the yarn for Examples 1, 2 and 3 is melt-spun from the above polymer flake at a spinning speed of 517 yards per minute. Melt-spinning conditions are used which are considered optimum for melt-spinning conventional 6-6 nylon, except that the temperature of the melt just prior to extrusion is 260C.
  • the as-spun yarn has a denier of about 72 to yield 18 denier yarn when drawn, and consists of three filaments, each about 24 denier per filament.
  • the yarn for comparison in Examples A, B and C is melt-spun from conventional 66 nylon flake of 37 relative viscosity.
  • the melt-spinning conditions are identical to those used for Examples l-3, except that the temperature of the melt just prior to extrusion is 293C.
  • the as-spun yarn also has a denier of about 72 to yield 18 denier yarn when drawn, and consists of three filaments.
  • the modulus of a 6-12 nylon yarn more than 20 percent less then the dry 10 modulus (percentages of dry modulus are shown in parentheses). At 55 percent RH, the modulus is at least equivalent to the dry modulus. Steaming or boiling in water simulates processing treatments usually given to H a 50, a d ,y 560 kntt fabI'lCS.
  • Tables 11 and III present the variations of initial modulus with relative humidity, modulus being determined by the skein method described hereinabove. Results in Table II are obtained on textured yarns before they are steamed. It is apparent that, although the 6-12 nylon The 6 textured yarns of the examples are separately knitted into legs of womens sheet stretch hosiery. Single feed, plain-stitch circular knitting is used. Hose power and percent recovery are measured as described hereinabove. Results are in Table IV.
  • Example C had 2304 courses.
  • the yarn-on -yar n coeffi- Example 07/5 CPI a/fi XPI AWw) AXPI c1ent of fr1ct1on for the yarn of th1s 1nvent1on is always less than for correspondingly textured 6-6 nylon yarn, i 233 g 458 5i] 3i] and is always less than 0.5.
  • the yarn was also tested for twlst-hvellness by measuring the values for TPI off-pirn and TPI Example I A 2 B 3 C steamed. These results are shown in Table VII along Coefficient 0.48 0465 046 M4 025 038 with the ratios of CPI (restrained) to TPI (see Table I V for CPI).
  • the yarns of the examples are also submitted to flatfilm 'X-ray diffraction.
  • Microdensitometer traces along the equator, the meridian, and a specific azimuth are used to compute both XPI (crystal perfection index expressed as a percentage) and 01/3 ratios of amounts of crystal forms (the even-even aliphatic polyamides like 66 and 612 have triclinic crystallite cells with either a or B crystalline forms).
  • XPI crystal perfection index expressed as a percentage
  • 01/3 ratios of amounts of crystal forms the even-even aliphatic polyamides like 66 and 612 have triclinic crystallite cells with either a or B crystalline forms.
  • P. F. Dismore and W. O. Statton, J. Poly. Sci., Part C. No. 13 (1966), page 134 describes the measurement and calculation of XPI, The 01/13 ratio of crystalline forms is obtained from microdensitometer traces of the same film used to determine XPI.
  • Triclinic diffraction patterns are charac terized by off-equator layer lines.
  • the percentage of B form is taken as proportional to the maximum intensity at the second layer line along the meridian.
  • Diffraction spots at each end of each layer line are contributed by the a form.
  • the azimuthal maximum intensity through one of the spots on the second layer line is taken as proportional to the percentage of a form.
  • Baseline and background corrections customary for X-ray diffraction measurement are, of course, made.
  • the 07/13 ratio is, 'then, the direct ratio of two measured scattering intensities.
  • Table VI summarizes the X-ray results. XPI and 11/8 ratio are given where applicable, for each yarn as The 612 nylon yarns of Examples 1 to 3 are to be compared with 6-6nylon yarns of Examples A to C. While the TPI results for the yarns of this invention are less than for 6-6 nylon yarns, the really significant comparison is in the CPI/TPI ratios.
  • the numbers of crimps per inch (CPI) are preferably as large as possible. False-twist crimping is always accompanied with yarn-torque (here measured as TPI). Torque off the pirn causes difficulties in knitting, and the higher torque in steamed yarns causes stitch distortions in knitted fabrics.
  • TPI should be minimized.
  • the CPI/TPI ratio off-pirn for the 612 nylon yarns of Examples 1 to 3 is seen to be at least 1.6, and is more than twice the ratio for the similarly processed 66 nylon yarns.
  • the ratio after steaming is at least 0.75 for the yarns of Examples I to 3, and is about twice that of similarly processed 66 nylon yarns. It is not understood why the false-twist textured 612 nylon yarn of this invention should have such remarkably improved ratios of crimp to twist-liveliness.
  • a polyamide feed yarn for drawing and texturing which has a break tenacity of at least 6.5 grams per denier and a yarn-on-yarn coefficient of friction of less than 0.50, free from stick-slip behavior, said polyamide consisting essentially of polyhexamethylenedodecanedioamide of 30 to 70 relative viscosity having a triclinic crystallite cell structure characterized by a crystal perfection index of less than 50 percent with substantial freedom from the a-crystalline form.
  • a feed yarn as defined in claim 1 in an undrawn form which drawn-textures at a draw ratio of 3.5X to 4.5X, an applied twist of 170 to 200 turns per inch, and a texturing temperature of 150 to 200C. to provide about 45 to 65 crimps per inch (restrained), a crimp elongation of at least 40 percent and a ratio of crimps per inch (restrained) to t-urns per inch (off-pirn) of at least 1.6.
  • the improvement which comprises draw-texturing the polyhexamethylenedodecanedioamide feed yarn defined in claim 1 at an applied twist of 170 to 200 turns per inch and a texturing temperature of 150 to 200C. to produce textured yarn having about 45 to 65 crimps per inch (restrained), a crimp elongation of at least 40 percent and a ratio of crimps per inch (restrained) to turns per inch (off-pirn) of at least 1.6; said textured yarn having a triclinic crystallite cell structure characterized by a crystal perfection index of at least 75 percent and a. ratio of 01/6 crystalline forms of at least 1.0.
  • a textured polyamide yarn which has a break tenacity of at least 6.5 grams per denier, a yarn-on-yarn coefficient of friction of less than 0.50, free from stickslip behavior, about 45 to 65 crimps per inch (restrained), a crimp elongation of at least 40 percent and a ratio of crimps per inch (restrained) to turns per inch (off-pirn) of at least 1.6; said polyamide consisting of polyhexamethylenedodecanedioamide of 30 to relative viscosity having a triclinic cell structure characterized by a crystal perfection index of at least percent and aratio of 01/8 crystalline form of at least 1.0.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Artificial Filaments (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
US375941A 1973-07-02 1973-07-02 Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof Expired - Lifetime US3858387A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US375941A US3858387A (en) 1973-07-02 1973-07-02 Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof
FR7422833A FR2236032B1 (ja) 1973-07-02 1974-07-01
ZA00744206A ZA744206B (en) 1973-07-02 1974-07-01 Textured polyamide yarn and production thereof
JP49074391A JPS5036727A (ja) 1973-07-02 1974-07-01
GB2913974A GB1471688A (en) 1973-07-02 1974-07-01 Polyamide yarns
AR254511A AR202560A1 (es) 1973-07-02 1974-07-01 Hilado inicial de poliamida para estirar y texturizar, procedimiento para texturizarlo por estiraje e hilado de poliamida texturizado
CA203,772A CA1040403A (en) 1973-07-02 1974-07-02 Textured polyamide yarn

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US375941A US3858387A (en) 1973-07-02 1973-07-02 Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof

Publications (1)

Publication Number Publication Date
US3858387A true US3858387A (en) 1975-01-07

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US375941A Expired - Lifetime US3858387A (en) 1973-07-02 1973-07-02 Polyamide feed yarn for false-twist texturing, process of false-twist texturing, and product thereof

Country Status (7)

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US (1) US3858387A (ja)
JP (1) JPS5036727A (ja)
AR (1) AR202560A1 (ja)
CA (1) CA1040403A (ja)
FR (1) FR2236032B1 (ja)
GB (1) GB1471688A (ja)
ZA (1) ZA744206B (ja)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103480A (en) * 1976-03-12 1978-08-01 Bayer Aktiengesellschaft Method for producing textured filament yarns with improved yarn qualities from preorientated polyamide 6
US4816550A (en) * 1985-09-17 1989-03-28 Monsanto Company Polyamide feed yarn for air-jet texturing
US20060096270A1 (en) * 2004-11-10 2006-05-11 Keith Kenneth H Yarn manufacturing apparatus and method
CN103060977A (zh) * 2013-01-13 2013-04-24 经纬纺织机械股份有限公司 全自动假捻变形机热导丝盘装置
CN111676555A (zh) * 2020-06-08 2020-09-18 山东祥瑞祥纺织有限公司 变支在59tex以上密度纱自动落纱环节中的应用

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59187602A (ja) * 1983-04-01 1984-10-24 東洋紡績株式会社 ストッキング
JPS6189301A (ja) * 1984-10-08 1986-05-07 東洋紡績株式会社 パンテイストッキング
JP4896575B2 (ja) * 2006-04-24 2012-03-14 サンウエーブ工業株式会社 棚装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184436A (en) * 1959-09-04 1965-05-18 Du Pont Polycarbonamides of improved dye affinity having the benzene sulfonic acid salt moiety as an integral part of the polymer chain
US3418199A (en) * 1964-10-01 1968-12-24 Du Pont Crimpable bicomponent nylon filament
US3560448A (en) * 1966-09-13 1971-02-02 Ici Ltd Synthetic polyamides
US3608299A (en) * 1970-04-15 1971-09-28 Du Pont Process for producing torque stretch yarns
US3696074A (en) * 1969-03-25 1972-10-03 Toray Industries Copolyamide from (a) dodecamethylene diamine,(b) hexamethylene diamine,(c) terephthalic acid and (d) adipic acid

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184436A (en) * 1959-09-04 1965-05-18 Du Pont Polycarbonamides of improved dye affinity having the benzene sulfonic acid salt moiety as an integral part of the polymer chain
US3418199A (en) * 1964-10-01 1968-12-24 Du Pont Crimpable bicomponent nylon filament
US3560448A (en) * 1966-09-13 1971-02-02 Ici Ltd Synthetic polyamides
US3696074A (en) * 1969-03-25 1972-10-03 Toray Industries Copolyamide from (a) dodecamethylene diamine,(b) hexamethylene diamine,(c) terephthalic acid and (d) adipic acid
US3608299A (en) * 1970-04-15 1971-09-28 Du Pont Process for producing torque stretch yarns

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103480A (en) * 1976-03-12 1978-08-01 Bayer Aktiengesellschaft Method for producing textured filament yarns with improved yarn qualities from preorientated polyamide 6
US4816550A (en) * 1985-09-17 1989-03-28 Monsanto Company Polyamide feed yarn for air-jet texturing
US20060096270A1 (en) * 2004-11-10 2006-05-11 Keith Kenneth H Yarn manufacturing apparatus and method
US7406818B2 (en) 2004-11-10 2008-08-05 Columbia Insurance Company Yarn manufacturing apparatus and method
CN103060977A (zh) * 2013-01-13 2013-04-24 经纬纺织机械股份有限公司 全自动假捻变形机热导丝盘装置
CN103060977B (zh) * 2013-01-13 2015-07-22 经纬纺织机械股份有限公司 全自动假捻变形机热导丝盘装置
CN111676555A (zh) * 2020-06-08 2020-09-18 山东祥瑞祥纺织有限公司 变支在59tex以上密度纱自动落纱环节中的应用

Also Published As

Publication number Publication date
FR2236032B1 (ja) 1979-02-16
JPS5036727A (ja) 1975-04-07
AR202560A1 (es) 1975-06-24
FR2236032A1 (ja) 1975-01-31
CA1040403A (en) 1978-10-17
ZA744206B (en) 1975-08-27
GB1471688A (en) 1977-04-27

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