US3570083A

US3570083A - Strand-treating apparatus

Info

Publication number: US3570083A
Application number: US822429A
Authority: US
Inventors: Robert K Stanley
Original assignee: Techniservice Corp
Current assignee: Techniservice Corp
Priority date: 1967-10-26
Filing date: 1969-05-07
Publication date: 1971-03-16
Anticipated expiration: 1988-03-16

Abstract

APPARATUS IS PROVIDED FOR TREATING DRAWABLE TEXTILE STRANDS, INCLUDING MEANS FOR DRAWING THE SAME TO INCREASED LENGTH AND MEANS FOR COMPRESSIVELY CRIMPING THE DRAWN MATERIAL, ARRANGED FOR OPERATION IN ESSENTIALLY CONTINUOUS MANNER WITH A MINIMUM OF TIME AND SPACE THEREBETWEEN. IN THE EXTREME THE DRAWING AND CRIMPING MEANS ARE ARRANGED TO PROVIDE CONTIGUOUS DRAWING AND CRIMPING ZONES. PREFERABLY THE MEANS FOR FORWARDING THE DRAWN STRAND OUT OF THE DRAWING ZONE AND THE MEANS FOR FEEDING THE STRAND INTO THE CRIMPING ZONE ARE ADAPTED TO UNDERFEED THE STRAND FROM THE FIRST TO THE SECOND.

Description

' March 16, 1971 R. K. STANLEY 3,570,083

STRAND-TREAT ING APPARATUS Filed May 7, 1969 2 Sheets-Sheet l &

7 INVENTOR. 77 ROEBW m STA/V115) R. K. STANLEY STRAND-TREATING APPARATUS March 16, 1971 Filed May 7, 1969 2 Sheets-Sheet 2 m 4 y. NO 0 0V V w w mvsm'ron. 19015697 A? Jill/V44 7 BY Me 1 4/62 21 Tram/31 United States Patent 3,570,083 STRAND-TREATIN G APPARATUS Robert K. Stanley, Media, Pa., assignor to Techniservice Corporation, Kennett Square, Pa. Continuation-impart of application Ser. No. 678,428, Oct. 26, 1967. This application May 7, 1969, Ser. No. 822,429 The portion of the term of the patent subsequent to Apr. 9, 1985, has been disclaimed Int. Cl. D02g 1/12 U.S. Cl. 281.6 22 Claims ABSTRACT OF THE DISCLOSURE Apparatus is provided for treating drawable textile strands, including means for drawing the same to increased length and means for compressively crimping the drawn material, arranged for operation in essentially continuous manner with a minimum of time and space therebetween. In the extreme the drawing and crimping means are arranged to provide contiguous drawing and crimping zones. Preferably the means for forwarding the drawn strand out of the drawing zone and the means for feeding the strand into the crimping zone are adapted to under-feed the strand from the first to the second.

This application is a continuation-in-part of my copending patent applications for strand treatment, Ser. No. 678,428 filed Oct. 26, 1967, now US. Pat. 3,462,814 granted Aug. 26, 1969, and Ser. No. 684,230 filed Nov. 20, 1967, now US. Pat. 3,462,815 granted Aug. 26, 1969. Reference is also made to my prior copending application, Ser. No. 302,758 (now Pat. 3,376,622), of which each of the foregoing was a continuation-in-part and which in turn was based at least in part upon any prior application Ser. No. 216,524 filed Aug. 13 1962 and subsequently abandoned.

Textile strands can be produced by extrusion of fiberforming compositions through spinneret orifices and collection of the resulting filaments or fibers. Many polymeric fiber-forming compositions so treated produce strands of relatively low tensile strength because of relatively low macromolecular orientation with respect to the longitudinal axis. In most such compositions the orientation and tensile strength can be increased readily because the strand components (usually continuous filaments) are drawable to an attenuated and extended condition of high orientation from which there is little or no tendency to return to the original condition. Nylon strands, for example, can be drawn so readily at room temperature that they are commonly indicated as being cold-drawable. The strand temperature normally increases during drawing because of intermolecular friction and friction with any snubbing pin or similar means employed to restrict the drawing location. In actual practice the strand, regardless of composition, may be heated to facilitate and to localize the drawing operation.

Strands of continuous filaments, whether oriented or unoriented, are inappropriate for many uses because of their rectilinearity, which is conducive to slickness, translucency, and low bulk, all of which can be eliminated or modified by any of a variety of processes usually called crimping or texturing. Nearly all of those processes (e.g., edge-crimping, gear-crimping, jet-crimping, and twist-crimping) tend to extend the strand axially while deforming it transversely of the longitudinal axis and, therefore, may be expected to be compatible with an immediate predrawing operation. Longitudinally compressive crimping, such as stulfer-crimping, of drawn strands may be expected to be separated from the drawing process in location or time (the drawing being prior,

3,578,083 Patented Mar. 16, 1971 usually long prior) rather than adapted to follow immediately upon an attenuation of the strand to increased length. Even in some recent attempts to st'ulfer-crimp drawn strands it has been suggested, perhaps because of a tendency of the drawn strands to retract somewhat to overfeed the drawn strands to the crimper and thereby avoid undue tension therein. There is a considerable need for improved apparatus, technique, and results.

A primary object of the present invention is provision of novel drawing and crimping apparatus for textile strands.

Another object is provision of means for crimping textile strands by longitudinal compression along the strand axis immediately following permanent extension therealong.

A further object is arrangement of certain strand-forwarding rolls as part of both strand-drawing and strandcrimping means.

Other objects of this invention, together with means and methods for accomplishing the various objects, will be apparent from the following description and the accompanying drawings.

FIG. 1 is a schematic representation of drawing and crimping steps with intervening time period;

FIG. 2 is a schematic representation of a continuous "draw-crimping process without intervening time period; "FIG. 3 is a perspective view (somewhat stylized) of a drawing system useful according to this invention;

FIG. 4 is a front elevation of a stutter-crimper for use according to this invention;

FIG. 5 is a side elevation of the stutfer-crimper of FIG. 4;

FIG. 6 is a sectional plan of the same stutter-crimper taken at VI-VI of FIG. 5;

FIG. 7 is a front elevation of a modification of apparatus according to this invention; and

FIG. 8 is a front elevation of a further modification of apparatus according to this invention.

In general, the objects of the present invention are attained by providing means for attenuating a polymeric textile strand to increased length in a drawing zone and for compressing the strand axially in a crimping zone immediately thereafter to buckle successive length increments thereof into crimped configuration, whereby the means defining the beginning of the crimping zone and the means defining the end of the crimping zone are located close together, or even overlapping. The invention comprehends particularly strand-drawing means and stuifer-crimping means as adjuncts to one another where in a drawn strand to be crimped is underfed to the crimper or a strand is drawn at the input thereto. In one embodiment a roller having a strand-supporting surface is common to both the strand-drawing means and the strand-crimping means.

FIG. 1 shows schematically zone 11 wherein a strand is attenuated to increased length or drawn and zone 13 wherein the strand is crimped, as by any conventional system. Intervening zone .12, shown in broken lines and traversed by an arrow leading from zone 11 to zone 13, represents the period (conventionally excessive) of time intervening between drawing and crimping. FIG. 2 shows schematically drawing zone 15, wherein the strand is treated as in zone 11, and compressive crimping zone 16 contiguous therewith according to this invention. The arrow indicates the passage of the strand immediately to the crimping zone from the drawing zone without appreciable time intervening. The meaning of this limitation will be apparent from the following details of the apparatus and process of this invention.

FIG. 3 shows, in perspective (stylized by omission of supporting, heating, driving, or other elements), rolls 21, 22, and 23 at the input end of a drawing zone, useful according to this invention, and rolls 31, 32, and 33 at the output end of the zone. Located in the space between the two sets of rolls is draw pin 27, use of which is optional. Strand 20, whose direction of travel is indicated by arrows, proceeds generally from left to right, passing about a quadrant of roll 21, downward through the nip of

rolls

21 and 22, about the lower half of roll 22, upward through the nip of

rolls

22 and 23, and over a quadrant of roll 23. It then makes a single turn about draw pin 27, after which it is denoted as After leaving the draw pin the strand proceeds about a quadrant of roll 31, downward through the nip between

rolls

31 and 32, about the lower half of roll 32, and then upward through the nip between

rolls

32 and 33.

It will be understood that at least one of the rolls in each of these two sets is driven by suitable motive means (not shown) and that all the rolls within each set rotate at constant speed, whether driven directly by the motive means or indirectly by contact (essentially nonslipping) with one another. The surface speed of the rolls in the second or forwarding set (31, 32, 33) is greater than the speed of the rolls in the first or input set, thereby determining the extent to which the strand is drawn therebetween. The draw pin does not rotate but is fixed so as to snub the strand passing about it, thereby frictionally heating the strand, which also is heated by the drawing step itself, as by reason of internal or intermolecular friction. The pin may, but need not, be heated by any conventional means (e.g., electrically or by steam, preferably supplied internally) as is customary in the art of strand drawing.

With some strand compositions it may be helpful to heat one or both sets of rolls (in addition to, or instead of, the draw pin). Heating the first set of rolls preheats the strand for drawing, possibly rendering it easier to draw, and incidentally preheating it for crimping as may the drawing itself. Heating the second set of rolls at least sufliciently to prevent the drawn strand from cooling in the interim (however brief) is conducive to a steady and high degree of crimping. Although not illustrated, methods and means for heating the rolls, preferably internally, will come readily to the mind of a person skilled in the art; e.g., circulation of heated fluid therein, or by electrical means as disclosed in my Pat. 3,111, 740. The herein illustrated arrangement of three rolls in each set, with their axes in a common plane, two of the rolls flanking and being contiguous with the other roll is a preferred arrangement, but it is not imperative for the practice of this invention, as will be apparent hereinafter.

FIGS. 4, 5, and 6 show, in front and side elevation and sectional plan, respectively, stufier-crimper 41 useful according to this invention.

Rolls

31 and 32, and 33 are shown incorporated in this apparatus, the latter two functioning also as stufiing feed rolls. The supporting frame comprises base plate 42, front plate 43, back plate 44, and top plate 45, all secured together by suitable means (not shown). Upstanding facade 46 is secured similarly to the front plate. Tubular stufiing chamber 50, which is nearly square in cross-section, is held in place against the front of the facade by four washers 51 overlapping the side edges of the front of the chamber and supported on four wing screws 52 threaded into suitable apertures in the facade. The front wall of the chamber overlaps portions of

rolls

32 and 33, and the rear wall does likewise, down to the roll nip, while the side Walls terminate adjacent the rolls, thereby forming a closefitting entrance to the chamber for strand stuffed thereinto by the rolls. The upper end of the chamber is covered by cap 55, which has cars 56 overlapping the front and back walls of the chamber and pivoted thereto by pintles 57. Extension springs 59 stretched from pins 58 on the cap to pins 60 on the chamber wall bias the cap closed against the otherwise open top of the chamber.

Motor 61 affixed to the top surface of top plate 45 has shaft 63 extending to the rear through journal 62 upstanding from and secured by bolts 67 to the rear face of back plate 44. Affixed to the end of the motor shaft is pulley 64 interconnected by belt 65 to pulley 66 on the end of shaft 73, which carries roll 33 at its front end and extends through the front and back plates and also carries gear 69. Meshing with this gear is gear 6 8 on the end of shaft 72, the other end of which carries roll 32. Stub shaft 71 journaled in front plate 43 carries roll 31.

Located below rolls 32 and 33 are several components not being used as staffer-crimper 41 is shown in FIGS. 4, 5, and 6. They are guide block 75, affixed to the facade by screw 76, and overlying guide clip 77, which is secured to the guide block by bolt 78 at the side. Both the guide block and clip extend arcuately toward the nip of the rolls. Use of these guide elements (and non-use of roll 31) appears in the embodiments shown in FIGS. 7 and 8, which are described hereinafter.

In the embodiment already described, strand 20 is attenuated to become strand 20 in the drawing zone between first set of

rolls

21, 22, 23 and faster running second set of

rolls

31, 32, 33, the strand passing in essentially non-slipping contact with the rolls in each group. Immediately after having been drawn to increased length and thereby molecularly oriented, strand 20' is fed upward through the nip of

rolls

32 and 33 and thus stuffed into the entrance of chamber 50. Although the surface speed of the rolls feeding the strand into the crimper is the same as the speed at which the strand leaves the drawing zone, i.e., neither an overfeed nor an underfeed according to roll speed, the tendency of the recently drawn strand to retract in length produces in effect an underfeed, be it ever so slight, to the crimping chamber. The chamber itself is filled with accumulation 20 of crimped strand, shown (stylized, for clarity) in FIG. 4 by a cutting away of part of the front wall of the chamber, and is otherwise unheated and may be positively cooled (e.g., by circulation of a coolantnot shown--between the exterior and interior walls thereof) as in my Pat. 3,111,740.

Because the stuffing chamber is always full during crimping operations each straight-length increment of strand entering the chamber is compressed axially (i.e., longitudinally) and is forced to buckle, much as an overloaded structural column buckles. Continual buckling of successive length increments at the chamber entrance produces a crimping of the strand. Of course, the continued stuffing of the strand into the chamber forces the terminal part of the strand accumulation therein to emerge gradually therefrom between the spring-loaded cap and the upper end of the chamber. Such spring-loaded cap may be replaced by alternative types of back-pressure or strand-impeding devices, such as those disclosed in the following US. patents, for example: serrated wheel, 3,027,619 and 3,174,206; plunger, 2,758,357 and 2,760,- 252; or spheroids, 2,949,659 and my 3,440,669. Alternatively, lateral confinement alone may be employed, as in my 3,279,025.

It will be understood that the term strand as used herein includes not only a monofilament strand but also a multifilament strand and that shorter lengths (e.g., staple) than usually termed continuous may be present. Suitable strand compositions will come readily to the mind of a person skilled in the textile arts. Prominent among the suitable compositions are the nylons (polycarbonamides), e.g., 66-nylon (i.e., polyhexamethylene adipamide), also 6-nylon, ll-nylon, 6l0-nylon, and fiber-forming copolymers thereof, including terpolymers. Other suitable polymeric materials for strands to be treated according to this invention include most of the thermoplastic fiber-forming materials, such as polyhydrocarbons (e.g., polyethylene, polypropylene), polyesters (e.g., polyethylene terephthalate), polyacrylonitrile and copolymers of acrylonitrile with other vinyl compounds, also copolymers of vinyl chloride and vinylidene chloride, and polyurethanes. This list is simply exemplary and is not intended to be exhaustive of suitable compositions, most or all of which are thermoplastic.

If a heated draw pin is used the appropriate temperature for it will depend upon the characteristics of the strand composition and the speed of the strand over the draw pin. Appropriate processing speeds lie in the range of from one hundred to one thousand yards per minute (y.p.m.), but somewhat slower or faster speeds may be employed. For 66-nylon at an input of 100 y.p.m. and output of 400 y.p.m. (draw of 4X) the draw pin temperature may conveniently be between 150 and 250 C. The speed at which the strand is fed into the stuffer-crimper correlates with the output speed from the drawing zone, of course, and the roll temperature preferably prevents the strand from cooling before entering the crimper, which itself is preferably constructed to maintain the strand temperature so long as the strand is under crimping compression, as in my Pat. 3,348,283.

As previously indicated, because of the immediate succession of drawing and crimping steps and of the heat engendered therein, preheating of the strand is not required for crimping according to this invention and may not be required for drawing. The moisture content of the strand, if appreciable, may have a deleterious effect upon the desired treatment or its results. In general, therefore, the strand should not be wet, the preferable content of water (and/or any lubricant or softening, swelling, or plasticizing agent or solvent, all of which may be collectively referred to as moisture) being less than about A strand at such low moisture content may be considered as essentially dry or moisture-free for the purpose of the present invention. The relative humidity in and about the chamber should not exceed about for the usual textile strand compositions, the upper limit of humidity varying somewhat according to the moisture content and sensitivity of the composition.

FIGS. 7 and 8 show (in front elevation, but rotated 90 clock-wise) the crimper of FIGS. 4, 5, and 6 but with strand passing therethrough being fed directly by and between

rolls

32 and 33 in line with their common tangent (through the -roll nip). Additional rolls ahead of rolls 312 and 33 may prove useful in attaining essentially non-slipping contact at a pressure that will not damage the strand. When, as illustrated, the compressive crimping is accomplished by a stutter-crimper, the means (such as final draw rolls) defining the end of the drawing zone should not be further from the means (such as stuffing rolls) defining the beginning of the crimping zone than the initial draw rolls are from the final draw rolls or the exit of the stuifer crimper is from the entrance thereof, and preferably not more than about three diameters of one of the stuifing rolls, measured along the strand path. Thus, in FIG. 7, added pair of nip rolls 82 and 83 are so located, and strand 20' passes therebetween. As shown in FIG. 8, the nip of

rolls

32 and 33 may be utilized to constitute a junction of the drawing and crimping zones by deleting the portion of strand path about illustrated roll 31 (which may then be deleted), a modification that is most useful with monofilament or small multifilament strands because of the likelihood of slippage with other strands by reason of reduced roll surface contact therewith. The rate of strand travel in such intervening portion of the strand path may be substantially the same as at the end of the drawing zone; it should not be less and may be more, thereby tensioning the strand further and, if desired, actually drawing it further.

Enhanced underfeed is accomplished conveniently according to the arrangement of FIG. 7, for example, by regulating the surface speeds of the various sets of rolls in any suitable manner, which may be conventional in itself, so that rolls 82, 83 have a speed intermediate that of slower rolls 2.1, 22, 23 at the beginning of the drawing zone and faster stuffer rolls 32, 33 at the crimper input. The latter rolls may run anywhere from several percent to perhaps ten percent, or somewhat more, faster than

rolls

82, 83 while merely tensioning the strand, which was already drawn to increased length between

rolls

21, 22, 23 and rolls 82, 83. An integrally contained drawing arrangement preceding a stufifer crimper, as in FIG. 7, permits modification of the crimper itself, such as by substitution of other stutfing means (e.g., fluid jets) for the more conventional stuffing rolls to feed the strand thereinto. Of course, conventional godets may be substituted for those nip rolls at either end (or both ends) of the drawing zone, regardless of the type of crimper infeed.

At greater than about ten percent roll overspeed, corresponding to strand underfeed, the strand probably will be drawn to further increased length, unless a maximum draw for the particular strand composition already had been imposed, and such further draw may equal or even exceed the previous draw if desired. It is preferred, although not necessary, that the strand not have been drawn significantly at a remote previous time, although appreciable benefit from the present invention may be attained if such previous draw did not exceed about half the total drawability of the undrawn strand, thereby leaving it still substantially drawable.

When operating upon strands made of either 6- or 66-nylon it is customary to employ a total draw of about 4X, i.e., a total drawing underfeed of 400% increase in strand length, although higher draw ratios may be employed. It is preferred to limit the degree of underfeed from

rolls

82, 83 to the crimper to at most half the total drawing underfeed, or in such instance to not much more than about 200%. A range of from 5 to 50% underfeed is preferred when little or no added draw is desired, and a range of from about to 200% when substantial added draw is desired at the crimper input.

FIG. 8 also shows the same stutter crimper with straightin feed of the strand into the stufling chamber but without added

intermediate rolls

82, 83. In both FIGS. 7 and 8 the strand passes between guide block 75 and overlying clip 77 to center it along the nip of

rolls

32 and 33. When using all three rolls, as in FIGS. 4 to 6, it may be desirable to locate a pigtail or other guide ahead of the first roll and centered from end to end thereof for a like purpose.

Other variations in or modifications of the described apparatus and process may be made without involving a departure from the inventive concept, Any similarly useful compressive crimping device may replace the illustrated stutter-crimper, which is merely exemplary, as is the spring-loaded cap as the device for applying backpressure to the strand accumulation in that crimper. Except when using the last previously mentioned type of stuffer crimper, windup of the crimped yarn expelled from the chamber preferably should be synchronized to accommodate the yarn so expelled without, however, withdrawing yarn from ahead of the back-pressure device. The portion of the cap covering the chamber illustrated herein may be used to control the windup rate, or a sensing device may be employed inside the chamber, such as disclosed in my Pat. 3,280,444, which is well adapted to use with a stuifer-crimper of the type disclosed in Pat. 3,027,619.

Strands crimped according to the present invention are characterized by excellent crimp stability, despite absence of conventional strain-relieving features, which have been customary despite the complication and expense attendant thereon. Control of the travelling strands, especially at high rates of travel, such as in the vicinity of a thousand yards per minute, is comparable to that obtainable with overfed strands at lower rates, such as several hundred yards per minute. Other benefits and advantages of this invention, which produces crimped textile strands of exceptional bulk, will become apparent and accrue to those who undertake to practice it as defined in the following claims.

I claim:

1. In apparatus for treating textile strands, including means for drawing a textile strand to increased length in a drawing zone and means for compressively crimping the drawn strand in a crimping zone, the improvement comprising means defining the beginning of the crimping zone and means defining the end of the drawing zone located closer to one another than a distance equal to the lesser in length of the respective zones.

2. Strand-treating apparatus according to claim 1, wherein the beginning of the crimping zone is defined by a pair of stuffing rolls defining a strand-receiving nip therebetween.

3. Strand-treating apparatus according to claim 2, wherein the length of the crimping zone is defined by the length of a stufiing chamber having an entrance and exit for the strand and having its entrance juxtaposed to the nip of the stutfing rolls.

4. Strand-treating apparatus according to claim 1,

wherein the end of the drawing zone is defined by a final draw roll.

5. Strand-treating apparatus according to claim 4, wherein the length of the drawing zone is defined by the spacing of an initial draw roll from the final draw roll, along a strand-drawing path therebetween.

6. Strand-treating apparatus according to claim 1, wherein a roll is common to the means defining the beginning of the crimping zone and the means defining the end of the drawing zone.

7. Strand-treating apparatus according to claim 6, wherein the intervening distance is less than the perimeter length of the common roll.

8. Strand-treating apparatus comprising means including initial and final draw rolls for drawing a textile strand to increased length, compressive crimping means including a stuffing chamber and means including stuffing rolls for stufiing the strand into the chamber to crimp it, means for rotating the initial draw rolls at a given surface speed, means for rotating the final draw rolls at a greater surface speed, and means for rotating the stuffing rolls at a surface speed at elast as great as the surface speed of the final draw rolls.

9. Strand-treating apparatus according to claim 8, wherein the means for rotating the stuffer rolls are adapted to do so at a greater surface speed than the surface speed of the final draw rolls.

10. Strand-treating apparatus according to claim 9, wherein the means for rotating the stuffing rolls is adapted to rotate the same at a surface speed from about 5 to 50 percent higher than the surface speed of the final draw rolls so as to tension the strand therebetween.

11. Strand-treating apparatus according to claim 9, wherein the means for rotating the stufifing rolls is adapted to rotate the same at a surface speed from about 100 to 200 percent higher than the surface speed of the final draw rolls so as to draw the strands to increased length therebetween.

12. In apparatus for treating textile strands, including means for drawing a textile strand to increased length in a drawing zone and means for compressively crimping the strand in a crimping zone, the improvement comprising means for underfeeding the strand from the drawing zone to the crimping zone.

13. Strand-treating apparatus according to claim 12, wherein the means for underfeeding the strand from the 8 drawing zone to the crimping zone comprises means for controlling the rate at which the strand enters the crimping zone relative to the speed at which the strand exits from the drawing zone.

14. In apparatus for treating textile strands, including means for drawing a textile strand to increased length and means for compressively crimping the drawn strand, the improvement comprising at least one strand-contacting roll common to both the drawing means and the crimping means.

15. Strand-treating apparatus according to claim 14, wherein a pair of strand-contacting nip rolls terminate the drawing means and begin the crimping means, the nip rolls being preceded by a strand-restraining component of the drawing means and being followed by a strand-confining component of the crimping means.

16. Strand-treating apparatus according to claim 15, wherein the strand-restraining component comprises a plurality of rolls, and the drawing means includes also means for rotating that plurality of rolls at a first surface speed and for rotating the nip rolls at a second surface speed greater than the first, and the crimping means includes means for withdrawing the crimped strand from the strand-confining component at a third speed less than the second.

17. Strand-treating apparatus according to claim 14, wherein the strand-contacting roll is one of a set of three, two of which are contiguous with the third, thereby establishing a pair of strand-receiving roll nips.

18. Strand-treating apparatus comprising a stuffer crimper having a stuffing chamber and nip rolls for stuffing a textile strand into the stufiing chamber, stranddrawing means having a set of initial and final draw rolls for drawing a textile strand to increased length and located immediately before the stuffing rolls, the entrance to the stuffing chamber being closely spaced to the final draw roll along the strand path therebetween.

19. Strand-treating apparatus according to claim 18, wherein the maximum separation between the final draw roll and the entrance to the stuffing chamber, measured along the strand path is three diameters of one of the stuffing rolls.

20. Strand-treating apparatus according to claim 18 wherein the final draw roll is one of a plurality of nip rolls and the entrance to the stuffing chamber is juxtaposed to a nip thereof in position to receive drawn strand therefrom.

21. Strand-treating apparatus according to claim 20, wherein the plurality of rolls comprises three rolls, two of which are contiguous with the third roll, thereby establishing a pair of strand-receiving nips.

22. Strand-treating apparatus according to claim 21, wherein the entrance to the stufiing chamber is juxtaposed to one of the trips in position to receive drawn strand therefrom, and the other nip is located upstream therefrom in the strand path.

References Cited UNITED STATES PATENTS 2,917,806 l2/l959 Spence et al. 2872.l4

LOUIS K. RIMRODT, Primary Examiner U.S. Cl. X.R. 2872.l4