US3108322A

US3108322A - Apparatus for melt spinning of synthetic filaments

Info

Publication number: US3108322A
Application number: US81461A
Authority: US
Inventors: John E Tate
Original assignee: Monsanto Chemicals Ltd
Current assignee: Monsanto Chemicals Ltd; Monsanto Chemical Co
Priority date: 1961-01-09
Filing date: 1961-01-09
Publication date: 1963-10-29
Anticipated expiration: 1980-10-29
Also published as: GB938889A; DE1221397B; CH382365A; BE612473A; NL272966A

Description

APPARATUS FOR MELT SPINNING OF SYNTHETIC FILAMENTS J. E. TATE Oct. 29, 1963 Filed Jan. 9, 1961 r OOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOO o ooooooAvyooooooooooooooooooo .u ooooooooooooooooooooooooooo INVENTOR John E.Tate

United States Patent Office 3-,lfib,3-ZZ Patented Oct. 29, 1963 3,168,322 1 APPARATUS FOR MELT SPINNING 9F SYNTHETIC FILAMFJNTS John E. Tate, Pensacola, Fla, assignor, by mesne assignments, to Monsanto Chemical Company, a corporation of Delaware Filed Jan. 9, 1961, Ser. No. 81,461

4 Claims. (Cl. 18-8) This invention relates to an apparatus for melt spinning of synthetic filaments from organic polymers. More particularly, this invention relates to an improved quench apparatus of the above type providing perforated means effective to prevent erratic filament action especially while processing heavy denier filament bundles or yarns.

The term heavy denier filament bundles or yarns as used herein has reference to yarn having a total denier of at least 700 and ot the type used for tire cord and the like.

Melt spinning, in general, consists of extruding molten polymers such as vinyl polymers, polyamides, and polyesters, into separately formed filaments and cooling the filaments to promote solidification thereof by means of a stream of filtered air directed against the filaments. The apparatus employed to condition the filaments is commonly referred to as a quench chamber, cell, or box, as

an air chimney, and as quench apparatus, the latter term being used hereinafter to describe such a device.

Quench apparatus of the usual type presently in service, comprises a vertical enclosure formed by a pair of upright spaced side walls and a' connecting foram- Yinous back wall, while the front side thereof, used to gain access to an elongated chamber defined by the A side and back walls, is fully uncovered to the ambient atmosphere. Synthetic filaments areextruded through orifices in a spinning unit positioned adjacent the upper end of the elongated chamber and the filaments are passed downwardly therethrough. Fluid under pressure, such as an inert gas or air, is forced through the pores in the forarninous back wall opposite the uncovered frontal side, into the elongated chamber to harden'the filaments. p

, When an endeavor is made to process heavy denier filaments and yarns such as, for example, 1680 denier yarn composed of 280 filaments extruded as a group through a single spinneret with conventional quench apparatus, many abnormal spinning conditions are encoun- :t ered; The force of the air stream acting on the fila 'mentsproduces a high unit pressure and the cool air coming into contact with the molten filaments creates air turbulence and eddy currents which combine to cause excessive filament arcing or bowing, straying of the fila-' ments' from their normal downward course, and erratic filament vibration or flutter. As a consequence of abnormal filament dislocation and displacement, yarn ofsub-standard quality, of variable denier, and of nonuniform cross-sectional area is produced and in many instances normal convergence of the filaments is prevented entirely. I p

Furthermore, the conventional construction does not provide a filament conditioning chamber having a substantially constant positive air pressure therein because the that flows into the elongated chamber through the pores of the foraminous back wall from a plenum chamber 'is quiclcly dissipated into the atmosphere through-the open frontal area. Effective uniform cooling oi filaments is prevented as a consequence of the air pressure being higher at the side of' the filaments nearest the foraminous wall than the air pressure at the opposite side or the filaments adjacent the frontal area. Different proposals have been suggested to control the through the chamber.

for melt spinning of synthetic filaments having uniform denier and uniform cross-sectional area. Another object is to provide melt-spinning apparatus of the type having pivotal perforated means for damping out undesirable air currents within a quench chamber and wherein the perforations in said perforated means are arranged in a predetermined pattern for quenching of filament bundles of heavy denier. A further object is to provide quench ing apparatus wherein a multiplicity of filaments may be spun in closely spaced relation with a minimum of fluttering and displacement of the filaments. Another object is to provide a quench apparatus having a partially closed frontal area. A still further object is to provide improved quench apparatus providing a positive quench chamber.

According to the present invention improved quench apparatus for melt spinning of synthetic filaments is provided. In general, the apparatus embodying the invention comprises an upright enclosure providing a pair of fluid pressure chambers defined therein having intercommunication therebetween through pores in a forminous wall interposed between the chambers. A spinning device is adapted to extrude molten filaments downwardly into the upper end of one of the chambers through an opening therein, the filaments then being passed In the meantime, fluid under pressure such as air at a predetermined rate is supplied 'by means of a blower or the like to the second chamber,

the air flowing through the pores in the foraminous wall into the first chamber. p

A controlled, smooth, and continuous cross current of airfiowi ng perpendicular to the passage of the filaments through the first chamber is provided by perforated means having throttling perforations therein arranged in a particular manner, described hereinafter, and positioned opposite the foraminous wall; the air being exhausted from the first chamber through the perforations The specific arrangement wall is effective to produce uniform quenching of the filaments and to produce a positive movement of air at a rate below the aforementioned predetermined rate through the first or quench chamber whereby erratic filament action is controlled and turbulent air currents are dampened. The filament-s are taken up after being conditioned in the quench chamber and passed out of the latter through an opening provided in the lower end thereof by usual take-up means.

In the accompanying drawing, FIGURE 1 is a front elevational view showing the improved apparatus for quenching of synthetic filaments embodying the inven- .tion.

FIGURE 2 is a side elevational view of the apparatus shown in FIGURE 1 with all but a small fragment of :the side wall 16, showing the arrangement of latch 18 thereon, removed for convenience of illustration.

Like components of the apparatus 1 shown in the several figures in the drawing are designated by the same reference numeral-s for purposes of simplicity.

Referring to the drawing, FIGURES 1 and 2, there is shown an improved apparatus 1 for quenching or cooling of synthetic filaments, of the type embodying the invention, including a spinning assembly 2 and a yarn take-up means 3. Spinning assembly 2 incorporates a spinneret 4 having a plurality of orifices through which a thermoplastic polymer, such as nylon, is extruded into newly formed filaments 5. The face of the spinneret 4 is horizontally disposed so that the normal extrusion axis extends vertically downward. The yarn take-up means 3 includes a reciprocal traverse guide 6 adapted tolay filament yarn on a bobbin 7 or the like suitably driven by such as belt means, to form a filament yarn package. The speed of yarn take up on bobbin 7 is coordinated with the extrusion speed of the polymer from the spinneret 4 so that proper melt spinning is accomplished. Ordinarily, the collection rate is considerably higher than the extrusion rate.

A pair of spaced vertical side panels or members 9 and 1d of solid construction, an upper and lower end pane-

l

11 and 12, respectively, suitably secured to the side panels, and a back panel 13 suitably attached to the side and end panels and formed of material pervious to gas, such as gauze fabric, felt material, or as illustrated, a fine mesh Wire screen, define an enclosure or receptacle having an elongated chamber 14 therethrough.

The uncovered front side of the enclosure is provided with a front panel 15 or door having a plurality of throttling perforations or orifices 16 therethrongh. Panel 15 is hingedly secured at one side thereof to one of the side panels 9 and at the opposite side thereof is provided with a pin 17 engageable with a latch 18 pivotally secured on the other side panel for fastening the door under normal operating conditions.

Spinning assembly 2 is suitably mounted adjacent the upper end panel 11 and spinneret 4 of the assembly is coaxially aligned with and is fitted within a transverse aperture in the upper end panel 11 to permit filaments emerging from the spinneret 4 to pass into and through elongated chamber 14, and through a convergence guide 18a. Guide 18a is suitably mounted on lower end panel 12 in overhanging relation over the mouth of a discharge tube 19 extending through a transverse aperture in the lower end panel 12, the latter aperture being in coaxial alignment with the aperture in the upper end panel 11. Filaments 5, after passing through the convergence guide 13a, are discharged from elongated chamber 14 through tube 19 and are strung through the traverse guide 6 and laced around bobbin 7 for purposes of collection.

A recessed housing 21 is sealingly attached to the side and end panels rearwardly of screen 13, and provides a plenum chamber 21 defined by the inner side walls of housing 20 and the outer face of screen 13.

Plenum chamber 211 is supplied with air under pressure from a blower 22 via a conduit 23 that opens at one end thereof into chamber 21. The later chamber 21 constantly in communication with elongated chamber 14.

In operation, plenum chamber 2 1 is pressurized with lluid'under pressure such as air to a predetermined pressure by means of blower 22 via conduit 23. Air under pressure from the plenum chamber 21 fiows through the pores in the screen 13 into chamber 14 in a direction at right angles to the longitudinal axis of chamber 14, thus supplying a constant cross flow of air thereto. The pores in the screen 13 cause dampening of the air and a resultant drop in air pressure in the elongated chamber 14 over that in the plenum chamber 21.

Meanwhile, a polymer is supplied to the spinning assembly 2 and after being heat treated thepolymer is extruded through the spinneret 4 and emerges from the orifices in the spinneret in molten streams or filaments 5.

With the front panel in an opened position, an operator strings the filaments downwardly through the elongated chamber 14, through the convergence guide 18a and brings the filaments into the region surrounding the entrance of tube '19, where the filaments are pulled through tube 19 by a vacuum created by suitable means, not h wn I The filaments pass through tube 19 and are then strung through the traverse guide 6 and laced around bobbin 7 for taking up the bundled filaments or yarn.

The front panel or door '15 is then closed and fastened by means of the latch thus providing a partially enclosed chamber. An adjusted rate of cross flow of air is forced from the plenum chamber 21 into the elongated chamber 14 and against the filaments to promote solidification thereof. The air is delivered into the elongated chamber faster than it can be exhausted therefrom through the perforations 16 in the panel 15, and a positive pressure in the elongated chamber G4 is established. The perforations 16 act to control the venting of air from the elongated chamber 14 at a throttled rate whereby a smooth transverse flow of air at a substantially constant velocity through elongated chamber 14 is provided and whereby turbulent air currents are damped out. Per-forations 16 may be arranged in different patterns, the size and shape of the perforations may be varied, and the door 15 need not cover the entire frontal areabut may be shorter than the length of the elongated chamber 14. The percentage of perforated area to the total area of the panel 15 is, preferably, at least percent. However, the best results are obtained by the arrangement described in the following example.

As an example of the advantages obtainable with the use of the improved quench apparatus, the following test Was performed utilizing first the open-front conventional type quench apparatus. Operating with a spinneret 5" in diameter having 280 orifices and a quench apparatus approximately 80" long, 10" wide, and 16" deep, a spinning .run was attempted spinning yarn having a total denier of 1680 and 280 individual filaments. The filaments flicked violently and normal convergence of the filaments was prevented.

A similar spinning run was then performed utilizing apparatus of the present invention. The dimensions of the improved quench apparatus were the same as that aforementioned; but in this instance the apparatus was provided with a pivotal perforated aluminum plate or door 15 covering the open frontal area. The aluminum plate 15 was 54" in length and was mounted with the upper edge thereof approximately 7%" down from the upper end panel 1 1, thus providing uncovered areas adjacent the uppermost and lowermost portions of the filaments, the latter portions being considered less critical in the quenching process. The perforations 16 extending through the plate 15 were in diameter, circular in shape, and arranged in two spaced longitudinal columns each comprising two vertical rows of perforations. Each perforation in a respective column was spaced 1 /2 apart vertically and 3" apart laterally in relation to each other,

of the filaments passing through the apparatus so as to control filament vibration.

With the use of the improved type of quench apparatus an operable setof conditions was established, filament action was controlled,'and 1680 denier yarn having 280 filaments was successfully spun.

In service, quench chambers are usually positioned in extended rows consisting of a series of chambers arranged in side by side relation so that a common side wall is shared by adjacent chambers, and, generally, another row of quench chambers is arranged in back to back spaced relation with the other row of chambers, the space between the rows being provided for a common plenum chamber.

It will be understood that the invention is not to be limited to above type of preferred construction and design, since it may be assumed that numerous modifica tions may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

Having described the invention, the following is claimed:

1. Improved quench apparatus for melt spinning of synthetic yarns of high total filament denier, said apparatus comprising a pair of vertical spaced side panels, an upper and a lower end panel connected to said side panels at a corresponding upper and lower end thereof and each having a transverse opening therethrough, a foraminous back panel having a plurality of pores therein and being connected to said side and end panels, a pivotal door fastened to one of said side panels opposite said foraminous back panel and provided with a plurality of throttling orifices therein arranged in longitudinal rows at opposite sides of a vertical central unperforated portion, means on said pivotal door and on one of said side panels for closing said pivotal door under normal operating conditions, an elongated chamber defined by the inner Walls of said side, end, and back panels, a convergence guide positioned within said elongated chamber and adapted to be mounted in overhanging relation over said transverse opening in said lower end panel, a spinneret mounted near said transverse opening in said upper end panel for extruding a group of filaments downwardly therethrough and into said elongated chamber, a recessed housing sealingly secured to said side and end panels rearwardly of said foraminous panel, said recessed housing having a plenum chamber defined therein normally charged with fluid under pressure and being in constant communication with said elongated chamber via said pores in said foraminous panel, blower means for supplying air under pressure to said plenum chamber, and takeup means positioned near said transverse opening in said lower end panel for collecting said filaments.

2. Improved quench apparatus as claimed in claim 1, wherein said pivotal door is further characterized in that the length of said pivotal door is shorter than the length of said pair of vertical spaced side panels so as to provide uncovered areas at respective ends of said pivotal door, and wherein the width of said vertical central unperforated portion on said pivotal door corresponds to the width of said group of filaments extruded from said spinneret.

3. Improved quench apparatus for melt spinning of synthetic yarns of high total filament denier, said apparatus comprising, in combination, an upstanding enclosure formed by a pair of spaced side panels, a foraminous back panel provided with a plurality of pores therein, a front panel having an unperforated central portion and perforated portions at opposite sides of said unperforated central portion, said perforated portions comprising a plurality of circular throttling orifices arranged in longitudinal rows and dispersed over at least 20% of the total area of said front panel, an elongated chamber open at its upper and lower ends thereof defined by the inner Walls of said side, back, and front panels, a spinneret mounted adjacent the upper open end of said elongated chamber and adapted to eXtrude filaments downwardly into said elongated chamber, blower means for forcing air under pressure at a predetermined value through said pores in said foraminous panel into said elongated chamber, said throttling orifices in said perforated portions on said front panel serving to exhaust air from said elongated chamber at a controlled rate at opposite sides of said filaments to prevent vibration and displacement of said filaments, and take-up means positioned near said lower end of said elongated chamber for collecting said filaments.

4. Improved quench apparatus as claimed in claim 3 wherein said throttling orifices are at least inch in diameter.

References Qited in the file of this patent UNITED STATES PATENTS 2,273,105 Heckert Feb. 17, 1942 2,289,860 Babcock July 14, 1942 2,940,122 Collat June 14, 1960 3,022,539 Massey Feb. 27, 1962 FOREIGN PATENTS 566,879 Belgium May 14, 1958 833,852 Great Britain May 4, 1960 554,453 Italy June 10, 1957

Claims

1. IMPROVED QUENCH APPARATUS FOR MELT SPINNING OF SYNTHETIC YARNS OF HIGH TOTAL FILAMENT DENIER, SAID APPARATUS COMPRISING A PAIR OF VERTICAL SPACED SIDE PANELS, AN UPPER AND A LOWER END PANEL CONNECTED TO SAID SIDE PANELS AT A CORRESPONDING UPPER AND LOWER END THEREOF AND EACH HAVING A TRANSVERSE OPENING THERETHROUGH, A FORAMINOUS BACK PANEL HAVING A PLURALITY OF PORES THEREIN AND BEING CONNECTED TO SAID SIDE AND END PANELS, A PIVOTAL DOOR FASTENED TO ONE OF SAID SIDE PANELS OPPOSITE SAID FORAMINOUS BACK PANEL AND PROVIDED WITH A PLURALITY OF THROTTLING ORIFICES THEREIN ARRANGED IN LONGITUDINAL ROWS AT OPPOSITE SIDES OF A VCERTICAL CENTRAL UNPERFORATED PORTION, MEANS ON SAID PIVOTAL DOOR AND ON ONE OF SAID SIDE PANELS FOR CLOSING SAID PIVOTAL DOOR UNDER NORMAL OPERATING CONDITIONS, AN ELONGATED CHAMBER DEFINED BY THE INNER WALLS OF SAID SIDE, END, AND BACK PANELS, A CONVERGENCE GUIDE POSITIONED WITHIN SAID ELONGATED CHAMBER AND ADAPTED TO BE MOUNTED IN OVERHANGING RELATION OVER SAID TRANSVERSE OPENING IN SAID LOWER END PANEL, A SPINNERET MOUNTED NEAR SAID TRANSVERSE OPENING IN SAID UPPER END PANEL FOR EXTRUDING A GROUP OF FILAMENTS DOWNWARDLY THERETHROUGH AND INTO SAID ELONGATED CHAMBER, A RECESSED HOUSING SEALINGLY SECURED TO SAID SIDE AND END PANELS REARWARDLY OF SAID FORMAMINOUS PANEL, SAID RECESSED HOUSING HAVING A PLENUM CHAMBER DEFINED THEREIN NORMALLY CHARGED WITH FLUID UNDER PRESSURE AND VEING IN CONSTANT COMMUNICATION WITH SAID ELONGATED CHAMBER VIA SAID PORES IN SAID FORAMINOUS PANEL, BLOWER MEANS FOR SUPPLYING AIR UNDER PRESSURE TO SAID PLENUM CHAMBER, AND TAKEUP MEANS POSITIONED NEAR SAID TGRANSCVERSE OPENING IN SAID LOWER END PANEL FOR COLLECTING SAID FILAMENTS.