US3258825A - Methods for the production of highshrink modacrylic yarn - Google Patents

Description

July 5, 1966 A. H. AGETT ETAL METHODS FOR THE PRODUCTION OF HIGH-SHRINK MODACRYLIC YARN 2 Sheets-Sheet 1 Filed March 26, 1962 July 5, 1966 A. H. Aer-:TT ETAL METHODS FOR THE PRODUCTION OF HIGH-SHRINK MODACRYLIC YARN 2 Sheets-Sheet 2 Filed March 26. 1962 Albert HenryAgeit William LotusAspyJn INVENTORS BY HMM Alm/,L u. M

ATTORNEYS United States Patent O METHODS FOR THE PRODUCTION F HIGH- SHRINK MUDACRYLIC YARN Albert H. Agett and William L. Aspy, Jr., Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N .Y., a corporation of New `lersey Filed Mar. 26, 1962, Ser. No. 182,500 The portion of the term of the patent subsequent to July 30, 1980, has been disclaimed 3 Claims. (Cl. 28--72) This application is a continuation-in-part of application S.N. 150,320, filed November 6, 1961, and now abandoned.

This invention relates to the production of high-shrink yarn. More particul-arly, this invention concerns a process and apparatus `arrangement whereby continuous filament yarn is given an air-jet treatment for the increasing of the high bulk and high shrink prope-rties as well as the linear speed of production thereof.

In our co-pending application Serial No. 150,320, we have disclosed la high-bulk and high-shrink yarn and method and apparatus for producing same. In said application we have disclosed the subjecting of yarn ends after `drafting up to 850% to a jet treatment for imparting a certain amount of entanglement to the yarn. The yarn is preferably taken up from the jet at a speed approximately equal to or slightly lower than the speed at which it is introduced thereto. Although such a procedure satisfactorily fulfills the needs of high-bulk yarn producers, by the use of such a jet or gas treatment there is a possible tendency, unless close supervision and control of this specific operation is provided, for air treatment to reduce the amount -of crimp recovery and high bulk retention and resilience which may be imparted to the yarn in accordance with the process which we have disclosed in said co-pending application. Also the yarn industry is Ialways desirous of increasing speed of production. It is apparent, therefore, that the development of a new, more eiiicient jet treatment which would provide increased resilience and crimp retention represents a highly desirable result. a process and apparatus arrangement for making highshrink, high-bulk yarn in which the speed of production as well `as the capability of imparting a lasting crimpis additionally enhanced or secured.

This invention has for one object to provide a method and apparatus arrangement for increasing the crimpretention or crimp-recovery produced by heat treatment in the production of high-shrink yarn. Another object is to provide ya method of increasing the cover yand improving the hand of high-shrink, high-bulk yarn. A further object is to provide a method and apparatus arrangement for preventing or substantially eliminating the capability of high-shrink, high-bulk yarn to lose at least a part of its crimp. Another object is to provide a jet construction with facilities for controlling the degree of entanglement and degree of gas treatment of yarn subjected thereto. Still another object is to increase the bulkiness, resilience and springiness in continuous-filament yarn. Other objects will appear hereinafter.

In the broader aspects of our invention we have found that by subjecting tow to ia special gas treatment which may be used alone Ior to supplement a yseparate crimping operation in the preparation of a high-bulk yarn, the tendency of the yarn to lose some of its crimp or resilience in further processing is minimized and the bulk is increased. The preferred gas treatment is provided by passing the yarn through La circular jet wherein it is subjected to a controlled gaseous expansion, preferably of compressed air, in a specially adapted venturi nozzle described in more detail hereinafter. The tow may be passed on to a crimping operation after being expelled After extended investigation we have found from the jet under the influence of the expanding gas flow. In accordance with our invention the jet is preferably equipped at the exit portion of such a venturi nozzle with a plurality of fiat spring members whereby the tow may be retarded or partially confined as it exits from said venturi. The tow may be passed to the jet treatment either as spun land preferably stretched or from tow packages.

For assistance in a better understanding of the present invention reference is made to the attached drawing forming a part of the instant application.

FIG. 1 is a ilow diagram of a process such as may be carried out in accordance with the present invention.

FIG. 2 is a cross-sectional view of a circular jet such as may be -used in carrying out the process of the present invention.

FIG. 3 is a side elevation view somewhat of a schematic nature illustrating the manner in which the straightening out yof the tow is decreased and the crimp retention aided by retentive fingers affixed to a venturi nozzle portion of the jet of FIG. 2.

FIG. 4 is a schematic side elevation view of "a jet without the retentive 'fingers shown in FIG. 3.

Reference is now made to rFIG. 1. In the spinning operation 10, one or more Ispinning cabinets (not shown) of any usual dry spinning or melt spinning equipment construction may be used to produce a plurality of individual filaments of suitable denier yand cross-sectional shape, for example 1.5-16 denier per filament and regular clover-section, Y or C yarn. More detailed descriptions of methods of spinning and spinning equipment which may be used -in the process of this invention are found in U.S. Patents 2,829,027, 2,750,653 and 3,000,053. Yarn ends produce-d by the spinning operation may be passed through lubricating zone 12 wherein Ian appropriate amount of lubricant is added prior to a drafting operation indicated at 14. Lubricant may be applied as described in U.S. Patent 2,807,864. After drafting up to 850%, that is, stretching to a length of up to 81/2 times their original length, preferably in accordance with an idler roll, preheat roll, first draft roll, second draft roll, third draft roll arrangement, described in more detail in our above-mentioned co-pending application Serial No. 150,- 320, the yarn ends are subjected to a jet treatment lat 16. The -desired degree or controlled amount of entangling is imparted to the yarn by use of a gas jet such as shown in detail in FIG. 2 described hereinafter. The pressure may be regulated in such a way as to further assist in limiting the amount of entangling to the desired degree. The preferred speed of take-up of the jet-treated yarn is approximately equal to or slightly lower than the imput speed. The yarn ends thus lubricated, drafted, and exposed to our controlled jet treatment may next be conducted into a crimping zone 18, preferably of a conventional stutter-box type or of the improved stutter-box construction of our co-pending Iapplication Serial No. 150,320 or of co-pending application Serial No. 36,881, now U.S. Patent No. 3,120,692. If desired, the crimper 18 may be positioned prior to the gas jet 16. The crimped yarn is then subjected to drying Iand heat action in a heat-setting zone 20 to `a high-bulk, high-shrink, high crimp-retention yarn product. The yarn may then be converted to cut-staple form and processed accordingly, packaged for movement to another point for further processing, or subjected to further processing in continuous filament form. If a cut-staple yarn is to be used in making a carpet, the yarn, =as indicated in the drawing, is first c-ut into staple at 22, next carded at 24, then subjected to drawing at 26 and roving at 28 prior to plying at 30. When continuous iilarnent yarn is used in forming a carpet the plying may be performed substantially directly after the heat-setting step. When the -jected to lateXing and curing at 38. yimpart further shrinkage and crimp retention, 1t may be will result. angle liare, the entangling of the tow will als-o be poor. l Best results are obtained when the length of passageway 72 is about six times its inside diameter and the included angle of the exit passage 74 is about 3 to 5 degrees.

erably about 90 degrees.

v 62 to facilitate threading the tow into the jet 46. also insures metering and impingement of the -air onto yarn is cut into staple fiber, after carding at 24 it may be converted to non-woven fabric, as indicated at 32, Y

using an appropriate bonding agent. For carpet use, after plying at 30 the yarn is formed on cones at 34 from which it may be tufted into carpet at 36 and then sub- If it -is desired to subjected to a further heat-treating step at 40. If it is desired to impart additional high bulk and characteristic retentive crimp to the yarn prior to converting it to a carpet or other appropriate product, it may be formed into skeins at 42 and then subjected to an Iappropriate heat treatment at 44.

Referring to FIG. 2, a shrouded circular jet such as we have found most effective in jet treating step 16 of FIG. 1 will now be described.

The jet 46 is composed of an outside shell 48 conl taining several inner members 50, 52 and 54 held in place y by threaded plugs 56 and 58. A passageway 60 extends through the jet device so that the continuous multililament y tow may be passed from the entrance 62 in member 50 to an exit 64 in member 54. The passageway in member 50 is substantially of uniform diameter. 'Ihe outer surface 66 of the lower end of member 50 is conical in shape with an included angle of about 40 to 80 degrees, for providing, in conjunction with the tapered surface 68 of thin plate orifice plate 52, |an annular orifice or passageway for metering the air flow into the venturi tube member 54.

The venturi tube member S4 is provided with a converging entrance section 70 of -about 30 to 40 degrees included angle, and in series a straight cylindrical tube passage 72 having a length of from 2 to 10 times the inside diameter of the passage 72, and a -liaring or diverging exit section 74 with an included angle of from 2 to 7.

This exact construction of this portion of the jet lassures a maximum controlled entangling effect on the tow. If

v this uniform passage 72 is too short, or the exit angle of passageway 74 is too great, less than optimum entangling and final yarn crimp-recovery and retention Likewise, if passage 74 has little -or no exit In -ad-dition, for proper functioning of the jet, the inside diameter of passageway 72 is best at about 0.75" for a tow of about 37,000 denier size, and is best at about 163% lof the diameter of the orifice plate orifice 68 and 400% of the inside diameter of the passageway 60 in inlet tube 50. The taper 66 of tube 50 is preferably about 60 degrees and about 30 degrees less than the angle of the taper of the orifice 68 in plate 52 which is pref- Proper sizing of these items insures that the jet 46 will produce a suction at entrance It the tow as it enters the orifice plate. The passageways in the jet should be in accurate concentric and axial alignment to insure uniform impingement of the air on the tow around the periphery of the tow and to insure a minimum of turbulence land swirling or twisting of the air flow. If the air flow swirls, it will tend to twist the tow rather than entangling it and separating the lilaments from each other.

Air is provided to the jet shell 48 through one or more openings 76 and 76 to an annular chamber formed by the outer surface of inlet member 50` and shell 48 and sealed at one end by threaded plug 56. It has been found that, while one inlet 76 is often adequate, better air flow distribution can be obtained with two or more openings equi-spaced around the shell periphery. The air from the chamber 78 then impinges on the tow by passing through the annular orilice formed by the tapered portion 66 of inlet tube 50 and the tapered opening 68 in orifice plate 52.

While the design and assembly of the jet have been described in a specific manner it will be recognized that variations in the size of the jet, the manner of assembling the component parts of the jet and variations in the shape of non-critical surfaces can be made without departing from the spirit of the invention.

Most effective crimp retention land high bulk was obtained when the venturi throat length to diameter ratio was about 6 to 1. The exit flare or ldiverging portion of the nozzle preferably has 4an included angle of about 3 to 5 degrees. It might also be Ipointed out that use 0f just a long str-aight tube with no divergent exit angle and no shrouded or restricte-d exit portion gives less controllable entangling as well as less satisfactory crimp retention in the final yarn product. Thus the venturi tube design is of :some importance to obtain optimum results according to our invention.

It has been further found that the entangling of the tow can be materi-ally enhanced if the liow of the tow as it exits from the jet venturi member 54 is retarded and partially confined. To achieve this end, a plurality of flat spring fingers 80, 80', 80" and others (not shown) are positioned equidistant `around the outer surface of the venturi member 54 and extend beyond the end of the member 54, for example for la -distance of 3 to 8" for the jet described hereinabove. The lingers 80 may be curved slightly outward, for example as at-82, to avoid snagging the tow, are slidable axially -on the member 54, and are held in place by a clamp ring 84 .and suitable thumb screw tightening means 86 lor other appropriate fastening device. The force to spring the lingers outward is adjustable by moving the clamp 84 closer to or farther away from the end 64 of the member 54.

The effect of these lingers is -to retard the exit of the tow from the jet and cause a temporary pile-up of a mass of disoriented filaments through which the exhaust air from 'the jet must pass.

Thus, as shown in FIG. 3, the filaments 88 exit from the confined zone 90 formed by fingers 80, 80', 80 of jet 46 in highly resilient crimped or crinkled form. The freshly spun filaments may have a certain -amount of natural or inherent resiliency or crimp which the jet lingers will enhance and tend to prevent removal of in later processing steps. The resiliency and crimp retention of the filaments, whether previously or subsequently crimped or not, are improved and the tendency of further processing to straighten lout the filaments or remove some of the resilience or crinkle therefrom substantially eliminated by passage through jet linger zone 90.

In FIG. 4, relatively straight but somewhat bulked or uncrinkled tow 92 is shown passing directly from the exit portion of an unfingered jet 46 without passing through a restricting or confining zone.

An understanding of the functioning of the apparatus parts disclosed in the several figures as they may be used in this invention is already apparent to a substantial extent from the preceding description. However, a further understanding of the functioning as well as an understanding of the process of the present invention will be had from a consideration of the examples which follow and which are set forth to illustrate certain preferred embodiments of the instant invention.

Examples I-III Three samples of modacrylic tow (4G-80% acryloni- -trile units) were extruded and processed in the steps diagrammatically indicated in FIG. 1 for continuous filament processing, including passage through a lingered or bustled jet such as illustrated in FIG. 2 and stuffer-box crimper prior to heat treatment as continuous filament, high-bulk yarn. The extrusion speed, draft ratio and other specific processing conditions for these three samples are set out in tabular form hereinbelow.

6 The yarn of Example V was of 1,500 total denier/ 100 filaments produced at 50 lbs/day per cabinet and the Denier per Extrusion Jet-Pas- Filament of Total Denier D/F of Sample No. Speed, Draft sage Shrinkage, Yarn Prior to of Lofted, Lofted,

m./m Ratio Speed, percent Jet Passage Heat-Set Yarn Heat Set m./m. and Heat- Yarn Setting yarn of Example VI of 2,700 total denier/ 200 filaments im Stage 2nd Stage produced at 100 lbs/day per cabinet.

Continuous multifilament cellulose acetate tow was Tow Dryer Temperamm,o o 120 140 spun from a polymer dope, stretched and jet-treated with Reli?? R011 Surface '.fempefatmes C 100110 a shrouded jet according to the procedure of Examples V Bulhlng or Entanglmg, 9()

r and VI to a yarn of 100 cu. 1n. per lb. bulk. Polypropylene filaments spun from a melt were likewise treated with Example IV Representative yarn samples conventionally processed without treatment with a bustled jet such as that depicted in FIG. 3 were compared as to bulkiness in both unsteamed and steamed form with yarn passed through a bustled jet such as that of FIG. 3. The results of this comparison are shown in 4the following table.

Cubic Cubic Sample Inches Inches Number Per Pound Per Pound Unsteamed Steamed Textured modacrylic Modacrylic yarn treated with 135 114 bustled jet. Modaerylie Yarn 75 83 Modaerylic high-bulk staple 92 105 Acrylle staple (Type 1) 89 93 Wool Yarn 83 107 Nylon Staple Yarn 83 88 Acrylic staple (Type 2) 103 108 Polypropylene Staple 96 100 Polyester Staple The above table illustrates that yarn jet treated in accordance with the process of the present invention (Sample 2) has a higher bulk both unsteamed and steamed than representative yarn which has not been jet treated.

Examples V-VI Separate samples of continuous filament modacrylic yarn were produced by dry-spinning and roll lubricated at the spinning machine, draf-ted (4.8/1) by the hot roll technique, and then passed through a jet such as depicted in FIG. 3 operated with air pressures from 10-35 p.s.i. Both samples were discharged on -a dryer apron and heat set in a dryer operated with a hold-up time of 3 minutes and a temperature of 110-155 C. The heat-set yarn was then drawn lthrough `a lubricator by a set of draw rolls and wound. The following table indicates various conditions and properties of the apparatus used and yarn produced in these samples.

Example V Example VI (Sample 1) (Sample 2) Spinning speed, m./m 46 45. 4 Top air temperature, C 40-60 40-60 Bottom air temperature, 140-150 140-150 Draft ratio 4. 6/1 4. 85/1 Relax ratio Q9 .99 Lubricant roll speed 3 3 Hot water shrinkage, perce 48-52 42-49 Percent entanglement 23 20-30 D/F from relax roll 8. 5-9. 0 8. 0-9. 0 Heat setting temperature, C 140 140 Heat setting time, minutes 5 5 Winding speed, m./m 104 10G-105 Speed at jet entrance, rn./m 203 20D-205 Speed at jet discharge, m./n1 166 1GO-175 Heat-set D F 15 (app.) 15 (app.)

a jet such as depicted in FIG. 3 with resulting enhanced resilience and bulk in the textile product.

Although in the preceding description we have shown the use of the jet treatment of our invention prior to crimping, it may also be used after the crimping operation or without a separate crimping step.

It is believed apparent from the foregoing that we have provided a simplified procedure and apparatus combination for the manufacture of yarn of increased bulk and resilience whereby any tendency of the yarn to lose some of its crimp, entanglement or resilience is minimized and the crimp retention and speed of operation are substantially increased.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

We claim:

1. In a process for the production of a high-bulk modacrylic yarn by jet treatment of a bundle of drawn continuous modacrylic filaments by blooming same, the improvement which comprises passing said bundle of drawn continuous modacrylic filaments through a circular jet, impinging upon said bundle in said jet without application of plasticizer a plurality of streams of gas supplied from an annular chamber surrounding said jet and directed upon said bundle by passing through an annular orifice, conducting said bundle in said jet through :a venturi exit section having a length to diameter ratio of about 6 to 1 and an included angle fof about 3 to 5 degrees, creating in said bundle as it passes through said jet a maximum amount of controlled entangling of the filaments of said bundle by said impinging of said air thereupon while controlling the pressure in said jet, enhancing the entangling of said bundle materially as it exits from said venturi section by retarding and partially confining same with `a temporary buildup of said entangled bundle before i-t exits from said jet, said retarding and confining of said bundle being accomplished by a plurality of outwardly movable fiexible fiat spring members positioned equidistant around the outer periphery of the venturi section of said jet and extending beyond the end of said venturi section for from about 3 to 8 inches, said spring members being adapted to avoid snagging of said bundle a-s it exits from said jet, and collecting the bundle as it exits from said jet in entangled, high-bulk, crimp-retentive form.

2. A process for lproducing a crimp-retentive, high-bulk thermoplastic yarn which comprises introducing continuous multifilament thermoplastic tow consisting of modacrylic filaments to a jet-treatment zone wherein said tow is treated without application of plasticizer, impinging upon said -tow in said zone a plurality of streams of gas supplied from an anular chamber surrounding said zone and directed upon said tow by passing through an anular orice, conducting said tow in said zone through a venturi exit section having a length to diameter ratio of about 6 to 1 and an included angle of about 3 to 5 degrees, creating in said Itow as it passes through said zone a maximum amount of controlled entangling of the laments of said tow by said impinging of said air thereupon while controlling the pressure in said zone, enhancing the entangling of said tow materially as it exits from said venturi section by retarding and partially conning same with a temporary buildup of said entangled tow before it exits from said zone, said retarding and confining of said toW being accomplished by a plurality of outwardly movable exible at spring members positioned equidistant around the outer periphery of the venturi sec-tion of said jet treatment zone and extending beyond the end of said venturi section for from about 3 -to 8 inches, said spring members being adapted to avoid snagging of said tow as it exists from said jet treatment zone, and collecting the tow as it exits from said jet treatment zone in entangled, high-bulk crimpretentive form.

3. The process of claim 2 wherein the collected tow 8 2,686,339 8/1954 Holt 19-66 2,914,835 12/1959 Slayter et al. 28-72 2,917,806 12/1959 spente et a1. 2,960,752 11/1960 Sonnino 19--66 X 2,962,794 12/1960 Field 28-72 2,968,857 1/1961 Swerdlo et al 28--72 2,995,801 8/1961 Cormier et al. 28-1 3,000,168 9/1961 Penland 57--34 X 3,026,597 3/ 1962 Swaney 28-1 3,036,357 5/1962 Cook et al. 28-1 3,055,080 9/1962 Claussen et al 28-1 3,057,038 10/1962 Soehngen. 3,093,878 6/1963 Fieldman 28-72 X 3,093,879 6/1963 Fieldman 28--72 X 3,099,594 7/1963 Caines et al 28-72 X 3,142,147 7/ 1964 Betsch.

FOREIGN PATENTS 1,289,491 2/1962 France.

838,796 6/1960 Great Britain. 848,037 9/ 1960 Great Britain.

is heat set and fashioned into a high-bulk textile product. 25 DONALD W' PARKER Primary Examine"- References Cited by the Examiner UNITED STATES PATENTS 7/ 1945 Mummery. 8/ 1953 Pfau.

RUSSELL C. MADER, MERVIN STEIN, H. G.

GARNER, R. R. MACKEY, Examiners.

Claims (1)

1. IN A PROCESS FOR THE PRODUCTION OF A HIGH-BULK MODACRYLIC YARN BY JET TREATMENT OF A BUNDLE OF DRAWN CONTINUOUS MODACRYLIC FILAMENTS BY BLOOMING SAME, THE IMPROVEMENT WHICH COMPRISES PASSING SAID BUNDLE OF DRAWN CONTINUOUS MODACRYLIC FILAMENTS THROUGH A CIRCULAR JET, IMPINGING UPON SAID BUNDLE IN SAID JET WITHOUT APPLICATION OF PLASTICIZER A PLURALITY OF STREAMS OF GAS SUPPLIED FROM AN ANNULAR CHAMBER SURROUNDINGG SAID JET AND DIRECTED UPON SAID BUNDLE BY PASSING THROUGH AN ANNULAR ORIFICE, CONDUCTING SAID BUNDLE IN SAID JET THROUGH A VENTURI EXIT SECTION HAVING A LENGTH TO DIAMETER RATIO OF ABOUT 6 TO 1 AND AN INCLUDED ANGLE OF ABOUT 3 TO 5 DEGREES, CREATING IN SAID BUNDLE AS IT PASSED THROUGH SAID JJET A MAXIMUM AMOUNT OF CONTROLLED ENTANGLING OF THE FILAMENTS OF SAID BUNDLE BY SAID IMPINGING OF SAID AIR THEREUPON WHILE CONTROLLING THE PRESSURE IN SAID JET, ENHANCING THE ENTANGLING OF SAID BOUNDLE MATERIALLY AS IT EXITS FROM SAID VENTURI SECTION BY RETARDING AND PARTIALLY CONFINING SAME WITH A TEMPORARY BUILDUP OF SAID ENTANGLED BOUNDLE BEFORE IT EXITS FROM SAID JET, SAID RETARDING AND CONFINING OF SAID BOUNDLE BEING ACCOMPLISHED BY A PLURALITY OF OUTWARDLY MOVABLE FLEXIBLE FLET SPRING MEMBERS POSITIONED EQUIDISTANT AROUND THE OUTER PERIPHERY OF THE VENTURI SECTION OF SAID JET AND EXTENDING BEYOND THE END OF SAID VENTURI SECTION FOR FROM ABOUT 3 TO 8 INCHES, SAID SPRING MEMBERS BEING ADAPTED TO AVOID SNAGGING OF THE BOUNDLE AS IT EXITS FROM SAID JET, AND COLLECTING THE BUNDLE AS IT EXITS FROM SAID JET IN ENTANGLED, HIGH-BULK, CRIMP-RETENTIVE FORM.

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