US3433008A - Bulked yarn - Google Patents

Description

T. B. GAGE BULKED YARN .March 18, 1969 Sheet Filed Nov. 19, 1965 .MMI

MINI O y mNI l lll/r Ill/l;

March 18, 1969 T, B, GAGE 3,433,008

BULKED YARN Filed Nov. 19, 1965 sheet 2 Acfs March 18, 1969 T. B. GAGE 3,433,008

BULKE'D YARN Filed Nov. 19, 1965 sheet 3 om United States Patent O 6 Claims ABSTRACT F THE DISCLOSURE An improved process and product prepared by applying a texturing finish of an ester of a polyethylene glycol of molecular `weight between 150 and 600 and an aliphatic carboxylic acid to continuous melt spun filaments before the filaments are drawn. The filaments are then drawn and bulked in a turbulent fluid jet to give the improved product.

This is a continuation-in-part of pending application Ser. No. 444,608, filed Apr. 1, 1965, now abandoned, which is a continuation-in-part of pending application Ser. No. 357,969, filed Apr. 7, 1964 now abandoned.

This invention relates to a process for producing meltspun, continuous filament yarn of greatly increased bulk at a high speed, and the product obtained, which has a high order of stability.

The high utility of conventional melt-spun, continuousfilament yarns has recently been increased by new technology such, for example, as that taught in U.S. Patents 2,783,609, 2,852,906, 3,017,737 and others. These yarns in relatively low total denier (say 40 to 70) are particularly useful in textile applications such as fabrics or knit articles. However fluid bulking adds costs to yarn production and consequently bulked yarns have had difficulty in competing as industrial yarns for such uses as twine, rope, belting material, etc.

Industrial yarns are generally of at least 4 denier per filament and at least 200 denier total. The permissible speed of bulking, if `a product of good quality is desired, varies as an inverse function of total denier. For example, in bulking according to the technology of U.S. Patent 2,852,906, only speeds below 100 yards per 'minute are operative for S40-denier yarn, and only speeds below 50 yards per minute are operative for 4200'denier yarn. O-f course, the cost of bulking is a function of the speed and therefore the denier of the yarn being processed. Speeds above the designated maxima result in poor bulking, and the bulked yarn debulked to a high degree under tension.

It is accordingly a principal object of this invention to provide a low-cost, stable, bulked yarn of meltspun, continuous filaments. Another object is to provide a process for bulking high-denier bundles of synthetic, polymeric filaments at high speeds, without impairing the quality and stability of the resulting ybulking effect.

The invention will be described, especially las to its processing embodiments, in conjunction with the attached drawing, in which:

FIGURE 1 is a diagrammatic representation of the apparatus and treatment sequences, according to common practice and according to this invention. Where these practices differ, the diagram indicates the old practice (by bracketed legends and the new practice by underscorng;

FIGURE 2 is a diagram on an enlarged scale of a section, axiswise, of the textured yarn, indicating the magnitudes employed in the definition of the function o;

FIGURE 3 is a diagrammatic representation orf a second arrangement of apparatus for use in practicing an embodiment of the invention; and

3,433,008 Patented Mar. 18, 1969 FIGURE 4 is a diagrammatic representation of still another arrangement of apparatus with which to practice the invention.

In this invention, the objects are accomplished wherein man-made `filaments are prepared in a process comprising: (l) melt-spinning to produce a continuous-filament yarn, (2) applying a texturing finish to the yarn, (3) drawing the yarn, (4) applying a wetting liquid to the idrawn yarn, and (5) texturing in a fluid jet to produce a stable bulked yarn comprising entangled, convoluted filaments with random, crunodal, filament loops. A particular characteristic of the process is that the texturing finish is applied to the filament bundle `at an early stage after its formation and, in any event, before drawing, instead of after drawing as has hitherto been practiced. Supplementary improvements in the process comprise the selection of the texturing finish from a preferred group, which is characterized by certain preferred physical properties, and the application of a wetting liquid to the filament bundle Ibefore it enters the texturing jet.

It should be appreciated that the texturing finish applied prior to drawing in this invention is not a mere yarn lubricant commonly applied to textile fibers when they are subjected to processes involving movement in contact with machinery. The important distinctions between the two aregiven in U.S. Patent No. 2,807,864. In that patent, the finish is referred to as a yarn treating composition, special treating composition or simply treating composition, and is made upy of a mixture of mineral oil, certain petroleum sulfonate derivatives, certain terpene derivatives, long chain aliphatic acids, and alkylol amines.

For the present invention the texturing finish is best defined by its physical characteristics. Thus, it should be an organic liquid which has, at room temperature, a surface tension not greater than 46 dynes/cm.; a viscosity less than centipoises (cps.) and preferably not greater than 23 cps.; and a boundary fricion not less than 0.15. These finishes should not be reactive toward the wetting liquid selected -for application just prior to texturing, and the texturing finish should disperse in that wetting liquid. The foregoing properties are of the texturing finish absent the water generally employed to provide the finish in emulsion or solution form. If the surface tension exceeds 46 idynes/ cm., the :finish 'does not have sufficient coverage for acceptable process performance. When the viscosity is greater than 75 cps., the yarn does not splay out when contacted by the jet vortex and therefore the yarn does not have adequate bulk.

The texturing finishes for this invention should also be inert to the yarn, non-corrosive to carbon steel, non-toxic and :non-flammable; and they should have low volatility.

Particularly suitable organic liquids meeting the above requirements are the esters (monoand di) of a polyethylene Iglycol of molecular weight between and 600 and carboxylic acids of the form R-COOH wherein R is an aliphatic hydrocarbon radical (saturated or unsaturated, str-aight-chain or branched) of 7 to 17 carbon atoms.

Particularly good results have been obtained in this invention by using as texturing finish a liquid organic composition comprising, in an amount not less than 10% by weight of the total mixture, at least one ester of the group consisting of the monolaurate of polyethylene glycol 400, and the bis(2ethyl hexoate) of polyethylene glycol 200. (The numeral at the end of the glycol refers to the nominal molecular weight of the polyethylene glycol before esterification with the indicated carboxylic acid.) Other components of the texturing finish that may be present (but are not necessary) are water, organic diluents or solvents and emulsifying agents.

The bulked yarn product of this invention should preferably contain not less than 0.01% (on weight of yarn) of an ester of said class. To provide such a residual content, the yarn entering the texturing jet should contain not less than 0.03% (on weight of yarn) of the ester.

Boundary friction is a term relating to the capacity of a given finish to impart surface friction to the individual filaments of a treated bundle to hinder slippage with respect to each other. This property may be determined as follows: About 750 yards of yarn are wrapped around a cylinder, 2 inches in diameter and 3 inches long, the yarn containing 0.03 to 5%, based on the weight of yarn, of the texturing finish to be tested. A l2-inch length of the same yann is then placed over the top of the cylinder so that it rests on top of the wrapped yarn and is directed parallel to the turns thereof, while one end of it hangs down and supports a 30-gran1 weight. The other end of the overlaid yarn is attached to a strain gauge. The cylinder is then rotated at a peripheral speed of less than 0.01 cm./sec., so that the strain gauge is under tension. The boundary friction f of the texturing finish is calculated from the equation: T/:efa where T is the average peak tension, in grams, on the strain gauge and a is the angle, in radians, of the wrap described by the single length of yarn on the cylinder.

The process of this invention produces, in the high bulk yarns, a new product having a novel texture, the latter being best defined by the numerical value of a mathematical function qb, defined as follows:

In this expression, DL represents the average diameter or height, in mils, of the random, crunodal loops in the outer filaments of the entangled, convoluted filament mass forming th-e textured yarn, and is determined as indicated below; DC represents the average diameter, in mils, of the yarn core; FL represents the loop frequency, that is, the average number of r-andom, crunodal loops protruding all around the outer surface of the core per inch length of the textured yarn; and W constitutes the denier of the textured yarn. DC, the yarn core diameter (FIG. 2), is the diameter of the bulked mass of filaments, the mass being identified by ignoring the protruding crunodal loops. DG is the over-all diameter. -DC and DG are measured (in mils) by direct observation at a magnification of 25 times. The loop diameter DL is computed as:

The loop frequency FL is also determined by direct observation at 25 X. For accuracy, average diameters are determined by computing an average of 25 measurements, and average loop frequency is determined by computing an average of countings. As thus defined, the high bul-k yarns (overfeed greater than bulked according to the novel process of this invention have consistently been found to have a p-value of 70 to 335, whereas industrial yarns bulked by the hitherto practiced methods have 4S values less than 70.

The novel texture is further characterized by the nurnber of surface loops in relation to the total number of loops per unit of length of the textured yarn. A surface loop is defined as a crunodal loop having its cross-over point separated from the bundle core by a distance equal to or greater than two filament diameters. A bundle loop is defined as one whose filament cross-over is closer than two filament diameters or whose cross-over occurs within the bundle core. The surface loops and bundle loops may be counted by direct observation under low magnification and the result expressed as the percent of surface loops based on the total number of loops per unit length of yarn. 'Ihe new yarns of this invention have at least 15% of all the loops present as surface loops.

The novel high bulk yarn is further characterized by a favorable stability index which equals no more than about 0,1 of the percent denier-.increase effected by the yam passa-ge through the texturing jet. Percent denier-increase may be ymeasured by subtracting from the denier (Db) of a piece of bulked, continuous yarn the denier (Dd) of a debulked piece of the same bulked yarn, the second piece being equal in length to the first piece, dividing the difference by the denier of the debulked yarn and multiplying by thus,

g- X 1 00 Percent denier-increase Debulking is accomplished by individually straightening out (with tweezers or similar appliances) each filament of the piece of yarn so that no loops, entanglement, convolutions, or waviness are in such debulked yarn. The denier of the debulked yarn is not necessarily the same as the denier of the unnbulked yarn. In the yarns cornprehended by this invention, filament length distribution of such debulked yarn is in a normal Gaussian distribution.

Stability index in a bulked yarn is the measure of the potential loss of yarn bulk during subsequent processing such as twisting, Weaving and knitting, when tensile forces are applied to the yarn. It is determined by first making taut a test piece of yarn 100 centimeters long by attaching a load not greater than 0.011 g.p.d. and measuring the length of the test piece. Next, a 0.5 g.p.d. load is attached and left on the test piece for l2 seconds. Then the 0.5 g.p.d. load is removed, the test yarn remains for about 10 seconds with the original load, and finally the length of the test piece is measured again. The percent stability, or the stability index, is the increase in length expressed as a percentage of the first measurement of length. During the determination of stability, loads must be applied and removed slowly so that oscillation of the test piece does not occur.

The invention will be described further in conjunction Iwith the drawings. Where an item appears in different figures it has been given a single number throughout.

Referring to FIGURE 1, a bundle of filaments 10 spun from a spinneret 11, passes through a conventional quenching chimney 12 and then in contact with liquid applicator roll 13, over a feed roll 114 and separator roll 14a, and into a system of drawing apparatus 15, for instance as in U.S. Patent 3,043,088, FIGURE 1l. As the yarn 10 issues from the drawing zone, it contacts liquidapplicator device 16 (e.g., Wick, roll, or trough) and then guide roll 17, and then enters a jet-bulking apparatus 18. In an alternate arrangement 17 may precede 16. Upon emerging from a jet 18, the resulting textured yarn passes around tensioning device 19 to eventual fwindup.

Prior to the present invention, texturing finish was applied to the yarn 10 just before entering the bulking apparatus 18 and, therefore, after drawing. Incidental to that practice ordinary lubricant had to be applied to the yarn before it entered the drawing zone, say at 'applicator roll 13. In the present invention, on the other hand, the texturing finish is applied, at roll 13, before the yarn is subjected to drawing in zone 15. In addition a wetting liquid, such as water or a volatile organic liquid other than a common lubricating finish, is applied to the drawn yarn, at roll 16, before it enters the bulking or texturing zone 18.

The product obtained is shown in FIG. 2, where 101 represents the entangled, convoluted mass of filaments which constitutes the core of the yarn and 102 are the randomly distributed crunodal loops fwhich protrude from the core all around its outer surface.

The sequence of operations indicated in FIG. l may, in practice, be divided into two or more distinct stages. In a preferred embodiment, the process is divided into two stages whereby melt-spinning and the application of texturing finish are effected continuously in a first stage, and drawing, application of a wetting substance, and

texturing are continuously effected in a second stage. This is shown diagrammatically in FIG. 3.

Referring to FIG. 3, in a first stage, a bundle of laments is spun through a spinneret 11 from a melt of, for example, poly(hexamethylene adipamide) or other desired polymer, and is passed down through a quenching chimney 12. A texturing finish is applied to the yarn at a nish roll 13 located directly below the quenching chimney 12. After contacting the finish roll 13 the yarn is wound to a package 30 in any conventional manner.

In a second stage, `tive single ends of the yarn 10 are plied from 5 packages 30a, 30h, 30C, 30d and 30e into a single tow that is passed over a feed roll 31 provided with a drive roll 31a. Obviously any other number of ends could be plied to form the tow. The tow is then drawn using, for example, a combination of a draw pin 32, a hot plate 33, and draw roll 34 provided with separator roll 34a. The drawn yarn is then passed in contact with, and therefore made wet by, a water-wetted felt 35 just before entering a texturing jet 18, for example a jet as disclosed by Hallden in U.S. Patent 3,084,413. Other known jets could be used if desired. However, the jet specified in the examples given hereinafter is a modied rectangular jet as in the Hallden patent. After issuing from the jet, the bulked yarn enters a conventional tensioning device 36, and then passes over a let-down roll 37 provided with separator roll 37a. From the let-down roll 37 the yarn is packaged at a windup-roll 38.

In another embodiment, represented in FIG. 4, the drawing procedure is accomplished in the rst stage, but the process is otherwise similar to that just described. Referring to FIG. 4, in a rst stage filaments 10 are spun from a melt through a spinneret 11 and passed through a quenching chimney 12. A texturing iinish is applied to the yarn from a finish roll 13 located below the quenching chimney. After contacting the nish roll 13, the yarn passes around a feed roll 14 and a separator roll 14a to a drawing stage and is drawn in a conventional drawing apparatus 15, e.g., draw rolls, and then is formed to package 40.

In the second stage, yarn is withdrawn from a package 40, passes over an overfeed roll 41 provided with a drive roll 41a and then is passed in contact with a Water-wetted felt 42 just before entering a jet 18 ywhere the yarn is bulked. From the jet, the bulked yarn passes over a tension device 43 through step rolls 44, 44a and then to a windup roll 45.

The invention also may be practiced in a three stage operation. In such an embodiment spinning and the application of a texturing linish occur in a rst stage, drawing is effected in a second stage, and the application of a wetting substance followed by texturing are carried out in a third stage. lIt should be appreciated that where the invention is practiced in a plurality of stages, the various stages may be separated, if desired, by intervals of storing and/or transporting the intermediate yarn product from one location to another.

Denier increase in yarns of this invention is obtained upon overfeeding yarn to the texturing jet. Overfeed for purposes of this invention is always at least 5% and may be as high as about 40%; by way of example, where the speed of the yarn entering the texturing jet is 335 yards per minute, the exit speed could range from 239 to about 319 yards per minute.

The wetting liquid applied to the drawn yarn before texturing should preferably be a low-viscosity liquid having a surface tension not greater than 75 dynes/cm. and a viscosity not greater than 3 (and preferably 1 or less) centpoises at 25 C. Water is very useful and commonly preferred. Other suitable -wetting liquids are carbon tetrachloride, methanol, toluene and methylene chloride, but in the use of these, precautions should be taken to ensure proper ventilation.

The following examples illustrate the invention, and are not intended to be limiting. The texturing nish employed in the examples has a viscosity at 24 C. of 23 centipoises, a surface tension of 33.16 dynes per cm. and a boundary friction in the range of 0.25 to 0.33.

EXAMPLE I The apparatus employed for this example is shown diagrammatically in FIGURE 3.

In a rst stage, round-lament yarn of approximately 4000 denier is spun through a spinneret from a melt of poly(hexamethylene adipamide) and passed through the quenching chimney. A texturing finish, at arnbient room temperature, of an aqueous emulsion comprising 15 pounds of the monolaurate of polyethylene glycol 400 and 35 pounds of bis(2ethyl hexe-ate) of polyethylene glycol 200 is pounds of water, is applied to the yarn from a nish roll located directly below the quenching chimney. After contacting the lnish roll the yarn, now containing 0.9% finish on weight of yarn, is packaged.

In a second stage, 5 single ends of the approximately 4000 denier (as spun) yarn are plied from 5 packages into a single tow, are passed by a feed roll to a drawing zone, and then are drawn using a combination of a cold draw pin, a hot (190 C.) plate and draw roll with separator roll, for a machine draw-ratio of 4.95. The resulting drawn yarn is then passed in contact with, and therefore made wet by, a water-wetted felt at room temperature just before entering a modied rectangular jet. The jet is enclosed in a soundand splash-proof box. The drawn yarn speed to the jet is controlled by the draw roll which rotates at a surface speed of 85 yards per minute. Only individual warps of yarn are kept on the draw roll and separator roll. The air supply to the jet is 140 pounds 'per square inch gauge measured at ambient room ternperature. On issuing from the jet, the bulked yarn changes its direction 'by about 90 and then enters a tensioning device. The yarn tension between the jet exit and tensioning device is 39 grams. From the tensioning device, the yarn passes over a let-down roll provided with a separator roll. The tension in the yarn between the tensioning device and the let-down roll is 475 grams. The surface speed of the let-down roll is 72.5 yards per minute. The overfeed, based on speeds of draw roll and the let-down From the let-down roll the yarn is packaged at a windup roll speed of about 72 yards per minute. The tension in the yarn between let-down roll and windup roll is 500 grams. The woundup textured yarn has the following properties:

Bulked denier 4664 Stability index percent-- 0.2

Instron tenacity grams/denier 5.6

Elongation percent-- 17.8

Modulus gramS/denier 12.2

EXAMPLE II The procedure of Example I is repeated but with one end of yarn and the following changes in operating details. The hot plate employed is at C., the machine draw ratio is 4.88, the draw roll rotates at a surface speed of 305 yards per minute and the air supply to the texturing jet is 120 pounds per square inch gauge. The let-down roll is operated at a surface speed of 256 yards per minute. The overfeed, based on speeds of the draw and let-down rolls is 19%. From the let-down roll the yarn is packaged at a wind-up roll speed of 264 yards a minute. In this example the tension in the yarn between the jet and the tension device ranges between 11.4 and 12.3 grams, the yarn tension bet-Ween the tension device and the let-down roll is 110 grams and the tension in the yarn between the let-down roll and the windup roll is 90 grams.

The resulting wound-up textured yarn has the following properties:

Bulked denier 932 Stability index percent 0.2 Instron tenacity grams/denier 5.1 Eiongation percent 13.2 Modulus grams/denier 28.7

EXAMPLE III Following the general procedure of Example I, in a first stage, 140 round filament yarn is spun at 585 yards per minute through a spinneret from a meit of poly(hexa methylene adipamide) and is quenched in a quenching chimney. A texturing finish, at ambient room temperature and as a 25% aqueous dispersion, comprising as active components 70% by Weight bis(2ethyl hexoate) of polyethylene glycol 200 and 30% 'by weight the monolaurate of polyethylene glycol 400, is applied to the yarn from a finish roll located directly below the quenching chimney. After contacting the finish roll the yarn, now containing 0.9% (i0.2%) finish on weight of yarn, is packaged.

In a second stage, 7 single ends of the yarn are plied from 7 packages into a single tow by coverging at a feed roll, and the tow is then drawn using a combination of a cold draw pin, a hot (190 C.) plate and draw roll provided with a separator roll. The drawn yarn is then passed in contact with a water (l ml./min.) wetted felt at room temperature just before entering a modified rectangular jet. The draw machine ratio is 4.95. The drawn yarn is lfed to the jet by the draw roll which has a surface speed of 85 yards per minute. The air supply to the jet is 140 pounds per square inch gauge at ambient room temperature. On issuing from the jet, the bulked yarn changes its direction by about 90 and then enters the tensioning device. From the tensioning device the yarn passes over a let-down roll. The overfeed is calculated to be 32%. From the let-down roll, the yarn is packaged on a windup roll at a yarn speed of 65 yards per minute and with a yarn tension of 750 grams. The wound-up textured yarn upon examination is found to have a core diameter of 91 mils, an over-all diameter of 147 mils, and a loop frequency of 380 as well as the following properties.

Bulk denier 6543 Approximate percent denier increase percent 16.8 Stability index do 0.2 Instron tenacity grams/denier 4.3 Elongation percent 19.2 Modulus grams/denier 9.6 ,b Value 148 EXAMPLE IV High-bulk, 700 round-filament, yarn of poly(hexa methylene adipamide) made from 5 plied ends, is provided by the process and apparatus described in Example I, but with the following changes. The yarn contains 1.1% texturing finish (of the same composition of Example I), `by weight of yarn, before drawing. The machine draw ratio is 5.02. The let-down roll has a surface speed of 65 yards per minute. Since the draw roll speed is 85 yards per minute the overfeed is 31%. The windup roll speed is 195 revolutions per minute, and the tension in the yarn between the let-down 4roll and the windup roll is 470 grams.

The wound-up textured yarn has the following properties:

Bulked denier 4923 Stability index percent 0.7

Instron tenacity grams/denier 3.96

Elongation perceut 24.8

EXAMPLE V High bulk, 52 trilobal (modification ratio about 1.6)

filament yarn of ypoly(hexamethylene adipamide), 697 bulked denier, is provided as follows: The yarn is processed as a single end by the process and the apparatus of Example I, with the following exceptions. The spun yarn (about 2450 denier as spun), before drawing has 1.02% (by weight of yarn) of the texturing finish specified in Example I. Also, the yarn in this example is drawn only with a draw pin and draw roll (hot plate is omitted) for a machine draw ratio of 4.60. The air to the modified rectangular jet is 135 pounds per square inch. The surface speeds of the draw roll and of the let-down roll are 120 yards per minute and 84 yards per minute respec tively. Therefore, the overfeed is 43%. From the let-down roll the yarn is packaged at a windup roll speed of 235 revolutions per minute. The yarn tension between the letdown roll and the windup roll is grams.

The woundup textured yarn has the following properties:

Bulked denier 697 Stability index percent 0.5

Instron tenacity grams/denier 2.3

Elongation percent 20.5

Modulus grams/denier 7.9

EXAMPLE VI Low bulk, 140 round-filament yarn of Ipoli/(hexamethylene adipamide), 910 bulked denier, is provided by processing a single end of yarn by the process and the apparatus of Example I, except that the let-down roll is not used, and with the following process changes. The amount of finish applied to the spun yarn, before drawing and of the same composition specified in Example I, is about 0.8% on the weight of the yarn. The machine draw ratio is 5.02. The air supply pressure to the modified rectangular jet is pounds per square inch and the `air fiows at the rate of 8 standard cubic feet per minute. The water for the wet felt at the inlet to the jet fiows at the rate of about 9 milliliters per minute. The surface draw roll speed is 300 yards per minute and the yarn is wound at 252.5 yards per minute. Therefore, the overfeed is 19%. The tension in the yarn `between the tensioning device and the windup roll is 85 grams.

The woundup textured yarn has the following properties:

Bulked denier 910 Stability index percent 0.6i0.l Instron tenacity (at 0 twist) grams/denier 5.53 Modulus do 22.1

The finish on the bulked yarn is 0.37% on Weight of yarn.

EXAMPLE VII High bulk, round-filament yarn of poly(hexa methylene adipamide), 997 bulk denier, is provided as in Example VI except that the windup speed is 231 yards per minute. Therefore, using the drawing speed of 300 yards per minute the overfeed is 30%. The woundup textured yarn has the following properties:

Bulked denier 997 Stability index percent 0.9i0-2 Instron tenacity (at 0 twist) grams/denicr 3.66 Modulus do 1.51

The finish on the bulked yarn is 0.4% on weight of yarn.

EXAMPLE VIII The apparatus employed for this example is shown diagrarrimatically in FIGURE 4.

In a rst stage 140 round filament yarn is spun through a spinneret from a melt of poly(hexamethylene adipamide) and quenched in a quenching chimney. A texturing finish, at ambient room temperature, of an aqueous emulsion identical to the texturing finish specified in Example I, is applied to the yarn from a finish roll located directly below the quenching chimney. After contacting the nish roll, the yarn, containing about 1% finish on weight of yarn, passes over a feed roll and a separator roll and is drawn at a draw ratio of 5.13 to a 827 drawn denier and then packaged.

In a second stage, the drawn yarn is taken from the package, passes over a driven feed roll and then is passed in contact with, and therefore made Wet by, a waterwetted felt at room temperature just before entering a modified rectangular jet. The yarn is bulked in the jet with air at 80 pounds per square inch gauge pressure. The yarn enters the jet at 335 yards per minute and leaves the jet at 268 yards per minute. Therefore, the overfeed is 25%, providing a high bulk yarn.

From the jet, the yarn passes over a tension device,

through a step roll :and then is wound on a windup roll.

The woundup textured yarn has 0.02% nish, on weight of yarn, and upon examination is found to have a core diameter of 30 mils, an over-all diameter of 118 mils and a loop frequency of 270 as well as the following properties:

Bulked denier 1066 Approximate percent denier increase percent 25.4 Stability index do 0.5 Instron tenacity grams/denier 2.60 Elongation percent 30.7 Modulus grams/denier 19.6 rp Value 334 EXAMPLE IX Low bulk, 140 round-filament yarn of poly(hexa methylene adipamide) is prepared as in Example VIII but with the following changes from the procedure given. The yarn has approximately 2.0% finish before it is drawn, and it has a denier, after drawing at a machine ratio of 5.13, of 813. The overfeed, with a windup speed of 313 yards per minute is calculated to be 7%. The lwoundup textured yarn has less than 0.01% finish on weight of yarn. Its core diameter is 29 mils, its overall diameter is 109 mils, its loop frequency is 169 and it also has the following properties:

Bulk denier 897 Approximate percent denier increase percent 6.8 Stability index do 0.1 Instron tenacity grams/denier 5.08 Elongation percent 20.2 Modulus grams/denier 21.2 p Value 218 EXAMPLE X This example provides a yarn wherein a conventional lubricating linish, rather than a texturing finish, is applied to the yarn before drawing. The yarn is processed by the apparatus and by the process of Example VIII, but with the following exceptions. The yarn, after drawing at a machine ratio of 5.13, has 1.84% (on weight of yarn) of a conventional lubricating finish. The woundup textured yarn has 0.035% (on weight of yarn) of linish, a core diameter of 28 mils, an overall diameter of 96 mils, a loop frequency of 330 and the following properties:

Bulked denier 1016 Stability index percent 8.0 Instron tenacity grams/denier 3.72 Elongation percent 32.8 Modulus grams/denier 7.1 p Value 309 The yarn of this example has a satisfactory p value, but

an unacceptable stability index which is also indicated by the low modulus. However, if the yarn of this example were to enter the jet at a speed no higher than yards per minute, the stability index and the modulus would be satisfactory.

The tensions, in the yarn between the modified rectangular jet and the windup roll, are important. The tension in the yarn between the jet and the tension device should vary directly with the yarn denier at constant overfeed, and this tension also should vary inversely with the overfeed. At constant bulking speeds and constant overfeed, the tension in the yarn between the jet and the tension device should vary directly with the pressure of the air to the jet. The tension in the yarn between the tension device and the overfeed roll should vary just as does the tension in the yarn between the jet and the tension device.

The tension in the yarn just before windup should vary directly with the yarn denier at constant overfeed, and the tension also should vary directly with the overfeed. At constant overfeed, the windup speed should vary directly as the tension in the yarn just before windup.

A similar yarn may also be prepared by a process identical to that used for the preparation of the yarn of Example VIII except that no finish at all is applied to the control yarn. This finish-free bulked yarn has an unacceptably large number of filament breaks and has an unacceptably high stability index. However, when this similar yarn is textured finish-free and at 50 yards per minute speed, the resultant product has acceptable stability.

If the process of producing the yarn of Example X above is repeated except that, in addition to a lubricating finish applied to the just-quenched yarn, the texturing linish used on the yarn in Example I is applied to the yarn of Example X after it has been drawn and before it is made wet prior to texturing, and if the yarn is then textured at an entering speed of 335 yards per minute, the product has large loops and sinusoidal waves, and the stability index thereof is unsatisfactory.

The procedure of :preparing the yarn of Example X may be further modied by removing (with an air-jet without overfeed) substantially all the lubricating finish before application of the texturing linish (in the stage subsequent to drawing), but the product is still inferior in having, for instance, an unacceptably high stability index.

Again, if no texturing finish is applied at all (at any stage) and lubricating finish, applied before drawing, is removed prior to texturing, bulked yarn of good stability can be obtained, but only if the yarn is textured at a speed no greater than 50 yards per minute. If textured at 335 yards per minute, the same yarn has an unacceptable stability index.

It follows from all the aforegoing observations that the lubricating finish is not of itself deleterious, although it is ineffectual for fast texturing, and that it is of critical importance to apply the correct texturing finish in the right sequence. Furthermore, by applying the preferred texturing finish above discussed at the stage before drawing, rather than just before texturing, in accordance with this invention, production of melt-spun, continuous-filament, stable bulked yarns as heavy as 7000 denier can be accomplished at texturing speeds of approximately 100 yards per minute. For less than 7000 denier yarn, the texturing speeds are greater than 100 yards per minute.

Also, by applying the preferred texturing finish above discussed at the stage before drawing, rather than before texturing, in accordance with the invention, superior bulked yarns are provided in bulked yarn deniers of 200 and less, and of 3 deniers per filament and less.

EXAMPLE XI Yarns of 66 nylon prepared by the present invention were further characterized by direct observation and the number of surface loops and total loops as herein before defined counted. The results are tabulated as follows:

Items Yarn speed at Bulk Number of Surface loops,

jet (yprn.) percent: loops in 2' percent of total Commercially available textured yarns of 66 nylon and textured yarns of 66 nylon prepared by the process by Breen U.S. Patent 2,852,906 are similarly characterized with the results tabulated below.

Items Yarn(speed at Bulk Number of Surface loops,

Jet y.p.m.) percent loops in 2." percent of total 190 4 181 11 124 6 357 10 286 4 283 5 248 12 28B 7 24B 4 282 9 414 l0 466 8 265 12 174 6 438 14 230 12 The surface loop percentage determinations for the above two tables are made as follows: A random section of yarn, 2 inches in length, is visually examined at 10 to 15 magnification. The total number of loops and the number of surface loops l(as hereinbefore defined) in view are counted and noted. Then the ratio of surface loops to total loops is calculated and expressed as a percentage. It will be evident that any other length sample could be employed, and if desired one may average a number of samples from a given yarn for each determination.

From inspectiaon of the above data it is readily seen that the yarns of the present invention have at least 15% of all of the loops present as surface loops while other textured yarns have as an average only 8% of the total loops present as surface loops.

Because of their relatively higher tenacity, bulked yarns spun from a member of the class comprising polyamides, polyesters, polyolefines, and copolyamides and blends thereof, are preferred in this invention.

Typical of preferred polyamides are poly(hexamethyl ene adipamide), polycaproamide, poly(hexamethylene isophthalamide), polyundecanoamide, poly (hexamethylene sebacamide), poly(rnetaxylylene adiparnide), poly- (metaxylylene sebacamide), and polyamides derived from para xylene aux diamine and azelaic acid, 4,4methylene bis-cyclohexylamine and aliphatic acids such as azelaic, dodecanedioic and sebacic acids and their homologues.

Typical of preferred polyesters are poly(ethylene terephthalate), poly(hexahydro-p-xylylene terephthalate), poly(hydroxypivalate), poly(diphenylol propane isophthalate), poly(bicyclohexyl dimethane bibenzoate), polyesters from naphthalene dicarboxylic acids, polyesters where bibenzoic acid is a replacement. for terephthalic acid, and the copolyester of ethylene isophthalate and ethylene terephthalate.

The filaments comprising the yarns for the purpose of this invention may be non-round as well as round, and among the non-round shapes are included multi-lobed, particularly trilobal, cruciform, Y-shaped, delta-shaped, dog-bone, ribbon and other odd shapes. Greater bulk at a given percent denier-increase is attained with trilobal filaments than is attained with round filaments.

Example I specifies one of the preferred texturing finishes for the process of this invention. Other text-uring finishes for use in the process of this invention have the following compositions, by weight. The components of these finishes are articles of commerce.

Finish A: Percent White petroleum oil, 50 S.U.S. viscosity of F. 70 -Monolaurate of polyethylene glycol 400 15 Glycerol monoleate 15 Finish B:

Butyl stearate 70 Monolaurate of polyethylene glycol 40() 15 Glycerol monoleate l5 Finish C:

Bis(2ethyl hexoate) of polyethylene glycol 200 60 Condensation product of 6 moles of ethylene oxide of ethylene oxide with l mole of nonyl phenol 35 Sodium salt of bis (2ethyl hexyl) sulfosuccinate 5 Finish D:

Bis(2ethyl hexoate) of polyethylene glycol 200 65 Condensation product of 6 moles of ethylene oxide of ethylene oxide with 1 mole of nonyl phenol 35 Finish E2 Bis(2ethyl hexoate) of polyethylene glycol 200 60 Condensation product of 5 moles of ethylene oxide with 1 mole octyl phenol 4() Finish "F:

Bis(2ethyl hexoate of polyethylene glycol 200 70 Glycerol monoleate l5 Monolaurate of polyethylene glycol 400 15 Finish lG:

Dioleate of polyethylene glycol 300 70 Monolaurate of polyethylene glycol 400 30 Viscosities of the finishes at 24 C., in centipoises, are: For finish A, 18; finish B, 14; lfinish F, 24; finish G, 55. he boundary friction of the taubulated finishes ranges from 0.25 to 0.45. In general, particularly suitable finishes contain as emulsifier and at least 15% by weight of a surfactant. In instances certain components of the `finishes can serve either of these functions.

It should be understood that variations and modiications may be made in this invention without departing from its scope.

I claim as my invention:

1. A bulked yarn composed of filaments containing randomly distributed crunodal loops and being characterized particularly by (1) a stability index not exceeding 0.1 times the percent denier-increase acquired during texturing, and

(2) a texture expressible by q-value of at least 70,

wherein fp is defined by the equation DL being the average diameter, in mils, of the randomly distributed crunodal loops protruding from the core of the bulked yarn,

DC being the average diameter, in mils, of the core of the bulked yarn,

FL representing the average number of crunodal loops per inch length on the outer surface of said yarn core, and

W being the denier of said bulked yarn.

2. A bulked yarn as in claim 1 including a texturing finish on the yarn having a boundary friction of at least 0.15.

3. A bulked yarn as in claim 2, wherein the texturing finish comprises an ester of a polyethylene glycol of molecular Weight between 156 and 600 and an ester of a carboxylic acid of the form R-COOH where R is an aliphatic hydrocarbon radial of 7 to 17 carbon atoms.

4. A bulked yarn as in claim 3, wherein the texturing finish comprises bis\(2ethyl hexoate) of polyethylene glycol 200 and monolaurate of polyethylene glycol 400.

5. A stable high bulked yarn comprising an entangled, convoluted mass of melt-spun continuous filaments, the bulked yarn having a denier at least 5% greater than denier of the nnbulked yarn, the entangled, convoluted mass containing a number of filament loops including random crunodal loops protruding from the outer surface of the bundle, the number of surface crunodal loops being at least 15% of the total number of loops present in the bulked yarn.

6. A stable high bulked yarn as in claim 5 including a texturing finish on the yarn having a boundary friction of at least 0.15, the yarn having a stability index not exceeding 0.1 times the percent denier increase of the bulked yarn.

References Cited UNITED STATES PATENTS 3,103,448 9/1963 Ross 28-75 XR 3,113,369 12/1963 Barrett et al 28-75 3,150,481 9/1964 Bilsky et al 28-75 XR 3,271,943 9/1966 Williams 57-140 STANLEY N. GILREATH, Primary Examiner.

WERNER H. SOHROEDER, Assistant Examiner.

U.S. Cl. XJR.

Images