US2979766A - Melt-spinning apparatus - Google Patents

Description

A ril 18, 1961 2,979,766

J. A. BRIGGS, JR.. ETAL MELT-SPINNING APPARATUS Filed. Feb. 23, 1960 2 Sheets-Sheet 1 INVENTORS JOSEPH A BRIGGS, JR. MROBERT L. GARDNER ATT R/VEY April 18, 1961 J. A. BRIGGS, JR., ETAL 2,979,766

MELT-SPINNING APPARATUS Filed Feb. 23, 1960 2 Sheets-Sheet 2 POLYMER .10 PH A %?9 I? ko nr 1.. ARDNE B ATTORNEY 2,979,766 I MELT-SPINNING APPARATUS Joseph A. Briggs, Jr., and Robert L. Gardner, Pensacola,

Fla., assignors to The Chemstrand Corporation, Decatur, Ala., a corporation of Delaware Filed Feb. 23, 1960, Ser. No. 10,293 7 Claims. 01. 18-8) This invention relates to the production of filaments by the melt-spinning method. --More particularly, it relates to improvements in an apparatus-for producing filaments and the like from linear high polymeric thermoplastic organic filament-forming compositions according .streams of polymer ;The molten; polymer streams issuing from the spinneret are directed vertically downward from the spinneret into a cooling atmosphere: usually air, where they are cooled and caused to solidfy into individual filaments. The filaments are then brought together. A finish is applied to the filaments, and the filaments. are collected in an orderly manner for further processing. To assist in cooling and solidifying the molten streams, air orlike gas is impelled or blown against the filamentary streams. It can. be appreciated readily that the filamentary streams after emerging from the spinneret until sufiiciently cool are particularly sensitive to deformation. Accordingly, the art has found it generally necessary to direct the coolinggas against the filamentary streams while the streams pass downwardly through a protective cell. or chamber. and to avoid a turbulent flow of the cooling gas. Particularlyadvantageous results are obtained when the directional movement of the cooling air is transverse with, respect tothe downward direction"v taken by the moving "streams of polymer, care being taken that the gas-fiow ata given [point is uniform in-magnitudeand direction. Such mode ofsolidifying the molten streams of. polymerby cooling with air may be accomplished by providing along one side of a conventional spinning chamber a foraminous or perforated partition pervious 'to air and by impelling the United wsPat f cooling air to pass through said partition and horizontally across the chamber in heat-exchanging contact with the traveling filamentary streams. The air is allowedto escape through .the side of the chamber opposite to the foraminous partition. The force of the air contacting the filamentary streams is usually suflicient to cause the streams to assume anarcuate path during paitof their travel down the spinning chamber. That is'to say,.1the filamentary streams are blown outwardly, by the cooling air and thereby do not follow the long axis of the' conventional spinning chamber as they would if no positive transverse movement of the air.

For various reasonsthe physical characteristics and properties of the filaments produced may vary over a period of time as they are being melt-spun and collectedon tal eup devices, e.g. reeled onto .bobbins ,one this.

variation occurs. in the denier or -cross-section of the filaments; Hardly ever is thegvariationinjthe denier by way of increase. That, is, to say, variations of increased denier have not beenfound. generally tr pe a problem.

It been found that the denier of themeltextruded fila- I 2,979,766 Patented Apr. 18, 1961 ments is reduced when leaks in the metering pumps which are propelling the molten polymer to the spinneret, channeling of the molten polymer in the filter sand pack of the spinneret assembly, clogging of the spinneret orifices, fluctuations of the gas flow through the spinning chamber or the like are experienced. Such reductions in denier give rise to considerable processing difiiculties in textile mills during conversion of the filamentary material into fabric or the like, as well as in the orientation stretching of the filaments usually performed in an opera- .tion subsequent to the melt-spining by the filament manufacturer. I In the past various devices have been proposed for detecting variations in denier of filamentary materials; but .thesehave not been completely satisfactory for a variety of reasons when same are used in connection with a meltspinning apparatus. In the first place, these devices almost invariablyrequire considerable instrumentation. In addition, they are complicated in operation, often involve various moving parts and are quite expensive to construct.

Perhaps even more important is the fact that the devices of the prior art primarily are concerned with detecting-defects or variations in denier of filamentary material during variousprocessing operations conducted subsequently to the initial winding of the filaments on spin bobbins after melt-spinning. The known devices ordinarily include means responsive to the variations in fdenier of. the moving filamentary material to stop the supply thereof. However, once extrusion of molten polymeris commenced in the melt-spinning operation, it is not at allconvenient to stop extrusion of the polymer through the spinneret until the polymer in the reservoir of the spinneret' is exhausted. Hence, the prior art apparatus have not been found suitable for detecting varia- ;-tio ns in denier of melt-spun filaments during the production thereof.

It is an object of the present invention to provide a .new and novel-spinning apparatus for use in the production of melt-spun filaments-1 7 It is a furtherobject-of this invention to provide a newand novel spinning apparatus adapted to prevent collection of melt-spunvsynthetic filaments when they exhibit an undesirable deviation as to denier uniformity during production thereof. J

is a further object of this invention to provide a new and novel apparatusadapted toprevent collection ofnnelt-spun synthetic filaments when they exhibit an undesirable reduction in denier during melt-spinning ,without stopping the extrusion of the polymer being 56 description when considered in'connection with the acthere were companying drawing in which like reference numerals designatelike parts throughout the figures thereof.

- In general the objects of the present invention are accomplished by providing one or more melt-spinning devices adapted to shape and discharge molten or plastic organic filament-forming. materials into one or more streams, to cool thestreams into solid filaments and thereafter to collect the filaments ina'n orderly form. Each spinning device includes means for shaping the molten or plastic material into streams, such as a spinner'ethaving a suitable number of orifices intheface thereof, and means for collecting the filaments produced. The device includesap'rotective spinning chamber adapted -to. recei,v'e' the'shapedfstr'eams which are directed down are provided for difiusing the gas flow and directing the gas against the shaped streams transversely of the normal extrusion axis and with suflicient force that the streams moving downwardly are caused to assumean arcuate or curved path during their passage through said spinning chamber.

Each spinning device containsa filament, accumulator for gripping filaments being produced that display variations in denier. The accumulator'is positioned. in proximity of the arcuate path and preferably between the shaping means and collecting means and in the area defined by the arcuate path of the filaments and the normal extrusion axis. The accumulator is adapted to collect .irregular filaments at arate such that the filaments are .broken between the accumulator and the collecting means but at a linear rate less than the linear extrusion rate such that the filaments are caused to amass or heap in a conspicuous assemblage interjacent to the shapingmeans and collecting means. The operator of the melt-spinning apparatus upon noticing 'said'assemblage of filaments can .then investigate and correct the cause of the spinning difliculties with a minimum of filaments of non-uniformity of denier being collected .in package form. 1

With reference now to the drawing, Figure l nines: elevational view of a melt-spinning apparatus incorporat -ing one embodiment of. the improvement of the present invention; 1

Figure 2 is a fragmentary sectionalview of part of the apparatus taken along line 2.-2 of Figure l and looking in the direction of the indicating arrows which illustrates the arcuate path of the filaments curving from the ex t'rusio'n'axis; M

Figure 3 is a side elevational view partly in section of the apparatus .taken from the right hand side. of Figurel with the side wall ofthe apparatusremoved for conven- "ience' of illustration and showing the conspicuous accumulation of defectivemeltspun'filaments; and 7 j Figure 4 is a fragmentary side elevational view of part of theapparatus taken from the lefthand side of Figure land showing a specific mounting means for a motor employed in the apparatus of the present invention for powering the filament accumulator. i e

In the drawing reference numeral 10ge'nerally indicates a spinneret assembly which incorporates a spinneret ll throughwhose orifices a molten or plastic filament- "forming polymer is extruded or shaped into a plurality "of filaments 1 25 The molten polymer-is pumped or pro- .pe'lled to the spinneret under-pressure through a' 'conduit 13 f rom a suitable source where the polymer is heated: "to" a molten or plastic condition. The face of" the spinneret preferably'ishorizontally disposed so that the nor- 7 mal extrusion axis extendsvertically'downward. -Upn extrusion the molten polymer assumes the form ofa the cooling zone within chamber 14' and thence to and "through yarn converging guides 16 where the filaments are gathered together in more compact bundles. Thereciprocatably mounted traverse guides 17 adapted to lay the melt-spun filaments on bobbins '18 or the like. suitls'will becoordinated'properly withhtheiextrusion speed so that propermelt-s'pinningisaccomplished.j

L i The spinning hamber- 14 having an open front com prises two solidvertical side walls 22 and 24in spaced apart relationship, a :top panel-:.;26;:,through.which .the 7 ,spinneret assemblyprojects a Short: distance and a bottom air against; them. Accordingly, instead of'being blown a e-res anel 28 provided with openings therein through which the gathered bundles of filaments pass in operation. The back wall of the chamber 14 bridging said side walls 22 and 24 and extending from panel 26 to panel 28 is made of material pervious to gas, such as gauze fabric, felt material, or as illustrated, a fine mesh wire screen 30. The screen will impart a diifused but substantially straight line flow to the cooling gas impelled .therethrough so that the cooling gas contacts laterally the vertically moving streams of'polymer to cool same into solid filaments.

Between the filament bundles 15 and the wire screen 30 there is positioned a filament accumulator adapted to catch the filaments coming into contact .therewith and to entangle same thereon'so that the caught filaments will be accumulated. The movement of the filaments will be so impeded or snubbed by the accumulator that the filaments will break between the accumulator and the fila- 'ment take-up means. The accumulating means illustrated is a rotatably mounted circular brush 32 having projecting bristles adapted to take and retain filaments coming in contact therewith. The brush is mounted on-a shaft 34 having a chuck end 36 keyed to an output shaft 38 of an electric motor 40; The motor is energizedby-suitahle electrical connections, not shown. 'The axis of shaft 34 is perpendicular with-respect to the-extrusion axis. Instead of a bristled brush, as illustrated, other devices composed of wire, steel wool, coarse fibers, etc., set in *a suitable "back or handle maybe used ifdesired, the objective being" to catch and accumulate filaments coming in contact therewith; The peripheralspeed of the brush 32 in operation is control-led to be less than either thetake up speed or the extrusion speed of the filaments.

It will be seen from Figure 2 that in the normal operathe traveling filaments to assume a-bow-shaped or-arcuate configuration;- Thexbrush 32in operation "'s positioned "preferably in the area defined by the arcuate path and the extrusion axis. When for some reason, such as-has jbeen outlined above, a reduction of denier occurs in the filamentsbeing formed, they will no longer billow outwardly and will not follow the arcuate path. In this event the filaments instead will descend directly downward from the spinneret 11 and come intoengagernent w'th thebristles of the brush 32. Since thefilaments are accumulated at a speed less thanthe extrusion speed or v collectionspeed, the filaments consequently will be broken V between the brush and; take-up deviceandwill bcgin to spill along the bottom of chamber 14 and onto the fioor or platform on which the chamber is supported,,as can be seenin Figure 3. As indicated above, the attending f operator upon 1seeing thisfsituati on then cantake the proper steps to obviate the cause of the reduction of the denier ofthefilamentsbeing produced.

after, the bundles of filaments are taken up'in an orderly manner. -As illustrated the takeup {means includes rer 'ably driven to form filameptjpackages 20. in .wi-ll' be appreciated that the speed of filament takeup 9n bobbins I Although it is' not entirely clear why filmaentsof lower denier tend to follow the extrusion axis instead of being pushed outwardly by the horizontal flow of. cooling gas, two possible reasons for this have been advanced. Firstly, filaments of lower denier are finer and somewhat smaller 'indiarneter, and thusoifer less resistance to theflow of outwardly the filaments, will tend to follow apath more *closely. correspondingwith the extrusion axis. Secondly,

result in an increased tension on thefiiaments being'meltspun. 'The increased tension will cause the filaments to I assume -a path approximating the extrusion axis.

=ltf is often advantageous to mount j the brush 32 in such a manner soas to permit easy withdrawal from and horizontal adjustment -\vithinthe spinning chamber 14. To this end the motor4ll is attached toa spacer block 42 and the lower-leaf of a double-leaf hinge 44. The motor, together with the block 42 and the lower leaf of hinge 44, is mounted on a backing plate 46 by the use of securing means 48 and 50 to form a rigid construction. Reference numeral 52 indicates a housing for the bearing supporting the output shaft 38 of the motor 40, which extends through an opening (not shown) within the plate 46 and a corresponding opening 53 in the sidewall 24 of the spinning chamber 14. I I r It will be noted that structurally the hinge articulates around a bolt 54 and is fastened at its top to a horizontally adjustable bracket 56 by means of ,nut andbolt assemblies 58. I A

The supporting bracket 56 att ached to and supported from the sidewall24 byfseeond securing means 60. Elongated slots 62 are provided in bracket 56 to permit horizontal adjustment of the inotor and its associ ated brush in the oval-shaped opening 53 provided in the sidewall 24. With this arrangement the. brush ,32 can be inserted into the spinning chamber 14 or withdrawn therefrom when the brush 32 is connected with motor 40.

From the above description it is apparent that when it is desired to move the brush 32 from the area within the spinning chamber 14, this can be accomplished by pivoting motor 40 upwardly and to the left, whereupon the brush 32 and the brush shaft 34 are led outwardly through opening 53. After cleaning or changing the brush 32 or perhaps cleaning the spinning chamber, the brush may then be reinserted into the spinning chamber by pivoting the hinge-mounted motor 40 downwardly and to the right. V

In the operation of the melt-spinning apparatus as shown the extrusion of the molten or plastic polymer through the spinneret is commenced first during start up. The fans or other gas impelling means situated behind the screen 30 (not shown) are then actuated to cause a flow of gas into compartment 64 through the screen 30 and horizontally through the spinning chamber 14 as shown in Figure 2 by the arrows. The operator then threads the filament ends through the converging guides 16 and traverse guides 17 and onto bobbins 18 to initiate the collection of the filaments thereon. The particular curved path followed by the filaments is a function of extrusion speed, windup speed, cooling gas velocity, etc. Once these variables have been set, then filaments of a particular and predetermined denier are formed and continuously collected on bobbins 18.

With the normal arcuate path of the cooling filament. streams having been established, the motor 40 and the brush 32 are swung downwardly so as to position the brush at a point behind the descending filaments and within the curve of the arcuate path. .The horizontal positioning of the brush is, of course, accomplishedby sideways adjustment of securing means 60 within slots 62. The motor 40 is-energized to start'the rotation of shaft 34. Y a V V When the denier of the filaments becomes reduced, the filaments will tend to move backwardly and come in contact with the rotatingbrush 32 (as explained above) which causes the filaments to be snubbed and broken in their path of travel on the way to the windup bobbins 18. The filaments which are being extruded then begin to spill upon the floor or spinning :platform, ,thereby giving immediate notice to the operator in attendance that a variation in denier has occurred so take necessary corrective measures. r

In the embodiment shown in the drawing the .brush' 32 is positioned in back of the filament bundlesso as to be in a path between the spinneret and the converging guides which path is shorter than the normal arcuate path folthat he ean 6 is longer than the normal arcuate'path and which point lies closer to the open front of the spinning chamber 14. When the filaments billow outwardly too far, they ,will be snubbed in a manner similar to that discussed above. The invention is generally applicable to any substance that can be melt-spun. Specific polymeric materials capable of being mclt-spun include: nylon 66, nylon 6, nylon 4, nylon 610, nylon 11, and their filament-forming copolyrners thereof, e.g., 6/66, 6/610/66," etc.; polyesters derived from terephthalic acid and ethylene glycol and from terephthalic acid-and bis-1,4-(hydroxymethyl) cyclohexane; polyethylene and polypropylene; and other substances.

Hence, there has just been described above a simple, inexpensive, and effective apparatus for detecting variations in denier of melt-spun filaments as they are being produced, which apparatus gives notice of irregularities occurring in the spinning process to the operator in attendance By virtue of this apparatus the collection of filaments of too low a denier is prevented in the early stage of processing; and costly delays and waste' of filamentary material in later stagesare avoided.

Obviously, many modifications and variations of the present invention are possible in the light of the above teaching. It should be understood, therefore, that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. A melt-spinning apparatus for use in the production of filaments from a thermoplastic filament-forming polymer comprising a spinneret for extruding said polymer in a molten condition into streams in a path. extending downwardly along a vertical extrusion line at a predetermined extrusion rate, means for collecting the resulting filaments in package form at a predetermined collection rate positioned below said spinneret, a spinning chamber having a top panel through which said spinneret projects and adapted to receive the streams of polymer immediately upon extrusion thereof, means for directing a cooling gas laterally against said streams of polymer so as to cool same and with sutficient force to cause same to assume an arcuate path curving from said extrusion line, a rotatably mounted brush having bristles projecting therefrom and adapted to take and retain filaments coming in contact therewith, said brush being positioned in the-area defined by said extrusion line and said arcuate path and being adapted to collect said filaments at a rate less than the extrusion rate and, at a rate less than the collection rate when denier reduction occurs in the production thereof, whereby the filaments become broken between said brush and said collecting means and collect in a heap interjacent to said spinneret andbrush when denier reduction occurs. V a

2. A melt-spinning apparatus for, use in the production of filaments from a thermoplastic filament-forming polymer comprising a spinneret for extruding said poly mer in a mo ten condition into streams in a path extending downwardly along a vertical extrusion line at a PIE-1 determined extrusion rate, meansfor collecting the re- 7 sulting filaments in package .form at a predetermined collection rate positioned below said spinneret, a'spinningchamber having a top panel through which said spinneret projects and adapted to receive the streams of polylowed by the blown filaments. Should a variation in physical characteristics of the filaments be anticipated normal, a filament accumulating brush or the like. can an be tis a a a heg' we ,lwi i 0 which causes the filaments to billow outwardly more than i mer immediately upon extrusion thereof, means, for-adi: recting a cooling gas laterally against said streams of polymer. so as to cool same and with sufiicient force to cause same to assumean arcuate path curving from said extiusion line, a rotatably mounted brushj: of circular cross-section having bristles projecting therefromandn adapted to take and retain filaments coming-finicontactl therewith, said brush being positioned in, the, areadefined. y we when l and. r e P t w en a astens" 7 adapted to collect said filaments at a rateless'thaii the extrusion rate and at a rate less than the collection rate when denier reduction occurs in the" production thereof, a motor operatively connected with said brush for impartingrotation thereto, whereby the filaments become broken between said brush and said collecting means and collect in a heap intcrjacent" to said spinneret and said brush-when denier reduction occurs; v

3. A melt-spinning apparatus for use inproduction of filaments from a thermoplastic filament-forming polymer comprising a spinneret for extruding said polymer in a molten condition into streams in-a path extending downwardly along a vertical extrusion line at a predetermined extrusion rate, means for collecting" the resulting filaments in package form at a predetermined collection rate positioned 'belowsaid spinncret, a spinning chamber having-a top panel through whichsaid spinneret projects and adapted to receive the streams of polymer immediately upon extrusion thereof, means foridirectinga cooling gas laterally against said streams of polymer so as to cool same and with sufficientforce' to cause same to assume an arcuate path curving from said extrusion line, a'rotat-ably mounted brush having bristles projecting therefrom and adapted-to take and retain filaments coming in 'contact therewith, said brush being positioned in the area defined by said extrusion line and said arcuate path and being adapted to collect said filaments at a rate less than the extrusionirate and at a'rate less than the collecting rate when denier reduction occurs in the production there of, a motor operatively connected with said brush for imparting rotation thereto, said motor being vpivotally mounted on a side wal of said spinning chamber so as to permit convenient withdrawal of said brush from said chamber while said brush isconnected with said motor, whereby the filaments become broken'between said brush and said collecting means and collect in a heap interjation'occurs. Y

4. A melt-spinning apparatus for use in the producso as tocool same'and with sufficient force to cause same to assume an arcuate path'curving from said extrusion line, a rotatably mounted brush of circular cross-section cent to said spinneret and said brush when denier reducv having bristles projecting therefrom and adapted to take W and retain filaments coming in'contact therewith, said brush extending axially horizontally in the area defined b'y-said extrusion line and said arcuate path andbeing adapted to collect said filaments at a'rate' less than the extrusion rate and at a rate less than the collection ratewhen denier reduction-occurs in thep roduction thereof,

an electrical'motor operatively connected with said brush by means of a drive shaft for imparting rotation thereto,

said motor beingmounted on a bottom and pivotal leaf V of a double-leaffhinge whose upper leaf issecured to a sidewall of said chambervbut mountedto be horizontally adjustable with respect to said sidewall, whereby the'fila-' ments become broken between said brush and said collecting means and collectjin' a heap interjacent toisaid spin neret'and said brush when denierireduction occurs. 5; A melt-spinning apparatus for use in the production of filaments from a thermoplastic filament-forming poly tmer comprising a spinneret for extrudin'gsaid polymer 7 in a-molten'conditionintostreams in a path extending downwardly-along a vertical extrusion line at a prede-f g, g g tcrniined'e'xt'rusionrate meansfor c'ollec'tin g'thei'e'sulting" 75" 2838,879 Schiillbr zontally adjustable withrespect to one of said sidewalls, whereby the filaments become broken between said brush 8 filaments in package form at a-predetermined collection rate positioned below said spinneret, an open" front spinhing chamber having a? top panel through which said spinneret projects" and" adapted to mavens streams of polymer immediately upon extrusion thereof, means for directing a cooling gas laterally against-said-streamsof polymer so as tocool same and with sufficient force vto cause same to assume anarcuate path curving from said extrusion line, a rotatably mounted brush of; circular cr'o'ss-sect'ion' having bristles projecting therefrom and adapted to take and retain" filaments comingin contact therewith, said brush extending axially horizontally in the area defined by said extrusion line and said arcuate path and being adapted to collect saidfilaments at a crate less than the extrusion rate and at a rate less than the collection rate when denier reduction occurs in the production thereof, an electrical. motor operatively connected with said brush by means of a drive'shaft for imparting'rot ation thereto, said motor being mounted on a bottom and pivotal leaf of .a double-leaf hinge whose upper leaf is secured to a sidewall of said chamber'but mounted to be horizontally adjustable with respect to said sidewall, whereby the filaments become broken between said brush and said collecting means and collect in' a heap interjacent to said spinneret and said brush when denier reduction occurs;

6. A melt-spinning apparatus for'use in the produc- V tionoft filaments from a thermoplastic filament-forming polymercomprising a spinneret for-extruding said polymer in'a molten condition and discharging said polymer into streams in a path extending downwardly along a vertical extrusion line at'a predetermined extrusion rate, means for collectingj f'the resulting filaments in package form at a predetermined collection .rate positioned be low said spinneret, an open front spinning chamber defined by a top panel thorughwhich said 'spinneret projects, a bottom panel having an opening axially aligned with said spinneret, two side walls in vertical spaced relation anda back wall briding'said side walls and being pervious to'gas and extending between said panels, said chamber being positioned between said spinneret and said collecting means and ,adapted to i receive therein the streamsof polymer immediately upon extrusion thereof, means for directing a cooling gas through said back 1 wall and la erally against said streams of polymer so as to 'cool same and with sufiicient force to cause same to assumean arcuate path curving from said extrusion line, a rotatably mounted brush of circular cross-section having bristles projecting therefrom and adapted to take and retain" filaments coming in contact therewith, said brush extending axially horizontally into the area defin d by; said ext'r u'sionline and said arcuate pathand being adapted to collect said filaments at a rate less than the extrusion rate and atarate less than the collection rate when denier reduction occurs in the production thereof,

an electrical motor operatively connected with. said brush by means of "a drive shaft for imparting rotation thereto',said motor being mounted on a bottom and pivotal leaf of a double-leaf hinge whose-upper leaf issecured to a sidewall of said chamber but mounted to be horiand. said collecting'means and collect in a heap interjece'nt'tosaid spinneret and said'brush when denier reduction occurs-.-

7. The apparatus defined in claim 6 wherein the collecting means include a driven bobbin and an associated traverse guide. f

References Cited in'zthe file of this. patent" "UNITEIJSTATES PATENIS 2,255,426 a ,Lamesch ee Se t. 9,1941; 535;561"'1 Bastian Dec. 26 ,:19 50' ,711 54 Urbah 11111521; 19,5

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