Note: Descriptions are shown in the official language in which they were submitted.
218~775
C~IlIPED pT~V~nr~r CONJUGATE FIBER8
s BACKGROUND OF THE INVENTION
The present invention is related to crimped,
pigmented con~ugate fibers and - ~ Yel~ fabrics p ~-Iu- éd
theref rom .
~ vel~ fabrics containing crimped colljuyate fibers
10 or f~l L~ provide desirable flln~-~ioni~l and textural
properties, including soft hand, flPYihi 1 ~ty, drape and
porosity, when ~ ed to = ~._.l fabrics containing
uncrimped f ibers . Crimped ~ J u~ate f ibers or f i 1 i ts
suitable for n~,l. .ve.l fabrics contain at least two
lS polymeric ~ L compositions which are aLLall~ed in
substantially distinct soc tinn~ across the ;LoS5 se_Lion
along the length of the fibers or filaments, and they can
be th~ lly~ ~hom;oi~lly or ~nici~lly crimped.
Nonwoven fabrics containing thermally crimped conjugate
20 fibers are ~ clofiocl~ for example, in U.S. Patents
3,423,266 to Davies et al.; 3,595,731 to Davies et al.
and 5,382,400 to Pike et al. In general, thor~-lly
crimped C~ ate f ibers are ~L ,duced by heat treating
cvll~u~a~e fibers having latent cri _ hi 1 ity. Such
2s cullju~<lte fibers having latent cri -hi 1 ity are formed
when the ~ L polymers of the fibers have different
shrinkage and/or crystallization reD~ es to a heat
LL~ai
Typically, however, it is difficult to control the
30 level of crimps imparted in the f ibers during the course
of a thermal crimping process. If the level of crimps is
too high, interfiber entanglements among the fibers
become too f irm and irregular . Such overly crimped
fibers produce noll..~vell fabrics exhibiting non-uniform
:~5 fiber coverage and caliper. In contrast, if the level of
crimps is too low, the resulting n~ vèn webs may not
provide desired textural properties . U. S. Patent
5,382,400 to Pike et al. teaches a method to ~V~LC
~ ~ 3~^7~
this crimp level control problem. Although the patent
teaches a method for imparting different levels of crimps
by applying different activating t~ aLuL~s, there
remains a need for additional means that can be used in
s conjunction with the t~ aL~-: control method or used
separately to control the level of crimps in c;~lljuyate
f ibers .
8~aRY OF T~
o The present invention provides a h~l ~cnl ly crimped,
pigmented multi~ t C~l-juyate fiber containing at
least a first composition and a second composition. The
first composition has a first 1 , lnqtic polymer and
the second composition has a second t~ , lnf~tic polymer
which has a different solidification period than the
f irst thermoplastic polymer, wherein one of the f irst and
second compositions contains an effective amount of a
pigment. The invention additionally provides a helically
crimped, pigmented multit L ~ Juyate fiber having
at least two, ~ compositions that have different
amounts of a pigment. The term "solidification period"
as used herein indicates the amount of time that a melt
spun polymer composition that exits the fiber-forming
spinneret takes to solidify in a given con~ugate fiber
pro~ t~tit~n set up, more specifically g-lt~nt hin~ and
drawing set up.
The invention also provides a process for
simult~nt~o~qly pigmenting and controlling the level of
latent crimpability of a crimpable multi~: L
conjugate fiber, wherein the conjugate fiber contains at
least a first polymer composition and a second polymer
composition, and the first composition polymer has a
faster solidification period than the second composition
polymer. The steps of the process include adding
disparate amounts of a pigment in the f irst and second
218377~
composltions and ~pinning a conjugate fiber having a
crimpable configuration from the compositions, wherein
the process increases the level of latent crimpability
when a higher amount of the pigment is added in the first
s composition and decreases the level of latent
cri hi l; ty when a hiqher amount of the pigment is added
in the second composition. The term " crimpable
configuration" as used herein indicatefi a cross-
sectional configuration of a Cv~ l e fiber that does
10 not impose g~ LLlcal or configurational constraints in
the fibers to prevent the formation of crimps when the
latent crimpability is activated. For example, a
cv--~èl-LLlc sheath-core configuration is not a crimpable
configuration since the cv..ve..LLical ~y ~Ly of the
15 ,:LV5S ~ irnl: of the _ t polymers does not readily
allow the fibers to form th~ l ly activated crimps.
Additionally, the terms "web" and "fabric" are
used interrhAn~eAhly~ unless otherwise indicated, and the
terms " f ibers " and ' ~ f; 1 " are used
20 interrh~nge~hly~ unless otherwise indicated.
BRIEF }~ ,_ OF T}~S ~
Figure 1 illstrates a ~rocess for producing the5 pigmented v u..~ u~te f iber of the present invnetion and a
. fabric containing the conjugate fiber.
TT ~ ,, _ OF Tl~ ln ~
The ~v..J ~ e f ibers of the present invention may
30 contain more than two polymer ~ L . However, for
illustration purposes, the present invention is described
with two . L (bi~ -nt) conjugate fibers.
The present invention provides a crimped cv..; u~lte
fiber that contains a crimp-in~ r;n~ pigment (pigment) in
3s one of the two - L composition or contains
~1%3~7B
disparate amounts of a pigment in the two compositions.
Additionally, the present invention provides a method for
simultAn~o~ y pigmenting and controlling the level of
crimps in cu..; u~te f ibers .
S The vv~juyate fibers of the present invention have a
crimpable configuration. Suitable configurations include
side-by-side conf igurations and eccentric sheath-core
configurations. In addition, the polymer c of
the conjugate f ibers contain two - ~ polymers that
o are s~l ec~ from semi-crystalline and crystalline
~h~ , lA~:tiC polymers which have different
sol; ~l l f irAtion periods with respect to each other
~Itively~ a fast solidifying and a slow solidifying
polymers . It is believed that the solidif ication period
is influenced by different parameters inr l~ n~ the
melting tr _ a.~u~-it and the rate of crys~Al l; 7ation of
the _ polymer. Accordingly, the fast solidifying
1. polymer of the aol.; u~te f iber desirably has a
melting point about 10C or higher, more desirably about
20C or higher, most desirably about 30C or higher, than
the slow solidifying ~ polymer. However, the two
~ polymers may have similar melting points if
their crystAl l; ~s~tion rates are measurably different.
In aavv~-la~ce with the present invention, one of the
two polymer ~ _ L~ contains an effective amount of a
pigment. The pigment is added to the l.
composition not only to impart desired color to the
v v~ ate f ibers but also to control the degree of latent
cr; -hi l ity. In general, a high degree of latent
~-r; -h; 1 ;t-y provides a high level of crimps when the
fibérs are exposed to a given latent cr; -h;l;ty
activating temperature. Accordingly, the level of crimps
in the conjugate f iber of the present invention can be
controlled by regulating the degree of latent
35 cri -hi l ity with the addition of a pigment. In
2183776
accordance with the present invention, the level of
crimps in conjugate fibers having latent crimpability can
be increased by adding an effective amount of a pigment
only in the fast solidifying polymer -~, and the
5 level of crimps can be decreased by adding an effective
amount of a pigment only in the slow solidifying polymer
^ t. Desirably, between about 0. 005% and about 2%,
more desirably between about 0.01% and about 1%, based on
the total weight of the ~ L composition of the
cvl.~u~te fiber, of a pigment is added in the polymer
composition .
Alternatively, disparate amounts of a pigment can be
added to the two polymer ~:~ to control the degree
of latent cr; h;l;ty and to pigment the fibers. Por
15 example, when both 1,8 of the culljuy~te fibers
contain a pigment, a larger amount of the pigment can be
added to the fast solidifying polymer ~ ent to
increase the degree of latent cr; -h;l;ty, and a larger
amount of the pigment can be added to the slow
20 solidifying polymer ~ to de.L~ ase the degree of
latent cr; _ h; l; ty. In ~c- VL~ l e with the present
invention, the L composition containing the
larger amount of the pigment contains, desirably, at
least about 25% more than the other t
25composition.
In addition, more than one pigment can be added to
the ~_ ~ compositions to control the degree of
latent crimpability. For example, when an equal amount
of a pigment is added to the ~ L compositions, a
30 second pigment can be added to one of the ~ L
compositions to control the degree of latent
cr; -h; 1 i ty.
Suitable crimp-;n~ ;n~ pigments for the present
invention include organic and inorganic pigments known to
3s be suitable for crystalline and semi-crystalline
218377~
thermoplastic polymers. Desir~bly, suitable pigments
have an average particle size equal to or less than about
o . 5 ~m, more desirably equal to or less than about 0 . 3
~m. The lower limit of the particle size is not critical
s provided that the pigment particles are not as small as
to lose their color. Exemplary suitable organic pigments
include monoazo pigments, e.g., hanasa yellows, toluidine
reds, naphthol reds, tartrazine lake, ponr-nont red 2B
and peLIl.a~ .L yellow FGL; benz1mi~loA7~ no pigments;
lo disazo pigments, e.g., diarylide yellows, diarylide
oranges and tliAn~ 11ne red; disazo con~oncation
pigments; quinacridone pigments; ~ yAn7~no violet; vat
pigments, e.g., flavanthrone yellow, dllUI~ ~I yLlmidine
yellow, pyranthrone orange, perinone orange, brominated
15 anthanthrone ordnge, brominated pyranthrone, anthramide
orange, illda..U.Lol~e blue, isoviold,.~ ..e violet;
perelene r~ Ls; thiQ~ntl~qo pigments; phthalocyanine
pigments, e.g., copper phthalocyanine blue;
tetrachloro~in~lolinone pigments; and mixtures thereof.
20 Inorganic pigments suitable for the present invention
includes metal oxides, e.g., "1~ n oxide, lead oxide,
iron oxide, titanium dioxide, antimony oxide and calcium
oxide; metal particles; mineral particles and cadmium
pigments, e.g., cadmium sulfide. Of these suitable
25 pigments, particularly suitable for the present invention
are organic pigments including phthalocyanine pigments,
disazo pi~ , disazo c~n~lon~ation pi~; L6
quinacridone pigments and mixtures thereof.
Crystalline and semi-crystalline polymers suitable
30 for the present invention include polyolefins,
polyamides, polyesters, vinyl acetate-based polymers, and
blends and copolymers thereof . Useful polyolef ins
include polyethylenes, e.g., high density polyethylene,
medium density polyethylene, low density polyethylene and
35 linear low density polyet~ylene; polypropylenes, e.g.,
- . 2~8377~
isotactic polypropylene an~l syndiotactic polypropylene;
polybutylenes, e.g., poly(l-butene) and poly(2-butene);
polypentenes, e.g., poly(2-pentene), and poly(4-methyl-1-
pentene); and blends thereof. Useful polyole~in
s copolymers include ethylene-propylene copolymers. Useful
vinyl acetate-based polymers include polyvinyl acetate;
ethylene-vinyl acetate; saponified polyvinyl acetate,
i . e ., polyvinyl alcohol ; ethylene-vinyl alcohol and
blends thereof. Useful polyamides include nylon 6, nylon
lO 6/6, nylon 10, nylon 4/6, nylon 10/10, nylon 12,
hydrophilic polyamide copolymers such as caprolactam and
alkylene oxide diamine, e.g., ethylene oxide diamine,
copolymers and h. ylene A-lirAmide and alkylene oxide
copolymers, and blends thereof. Useful polyestèrs
5 include polyethylene terephthalate, polybutylene
terephthalate, and blend6 thereof. Of these,
particularly suitable polymer combinations include
polypropylene/polyethylene, e.g., isotactic
polypropylene/high den&ity polyethylene and isotactic
20 polypropylene/linear low density polyethylene;
nylon/polyproplene, e.g., nylon 6/isotactic polypropylene
and nylon 6, 6/isotactic polypropylene;
nylon/polyethylene, e.g., nylon 6/high or linear low
density polyethylene and nylon 6, 6/high or linear low
2s density polyethylene; polyester/propylene, e.g.,
polyethylene terephthalate/isotactic polypropylene and
polybutylene terephthalate/isotactic polypropylene;
polyester/polyethylene, e.g., polyethylene terephthalate
/high or linear low density polyethylene and polybutylene
30 terephthalate/high or linear low density polyethylene.
As stated above, the latent crimpability of the
conjugate fibers is activated by a heat treatment. The
heat treatment heats the fibers to a t~ ULe equal to
or higher than the temperature at which the slow
3~; solidifying ~ t polymer star~s to resume its
218377~
crystallization but below the melting point of the loweDt
melting ~. t polymer . ~r~n~ i ng on the polymers
selected for the conjugate fibers, the heat ~Lea;
temperature will vary widely. However, the heat
5 treatment in general needs to raise the tA, ~I~UL~a of
the fibers to about 45C or higher in order to
appreciably activate the latent crimp. In general, a
higher temperature induces a higher number of crimps in
the fiber. The latent crimp6 can be activated before,
lo during or after the fibers are deposited or laid to form
a n~....~ ven web. ~owever, it is highly desirable to
activate the crimps in the fibers before they are
deposited to form a nv.._.v~.l web since the crimping
process inherently causes shrinkage and dimensional
changes that are dif f icult to manage and tend to
adversely affect uniformity and fiber coverage of the
web. Therefore, it is highly a-lva~ gèous to crimp the
c~..lJuy~lte fibers before they are formed into a - J~
web in order to provide a dimensionally stable web that
20 has uniform fiber ;U.~L Je and uniform bulk.
The cvllju~te fibers of the present invention can be
oduced by various known ~L.acess~s for producing
~ juy~te fibers, ;n~ 1n~ staple fiber pro~lllrt;rn
processes, Dl~ h" l fiber production E,Locesses and
25 meltblown fiber prr,~ rt;On process. of these,
particularly suitable ~Locesses for the present invention
are ~ ,h-~- -1 f iber procl~lrt ion processes .
A particularly suitable process for the present
invention that produces crimped c~,--J u~lte f ibers and
30 n.,... ~vtn fabrics containing thereof is ~ rlo8Dd in U.S.
Patént 5,382,400 to Pike et al. The patent in its
entirety is herein in~;uL~L~ted by reference. Turning to
Figure 1, there is illUA~LC~ted an exemplary conjugate
fiber spunbond nonwoven fabric production process 10 that
35 is particularly suitable for the present invention. A
~3776
pair o~ extruders 12a and 12b separately extrude the
, L compositions for the conjugate fibers, in which
one of the compositions contains an effective amount of a
pigment. The compositions are separately fed into a
5 first hopper 14a and a second hopper 14b, to
simultaneously supply molten polymeric compositions to a
spinneret 18. Suitable spinnerets for extruding conjugate
fibers are well known in the art. Briefly, the spinneret
18 has a housing which contains a spin pack, and the spin
lo pack contains a plurality of plates and dies. The plates
have a pattern of opPnin~C ~ILLcl~ged to create flow paths
for directing the two polymers to the dies that have one
or more rows of opDn;ngc~ which are designed in
accordance with the desired configuration of the
15 re6ulting conjugate fibers.
me spinneret 18 provides a curtain of conjugate
f; 1 ~s or continuous f ibers, and the continuous f ibers
are quenched by a quench air blower 20 and develop latent
cr; -hi 1 ity. me quenched fibers are then fed to a
20 fiber drawing unit. Any pneumatic fiber drawing unit or
aspirator that is known to be suitable for a ~.. h.~l,A
process can be used for the present invention provided
that the f iber draw unit is modif ied to utilize heated
air, instead of conventionally used ambient air, to draw
25 the fibers. Of these, particularly suitable fiber draw
units for the present invention are linear fiber
aspirators of the type disclosed in U.S. Patent 3,802,817
to Matsuki et al., which in its entirety is incu.~,La~ed
by reference. Briefly, the fiber draw unit 22 ;n~ D~ an
30 elongate verticâl passage through which the f ilaments are
drawn by fiber drawing air entering from the side of the
p;~ca~e. The drawing air, which is supplied from a
~ ~ssed air source 24, draws the filaments and imparts
molecular orientation in the filaments. In accordance
3s with the present invention, the drawing air is heated
2~776
with a temperature adjustable heater in order to
simultaneously draw the ~ibers and activate the latent
cr; hi 1 ity. The tf Cl~UL~ of the drawing air can be
varied to achieve different levels of crimps, as
5 indicated above. In accordance with the present
invention, the solidifying periods of the ~_
polymers are detPrminPcl in this fiber ~lo~hinq and
drawing environment.
The process line 10 further inrlll~lDc an endless
o foraminous forming surface 26 which is placed below the
draw unit 22 and is driven by driver rollers 28 and
positioned below the fiber draw unit 22. The drawn
filaments eYiting the fiber draw unit are generally
deposited in isotropical or random fashion onto the
15 forming surface 26 to form a r ~V~:II web of uniform
~h; e~nP~s: and f iber cvv~ ge . The f iber depositing
process can be better facilitated by placing a vacuum
apparatus 30 directly below the forming surface 26 where
the fibers are being deposited. The abv~c desv ibed
20 simultaneous drawing and crimping process is highly
useful for producing lofty r~L~ ~ h~ webs that have
uniform fiber ~.v~ e and uniform web caliper.
The deposited nv~ v-:n web is then bonded, for
example, with a through air bonding process. Generally
2s described, a through air bonder 36 in~ P~ a perforated
roller 38, which receives the web, and a hood 40
~uLLvullding the perforated roller. ~eated air, which is
hot enough to melt the lower melting ~ ~ polymer of
the cvllJu~clte fiber, is sllrpl ied by the hood 40 to the
30 web through the perforated roller 38. The heated air
melts the lower melting polymer and the ~elted polymer
forms interfiber bonds tllL~u~llvu~ the web, P~poc;Al ly at
the cross-over contact points of the f ibers . Through air
bonding processes are particularly suitable for producing
35 a lofty, uniformly bonded spunbond web since these
~ 218377~
processes uniformly effect interfiber bonds without
applying significant ' ^c~inq ~La~.,u,e. Alternatively,
the llnh- n(l~3 nu.. ~v~. web can be bonded with a ~Al-~n~lDr
bonding process . A CA l ~ r bonding process typically
5 utilizes an assembly of twû or more of abuttingly placed
heated rolls that form a nip to apply a combination of
heat and ~LeS~u. a to melt fuse the f ibers of a web to
form bonded regions or points in the web. The bonding
rolls may be smooth or contain a pattern of raised bond
o points.
As indicated above, the conjugate fibers of the
present invention can be controlled to have varying
levels of crimps, and thus, the bulk of the nv-- .v~n
fabrics containing the cu..juyclte fibers can be adjusted
15 to desirable levels. For example, when a combination of
selected : polymers provides an undesirably low
level of crimps, a pigment can be added to the fast
solidifying composition to simul~An~o~cly increase the
crimp level and to pigment the f ibers, and if a
20 combination of selected c 1. polymers provides an
overly high level of crimps, a pigment can be added to
the slow solidifying composition to decrease the crimp
level and to pigment.
In addition to the pigment, the polymer compositions
25 of the coniugate f ibers may contain minor amounts of
various additives and fillers that are conventionally
used in the pro~ cti~n of fibers and nu-~ ... fabrics.
Useful additives include compatibilizing agents, dyes,
optical brighteners, ultraviolet light stabilizers,
30 antistatic agents, lubricants, abrasion resistance
~nhAn--;n~ agentg, nucleating agents and other processing
aids .
The 1lvll u v~ fabric or web of the present invention
that contains pigmented conjugate fibers having a
35 controlled level of crimps can be used in a wide variety
11
2183~76
of pLuduuLs. ~ l..uvtl~ f~brics of the present invention
that have a high level of crimps and thus have a high
bulk and a high poro6ity are, for exalDple, highly
suitable for fluid r~-r- ~ ~ L layers of absorbent and
5 personal care articles, e.g., diapers, in~ ontinonce care
articles, sanitary napkins and training pants; active
agent delivery system, e.g., c- ~ic scrubbing pads and
polishing agent applying pads; and filters. Present
nu.. .~ fabrics that have a low level of crimps and thus
lo a low bulk are, for example, highly suitable for
protective 'J~ ~~ r, drapes, wraps and cloth-like outer
cover materials for absoLI,~ and personal care articles.
The fQllowing eYamples are provided for illustration
~uL~06es and the invention is not limited thereto.
r
~campl~ 1 (Exl)
A 1.5 ounce per square yard t51 g/m ) r.~
bi~ ^ t fiber web was pLvluced in a~u,d~ e with
aforementioned U.S. Patent 5,382,400. A linear low
density polyethylene tLLDPE), Aspun 6811A, which is
available from Dow t'h~ l, was blended with 2 wt% of a
2s Tio2 ~-...c6-.~L~te which had 50 wt~ of Tio2 and 50 wt96 of a
polypropylene, and the miYture was fed to a first single
screw extruder. The Tio2 used was commercially available
conventional Tio2 which has an average particle size of
about 0.5 ~Lm. A polypropylene, PD3445, which is
30 available from Exxon, was blended with 2 wt% of the
above-described Tio2 ~v~c~ te and with 1 wt96 of a blue
pigment. The blue pigment used was SCC 3185, which is
available from Standridge Color Corporation, GA. The
main ~ contained in SC 3185 are about 1. 4 wt96 vf
3s phthalocyanine blue and about 0. 296 of magenta
12
~ 18~776
.
quinacridone. The mixture was fed to a second single
screw extruder. In this c .rnt polymer combination,
polyproyplene is the fast solidifying polymer and LLDPE
is the slow solidifying polymer. The ~LLuded polymers
S were spun into round bi~ 1. fibers having a side-by-
side conf iguration and a 1:1 weight ratio of the two
~ polymers using a hj- L spinning die,
which had a 0 . 6 mm spinhole diameter and a 6 :1 L/D ratio .
The melt t~, ,-LuL~g of the polymers fed into the
lo splnnin~ die were kept at 450F (232C), and the spinhole
tllL~ uyll~uL rate was o s gram/hole/minute. The
bi~ L fibers exiting the spinning die were ~ .- l ed
by a flow of air applied at 45 ft3/min/inch (0.5
m3/min/cm) and at a t~ c.tuLæ of 18C. The 5u~n~hing
15 air was applied about 13 cm below the spinneret, and the
quenched fibers were drawn in a fiber drawing unit of the
type which is described in U.S. Patent 3,802,817 to
Matsuki et al . The aspirator was ~T~ i rped with a
temperature controlled fiber drawing air source, and the
20 feed air t~ CILUL~ was kept at about 350F (177C).
The ~ d fibers were drawn with the heated feed air
to attain a fiber size of about 2.7 denier (3 dtex).
Then, the drawn fibers were deposited onto a foraminous
forming surface with the assist of a vacuum flow to form
25 an l~nhrn~rd fiber web. The .~ d fiber webs were
bonded by passing the web through a through-air bonder
which is equipped with a heated air source. The heated
air velocity and the t~ _L~ILUL~ of the heated air was
200 feet/minute (61 m/min) and 272F (133F),
30 respectively. The residence time of the web in the hood
was about 1 second.
Based on the fact that the bulk of a ~ .væ.. fabric,
in general, ~JLL ~ ingly increases with the increasing
level of crimps in the fibers that forms the n-,--.~,vl:n
35 fabric, the bulk of the resulting web was measured and
13
~183776
compared to study the crimp ;n~ll-~in~ effect of utilizing
a pigment. The bulk of the resulting web was measured
using a ,Starret-type bulk tester under 0.5 psi (3.4 pKa).
The result i5 shown in Table 1.
s
Co~par~tiv- l~campl~ 1 (Cl)
Example 1 was repeated except 1 wt% of SCC 3185 was
also added ln the LLDPE ~ nt. The result is shown
in Table 1
~ample 2 (Ex2)
Example 1 was repeated except 1 wt96 of SCC 3185 was
added to the LLDPE ~ , L and not to the polypropylene
_, -nt. The conjugate fibers of the ~Lùduced r Jvcn
15 web had a lower level of crimps than the f ibers of
Comparative Example 1, and the nul-..Jvcll web had highly
u~ uniform Cv~ c and uniformity , ~Gad to the
nul...uvcll web of C ~l.ive Example 1. This formation
u~ is believe to result from the reduction in
20 the ~.asGI~ce of u~ Limped fibers in the web. The bulk
result is shown in Table 1.
Exam~le Bulk
( inch) (mm)
Exl 0 . 0825 2 .10
Cl 0 . 0790 2 . 00
Ex2 0 . 077S 1. 97
The abovQ results, which shows that the bulk of the
web' of Example 1 is thicker than that of the web of
Comparative Example 1, clearly ~ te that adding a
pigment in the fast solidifying ~ _ t polymer
composition increases the degree of- latent crimpability
and thus improves the crimp level of the conjugate fiber.
14
n addition, Example 2 and Comparative Example
_Ltlte that adding a pigment in the 510w solidifying
L polymer composition decreases the degree of
latent cri hil ity and thus decreases the crimp level of
s the conjugate fiber, while improving the fiber coverage
and uniformity of the web.
'lhe conjugate fibers can be ~Lvduced to have a
controlled level of crimps while pigmenting the fibers
and, thus, can be used to produce nv~ v~ fabrics having
o different levels of bulk and porosity, textural
properties and colors.
Although pref erred : ' ~o~ of the invention have
been described herein, it will be understood by those
skilled~ in the art that variation~, modifications, and
e~uivalents may be made thereto without departing from the
spirit of the invention or the scope of the appended
c~ :lml~.
