Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
-1- 14-~4(8091)
EASILY SPLITTABLE SELF-T~XTURING CONJUGA~E YAR~I
=
SPECI~ICATION
The inv0ntion relate~ to the ~rt of melt-
spinning splittable conjugate filaments. More
particularly it relates to ~plnning filaments which are
more readily splittable and ~hich have improved dyeing
propertie~.
It 19 kno~n to spin ~plittable conjugate
filament~ by merging side-by-side a plurality of sub-
~tream~ of incompatible polymer~ into a combined orconjugated stream within the ~pinneret9 the combined
stream flo~ing along the spinneret capillary for several
thou3andth3 of an inch, e.~., 0.012 inch (0.305 mm.).
The combinsd ~tream is then quenched to form a ~pun
conjugate filament. The 8pun conjugate filament i 8 then
typically hot drawn or draw-textured. The resulting
drawn conjugate filament can be vigorously treated
~ith chemicsls or mechanically worked, or both, 90 as to
split the conjugate filament into sub-filaments, each of
which is composed o~ one of the incompatible polymers.
Typical references in this area are ~anner U. S.
3,181,224, Tann~r U. S. 3,418,200, and Ni~hida U. S.
. 4,073,988. The required vigorou0ness of treatment of
the filamont (or of a fabric containing the filament) is
disadvantageou 9 because the hot drawing step reduces the
dyesbility of the filament, becau~e of the added cost of
the step of working th~ fabric, and because of po~sible
damaga to the fabric. If chemical treatment is
involved, there i8 1093 of fiber polymer in ~ome cases
and the added problem of disposal and handling of the
chemical 8 involved 80 a 3 to avoid environmental
pollution.
hccording to the invantion, these and other
disadvantage3 in the prior art are avoided by a novel
~odification of the 3pinning process providin~ an
~z~
-2- 14-54(8091~
improved yarn with increa~ed productivity and reduced
manufacturing cost.
According to a first principal aspect of the
invention, there i~ provided a process for melt-~pinning
an easily splittable deep-dyeing conjugate filament from
flrst and Recond incompatible polymers, the yarn being
self te~turing in fabric ~orm, comprising ~enerating a
first molten sub-stream of the first polymer and a
second molten sub-3tream of the ~econd polymer
converging at substantially the s~ma apeed to merga
~ide-by-side as a combined stream below thç face of a
spinneret, quenching the combined ~tream to form a
con~ugat~ filament compri~ing a first sub filament of
the first polymer lightly conjugated side-by-~ide ~ith a
~econd sub-filament of the second polymer, ~ithdrawing
the filament from the combined stream at a predetermined
spinning spesd, and winding the filament at a given
~inding speed on a bobbin, the polymers and the spin~ing
speed being selected such that the filament on the
bobbin splits substantially completely into the
~ub-filaments upon exposure to boiling water while under
no tension. ~he first sub-~tream is preferably a
polyamide (preferably nylon 66) and the second
~ub-stre~m is preferably a polye~ter (preferably
poly( thylene terephthalate)). The spinning speed i3
advantageously at lea~t 2200 MPM and the filament
shrinkage i9 prefer&bly at least 10% (advantageously at
least 20%). Preferably the filament i~ drawn prior to
being wound on the bobbin. Th0 winding ~pead and the
amount by which the filament i9 drawn ars adv~ntagaously
selected ~uch that the filament wound on tha bobbin has
an elongation less than 70%, with be~t re~ults being
obtained when the ~indinB speed and the amount by ~hich
the filament is drawn are selected such that the
fila~ent ~ound on the bobbin haq an elongation less than
50%.
~2~i~
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According to a second principal aspect of ths
inventlon, there i~ provided a yarn package haYing ~ound
thereon a substantially constant denier deep-dyeing
conjugRte filament comprising thermopla9tic incom~atible
sub-filaments temporarlly adherln~ ~ide-by-3ide alon~
the length o~ the conju~ate filament, the Adhesion
betwesn the sub-filAments being 3ufficiently light that
the conju~ate filament splits sub3tantial1y completely
into the sub-filaments upon exposure to boiling ~ater
while under no tension. One of the 3ub-filaments i~
prefarably nylon 66 and the other of the sub-filament~
i 3 preferably poly(ethylene terephthalate). The
filament preferably ha~ a ~hrinka~e greater than 10%,
and advantageou~ly the shrinkage i9 greater than 20%.
The filament preferably has an elongation less than 70%,
and especially preferred i~ an elongation less than 50g.
According to a third principal aspect of the
inventiGn, there i8 provided a proce~s for melt spinning
an easily splittable deep-dyein~ conjugste filament from
~irst and second incompatible polymers, the yarn being
self-texturing in fabric form, comprising generating a
first molten sub-stream of the first polymer and a
aacond ~olten sub-stream oY the ~econd polymer
converging at substantially different speed 9 to merge
side-by-side as a combined 3tream below the face of a
~pinneret whereby an oscillation of the sub-streams
occurs just below the face of the spinneret, quenching
the combined stream to form a conjugate filament
comprising a firat sub-filament of the first polymer
liæhtly conjugated ~lde-by-6ide ~ith a ~econd
~ub-filament of the second polymer, withdrawing the
filament from the combined st~eam at a predetermined
spinnin~ speed, a~d winding the filament at a eiven
~inding speed on a bobbin, the polymer and the spinning
speed being selected such that the filament on the
.
. ,~
~235~
_~_ 14-54(8091)
bobbin split~ substantially completely into the
~ub-filal~ents upon exposure to boiling ~ater while under
no tension. The fir~t sub-stream is preferably a
polyamide (preferably nylon 66) and the second
~ub-stream i 8 preferably a polye~ter (prefer~bly
poly(ethylene terephthalate)). The spinning speed is
advantageously at least 2200 MPM and preferably the
filament ~hrinkage i~ ~raater than 1Q% (advantageously
greater than 20%)o The filamsnt i9 preferably draw~
prior to being ~ound on the bobbin. The ~inding speed
. and the amount by which the filament is drawn are
advantageously selected such that the filament wound on
the bobbin has an elongation less than 70d, with best
re~ults being obt~ined when the winding speed and th~
amount by ~hich the filament i~ dra~n are selected such
that the filament wound on the bobbin has an elongation
le~ than 50~.
According to a fourth principal aspect of the
invention, there is provided a yarn package having ~ound
thereon a substantially variable denier deep-dyein3
conju~ate filamant comp~ising thermoplastic incom~atiblesub-
filaments temporarily adhering 3ide-by-side along the
length of th~ conjugate filament, the adhesion between
the sub-filaments being ~ufficiently light that the
conjugate filament splits ~ubstantially completely into
the sub-filament~ upon exposure to boilin3 water while
under no tension. One of the ~ub-filament~ is
preferably nylon 66 and the other of the sub-filaments
i~ preferably poly(ethylene terephthalate~. The
filament prefarably has a shrlnkage greater thAn tO%,
and advantageously the ~hrinkaBe i B greater than 20%.
The ~ilPment preferably hae an elon~ation less than 7Q%,
and e~pecially preferred i8 an eloneation le99 than 50%.
Other a~pects will in part appear hereinafter
and ~ill in part bo obvious from the Iollowing detailed
de~cription taken together ~ith the accompanyine draw-
ing, ~herein:
~35)~
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~ I~UR~ a vertical elevational schematic of
a ~pinnine app~ratus u~able according to the invention;
FIGU~B 2 i~ a graph qualitativaly ahowing ho~
tha ~hrinkage of PET and nylon 66 Yary ~ith spinning
spesd;
FI¢U~ a vertical sectional view o~ a
epinneret showing a co~bined ori~ice according to
certain aspects of the invention;
~ I~U~ 4 i 8 a bottom plan vieu of the ~IGUR~ 3
~pinneret;
J~GU~ 5 i8 a ~ectio~al view of a ~ ent
according to the i~vention;
FIGURE 6 is a ~hematic eleYation view 3howing
the oscillAtion o~ the molten streams ~U9t below the
face of the ~pinnaret; and
FIGURE 7 i~ a graph ~howing qualitatively the
oscillation frequencies of a plurality of combined
~rifice 8 in the ~ame spinneret.
A~ shown in FIGUR~S 1, 3, 4, and 6, fir~t and
second polymers are con~ugately melt spun as molt~n
stream~ from ~pinncret 20. Molten ~treams 22 are
quenched into filaments 24 by tran varsa quench air in
quench ch~mber 26. The fil~ment~ are converged into
yarn 27, w$th conventional ~pin fini~h applied at 28,
the filhment~ being ~ithdra~n from tha molta~ atre~ms at
a ~pinning spaed detarmined by unheatsd godet 30. The
yarn ne2t pa 88e ~ over unhaated godet 32 prior to being
~ound onto a package by winder ~4. Godet 32 preferably
i~ driven ~t laa~t ~lightly fa~ter tha~ godet 30, and it
i 8 particularly ~referrad that ~od~t 32 be dri~sn at a
~ignificantly hi~her ~peed qo as to apply a dra~ to the
filament~. The fila~ents may be entangled by
conventional tangle chamber 36. While godets are
praferred, godetle~s spinning i~ in accord with certain
a~pect~ of the i~ventio~, in ~hich case the spinning
3paed ~ill b~ determined by the winder. It i~ preferrad
that the ~odst~ be unheated $f god~t~ ara usad.
-6~ 54(8091)
As sho~n in PIOUR~S 3 a~d ~, the prefs~red
spinneret construction haa counterbores ~a and 40 formed
in the upper sur~ace of spinneret 20. Capillar~ ~2
~xtends ~rom the botto~ of co~nterbore ~8 to bottom Pace
44 o~ spi~nerst 20, ~hile oapillar~ 46 extends frs~ th~
bottom of counterbora 40 to faoe 4~. Capillarles 42 and
~6 are ~eparated by land ~8 on ~ace 4~,and their a~e8
form an included angle 80 that the molten polymer
~tream~ metered therethrough converge to merge Qide-by-
side belo~ spinnaret face ~ a~ a comblnsd ~tream. The
combined ~treRm i8 conventionally quenched (as b7
tran ~er~ely moving air) into a conjugate fllament which
i3 ~ithdrawn ~rom the combined stream at the predeter-
mined spinning speed set by godet ~0. The ~pinning
~pe0d i~ muoh highar than the speed of any o~ the ~olten
sub-stream~, 80 that tha co~bin~d str~sm i8 attenuatad
~ubstantially aa it i~ bein~ quenched. Since the psir
o~ capillarie~ 42 and 46 coop~ratc to form a si~gle
combined stream, and ultimately a single Pilament, they
are collectively referr~d ~o herein as a combined
oriPice.
E~AMPL~ I
This i 8 an e~smple ~herein the yarn ha 8
constant deniqr. A 3pin~eret i~ provided contsinin~ 18
¢ombined orifice~, each combined orifice being as
di~clo~ed in thls e~ample. Thu~ the 0pinneret produces
t8 eonJugate ~ilaments. Wlthin each combined orifice,
cspillarics 42 a~d ~6 have dia~etcrQ of 0.009 inch (0.23
m~.) and ar~ 0.1 inch lon~ (2.54 amO). Ths a~is of
each capillary i9 incllned 12 Prom the vertical, and
thus the ase~ ~ithin a combined orifico Por~ an included
a~gl~ o~ 24. Land ~3 saparatlng capillarie~ 42 and 46
on f~ce ~4 ha~ a ~ldth o~ Q.017 inGh ~0.4~ mm.).
Whil~ thic paragraph ~or ~implicity refers
only to ~pinning of a ~in~l~ filament from a single
~æ~s~
-7- 14-54(80gt)
com~ined orifice, it ~ill be undar~tood that the ~s~e
de~cription applie~ to each o~ the sther combined
orifice~ in the spinneret. Moltan nylon 66 polymer of
normal ~olacular ~eight for appsrel end use i 3 meterod
and e~truded as a ~irst ~ub-~tream through capillary 42,
whlle molt0n poly(ethylene ter2phthalate) polgmer of
normal ~olecular weight for apparel end uae 1~ metered
through capillary 4S to form a 02cond sub-~trea~. The
polymer melt temperatures are 285C. Tha resultine
combinad ~traa~ $8 con~entionally quenched into a
oon~ugate filament by transYersely directed air havin~
an avsrage speed of about 15~20 meters per minute, and
the filament i8 withdra~n from the co~bined stream at a
~pinning speed oP 3795 meter~ per minute (MPM). The
pol~mer meterinB rata 8 are ~elected such that equal
volumes Or polymer are extruded through capillarie~ 42
and 46 per unit o~ time, and ~uch that ths conjugate
fila~ent ha~ a denier of 3.87. A con~entional spin-
finish i8 applied prior to ~indine at normal ~inding
tension of about 0.1 gram per denier. The multi-
~ilament conjugate ~arn thu~ produced according to the
invention comprlseo ther~opla~tic (nylon and polyester)
sub-~ilaments temporarily adhering ~ide-by side along
the length of the Qon~u~Ate filamento. ~he adhesion
bet~een ~ub-~ile~ent~ i8 ~uf~icient that the filament
(or ~ yarn compri~in~ a plurality of ~uch filaments) can
be h~ndled normally in sueh oparations ao te~turing,
knitting or weaving without difficulty, yat i 3
~u~ficiently light or wesk as to readily be o~ercome
~h~n the conju~ate ~llament i8 e~posed to boiling ~ater,
as i~ the nor~al scourine and dyelng operation~ employed
i~ proGasoing o~ fabric~. Under ~uch condition3, the
con~ugate fila~snt ~pontaneously and oubstRntially
completely 3plit8 into it~ con~tituent ~ub-filaments,
thu~ avoiding the n~e89ity for vigorou~ly working tha
'~3~
-8- 14-54(80g1)
~abric to ~chieve splitting as is nece~ary with prior
art oplittabls conjug~te filament~. Ordinarily no added
~tsp of working o~ the fabric i8 nece~sar~ ~ith
Pilament~ and yarns accordlng to tha present invsntion.
The ~arn i8 woven as filling across a
conventional warp9 then con~entionally scoured and dyed
at the boil. The filling filaments split substantially
completely into their constituent sub-filament3
spontaneously upon contact ~ith the boiling water with
the PET sub-filament~ ~hrinking most and forcing the
nylon 3ub-filsment3 to protrude from the 2urface of the
fabric in loopa or arches. The fabric dyes more deepl~
than fabrics made from yarn~ which have been hot dra~n.
A po~sible partial explanation for the unusual
behavior of the yarns of the invention may be had with
reference to FIaUR~ 2 of the dra~inB. As generally
~ho~n therein, the shrinkage of a 100% PET yarn falls
rapidly from ~ery high value 8 of about 50-70% at
intermediate spinning ~peeds to value 8 below 10% over a
fairly narro~ range of somewhat higher spinnine speeds,
while the shrinkage of nylon 66 does not exhibit such
behavior. ~he e~act spinning speed range in which
polyester yarn e~hibits the l~rge change in shrink&ge
~ith 0pinning speed ~ill vary Nith capillary diameter
(jet stretch). Yarn~ according to the invention may be
made to be ~elf-texturing i~ fabric form by selection o~
the spinning speed such that the PET sub-filament has
subotantially higher ~hrinkage than the nylon 66
~ub-fila~ent, a~ in the E~ample I yarn aboYe. When such
yarns are put in fabrie ~orm, then subjected to the
cuatomary 3courin3 and dyeing operations, the filaments
Rplit into th2ir constituent sub-filament~ ~ith the PET
~ubfilame~t~ then shrinking sub~tantially more than ths
nylon subfilament~. This forces the nylon subfilaments
to th~ Rurface of the fabrio in protrudin~ arches or
3~
-9- 14-54t8091)
loop~, eiving tsxture to the fabric. When the filaments
have ~ub~tantially con~tant denier as in Example~ I and
II herein, be~t ~elf-texturing effects are obtainad ~h~n
the yarn ~n the bobbin has a shrinkage of at least 10%,
preferably at lea~t 20%.
Additional runs are made at different ~pinning
cpeeds with the polymer metering rates adjusted to
provide about 40 yarn denier, with re~ult~ as follo~a.
TABLE 1
__
Godet ~0 Godet ~2 Elongation, Shrinkaee~
Item MP~ MPM % %
~700 3700 94 48
2 4000 4000 86 3 5
3 4250 4250 75 24
lS 4 ~500 4500 73 9
~ he re~ulting yarn~ are woven as filling across
oonventional warps, with the re~ulting fabrics
conventio~ally ~coured and dyed at the boil. The
filAments ~plit 3ubstanti~11y completely into the
~ub-filaments and pro~ide pleaeing texture to the
fabrice. Ho~ever, the fabric from Item 4 ha~ noticeably
less texture than the fabric~ from the other items.
E~am~le II
A series of runs are made using the same
~pinneret and polymar~. Tha poly~er m~tering rate 8 arg
reduced to produce sbout 40 yarn danier (about 2.2 d~nier
p~r filament) ~hile ~aintaininB equal Yolume~ of nylon
and polye~ter. In each run, the actual ~indin~ speed i~
slightly lower than the ~peed o~ godet 32 in order to
ad~ust the ~inding ten~ion to about 0.1 gram per denier.
Godet speeds and yarn propertie~ are a ~ 8et forth in
T~ble 2.
~L%;~ 8
-10- 14-54(8091)
TA~LE 2
Godet 32, Godet ~0, Elongation, Shrinkage,
Item MP~ ~P~ _% %
1 400~ 36~0 76 53
2 4000 3000 74 61
3 ~500 3600 66 5~
4500 3400 63 57
4500 3200 58 60
6 4500 3000 5~ 62
lO 7 5000 3600 48 51
8 5000 3400 49 54
9. 5000 3200 49 55
5000 ~000 ~5 ~6
The yarn~ of Table 2 are sup~rior to that of
Example I above, particularly in term~ of dye-fa3tnes~ of
the nylon co~ponent with respect to di~perse dye~. A
~mall amount of dra~ in conjunction with high Qpeed
spinning i~ highly desirable in this regard. Within the
~able 2 yarns, item~ 5 and 6 are more desirAble than
lte~ 4, ~hile items 7-10 are still further improved.
Superior re 8ul t 8 are obtained when a ~mall
amount of in-line dra~ i 9 applied a~ in this example. It
i~ b0lieved that the more viscous PET ~ub-atream bears
most of the stress of the high speed spinnine, pr~venting
25 the nylon ~ub-stream fro~ receiving ~ufficient RtresQ for
proper orientation of the molecules if the solidifisd
~ nt i9 not dr~n prior to winding. After the
filament has solidiflsd, ho~ever, a ~mall amount o~ dra~
appliod be~ore ~indin~ orients the nylon enough ~or
dye-faAtne~. It ia ~urther believad that if the
~pin~in~ speed ~sre su~ficiently hi~h that the yarn would
havo a shrinkage b~low 10% or 80, a ~mall a~aunt o~ dra~
~ould increa~e tha PET shrinkage ~hile not greatly
affecting that of the nylon~ thus providing the large
35 shrinkage difference bet~een the nylon and polyester
~3S~;8
-11- 14-54(8091)
components necessary for the self-te~turing effect in
fabric form.
EXAMP~E III
.
In contrA~t to the constant denier filsments
produced in E~ample I snd II, a variable denier fil~ment
i3 readily produced by merging sub-streams e~truded at
aubstantially di~ferent speed~, producing an oscillation
o~ tha sub-stream~ just below t~e spinneret. ~hi~ i~
preferably done by use of the ~ICUR~S 3 and 4 type of
combined orifice. The axes of capillaries 42 and 46 are
each lnclined 4 from the verticalO The axe3 thus form
a~ included angle of 8 , and capillaries 42 and 46 are
separated by land 48 o~ face 44. Capillary 42 haa a
diameter of 0.009 inch (0.23 mm~) and a length of 0.032
inch (0.81 mm.) while capillary 46 has a diameter of
0.016 inch (0.41 mm.) and a leneth of 0.146 inch (3.71
mm.). Land 48 has a ~idth Or 0.004 inch (0.1 mm.).
The sAme polymer~ are u~ed as in Example I
abo~e, and the spinneret contains 18 combined orifice as
described in the preceding paragraph. The polymer
temperatures are each 282C~, ~ith the polyester being
e~truded through cApillarie 8 42 and the nylon throu~h
capillaries 46. The metering rates are sel~cted ~uch
that the polyester/nylon ratio is 60/40 by volu~eg and
the resulting 18 filament yarn has a total denier of
41.1. The ~pinning speed is 3658 ~PN and the molten
stream~ are quenched and ginished prior to ~inding, as in
E~ampla I.
~he yarn i~ woven aR filling across ~
con~entional warp, then conventionally ~coured and dyed
Rt the boil. The filling rilaments split ~ubstantially
completely into their con~tituent ~ub-rilaments
spont~sneously upon contact with the boiling ~ater and
provide fabric te~ture, a~ do the filaments in E~ample I
above. Again, the polyester sub-filament has the higher
:~3~
-12- 14-54(8091)
~hrinkage, forcing the nylon sub-filaments to the surface
of the y~rn. Yarn3 accordine to thi~ example give in
~abric form various noYelty sffects not svailable ~ith
tha Exa~ple I yarn~ A~ ~ith the Example II yarn aboYe,
an ln-line dra~ (prior to winding) i~ exp0ct~d to
lncrease the crimp level and improve the dye atability of
the nylon sub-filaments to disper~e dyes.
Yarn shrinkage i8 determined by tha followin~
method. The bobbin i~ conditioned at 21 C and 65%
relative humidity for one day prior to te~ting. 100
meters of surfac2 yarn are atripped off and discarded.
Using a Suter denier reel or equivalent, the yarn i 3
wound to form a skein having about 18,000 sksin denier.
Thst is, tha denier reel revolutions are 9000 divided by
the yarn denier. The ~ein yarn end B are tied together.
Ths skein i~ s~spended from a rod having a diameter of
one centimet~r and a 1000 gram ~eight i~ attached to the
bottom of the ~kein. After 30 aeconds, the skein length
is measured to provide length Ll. The 1000 gram weight
i~ then r~placed by a 50 gram ~eight, whereupon the rod
with s~ein and 50 gram wei~ht are placed in a vigorously
boiling ~ater bath sufficiently deep that the skein i8
unde~ tension from the 50 gram weight. After 10 minutes
in the boiling ~ater bath, the rod ~ith qkein and the 50
gram Neight ars removed from the bath and hung up for
three minutes to pe~mit excess ~ater to drain off. Tha
rod ~ith ~kein and s~spended 50 gram ~eight are then
piaoed in a 120C oven for 15 minutes, after ~hich the
rod ~ith ~kein and suapanded 50 gram weight are removed
from the oven and hung for 15 minutes at room
temperature. The ~uspanded 50 gram weieht 1~ then
removed and replaced by a 1000 ~ram ~ight. Aftsr 30
~cond~, the skein length i8 i9 measured to provide L2.
~he % ~hrinkaga i~ defined a8 lOO(Ll - L2) di~ided by Ll.
3L2;~ 8
-1~- 14-54(8091~
By "incompatible polymers" io meant that the
polymer~ ar~ chemically dis~imilar, as in the e~emplified
polyester and nylon~
The precise reason for the uneYpected incrsased
es~e of splitting of the filaments of the inYention ~8
compared to prior art splittable filaments is unkno~n.
