Jan. 7, APPARATUS Eon v. R. couvzmme rraw TO TOP Filed July 31. 194:5 42 40' IE Patented Jan. 7, 1947 2,413,969 UNITED STATES. PATENT OFFICE 2,413,969 APPARATUS FOR coma'rmd; I ' 'row TO TOP ; ' Vernal R. Hardy; Wilmington, L'DeL, assignor to E. 1. _du Pont de Nemours 8; Company, Wil mington, Del.,' a corporation of Delaware Application July 31, 1943, Serial No. 496,848 5. Claims. (01. 19-1) 1 2 This invention relates to a process and appa carried out. Other objects of the invention will ratus for drawing and breaking a tow oi’ continu_ be apparent from the description that follows. ous ?laments to form a top. More particularly. The objects of this invention are, in general, the invention relates to the conversion of a tow accomplished by subj ecting the yarn to a stretch of cold-drawable continuous ?laments, such as a 5 break system wherein the drawing rolls are of tow of nylon ?laments, into a spinnable top with such construction or are so positioned relative out destroying the continuity of they tow and sli- _ to the retaining rolls as to simultaneously apply ver and the substantial parallelism of the ?bers. varying amounts of stretch to the continuous ?la Herein, the expression “tow” is intended to ments at di?erent positions transversely in the cover a bundle of continuous ?laments in sub 10 tow between the retaining and drawing rolls prior stantially parallel relationship. Also herein, the expression "sliver” is intended to cover the struc ture formed when the continuous ?laments of the tow are severed into ?bers of predetermined lengths. Also herein, the expression "top” is in tended to cover the product resulting from draw ing the sliver. ’ to breaking said ?laments. ‘ In order to more fully explain the invention. reference will be made to the accompanying drawing forming a part of this speci?cation and 15 wherein: Figure 1 is a side elevation of a drawing frame illustrating the arrangement of the retaining and drawing rolls; In the conversion of a continuous ?lament tow to a spinnable top, the fibers formed must be dis Figure 2 is a plan view of the retaining and . tributed so that there is substantial overlapping 20 drawing rolls shown in Figure 1; of ends if yarn of acceptable physical properties is to be produced. Up to the present; no satis factory arrangement has been advanced to e?ect suitable overlapping or staggered relationship of Figure 3 is a side elevation showing a modi?ed arrangement of the retaining and drawing rolls; Figure 4 is a plan view of the retaining and drawing rolls shown in Figure 3; ' ?ber ends in a stretch-breaking system. Fur 25 Figure 5 is a side elevation showing a still fur thermore, in the conversion of tow to top by the ther modi?ed form of arrangement of the re~ breaking method, the ?bers produced may be tainingand drawing rolls; ,. varied in length and in physical characteristics Figure 6 is a plan view of the retaining and by varying the reach, i. e. the distance between drawing rolls shown in Figure 5; ' the bites of the retaining and drawing rolls, and 30 Figure 7 is a side elevation of still another mod the relative peripheral speeds of the retaining and i?ed arrangement of the retaining and drawing drawing rolls. However, for any setting or ad justment of the drafting frame now in existence, there are certain limitations in range of ?ber lengths and varying physical characteristics that 35 cannot be exceeded. , ' rolls; - ' Figure 8 is a plan view of the retaining and drawing rolls shown in Figure 7; Figure 9 is an enlarged plan view of one form of ?ber which is produced; and Nylon‘ and other cold-drawable ?bers have Figure 10 is an enlarged modi?ed form of ?ber. varying a?lnity for dyestu?’s‘, depending upon the Referring now to the drawing wherein like ref vdegree to which the ?bers have been drawn. (See erence numerals designate like parts, the refer Lewis U. S. Patent No. 2,278,888.) For certain 40 ence numeral 2 designates a plurality of ends of purposes this is considered desirable. In the tow supplied from any suitable source (not case of a spun yarn prepared from ?bers having shown) and which pass through a converging different dye characteristics, a pleasing variegat guide 4 in their passage to the stretch-break sys ed colored appearance or better color “depth” is 45 tem. The stretch-break system, as shown in Fig obtained. . ures 1 and 2, comprises a drawing frame in which An object of this invention is to provide an im the retaining rolls comprise, in the form shown in proved and novel method of converting continu-v Figure 2, a driven roll 8 and a heavy or weighted ous ?lament tow to top with better ?ber distri ?oating roll 8 cooperating therewith, and the bution. A further object of this invention is to provide a method of variously drawing cold-draw 50 drawing rolls comprise a driven roll I0 and a heavy or weighted ?oating roll l2 cooperating able ?lamentous material and breaking the same to produce staple-length ?bers, each of which has therewith. The rolls 6 and III are driven in the non-uniform characteristics. Another object of usual manner (not shown) so that the peripheral this invention is to provide a novel arrangement speed of the drawing rolls l0 and I 2 is higher of drafting rolls to enable this new process to be 55 than the peripheral speed of the retaining rolls 2,413,969 6 and 8, whereby the desired stretching, breaking rolls may be made irusto-conical. Such an ar rangement is shown in Figures 7 and 8, wherein the retaining rolls comprise a driven roll 58 and and drafting may be obtained. As is shown in the embodiment illustrated in Figures 1 and 2, the retaining rolls 8 and 8 are mounted at right angles to the direction of travel of the tow, while the drawing rolls HI and I! are mounted in angular relation thereto so that the distance between the bite of the two sets of rolls on one end may be as much as several times the difference between the bite of the two sets of rolls at the converging end. In other words, the reach between the retaining and drawing rolls varies in length from end to end. In view of the difference in the reach from one side of the web of ?laments to the other, varying amounts of stretch are applied and some of the ?laments will be broken, with a relatively short part of the ?la ments being undrawn while other ?laments will have longer undrawn portions or partially un a heavy, weighted or ?oating roll 52, and the drawing rolls comprise a frusto-conical driven roll 54 and a heavy, weighted or ?oating frusto conical roll 58. The axis of rotation of the rolls 54 and 56 may be only slightly canted with respect to the axis of rotation of the retaining rolls or may even be parallel thereto. By this arrange ment, not only is the reach different for the many different ?laments constituting the tow, but the peripheral speed of the ?ber-contact surface on the drawing rolls is made variable (depending on 15 the taper of the roll) and thus greatly alters the amount and distribution of the stretch to the ?laments. In this embodiment, it Will'be neces sary to have the ?laments subjected to a mini_ mum draft su?iciently great to insure breakage. drawn portions passed through the rolls before 20 In each of the preceding embodiments, by vary they are actually broken. The sliver resulting ing the relative speeds of rotation of the retaining from the breaking operation is also drafted by the and drawing rolls or by intermittently stopping rolls to produce a top. the retaining rolls, the non-uniformities of ?ber From the drawing rolls l8 and I2, the top lengths and denier may be further accentuated. passes through a condenser or trumpet ll, either 25 If desired, the tow may be comprised of ?laments of the stationary or rotary type, wherein the top of varying denier or a number of tows, two or is laterally compressed or condensed, particular more of which have different deniers, and may be fed into this drawing frame to produce a great ly to remove the feather edge obtained in the pre ceding drafting operation. The laterally com variety of ?ber deniers in the sliver or top and pressed top, after leaving the trumpet, passes be 30 in the spun yarn produced therefrom. When tween a driven roll l6 and a pressure roll I8 con the ?laments comprising the tow are of nylon or stituting condensing or compacting rolls which condense and compact the top passing there through. The condensing rolls l8 and I8 also other cold-drawable material, they may be en tirely undrawn, partially drawn or fully drawn, or the tow may be made up of any combination serve to deliver the top to a suitable collection 35 of such ?laments. If desired, the continuous ?la device. ment bundles or tows may be subjected to a pre Instead of having the retaining rolls at right weakening treatment, such as by partial fusion, angles to the direction of travel of the tow there partial solution or by any other suitable means between, such retaining rolls may be positioned at intermittently spaced points prior to the draft at an angle to the path of travel of the tow pass 40 ing and breaking steps of this invention. When undrawn nylon or other cold-drawable ing therebetween, and the drawing rolls may be material comprises the ?laments of the tow to be positioned at right angles or at an angle to the direction of travel-of the tow. ,The latter ar stretch-broken by means of this invention, the staple-length ?bers produced are characterized rangement is shown in Figures 3 and 4 wherein the retaining rolls comprise a driven roll 38 and 45 in general by the shape depicted in Figure 9. a heavy or weighted roll 32, said retaining rolls Starting from the lead end of the ?ber, there is being positioned in angular relationship relative a section of minimum diameter which is fully drawn, designated by the reference numeral 60. to the tow passing therebetween. In this embodi ment, as shown in Figures 3 and 4, the drawing This section may be extremely short or fairly rolls, which comprise a driven roll 34 and a heavy, 60 long, depending on whether the break occurred weighted or ?oating roll 36, are also positioned in near the back roll or at some other location be angular relationship with respect to the path of tween the two sets of rolls. Next, there will be a tapered section, designated 62, which at one end travel of the material passing therebetween. As may be substantially entirely undrawn and of the shown in Figures 3 and 4, the bite between the retaining and drawing rolls gradually decreases 55 maximum diameter and, at the other end, sub from position to position in the direction of the stantially completely drawn and of minimum di converging ends. ameter and therebetween all degrees of drawing In place of having one set of drawing rolls, from undrawn to substantially drawn. This two sets of drawing rolls may be utilized. In such portion is thus formed because, when the lead an embodiment, which is shown in Figures 5 and 60 end of the ?ber is broken, the portion that has 6, the retaining rolls, which comprise a driven not yet passed through the nip of the back rolls roll 40 and a weighted or heavy ?oating roll 42, is undrawn and cannot be subjected to drawing are positioned at right angles to the path of the until the lead and of the ?lament reaches the nip tow passing therebetween. As previously men of the front roll. If the drawn portion of the lead tioned, there are two sets of drawing rolls, each 65 end of the ?lament is very short, then the un set containing a driven roll 44 and a heavy, drawn section that follows will be caught by the weighted or ?oating roll 36. The two sets of drawing rolls are mounted so that the minimum nip of the front roll before any substantial draw ing can take place. A little further along, how and maximum reach between the retaining roll ever, more drawingtakes place until, at the time and each of the drawing rolls are substantially 70 of breaking, all of the following ?lament which the same. In order to direct the web of ?laments exists between the bites of the two sets of rolls, and into two substantially equal portions and divert it designated 64, will be substantially'fully drawn through the respective set of drawing rolls, there and of minimum diameter. In fact, there will be is provided a stationary member 48. an in?nite number of shapes, and the relative In place of using cylindrical rolls, the drawing portions of these three sections constituting the 75 5 ?ber will vary greatly, depending on the loca tion or the lead end and the following end or the ?ber when the breahoccurs. The two ends or the 8 f . .rayon or other cellulosic or synthetic ?lamentous structures,toobtainatoporrovingwithim proved distribution or ?ber ends. ?ber will always be substantially completely ‘ Since it is obvious that many changes and modi?cations can be made in the above-described details without departing from the nature. and spirit of the invention, it is to be understood that the invention is not to be limited thereto except drawn but may be extremely short as, for in stance, 0.1 inch or less, or may be several inches in length. It the lead end oi’ the ?ber is substan tially completely drawn for somedistance due to breakage near the front roll, there may be no forth in the appended claims. portion of the ?ber that will remain substantial 10 asIset claim: v r ly completely undrawn, and such a ?ber may . 1. An apparatus for converting tow to top by have the shape such as is depicted in Figure 10. the stretch-breaking method, which comprises The ?ber, such as previously“ described, can be retaining rolls and drawing rolls, said retaining produced in accordance with this invention over a very wide range or lengths and, together with 15 and drawing rolls being positioned relative to each other to provide therebetween a reach vary the in?nite variations in diameters possible, such ing in length from end to end. ?bers are eminently suited for use in certain sys 2. An apparatus for converting tow to top term of spinning, such as the worsted system. by the stretch-breaking method, which comprises Most important oi! all is the improved overlapping ‘retaining rolls and drawing rolls angularly dis oi’ ends that apparently results from these ar 20 posed relative to each other to provide a reach rangements or draft-breaking rolls, which en therebetween varying in length from end to end. 3. An apparatus for converting tow to top by ables subsequent spinning of yarns having excel lent physical properties. By means or this inven the stretch-breaking method, which comprises tion, a tow is converted into a top without de ’ straying the continuity of the tow and silver and 25 retaining rolls and drawing rolls angularly dis posed with respect to said retaining rolls to pro theparallelism oi’ the ?bers, and a top is produced vide a reach therebetween varying in length from from which yarn can readily be spun and in which end to end. the individual ?bers have varying a?lnity for dye 4. An apparatus for converting tow to top by stuil's so that many variegated colors and shades the stretch-breaking method, which comprises a can be produced by dyeing the‘ yarn in a single 30 set oi’ retaining rolls and two sets of drawing dye bath. Because there is excellent overlapping rolls, each of said sets‘ot drawing rolls being po of ?ber ends in the top, it is possible to draw the sitioned relative to said retaining rolls to receive top down to an acceptable yarn with fewer sub a separate group 01’ ?bers and angularly disposed sequent drawing, blending and twisting steps than have previously been found necessary, with sub- . stantial savings in spinning cost. Furthermore, I ‘?ner, stronger yarns can be made due to the ex with respect to said retaining rolls to provide a Leach therebetween varying in length from end > end. 5. An apparatus for converting tow to top by cellent distribution and overlapping of ?ber ends. the stretch-breaking method, which comprises re While this invention hasbeen described more taining rolls and drawing rolls, said drawing rollsv speci?cally in terms or converting nylon tow and 40 being irusto-conical in shape and positioned rela the like to top, it is also applicable to'any type tive to said retaining rolls to provide a, reach of continuous ?lament tow, whether the ?laments varying in length from end to end between said ‘constituting the same are cold-drawable or not, as retaining rolls and said drawing rolls. for instance, viscose rayon, cellulose acetate ~ , VERNAL R. HARDY.