Note: Descriptions are shown in the official language in which they were submitted.
ROAF~SS ~?~0 APP~`RA~'U~ ~0~' ~.LI' ~ ~ING ~IL.~ S
IN ~nfIC~I ~!,U7~rCF~ GAS TS I~ OJ1UC.T~D ~0 Trll~ FILA~lEl.~rS
~mou~l~ TÆ F~F~ p,r C~ Ill'~D SPIMI`1EI~ET
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The prescnt invention relates to the m~nufac~ure of
melt spun poly~eric filaments and, in particular, to the
quenchin~ Or spun fila~ents emerging from the spinneret. One
aspect of the invention is also concerned with the application
of a finishing liquid to the spun filaments after they h~ve
been quenched.
The manufacture of melt spun polymeric filaments
is typically achieved by extruding a molten polymer, such
as polyester or polye~ide through a spinneret ~nd then cooling
the filaments thus formed. Therebelow, the filaments are
conver~ed and gathered at a guide and delivered to a bobbin or
further treatment station. A finishing l-quid is applied to
the filaments below the quench zone. The finishing liquid may
comprise a substance suitable for imparting a desired property
to the filaments, such as smoothness, drape, lustre, water
repellancy, flame retardancy, or crease resistance, for
exampleO
The manner in which the filaments are cooled has
a significant impact on the resulting quality of the filaments.
A typical cooling technique involves a gas quench in which
cool air is blo~1n across the filaments as they emerge from the
spinneret In instances where the filaments are extruded
in the form of a circular array, it is common to utilize an
outflow auench technique in which the filaments are passed
do~mwardly in surrounding relation to an upwardly extending
air pipe, the latter being arranged generally coincidcnt
with the central axis of the group of filaments. Quench air
is directed radially or laterally outwardly through the
filament group from an upper, apertured end of the pipe, the
- air preferably dispersed by a porous sheathing surrounding
the apertures There is thus produced a controlled cooling
of the filaments. ~or example, see ~S Patents 3 135 811;
3 259 681; 3 858 386; and 3 969 462.
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According to the invention there is provided an
improved apparatus for the manufacture of melt-spun polymeric
filaments, said apparatus being of the type wherein molten
polymer is extruded downwardly through a filter pack and through
an annular array of holes of a spinneret to form a circularly
arranged group of filaments,quenching means for directing
quenching gas across the filaments emerging from said spinneret,
said quenching means comprising gas supply means, gas conduit
means and gas discharge means, and a stationary or rotating
guide therebelow at which all the filaments are gathered and
redirected, said conduit means including yas discharge means
disposed above said guide for discharging quench gas outwardly
through the group of filaments, wherein the improvement com
prises: said gas supply conduit means extending downwardly
through the middle of said pack, whereby polymeric filaments
melt-spun therefrom have reduced birefringence variability.
According to another aspect of the invention there is
provided an apparatus for the manufacture of melt-spun fila-
ments, said apparatus being of the type wherein molten polymer
is extruded downwardly through a filter pack and through an
annular array of holes of a spinneret to form a circularly
arranged group of filaments, quench gas supply conduit means
extending downwardly through said pack and said spinneret
coaxially relative to said row of holes, said conduit means in-
cluding gas discharge means disposed above said guide for dis-
charging quench gas outwardly through the group of filaments,
means for applying a finish substance onto said filaments, and
a guide below said finish applying means for gathering and re-
directing the filaments, the improvement wherein said finish
applying means comprises finish supply conduit means extending
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downwardly through said pack and said spinneret within said
quench gas supply conduit means, said finish supply conduit
means projecting below said gas discharge means coaxially with-
in the group of filaments and including a means for discharging
finish outwardly onto the filaments wherein said finish dis-
charge means disposed above the mid-point of the distance be-
tween said spinneret and said guide.
According to a further aspect of the invention there
is provided in a melt-spinning process of the type wherein
molten polyester polymer is extruded downwardly through a
filter pack and through an annular array of holes of a spinneret
to form a circularly arranged group of filaments, quench gas
is directed across the filaments emerging from the spinneret,
and the filaments are gathered and redirected at a stationary
or rotating guide, the improvement wherein essentially all the
quench gas is delivered downwardly through said pack and
spinneret coaxially relative to and completely within said
array of holes and then redirected and discharged radially out-
wardly through the group of filaments above said guide, thereby
bellowing said filaments radially outwardly and minimizing
quench gas drag and maximizing quench gas flow, and wherein all
said extruded filaments are converged at a common guide, whereby
filament birefringence variability is reduced.
According to a further aspect of the invention there
is provided in a melt-spinning process of the type wherein mol-
ten polyester polymer is extruded downwardly through a filter
pack and through an annular array of holes of a spinneret to
form a circularly arranged group of filaments quench gas is
delivered downwardly through said pack and spinneret coaxially,
relative to said row of holes and then redirected and discharged
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outwardly through the group of filaments, a finish substance is
applied to the filaments, and the filaments are gathered and
redirected at a stationary or rotating guide, the improvement
wherein the finish application comprises the steps of: conducting
the finish substance through said pack and through said
spinneret and at least partly internally of the flow of quench
gas, and discharging the finish substance, in mist form, out
wardly in a low turbulence spray pattern from within the group
of filaments at a level below the discharge of quench gas.
According to a further aspect of the invention there
is provided in a melt-spinning process of the type wherein
molten polyester polymer is extruded downwardly through a filter
pack and through an annular array of holes of a spinneret to
form a circularly arranged group of filaments, quench gas is
directed across the filaments emerging from the spinneret, a
finish substance is applied to the filaments, and the filaments
are gathered and redirected at a stationary or rotating guide,
the improvement wherein essentially all the quench gas is
delivered downwardly through said pack and spinneret coaxially
relative to and completely within said array of holes and then
.~ redirected and discharged radially outwardly through the group
of filaments above said guide, thereby bellowing said filaments
radially outwardly and minimizing quench gas drag and maxim-
izing quench gas flow, and wherein all said extruded filaments
are converged at a common guide, whereby filament birefringence
variability is reduced; and the finish application comprises the
steps of: conducting the finish substance through said pack and
through said spinneret and at least partly internally of the
flow of quench gas, and discharging the finish substance, in
mist form, outwardly in a low turbulence spray pattern from
within the group of filaments at a level below the discharge of
quench gas.
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According to a further aspect of the invention there
is provided an improved apparatus for the manufacture of melt-
spun polymeric filaments, said apparatus being of the type
wherein molten polymer is extruded downwardly through a filter
pack and through an annular array of holes of a spi.nneret to
form a circularly arranged group of filaments, quenching means
for directing quenching gas across the filaments emerging from
said spinneret, said quenching means comprising gas supply
means, gas conduit means and gas discharge means, means for
applying a finish substance onto said filaments and a stationary
or rotating guide therebelow at which all the filaments are
gathered and redirected, said gas conduit means including gas
discharge means disposed above said guide for discharging quench
gas outwardly through the group of filaments, wherein the im-
provement comprises: said gas supply conduit means extending
downwardly through the middle of said pack, whereby polymeric
.. filaments melt-spun therefrom have reduced birefringence
variability; and said finish applying means comprises finish
conduit means extending downwardly through said pack and said
spinneret within said quench gas supply conduit means, said
- finish supply conduit means projecting below said gas discharge
: means coaxially within the group of filaments and including a
means for discharging finish outwardly onto the filaments
wherein said finish discharge means is disposed above the mid-
point of the distance between said spinneret and said guide.
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In drawings which are illustrative of the prior art:
Figure lA is a front view in vertical section of a melt-spinning
apparatus according to the prior art;
Figure lB is a view similar to Figure lA but observed from the side
to illustrate the separation of filaments into bunches;
In Figures lA, lB there is depicted a conventional melt-spinning
apparatus 10 wherein a conventional filter pack 12 carries a conventional
spinneret 14 through which a molten polymer, such as polyester or polyamide
is downwardly extruded to form filaments. The spinneret is of a conventional
10 type comprising holes arranged in an annular pattern so that a group 15 of
circularly arranged filaments 16 is formed. The holes of the spinneret
are preferably arranged in a series of circular rows having a common central
axis. The spun filaments are split into two groups and travel downwardly to
two turning guides 9, or godets or rolls, at which they are gathered and
redirected, in conventional fashion.
The pack 12 is mounted on a conventional superstructure 20, and
the filaments travel downwardly within a cabinet 22 closed at least on three
sides and possibly open at the fourth side for operator monitoring purposes.
Quench gas in the form of air is provided to cool the filaments 16
20 emerging from the spinneret. The quench gas is delivered through an up-
wardly extending quench gas conduit 1 which includes a gas supply portion 2
and a gas discharge portion 3, which comprises a perforated hole pattern to
obtain a required profile. The gas supply portion extends horizontally into
the group of filaments and forms an elbow ~. Openings are provided in the
gas discharge portion to discharge quench air radially outwardly, with the
desired profile, through the surrounding filaments. A porous sheath 5 sur-
rounds the gas discharge portion to uniformly disperse the discharging air.
The upper end of the conduit 1 includes a pin 6 which is received
in an opening oE the spinneret 1~ to prevent lateral displacement of the
cQndu~t ~.
As is apparent from F~gure lB, the filaments 16 are separated
into two bunches 7, 8 to avoid contacting the elbow
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portion of the conauit 1. The separate filament bunches
are gatile~ d and redirected at a pair of turning guides 9.
In operation, quench air is delivered via the
conduit 1 and is discharged radially outwardly from within
the group of fil~ments emerging from the spinneret. The
quenched filaments are separated into bunclles 7,8 and are
gathered and redirected at the guides 9 for collection, or
further treatment.
It will be appreciated that -the conduit 1 is often
of substantial height,thereby increasing the overall height
of the machine and rendering it difficult to maintain the
conduit in alignment ~rith the longitudinal axis dcfined by
the filament group. This arrangement also renders it difficult
to maintain constant the distanoe from the spinneret to the
uppermost quench air stream. Air gaps 16A are formed between
the filament bunches 7, 8 which gaps promote undesirable air
turbulence. To limit the ability of the filaments to contact
the elbow, the diameter of the conduit 1 is minimized, but
this restricts the quantity of air flow that can be conducted
and also increases the pressure drop.
As previously indicated, the lower portion of the air
pipe forms an elbow and passes horizontally -through the group
of filaments above the turning guide. In order to prevent
the do~mwardly converging group of filzments from rubbing
against the elbow, the pipe diameter is minimized and the
filament group is divided into two buncles, each bundle fed to
a separate turning guide, as depicted herein in ~igure 1B for
example.
~he miDimization of the air pipe diameter at low
30 pressures below 0.3515 Kg/cm2 results in the quantity of air flow
being less than that normally desired for optimum cooling
performance. In addition, enlarged air gaps are formed between
thè separated bundles, which gaps promote air turbulence, non
uniform quenching of the filaments, and increased drag action
on the filaments. Also, the extra handling of the filaments
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increases the overall ~ear ~nd tear to which thcy are subjected.
As regards the air pipe itself, the elbow must be
placed at a level sufficiently below the quench zone to
allow the filamcnts to be effectively divided into separate
blmdles. This results in 2 relatively long air pipe height
which increases the overall machine hei~ht and renders it
difficult to maintain the pipe aligned with the central axis
of the filament group to assure that uniform quenching action
is achieved.
18 It will be understood that the vertical distance
~etwcen the extrusion holes of the spinneret and the uppermost
stream of cooling air is of critical importance regarding
the quality of filaments being produced. It is thus required
that a predetermined distance be maintained at all times, a
feat not easily accomplished with an air pipe of relatively
great height t~hich is anchored somewhere at its lower end
remote from the spinneret.
It will also be appreciated that the splitting of
the filament 6roup into bundles considerably limits the
available free area around the filament travel path and
thus restric-ts the operator~s access.
~ he application of finishing liquid has heretofore
been accomplished, for exam~le, by means of a stationary
applicator within which the filamentæ are gathered. ~inishing
fluid is caused to flow across the applicator surface and
onto the gathered filaments. Another technique involves spraying
the finishing liquid onto the filaments which have been ~athered
at the turning guide. It will be appreciated that the quality of
the filaments produced is affected by the uniformity of
;~ 30 application of the finishing liquid. The application of the
liquid to the fllaments ~rhen the latter are in a gathered or
bunched-up condition is difficult to achieve with the desired
uniformity.
According to the present invention we provide a melt-
spinning process in which molten polymer is extruded do~mwardly
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throu~h a ~ibre pack and through an annular array of holesin a spinneret to form a circularly alranged group of
filaments, quench gas is directed across the filamcnts
emcrging from the spinneret 7 and the filaments are gathered
and redirectcd at a stationary or rotating guide, characterised
in that quench gas is delivered downwardly through the pack
and spi.nneret coa~ially relative to the array of holes ~d
then redirected outwardly throu~l the group of fil~Dents above
the g~ide.
According to one aspect of such a melt-spinning
process a inish subst~nce is applied to the fi]aments, the
finish substance having been conducted through the pack and
through the spinneret and at least partly internally of the flow
of quench gas and being discharged outwardly from within
the group of filaments at a level below the discharge of quench
gas.
We also provide an apparatus for the manufacture of
melt-spun filc~ments in which molten polymer is extruded
do~mwardly tllrough a fibre pack and t~OU~I an annular array
of holes in a spi.nneret to form a circularly arranged group of
; filaments, the apparatus including quenching means for
directing quenching gas across the filaments emerging from the
spinneret and a stationary or rota~ing guide therebelow at which
the filaments are gathered and redirected, characterised in that
Wle quenching means co~prises a gas supply conduit extending
downwardly through the pack and the spinneret being positioned
coaxially relative to the array of holes, the conduut including
gas discharge means disposed above the guide for discharging
quench gas out-.;ardly through the group of filaments.
. 30 According to one aspect of the apparatus, a means isprovided for applying a finish substance on to the filaments,
such finish applying means comprising a finish supply conduit
extending do~m~lardly through the pack and the spinneret within
the quench gas supply conduit, the finish supply conduit
projecting below the gas discharge means coaxially within the
group of filaments and including a means for discharginæ finish
on to the filaments.
The objects and advantages of the invention will become apparent
from the following detailed description of preferred embodiments thereof
in connection with the accompanying drawings in which like numerals desig-
nate like elements, and in which:
Figure 2 is a vertical sectional view through a melt-spinning
apparatus according to the present invention.
Figure 3 is a vertical sectional view through a modified melt-
spinning apparatus according to the present invention including means for
applying a finish substance on to the filaments.
An apparatus according to this invention is depicted in Figure 2.
Quench gas is delivered by a quenching conduit 24 which includes a gas
supply portion 26 and a gas discharge portion 28. The gas supply portion
26 extends downwardly through the pack 12 and spinneret 14 in coaxial
relationship with the axis defined by the circular arrays of spinneret holes.
Thus, in contrast to the prior art, the presence of an elbow below the
quench is eliminated.
The gas discharge portion 28 is disposed immediately below the
spinneret 14 and includes a plurality of outlet openings for discharging
the quench air laterally outwardly with the desired profile, through the
surrounding filaments 16. It will, of course, be appreciated that the hole
arrangement for a given profile with this invention is necessarily different
from the hole arrangement of the prior art. Preferably, a sheath of porous
foam 30 surrounds the conduit discharge portion to uniformly disperse the
quench air. A collar 31 may be located on the conduit 24 to position the
sheath.
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It ~Jill be appreciated that quench air passes throu~h
the filaments, bcllowing them radially outuardly.
~ he section of the gas supply portion 26 extending
throu~l the pack 12 is preferably surrounded by an air gap
5 32 to ~inimize heat exchange be-tween the quench gas and
molten polymer within the pack 12. Alternatively, or in
addition, that section of the gas supply portion 26 could be
covercd with thermal insulation.
The gas supply conduit 2~ includes a fixed stop collar
10 34 ~hich rests upon a stop shoulder 36 on the pack to support
the supply conduit 24 and fixedly locate the latter relative
to thc spinneret. In this fashion, the spati~l relationship
be-tween the spinneret holes and the uppermost s-tream of quench
~as is maintained constant, to achieve uniformity of the
15 quenchin2 action and reduce birefringence variance in the
ilaments produced. These improvements occur within and
between melt-spinning positions.
; ~xtending downwar~ly from the lower end of the
discharge portion 28 of the conduit is a gas streamlining
20 member 38 in the form of a do-.rnwardly converging cone. The
ccne occupies a considerable portion of the space bounded
by the converging filaments 16. Air normally drawn do-mwardly
- by the rapidly travelling filaments is constrained by the cone
to f]o~r in a smoother non-turbulent fashion to minimi~e
undesired vibration of the filaments. The cone 38 can be
secured to the lower end of the conduit 28 in any suitable
ma~ner, preferably in a releasable manner, such as by scre~!s,
bayonet coupling, etc.
It i9 preferably that -the diameter defined by the
innermost circular row of holes in the spinneret be at least
5" to allow sufficient room for the gas supply conduit 26
to pass therethrou~h. Smaller diameters could be employed,
but the gas conduit would then probably be smaller than needed
to conduct an optimwn gas flow quantity.
If desired, a finishing liquid may be applied in a
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con~entionc~l m~nner to the fila~ents in the vicinity of a
con~entional stationary or rotating ~uide 46 at .hich the fil~cnts are gathered and redirectedq
The apparatus depicted in ~igure 3 is similar to tllat
depicted in ~igare 2 apart from certain modifications which
are no~ described.
: ~xtendi.n~ downwardly throu~ the quench conduit
24 and through the air strec~ining cone 38 is a fini~h supply
condui-t 40 which conducts a suitable finishing liquid. ~he
louer end of conduit 40 projects beyond the bottom of the cone
38 and carried a spray noæzle 42. The spray nozz].e 42 is fixed
by a collar 44 ~ld is oriented -to spray the finish liquid, in
~ist foxm, in a do~rn~ard and laterally outward direction, so
that the liauid passe; out~ardly througln the group of filaments
16 after the latter have been quenched.
It ~ill be mderstood that the location of 'che spray
nozzle relatively close to the quench zone and high above the
usual guide 46, or godet or roll, adv~ltageou~sly affects the
uniformity of the finish application. At such location the
filaments arc not gathered too closely together to i.nhibit a lmiform
travel of the finish substance, and are spaced sufficiently near
the centr21 axis of the group to reccive a concentrated quan`cit.y
of the sprayed finish~
The presence of the streamlinin~ cone 38 aids in
smoothi.ng-out the flow of air in the ViCillity of the nozzle,
thereby minimizing undesired turbulent s-~irling actions ~hich
could adversely affect the spraying action.
As a result, the filaments receive a subst2ntially
uniform application of the finish substance.
Spraying of the finishi.ng substance through the filaments
hile they are in a separated condition aids not only in
achieving a uniorm application of finish but also in au~mcnting
the filament cooling step because the finish substance is typically
at a lower temperature than are the filaments at the disclosed
region of finish application.
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~y locating the finish supply conduit within the
quench ~as conduit 24, the finish application can be
achievcd without reducing access space within the
cabinct 22 a~ld without inhibiting the travel of the filamcnts.
In operation, the filaments 16 are formed in circular
arrays in conventional fashion. Quench air is conducted
do~lwardly throu~h the pac~ 12 via the conduit 24 and
discharged radi~lly outwardly throu~h the group of filaments
to cool -the latter. Air currents immediate]y below the conduit
24 care guided in streamlined fashioll by the streamlining cone
38 toward the finish spray nozzle 42. Finish substance is
sprayed outwardly from the nozzle and uniformly covers the
cooled, still separated filaments 16. The smooth air flo~r
established by the ccne achieves a low turbulence spray pattern
to the filaments. Application of the finish spray also aids
in further coo]ing-down the filaments. Thereafter, the
filaments are gathered and redirected at the guide 46.
It will be appreciated that the application of
finish spray from within -the filament group and at a level
above the midpoint of the distance between the spi~lcret and
the tu~ning ~uide promotes a uniformity of the application
because of the proximity of the filaments to the longitudinal
axis and the still~separated condition of the filam~nts relative
to one another. The air strea~1ining cone minimizcs turbulence in
the spray pattern to aid in achievin~ such uniformity. There
is also achieved a final cooling of tho filaments.
~y conducting the finish substance throu~h the quench
gas conduit, operator accessibility within the cabinet
is not affected and no hindrance to filament travel is produced.
It will be appreciated that the present invention
eliminates the need for an elbow in the quench gas supply
conduit below the quench zone, and thercby eliminates the
need for dividing the filaments into separate bundles. As
a result, it is generc~lly unnecessary to restrict the size
of the gas supply conduit and thus an optimum amount of qucnch
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gas flow can be provided. Since it is unnccessary to provide
a quenching gas conduit of substantial height below the
spil~leret, the overall machine height i5 reduced, and it
is also easier to ali~n the quench conduit with the axis
of the filament ~roup.
~ ec~use the quench gas conduit is mounted on the
pack, a constant unifoIm distance between the spinneret
]loles and -the uppermost quench air stream may easily be
maintained, thereby assuring uniform quality and minimal
birefrin~ence variability of filaments produced.
The filaments are not subjec-ted to extra wear ~nd
tear by rubbillg against unlubricated surfaces such as quench
elbows. Also, since the filaments need no longer be
sep~ated into blmdles, air ~aps previously forme-l between
the bundles, ana which promoted air turbulence around the
fila~ents, no lon~er exist. Turbulence i~ further reduced
by the presence of the streamlining cone which extends below
the outlet of the quench gas duct.
Althoug~h the invention has been described in connection
with preferred embodiments thereof, it will be appreciated by
those skilled in the art that additions, subs-titutions,
modificatiorls, and deletions not specifically described may be
made without departin~ from the spirit or scope of the invention
as defined in the appellded claims.
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