US2481048A - Apparatus for preparing fiber products - Google Patents

Description

ill

R. A sMaTH 9 1:

APPARATUS FOR PREPARING FIBER PRODUCTS Filed April 6, 1946 INVENTOR. ROBERT A. SMITH Patented 6. 1949 APPARATUS FOR PREPARING FIBER PRODUCTS Robert A. Smith, Media,- Panamanito Ameri-'- can Viscose Corporation, Wilmington, 116., a

corporation of Delaware Application April 6, 1946, Serial No. 660,045

1 Claim. 1

This invention relates to an improved apparatus for converting a continuous filament bundle such as may be obtained from artificial fiber spinning machines into an aggregate comprising disrupted fibers, which aggregate is similar in characteristics to a top or sliver of natural fibers.

In the procedures heretofore employed for converting a heavy denier bundle of continuous filaments into a spinnable sliver of disrupted fibers, the filaments have been out along diagonal lines. However, in cutting, it is necessary to exert pressure against the fibers and generally this pressure is sumcient to cause a temporary welding or sintering of contiguous fibers adjacent the points or lines of cutting. This adhesion of the fibers at their ends caused by the mashing pressure gives rise to difiiculties in the subsequent processing steps, producing irregularities in yarns or requiring'special steps of opening the bonded fibers. The tendency to adhere is especially pronounced in thermoplastic fibers which tend to become more plastic because of heat developed by the mashing during cutting. Other processes have been proposed which replace cutting with a stretch-breaking procedure. This alters the characteristics of the filaments in that the stretching results in lowered elongations and somewhat less uniformity of dyeing characteristics. Such altered characteristics of stretch, dyeing, elongation and the like show up in the final yarns, fabrics and other textile products.

In accordance with the present invention, a novel and improved system is provided in which the difficulties of joining or welding and the disadvantages of non-uniform characteristics of fiber in the products are minimized. Other objects and advantages of the invention will be apparent from the description hereinafter.

,In general, the present invention contemplates replacing at least partially and preferably entirely, the cutting or stretch-breaking procedures by a filament-disrupting step involving subjecting the filaments in the form of a band at intervals to the are or spark formed between the electrodes of a high potential circuit while moving the arc and band relative to each other in a direction at least one component of which extends widthwise of the band. When the filaments are of cellulosic nature or are made of other combustible materials, it may be desirable to carry out the process in the presence of an inert gas which does not support combustion. Thus a nozzle on either side of the band may direct nitrogen, helium or carbon dioxide against the band to form a protective blanket of the gas around the region of the arc, or the procedure may be'carried out in a chamber containing the inert gas.

In the drawing, which is illustrative of my invention,

Figure 1 is a side elevation of one embodiment of the invention,

Figure 2 is a plan View of the embodiment shown in Figure 1,

Figure 3 is a section taken on line III-III of Figure 1,

Figure 4 is a side elevation of another embodiment, and

Figure 5 is a side elevation of still another embodiment.

With reference particularly to Figures 1 to 3, the aggregate of continuous filaments 2 proceeds in the form of a more or' less parallelized band over a guide rod 3 to the nip between driven rolls 4 between electrodes 6 and I and then between the nip of a roll 8 and belt 9 carried by rolls i0 and H. Rolls 4 and belt 9 are driven, preferably at the same linear speed so that there is no stretch applied to the filaments as they proceed from the rolls 4 to the belt 9. As the band of filaments 2 passes between rolls 4 and belt 9. at least one of the electrodes 6 and 1 is traversed across the band while subjected to a high potential. Preferably, the high potential is impressed across the electrodes only during one direction of traverse in the manner hereinafter disclosed. so that the filaments are disrupted along parallel diagonal lines D as shown in Figure 2. After leaving the belt 9, the band comprising disrupted filaments of spinnable length may be assembled into the form of a sliver and subjected to drafting procedures. all as in conventional practice in accordance with the .prior art. Preferably, the

relative speeds of travel of the continuous fi ament band longitudinally and of the electrodes widthwise of the band are so adjusted that all of the filaments are disrupted during each traverse of the electrodes with respect to the band. However, if desired, the speeds may be altered so that the arcing affects alternate spots iri'the diagonal line, leaving therebetween .undisrupted filaments, and in this event, the band may then with or without first assembling into a sliver-like bundle, be subjectedto a stretch-breaking step to disrupt the remainder of the filaments in the aggregate.

The arrangement for producing relative motion of the electrodes and the band widthwise of the latter may comprise a stationary frame l2 having a slotted guideway I 3 receiving slidably with respect thereto the electrode holder I4 made of'suitable insulating material. This holder is in the form of a T as viewed in Figure 1, whereby the top cross bar has overhanging shoulders which ride on the frame above the slot I'3. A spring I'5 having one end secured to the holder I4 as at I6 and the other end secured to a projection on the frame as at H, normally draws the holder toward the observer looking at Figure 1. The holder I4 has a rod I8 slidably guided in the strap I8a fixed to the frame I2 and terminating in a roller follower I9 engaging the cam 20. The cam is rotated by ashaft 2| driven by a gear 22 in turn driven continuously by a motor (not shown). The cam 20 has a gradually rising cam surface 20a and a descending surface 20b, the former serving to provide a uniform speed of movement of the electrode across the width of the band and the latter surface allowing a quickreturn in response to the action of the spring.

While the lower electrode 1 may be connected to the reciprocating rod I8 for simultaneous traverse with the upper electrode, it comprises as actually shown (see Figure 3 particularly) a strip extending across the width of the band of filaments and this strip may have a serrated upper edge to facilitate the arcing or sparking and to assure the proper direction thereof.

A bar 23 is slidably mounted in bearings 25 of the frame I2. This bar 23 also carries two collars 26 and 26a fixedly secured adjacent the ends thereof. Collar 26a carries an upwardly projecting pin 21 extending into a slot of the link 28 pivotally mounted at 29 on the frame I2. Link 28 has a metallic contact element 30-, preferably of spring metal, projecting therefrom so that it is adapted to be 'moved toward and away from the stationary contact element 3| carried by the frame I2. This movement is effected by the alternate striking of collars 26 and 26a by the laterally projecting right end of the holder I4, as viewed in Figures 1 and 2.

The electrical circuit for obtaining the desired arc comprises a supply which may be a 110-volt line 32 passing through a transformer 33 where it is reduced to a low potential of 5 to 10 volts. This low voltage current passes through induction coil 34 where the voltage is raised to 8,000 to 30,000 volts or higher. The numeral 35 designates the primary low-voltage circuit (5 to 10 volts) which may be provided with a condenser 36. while 31 is the high-voltage secondary circuit which supplies the electrodes 6 and I, being connected thereto by terminals 38 and 39, respectively. Member 40 is the vibrating arm which operates to build up and collapse the electrical field at frequent intervals. The electric supply is controlled by the contact elements 30 and 3| which are connected in series with the primary winding of the transformer 33 and line 32 and thereby act as a switch.

In operation, the band proceeds between the electrodes longitudinally and continuously while the cam 20 causes alternate back and forth motion of electrode 6 across the width of the band in response to the rise 20a. of the cam and the spring I5 pressing against the cam surface 2%. It will be noticed that when portion 24 of the electrode holder I4 strikes collar 26a at one end of its stroke, the line circuit 32 is closed because of contact made electrically between elements 30 and 3| and this condition remains throughout the immediate following traverse of the electrode 4 across the band. At the end of that stroke, however, the holder I4 strikes collar 26, thereby swinging lever 28 about its pivot 29 and disconnecting contact elements 30 and 3|, so that during the return stroke, no current is supplied to the circuit.

Although a single upper electrode 8 is shown, the distance of traverse may be shortened to one-half or one-third, etc., by supplying two, three or more electrodes equally spaced above the band and traversing the group as a unit. Likewise, the unit comprising the rolls and belt for carrying the band may be moved back and forth widthwise of the band relative to one or more stationary pairs of electrodes. Or a plurality of stationary pairs of electrodes arranged across the I path may be excited in sequence.

Figure 4 shows a modified arrangement in which the path taken by the band of filaments from rolls 4 to rolls 8a-and Illa is inclined downwardly at a steep angle to the horizontal. This facilitates maintaining continuity of the band even after it passes the position of disrupting between electrodes I5 and I. After leaving rolls 8a and Illa the band passes through a condensing means, such as thefunnel 40a.

In Figure 5, a modification is shown in which the band of filaments, which may have substantial thickness, passes between electrodes 6 and I, which may be relatively traversed and of essentially the same construction as in the previous embodiments, but the electrode 6 is offset from electrode 1 in the longitudinal direction of the traveling band. This tends to direct the arc through the band along a line inclined from right angles to the band. Severance along such a sloped line, whether clear-cut and regular or jagged and irregular aids in subsequent drafting operations and assures better separation of the individual filaments in the bundles during such operations. The holders for electrodes 6 and I may be provided with nozzles M and 42 respectively for directing carbon dioxide against the band in the vicinity of the arc.

Changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claim.

I claim:

Apparatus for converting a continuous aggregate of filaments of indefinite length into a staple fiber product comprising two opposed electrodes, means for continuously feeding the aggregate as a band of generally parallelized filaments between the electrodes, one of the electrodes being stationary and extending across the path of the band, the other being mounted movably in a direction generally parallel to the stationary electrode, means for impressing a high potential electric current across the electrodes, and means for reciprocating the movable electrode.

ROBERT A. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,309,696 Roberts et a1 July 15, 1919 1,746,208 Alexander Feb. 4, 1930 2,090,502 Oshima Aug. 17, 1937 2,248,057 Bond July 8, 1941 2,323,300 Abbott July 6, 1943 2,362,572 McLain Nov. 14, 1944

Images