US3491409A - Rotary ball apparatus for crimp deregistration - Google Patents

Description

1911.27, 1970 l D. F. MILLER 7 3,491,409

ROTARY BALL APPARATUS FOR CRIMP DEREGISTRATION Filed Jan. 25, 1968 2g@ j; k\\\\\\\\\\\\1 @1,

jGuE/VT l United States Patent O 3,491,409 ROTARY BALL APPARATUS FOR CRIMP DEREGISTRATION Donald Floyd Miller, Newark, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Jan. 25, 1968, Ser. No. 700,613 Int. Cl. D01b 3/04 U.S. Cl. 19-65 4 Claims ABSTRACT OF THE DISCLOSURE A continuous, crimped filamentary tow can be deregistered by an apparatus which maintains longitudinal tension on a tow passing over a surface and sequentially restrains and immediately thereafter allows free longitudinal motion of the individual filaments of the tow across its lateral dimension.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to treatment of filamentary tows and, particularly, to a novel method and apparatus for deregistering filaments in crimped tow.

Description of the prior art Several methods have been used in the past for opening, bulking, and spreading filamentary tows. Most techniques have been directed to converting a tow of a relatively high density of filaments to one of relatively low density of filaments. More recently, attention has been directed to the opening and to the separation within the tow bundle of crimped filaments which are closely spaced and in phase with the crimps of adjacent filaments. The opened and separated tow is not only of lower density than the original tow, but also most of the crimped filaments have been displaced longitudinally with respect to adjacent filaments so that adjacent crimps are out of phase with each other. This operation will be designated herein as deregistration of the crimped filaments; i.e., displacing neighboring crimped filaments so that adjacent filaments no longer have crimps which are in phase with one another. The term deregistration as used herein is not intended to convey any particular degree of perfection with respect to this displacement of neighboring cri-mps. Naturally, most uses for the deregistered tows will be optimized when a high proportion of the crimped filaments in a given tow bundle have had their crimps displaced out of phase, when the treated tow is stable, and when crimps do not return to the original densified and in-phase registry.

SUMMARY OF THE INVENTION The present invention provides a process for deregistering a continuous crimped filamentary tow. The process comprises (l) longitudinally forwarding the tow from a supply zone through a snubbing Zone and subsequently to a take-up zone, (2) longitudinally tensioning the tow between the supply zone and the take-up zone and (3) deregistering the tow within the snubbing zone by sequentially restraining and immediately thereafter allowing free longitudinal motion of the individual filaments of the tow across the lateral dimension of the tow. This process can be carried out by an apparatus which comprises a first forwarding means for forwarding the tow in a longitudinal direction, a second forwarding means for forwarding the tow after deregistration has been accomplished and for maintaining longitudinal tension upon the tow between the first and second forwarding means, a rotatable structure having a race therein, a rotatable ICC member adapted to fit and mounted in the race, the rotatable structure operably mounted in relation to the tow to provide rolling contact of the rotatable member with the tow, a surface means mounted in relation to the tow between the first and second forwarding means to intimately contact the tow between the rotatable member and the surface means.

BRIEF DESCRIPTION OF THE DRAWINGS Reference to the accompanying drawings will facilitate an understanding of the instant invention.

FIGURE 1 is a schematic perspective view with parts removed to illustrate the principle of instantaneous holding of filament movement in the novel apparatus;

FIGURE 2 is an elevational view in partial cross section of a crimp-deregistering apparatus of the present invention;

y FIGURE 3 is a plan view of FIGURE 2;

FIGURE 4 is an elevational View of another embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS The general principle of the use of rolling balls to effect sequential stop and go movement of adjacent filaments in a tow is shown in FIGURE 1. Crimped tow 10 moves in the direction of the arrows from the feed means, not shown, through puller rolls 11; in so doing, it passes in sliding contact with flat rigid or semi-rigid plate 12. While atop plate 12, round rigid balls 13 roll across the tow in a direction perpendicular to the direction of tow movement. The balls 13 are loaded so that they press upon filaments just underneath them causing these filaments to stop their forward movement. The area 14 illustrates a section of the tow wherein the filaments have been stopped in their forward movement by means of the loaded halls 13 and thus are temporarily elongated from their registered position. In the area 15, filaments adjacent those of area 14 move uninterruptedly to puller rolls 11. Thus, by the differential clamping action of the balls the crimps of' adjacent tow filaments are pulled out of registry with each other. Crimped, deregistered tow 16 moves to a further processing step.

As shown in FIGURES 2 and 3 crimp deregistration of a laterally spread tow is attained by passing the ribbonlike material through a rotary lball device 17 and the nip of a pair of pull rolls 11 downstream of the device. Rolls 22 feed the rotary ball device 17 with tow 10. Rolls 11 clamp the filaments securely and provide the necessary tension which is required to deregister the crimps of the filaments. Device 17 comprises a rotary disc 18 fixedly attached to the end of a rotary driven shaft 19 which is powered by a conventional drive (not shown). The underside of disc 18 is modified by at least one circularopen groove or race 20. Contained within the race 20 is a plurality of rolling members 13 which frictionally contact the upper surface of the spread tow. Members 13 can be' any geometrical configurati-on such as tapered, barrel-shaped rollers, but preferably they are spherical. Backing the spherical members 13 is a rigid fiat stationary surface 12 which is composed of a suitable material having high-friction characteristics. For eflicient action disc 18 is lightly preloaded against the tow to improve the clamping action of the rolling members 13.

As the tow filaments are pulled under the device 17 by the action of rolls 11, the rotary disc 18 is rotatably driven about the Vertical axis of the shaft 19. The various rolling members 13 thus roll across the filaments. Because of the slight clamping force of disc 18, a few fibers are momentarily pinched between the rolling members 13 and the fiat surface 12. As may be seen in FIGURE 3, therlcontact areas or footprints formed by the rolling members 13 create a plurality of instantaneous changes in the tension level of the pinched filaments. Since the pull of' rolls 11 acts uniformlyron al1 the filaments, the unconstrained fibers continue to ad- Vance at the original tension level as shown in lare-a 15 of FIGURE l. As a consequence, in a given iinstant, neighboring bundles of fibers tend to shift longitudinally an incremental distance.

Because the contact areas orrfootprints of the rolling members 13are small, only a fraction of the filaments are pinched momentarily; however, the rapidlyV rotating disc 18 translates the rolling members 13 across the tow many times per minute. The rapid rotation Y:causes momentary pinching actionto change continuously and produces amore complete deregistration of the filaments.

ESurface V12 of FIGURES 2 and 3VV can be replaced by the endlessY belt 31of FIGURE 4. The belt 31 is tracked around a pair of spaced rolls 30. The belt can be moved either in the direction of travel of the tow 1G or opposite the direction of tow travelHowever, in this embodiment the speed of the belt should be appreciably less than the speed of the moving tow; otherwise, less efficient crimp deregistration occurs. The belt 31 can be backed nby a stationary rigid 4surface 32nto maintain the portion of the belt contacting the tow in a planar or fiat configuration. The rotary ball device 17 and balls 13 remain the same as in the embodiment of FIjGURES 2 and 3.

Conventional drive and mounting means are used throughout the present invention, e.g., onfthe feed rolls 22 and on the pull rolls Y*11. Suitable mounting means not shown in the drawings are utilized to mount the'surface means 12 on a floor,or working surface on which the entire deregistration device is situated to position it in operable relationship with the Vtow 10. f

In the simplest embodiment, a single rolling member can be used to deregister, although at high process speeds a plurality of rolling members 13 performs more efiiciently. e

STATEMENTV177 OF UTLITY :The process and apparatus of this invention are particularly useful in the processing of iightor heavy-denier tows for deregistration of crimped filaments. Such tows may have a, total denier varying from 1,000 up to 1,000,000, and even higher. The instantaneous filamentholding action of the new apparatus servesYV to deregister the crimped tow more efliciently and more completely when applied to tows that have alreadybeen laterally spread to thin webs as, for example, bythe process of U.S. 2,709,282,1The invention may be applied in the deregistration of crimp of tows composed of natural, manmade and synthetic filaments oreblends thereof. The tows which would normally be crimped would possess a crimp such as the conventional zigzag crimp er they may contain a three-dimensional crimp, such as the known helical crimp, random crimp,fand the like. The deregistered tow is particularly suitable for subsequent treatment with liquids, resins, or the like, by dipping or spraying in a solution, dispersion or emulsion of a resinous binder.

What is claimed is:

:1. An apparatus for deregistration of a continuous filamentary tow comprising e Y first forwarding means for forwarding said tow in a longitudinal direction, L. f

a rotatable structure having a race therein, Vat least one rotatable member adapted to fit and mopnted in Ysaid race, said rotatable structure operably mounted in relation to said tow to provide rolling contact ofgsaid rotatable member with said tow,

means for rotating said Yrotable structure,

second forwarding means for forwarding said tow/1 after contact with said rotatable 'member and for maintaining lorrgitudinal'tension upon said tow between said first and second forwarding means, and

surface means mounted in relation to said tow between said first and second forwarding means and cooperating with saidV rotatable member to intimately Vcontact said tow between said rotatable member and said surface means so as to accomplish deregistration.

2.1 The apparatus ofV claim 1 wherein said surface means is rigid and stationary relative to said tow. f

3. The apparatus of claim 1 wherein the said surface means is a continuous, flexible belt supported by at least two rolls. 2

4. The apparatus Yof claim 1 wherein a rotatable member is a rigid sphere. u

References Cited UNIED STATES PATENTSY 3,032,829 5/'1962 Mahoney et al. 19-65 3,156,016 11/.1964 Dunlap et al. 19-65 XR 3,255,506 6/1966 Fritz ---7., 28-1 3,408,696

11i/,1968 cele 1'9-65 DoRsEY NEWTON, Primary Examiner

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