Note: Descriptions are shown in the official language in which they were submitted.
CA 0223394~ 1998-04-02
W O 97/13895 PCT~US95/12799 .
TIT~,F,
Improvements In And Relating To Fiber Identification
This invention concerns improvements in and relating to fiber
identification, and includes a novel method of making a multi-void fiber with a
characteristic by which it can later be identified, novel multi-void fibers so marked
as to be iclentifi~hle, and products and materials including such marked fibers,especially fiberfill filling materials (often referred to shortly as "fiberfill") and
products, including batts, fiberballs and other products comprising such marked
fibers and materials comprising them, and processes and a~p~dlus for obtaining
such multi-void fibers and their products and materials.
A fiber m~nuf~blrer~s customers clçrn~ncl consictency in ~clro~ ce
from the fibers provided by the m~nnf~cturer. In other words, the m~nllf~cturerls
customers require that the properties of any particular fiber not vary appreciably
from batch to batch of that fiber as the different batches of that fiber are produced
over several years. The fiber m~nllf~rtnrer, however, has a need to be able to
identify fiber from different production batches, while ~ g the consistency
and uniformity that the customers require. Much notoriety has been given to fiber
identification in criminology, for example, as a way to bring murderers or othercriminals to justice. ~nllf~cblrers also, however, have other more mlm~l~ne and
practical reasons for nee~ling to identify the production batch of particular fibers.
So it has long been desirable to find a cheap yet effective system for identifying
fibers. Previously, for in~tslrlce, one method has been to add a chemical or nuclear
marker to the fiber, but this method has added expense and complications and hashad disadvantages, such as the ease with which some one other than the fiber
mz~nnf:~eturer can add the same marker, after manufacture, and so confuse this
system for identification.
In particular, there has long existed a need for an economical way to
identify and differentiate resilient multi-void fibers (especially polyester multi-
void fibers) that are crimped and used as fiberfill in products such as batts,
fiberballs and other filling materials and filled articles, such as pillows, filled
apparel, comforters, cushions and such like bedding and fi~rni~hinp material. Asindicated, it is important that any identifier system should not change the
~ performance and L~lo~clLies ofthe fibers.
Examples of such crimped multi-void resilient filling fibers include
those disclosed by Ch~mp~r~eria et al in U. S. Patent No. 3,745,061, and in EP A2
0 067 684 (Jones et al), having 4 voids (sometimes referred to as holes) with a
solid axial core, and by Broaddus in U. S. Patent No. 5,104,725~ having 7 or more
CA 0223394~ 1998-04-02
W O 97tl3895 PCT~US95/12799.
voids, arranged ~,vith a central void and other voids arranged around the central
void. Both 4-void and 7-void polyester filling fibers have been produced and sold
commercially, and have been used as fiberfill. Broaddus compared properties of
fiberfill comprising his 7-void filling fibers with those of fiberfill comprising prior
corn~nercial 4-void filling fibers and also with those of fiberfill comprising hollow
filling fibers. The most i~ ol Li~lt ~l~ pCl lies to compare for use as fiberfill are the
bulk properties; measurement of bulk ~lo~cllies (referred to as TBRM for "Total
Bulk Range Measurement") have been described, e.g., by Tolliver in U.S. Patent
No. 3,772,137, and so have frictional p~ lies (that were also measured by
Broaddus and are also important for fiberfill). Both of these crimped multi-voidfilling fibers have shown significant advantages over resilient crimped hollow
filling fibers (such as disclosed by Tolliver in U. S. Patent No. 3,772,137) in their
performance as filling materials, especially when such multi-void filling fibershave had a smooth round peripheral surface. The disclosure of each of the above
patent specifications is expressly included herein by reference. In addition, multi-
void filling fibers with a smooth round peripheral surface and with only three
longitudinal voids, are disclosed by Hern~n~ et al. in U.S. Patent No. 5,458,971(DP-6320), the disclosure of which is also included herein, by reference.
The present invention solves this need to identify and differentiate
multi-void fibers by providing a visual identifying marker in the configuration of
the cross-section of the multi-void fiber. This marker identifies the multi-voidfiber only visually, i.e., without si~nific~ntly affecting perforrnance of the fiber.
Fibers with such a visual identifying marker according to the present invention are
often referred to herein as "identifier fibers" (or '~identifier fil~ment~")
The terms "fiber" and "filament" are often used herein inclusively,
without intending that use of one term should exclude the other.
Accordingly, this invention provides a process for preparing multi-
void filaments of a synthetic polymer, comprising the steps of post-coalescence
melt-spinning the synthetic polymer through segmented spirming capillarv orifices
so the resulting freshly-spun molten streams coalesce and form continuous
filarnents having at least three voids, and q~ nching to solidify the fil~mentc, and,
if desired, drawing the resultant solid fil~mlont~, and/or further proce~ing, and/or
converting to staple fiber, characterized in that molten polymer is also spun insmall amount through one or more separate small orifices located so as to form,
respectively, one or more small protuberances that are visually icl~ntifi~hle on an
inside surface of, respectively, one or more voids of the multi-void filaments.
There is also provided, as a new article, a multi-void synthetic
polymer fiber, having at least three continuous lon~ 1in~1 voids, wherein the
CA 0223394~ 1998-04-02
W O 97/13895 PCTrUS95/12799.
multi-void cross-section of the fiber shows characteristic polymer m~t~-ri~l that
protrudes into one or more of the voids from an inside surface of the void or
voids; in other words, the cross-section shows that one or more such void is
partially filled with characteristic polymer material that protrudes from a wall into
5 such partially-filled void, thus said characteristic protruding polymer material
dirr~,~;,llially identifies said fiber from similar multi-void synthetic polymer fibers
that do not contain any such protruding polymer material usually but does not
significantly differentiate the performance properties of said fiber from said
similar fibers.
According to a further aspect, this invention provides fiberfill filling
material, and articles comprising such m~teri~l, comprising resilient crimped
multi-void filling fibers that are of a synthetic polymer, wherein said multi-void
filling fibers have at least three continuous voids throughout their fiber length, and
wherein said fiberfill filling material is identified by all or a predetermined
15 proportion of said fibers having a multi-void cross-section that shows
characteristic polymer material that protrudes into a preclet~rmin~l number and
predetermined pattern of the voids from an inside surface of the void or voids.
According to other aspects disclosed herein, fiberfill (and including
filled articles thereof) is provided wherein said fiberfill comprises resilient
20 crimped multi-void filling fibers of synthetic polymer, apd wherein, e.g., at least
10 percent by weight of said fibers have a multi-void cross-section which shows
that one or more such void contains (i.e., is partially filled with) characteristic
protruding polymer material (i.e., that protrudes from an inside surface into such
partially-filled void), whereby said characteristic protruding polymer material
25 differentially identifies said fiber from a multi-void synthetic polymer fiber whose
multi-void cross-section is similar except that it does not contain any such
characteristic protruding polymer m~tcri~l and wherein the bulk properties of said
fiber as filling m~t~ri~l are ees~nti~lly similar to the bulk properties of such a
multi-void synthetic polymer fiber that is of similar cross-section except that it
30 does not contain any such characteristic protruding polymer material; such multi-
void fibers may contain at least three continuous longitudinal voids (i.e.,
throughout their fiber length), as will be understood.
Polymer material protruding from a surface of a wall of an internal
void of a (first) multi-void fiber of a synthetic material is used to identify said
35 (first) multi-void fiber and differentiate it from other multi-void fibers of similar
cross-section and having similar bulk properties to those of the first (identified and
differentiated) multi-void fiber, except, of course, that the other multi-void fibers
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799
do not have the polymer material protruding from a surface of a wall of an internal
void.
Other aspects include methods, ~ Lus and products disclosed
herein.
S Preferred features include using polyester polymer as the material for
the synthetic polymer of the multi-void fiber and/or the characteristic polymer
material, and preferably for both, including using the same polyester polymer for
both, and using the invention for 4-hole fibers, 7-hole fibers, and/or 3-hole fibers
with a smooth round periphery, such as are mentioned in the art and above,
especially any such multi-void fibers with only 1 of the holes (i.e., voids) partially
filled.
In most respects, the fiberfill filling m~teri~l~ and resilient crimped
multi-void filling fibers of the invention are prepared conventionally by methods
known in the art, such as referred to herein. Preferred multi-void filling fibers are
prepared from polyester polymers, especially poly(ethylene terephth~ te), and
this preferred embodiment is described herein more particularly, for convenience,
it being lm~ r~tood that applopliate modification can be made by those skilled in
the art for other synthetic polymers, such as polyamides or polypropylene, to take
account of their differences, e.g., in melting conditions and plo~l Lies, such as
melt viscosity. One such disclosure in the art is Ch~mp~neria et al U.S. Patent
No. 3,745,061, which discloses multi-void synthetic fil~mentc and a spinneret
capillary for spinning such fil~3mentc cont~ininp four substantially
equillimencional and equi-spaced parallel continuous voids from synthetic
polymers, including polyesters, in Figure 1 thereof.
Figures 1 and 2 of the accompanying drawings are m~gnified (625X)
photographs of cross-sections of 4-void filz~ment~, Fig. 1 being of preferred
filaments according to the invention, whereas Fig. 2 is of prior art filaments for
comparison, as discussed in Example 1.
Figure 3 is an enlarged view of a spinneret capillary, taken looking at
the lower face of the spinneret, for spinning ~lc;r~ d 4-void fil~ment~ of the
invention as in Fig 1, 4 and 5.
Figures 4-7 are m~gnified photographs of cross-sections of 4-void
fil~ment~, Figs. 4 and 5 being of preferred filz~ment~ according to the invention,
whereas Figs. 6 and 7 are of prior art fil~ment~ for comparison. Figs. 4 and 7 are
of m~gnification 500X. Figs. 5 and 6 are of m~gnification 1000X. These are
rli~cn~se~ in Example 3.
Figure 8 is a graph plotting TBRM data, heights in inches versus
pl'e~ ,S in psi, as discussed also in Example 3.
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799
Figure 9 is an enlarged view of a spinneret capillary, taken looking at
the lower face of the ~h~elc~l, for spinning preferred 3-void fil~ment~ of the
invention as in Figs. 10 and 11.
Figures 10-13 are m~gnified photographs of cross-sections of 3-void
S fil~ment~, Figs. 10 and 11 being of ~lerell~d identifier fil~ment.~ according to the
invention, whereas Figs. 12 and 13 are of filaments without identifier, for
comparison. Figs. 10 and 12 are of m~gnific~tion 500X. Figs. 11 and 13 are of
m~gnification lOOOX. These are discussed in Example 4.
Figure 14 is a graph plotting TBRM data, heights in inches versus
1O plC:S5ul~ in psi, as discussed also in Example 4.
Figures 15 and 16 are m~gnified photographs showing not only cross-
sections of preferred fibers of the invention, but also that the fibers are crimped, as
described later herein.
Referring to Figure 3 of the accompanying drawings, showing an
15 enlarged view of a spinneret capillary for spinning 4-void identifier filaments of
the present invention, the similarity to that of Figure 1 of Ch~mp~neria will benoted. The capillary is formed of four individual segments ~lesi~n~tP~I generally
11, 12, 13 and 14intheformofT-shapedslotswithfourradialslots 15, 16, 17
and 18 r~ tin~ outwards to join outer peripheral slots 19, 20, 21, 22 that are
20 curved to form arcs of an incomplete circle. At each end of each peripheral slot,
19, 20, 21 and 22, are enlarged "toes" 23 and 24, 25 and 26, 27 and 28, and 29 and
30, respectively, being enlarged ends of said slot to assist in post-coalescence of
the emerging molten polymer to form the desired multi-void solid fils~ment, as is
known in the art, such as Tolliver, U. S. Patent No. 3,772,137. An hllpoll~ll and
25 novel difference in Figure 3 herein (that differentiates from Figure 1 of
Ch~mp~n~ria) is the provision of an orifice 40. Molten polymer extruded through
orifice 40 solidifies and coalesces on an internal wall of one of the voids of the
fil~nnent formed by post-coalescence of molten polymer extruded through slots
11, 12, 13 and 14, to form a protuberance partially filling one of the voids. The
30 relative location of the protuberance within the void may vary along a length of
the filament, as will be understood.
Magnified cross-sections of such identifier filaments of the invention,
cont~ining 4 voids, one of which is partially filled with polymer that protrudesfrom an internal wall of such void, are shown in Figure 1, at 625X m~gnification.
35 In contrast, similarly m~gnified cross-sections of conventional 4-void filzlment~
are shown in Figure 2. As mentioned, the cross-sections in Figs. 1 and 2 have
been greatly magnified. Fiberfill fil~mente are so fine that, without m~gnification,
it is doubtful that anyone would be able to see any void in the cross-section, or
CA 0223394~ l998-04-02
W O 97/13895 PCTnUS95/12799
whether the filQment is solid, hollow, or multi-void, let alone be able to recognize
if any void is partially filled with protruding polymer.
As may be seen from Examples hereinafter, both types of fil~ment~
can be prepared to have comparable performance and properties as filling
S materials. In other words, an objective has been achieved in this respect. This
will be discussed more hereinafter.
To summarize this point, without ~ pa~ g and ex~mining greatly-
m~gnified carefully-cut cross-sections and co",p~ g the fil~ment~, most people
would be unable to determine significant difference between fil~ment~ of the
10 invention and conventional fil~ment~ of the art. So the objective of the invention
has been achieved economically by use of a ~lirre~ L spinneret capillary to givethe fil~ment a different cross-sectional configuration int~rn~lly, without affecting
the exterior of the fil~ment or its p~lrollllance, i.e., wherein the difference can
only be determined visually, after ex~mining a greatly-magnified carefully-cut
15 cross-section of the fil~ment
As will readily be understood, the invention lends itself to many
variations. For in~t~nce the number and pattern of the protuberances in relation to
the voids may be varied, especially with fil~mentc having larger numbers of voids,
such as 7 voids, bearing in mind that it has generally been thought desirable to20 maximize the void content to take advantage of the presence of the voids. It will
generally be desirable for the protuberance to fill about 25 to about 50% of thevolume of the void, and generally to extend to an amount of about 25 to 50% of
the average web thickne~ of the fil~ment between adjacent voids, bearing in mindthe above, and the objective of having a characteristic that is relatively easy to
25 detect visually, especially when using the sarne polymer material. It is not
n~ ce~c~ry to provide every fil~ment (i.e., 100%) with identifier, but a regulated
(i.e., predetermined) proportion (e.g., at least about 10% by weight) of
particularly-identified fil~ment~ may be included, and recorded, for a batch of
fiber that is sold. Furthermore, although it is less costly, so generally preferred, to
30 spin fil~ment~ from a single polymer, so the polymer m~teri~l is the same in the
protuberance as in the rest of the fil~ment different polymers may be used, if
desired, so as to provide better identification for merges or batches of fiber. In
other words, fiberfill (one or more batches) according to the invention can be
identified by providing a predetermin~d proportion (that may be recorded, and
35 may vary up to 100%) of the con~titllent filling fibers with a pre~etermined
number and predetermined pattern of voids co"l~ i"g visual identifier, i.e.,
characteristic polymer material protruding into, i.e., partially filling, such void(s),
as described, and these details may all be recorded.
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799
As mentioned above, and as demonstrated in the Examples, partially
filling one or more voids of the multi-void f1lling fibers (according to the
invention) did not significantly change the bulk properties or performance of the
fibers as fiberfill. Applicant has also found that the extent to which the voids are
filled has not significantly changed the bulk properties or performance. So long as
all the voids remain to some degree, the buL~c performance properties have not
been significantly affected. This is different from what has been taught in the art
for hollow fibers. So this was a new and surprising finclin~ In other words,
partially filling one or more voids in a multi-void filling fiber (according to the
invention) has not been found to affect the bulking properties of the multi-voidfilling fibers, whereas the art has taught that extruding extra polymer so it
coalesces onto the internal surface of a hollow fil~mçnt will change the blllkine~
of the resulting hollow fil~ment In contrast to hollow fibers, it seems that it is the
presence of the particular number of voids, located symmetrically or regularly
around the cross-section of the multi-void fiber, rather than the relative sizes of
the various voids in the cross-section, that determines the bnlkiness
The invention is further illustrated in the following Examples, all
parts and percentages being by weight, unless otherwise indicated. The levels ofcoatings (slickeners and finishes) applied to the fil~ment~ were OWF (with regard
to the weight of the fiber). Relative Viscosity (sometimes referred to as LRV) and
void content (by volume, by a flotation method) were determined by the methods
referred to in U.S. Patent No. 4,712,988 (Broaddus et al.). Bulk measurements
were determin.od by the method referred to in Tolliver U.S. Patent No. 3,772,137referred to hereinabove, and crimp measurements çcs~nti~lly as described therein.
Fiber-to-fiber friction values for fiberfill filling (staple) fibers are
generally obtained by what is known as Staple Pad Friction (SPF)
mea~u~ llL~.
As used herein, a staple pad of the fibers whose friction is to be
measured is sandwiched between a weight on top of the staple pad and a base
that is underneath the staple pad and is mounted on the lower crosshead of an
Instron 1122 m~rhinP (product of Instron Fngin~ering Corp., Canton, Mass).
The staple pad is prepared by carding the staple fibers (using a SACO-
Lowell roller top card) to form a batt which is cut into sections, that are 4.0 ins
in length and 2.5 ins wide, with the fibers oriented in the length dimension of
the batt. Enough sections are stacked up so the staple pad weighs 1.5 g. The
- weight on top of the staple pad is of length (L) 1.88 ins, width (W) 1.52 ins,
and height (H) 1.46 ins, and weighs 496 gm. The surfaces of the weight and of
the base that contact the staple pad are covered with Emery cloth (grit being in
CA 0223394~ 1998-04-02
W O 97/13895 PCT~US95/12799
220 to 240 range), so that it is the Emery cloth that makes contact with the
surfaces of the staple pad. The staple pad is placed on the base. The weigh~ is
placed on the middle of the pad. A nylon monofil line is ~tt~.'h,o~ to one of the
smaller vertical (WxH) faces of the weight and passed around a small pulley up
5 to the upper crosshead of the Instron, making a 90 degree wrap angle around the
pulley.
A cu~ uLer interfaced to the Instron is given a signal to start the test.
The lower crosshead of the Instron is moved down at a speed of 12.5 in/min.
The staple pad, the weight and the pulley are also moved down with the base,
10 which is mounted on the lower cr-)~shP~(l Tension increases in the nylon
monofil as it is stretched between the weight, which is moving down, and the
upper crosshead, which remains stationary. Tension is applied to the weight in ahorizontal direction, which is the direction of orientation of the fibers in thestaple pad. Initially, there is little or no movement within the staple pad. The15 force applied to the upper crosshead of the Instron is monitored by a load cell
and increases to a threshold level, when the fibers in the pad start moving pasteach other. (Rec~llce of the Emery cloth at the interfaces with the staple pad,
there is little relative motion at these interfaces; essenti~lly any motion results
from fibers within the staple pad moving past each other.) The threshold level
20 inr~ t~s what is required to overcome the fiber-to-fiber static friction and is
recorded.
The coefficient of friction is d~L~ uled by dividing the measured
threshold force by the 496 gm weight. Eight values are used to eolllL~uL~ the
average SPF. These eight values are obtained by making four d~Lt~ ti~-ns on
25 each of two staple pad samples.
l~XAl~lP~,lh 1
Filaments were spun from poly(ethylene terephth~l~te) of relative
viscosity (LRV) 20.4, at a polymer t~lllpt;:l~Lul~ of 291-297~C, at 1195 ypm (1092
30 mpm), through a spinneret with 388 capillaries, at a throughput per capillary of
0.234 lbs./hr. (0.106 kg./hr.), using capillary orifice designs as shown in Figure 3.
The spun l~l~mentc were assembled to form a rope of 922,000 relaxed drawn
denier. The rope was drawn in a conventional m~nner, using a draw ratio of
3.39X in a hot, wet spray draw zone ~ ed at 90~C. The drawn filaments
35 were crimped to three different levels, i.e., to obtain three different levels of
crimp, and co,~ olldingly of blllkine~ (namely, Support Bulk (i.e., bulk at 0.2
psi) heights of 0.6, 0.8 and 0.9 inches measured on a stack of carded webs, as
described by Tolliver), in a conventional stuffer box crimper of cantilever type
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799.
(3.5 in, 8.9 cm size), and the crimped ropes were relaxed in an oven at 180~C
before cutting. A conventional zlntict~tic overlay finish of about 0.07% by weight
was applied to every sample. The first (lowest bulk) fiber had, however, also been
slickened before relaxing with a finish co~ ;lli"g about 1% silicone per weight of
fiber. The resulting filaments were all cut to staple of length 2 inches (5.4 cm).
Cross sections of the reslllting cut fibers of the invention are shown in Figure 1,
and show a solid axial core and four parallel continuous internal voids, one of
which contains a protuberance on an inside surface of the void to serve as an
identification mark. The outside peripheries of the fibers were round and smooth.
The fibers were found to have an average void content of 17.1 % and a denier perfilament of about 5.5.
For comparison, these Samples of fibers of the invention were
compared with current conventional 4-void fibers, of average void content 15.5%,crimped to similar levels of crimp (providing similar Support Bulk levels), of the
same denier and which were made similarly, except for using a capillary similar to
that of Figure 3, herein, but without any orifice 40 for an identifier, in otherwords, similar to that in Figure 1 of Champaneria, as discussed above. The cross-
sections of these conventional fibers were similar to those of the invention (Figure
1) except that all four voids were clear, i.e., there were no protuberances that act
as identifier marks as shown in Figure 1.
As indicated, the performance and properties of the two sets of fibers
as fiberfill filling material were compared and found to be esse~ti~lly similar, i.e.,
the bnlkine~ of each pair of the fiberfill samples was found to be similar, despite
the differences in cross-section of the fibers. The friction measurements of theslickened fibers were, respectively, 0.265 and 0.293, i.e., e~nti~lly similar.
F.X~l~IP~,F 2
Two types of fibers (one according to the invention, with an identifier,
and the other of conventional cross-section, without such identifier) were prepared
30 e~nti~lly as described in Example 1, except that they were spun through
spinnerets having 212 capillaries, and were of higher density. The void contentsof the filaments, as drawn, were about 17.9% and 19.8%, respectively, and the
relaxed drawn deniers were about 14.4 and 14.3, respectively, for the fiber of the
invention (having the identifier) and the conventional fiber. The properties of
35 both types of fibers were again compared and both fibers were found to have
essentially the same properties, and the same performance as fiberfill.
CA 0223394~ l998-04-02
W O 97/13895 PCTIUS95/12799.
~,X~n~PT/F.3
Fil~ment~ were spun from poly(ethylene terephth~l~te) of relative
viscosity (LRV) 20.4, at a polymer temperature of 291-297~C at 1277 ypm (1167
mpm), through a spinneret with 363 capillaries, at a throughput per capillary of0.278 lbs./hr. (0.126 kg./hr.), using capillary orifice designs as shown in Figure 3
herein. The spun filaments were assembled to form a rope of 65,000 relaxed
drawn denier. The rope was drawn in a conventional manner, using a draw ratio
of 2.9X in a hot, wet spray draw zone m~int~in~-l at 95~C. The drawn filaments
were crimped to two different levels, to obtain two levels of crimp (and
10 correspondingly two levels of blllkiness, namely Support Bulk, measured as
described by Tolliver for carded webs in U.S. Patent 3,772,137), as given for
Sample A and for Sample C in TABLE A below, in a conv~llLional stuffer box
~,fi~ ,. of cantilever type (1.0 in, 2.5 cm size) and the crimped ropes were relaxed
in an oven at 180~C before cutting. A conventional ~nti~t~tic overlay finish of
15 about 0.15% per weight was applied to every sample. The resnlting filaments were
all cut to staple of length 2 inches (5.4 cm).
Cross-sections of the re~lllting cut identifier fibers are shown in
Figures 4 and 5. Each such fil~ment contains a solid axial core and four parallel
continuous voids, one of which contains a protuberance of an inside surface of the
20 void to serve as an identification mark. These fibers have a void content of about
12.5%.
The above fibers were compared with current conventional 4-void
fibers (crimped to similar levels of crimp, providing similar levels of blllkinec~, as
described above, as given for Sample B and for Sample D in TABLE A), of the
25 sarne denier and which were made similarly, except for using a conventional
capillary (without orifice 40, in other words, similar to Figure 1 of Ch:~mps~n~ria
as discussed above). These conventional fibers are shown in Figures 6 and 7.
These cross-sections were similar to those of the invention, except that they
contain no fiber identification marker, i.e., there are no protuberances that act as
30 identifier marks as shown in Figures 4 and 5.
Sarnple A (identifier fibers) and Sample B (conventional fibers) were
crimped to similar crimp levels of about 4.5 crimps per inch (CPI), and a Crimp
Index (CHI) of about 7. Table A shows that the TBRM data measured for such
Samples are very similar, so much so that, when the data are plotted on a graph, as
35 shown in Figure 8, Curves A and B are virtually indistinguishable. Similarly,Sample C (identified fibers) and Sample D (conventional fibers) were crimped to
similar crimp levels of about 7 crimps per inch (CPI), and to a similar Crimp
Index (CHI) of about 11, and give similar TBRM results (see Table A and Figure
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799.
8). In other words, when these two types of fibers are crimped to similar crimp
levels (similar CPI and CHI), the reslllting blllkinecc of the fibers (as measured by
TBRM) is almost the same, despite the differences in their cross-sections, whichare visible in magnified photographs, as shown in Figures 4 to 7.
s
TABT.F A
Pressure He~ht (inches) nnder such Pressure
(psi) Saml le A S~n~ple B S~n~le C S~n~le D
0.001 5.930 5.944 5.295 5.311
0.005 4.316 4.387 3.816 3.855
0.010 3.370 3.425 3.098 3.132
0.040 1.588 1.609 1.869 1.879
0.20 0.500 0.527 0.813 0.822
As indicated hereinabove, a 3-void filling fiber with a smooth round
peripheral surface is disclosed by Hernandez et al. in U.S. Patent No. 5,458,971,
so the following Example 4 was performed to make 3-void filling fibers with and
without identifiers in one of the voids, and to compare their properties and
performance as fiberfill.
Fig. 9 shows a spinneret capillary for spinning identifier filaments
with three voids. It will be noted that the capillary is segmenteA, with three
segmentc 51 disposed symmetrically around an axis or central point C. Each
segme~t ~L consists of two slots, namely a peripheral arcuate slot 52 and a radial
slot ~, the middle of the inside edge of peripheral arcuate slot ~ being joined to
the outer end of radial slot 53, so each segment forms a kind of "T-shape" with the
top of the T being curved convexly to form an arc of a circle. Each peripheral
arcuate slot 52 extends almost 120 deg. around the circumference of the circle.
Each radial slot 53 comes to a point 54 at its inner end. Points 54 are spaced from
the central point C. Each peripheral arcuate slot ~ is separated from its neighbor
by a distance which is referred to as a "tab". The short faces of neighboring
peripheral arcuate slots ~ on either side of each tab are parallel to each other and
parallel to the radius that bisects such tab. In many respects, the capillary design
shown in Figure 9 is typical of designs used in the art to provide hollow filaments
by post-coalescence spinning through segmented orifices. Points 54 at the inner
ends of radial slots 53 are provided in the spinneret capillary design shown in Fig.
9, however, to improve coalescence of the polymer at the center of the fil~ment,i.e., to ensure that the three voids do not become connected. An important and
novel difference in Figure 9 herein (that differentiates from orifice designs of the
CA 0223394~ l998-04-02
W O 97/13895 PCTrUS95/12799.
prior art) is the provision of an orifice 60. Molten polymer extruded through
orifice 60 solidifies and coalesces on an internal wall of one of the voids of the
filament formed by post-coalescence of molten polymer extruded through slots
51, 52 and 53 to form a protuberance partially filling one of the voids and acting
5 as an identifier when the cross-section of that fil~ment is çx~mined under
m~gnification. The relative location of the identifier protuberance within the void
may vary along a length ofthe fil~ment as will be understood. Also, as may be
understood and as has already been explained for multi-void fibers contz~ininp
more than three voids, the invention lends itself to many variations. For example,
10 more than one void may be partially filled by providing, correspondingly, more
than one orifice like orifice 60.
T~'XAl~IPT,F 4
Filaments were spun from poly(ethylene terephth~l~t.-) of relative
viscosity (LRV) 20.4, at a polymer temperature of 291-297~C at 1277 ypm (1167
mpm), through a spinneret with 363 capillaries, at a throughput per capillary of0.278 lbs./lLr. (0.126 kg.lhr.), using capillary orifice designs as shown in Figure 9.
The spun fil~ment~ were assembled to form a rope of 65,000 relaxed drawn
denier. The rope was drawn in a conventional manner, using a draw ratio of 2.9X
20 in a hot, wet spray draw zone m~int~inç<l at 95~C. The drawn fil~mentc were
crimped to two different levels, to obtain two levels of crimp (and
correspondingly two levels of b--lkiness, namely Support Bulk, measured as
described by Tolliver for carded webs in U.S. Patent 3,772,137, as given for
Sample A and for Sample C in TABLE B below), in a conventional stuffer box
25 crimper of cantilever type (1.0 in, 2.5 cm size) and the crimped ropes were relaxed
in an oven at 180~C before cutting. A conventional ~nti~t~tic overlay finish of
about 0.15% per weight was applied to every sample. The resulting fil~mentc wereall cut to staple of length 2 inches (5.4 cm).
Cross-sections of the resulting cut identifier fibers are shown in
30 Figures 10 and 11. Each such fil~ment contains a solid axial core ~nd three
parallel continuous voids, one of which contains a protuberance of an inside
surface of the void to serve as an identification mark. These fibers have a voidcontent of about 18%.
The above fibers were compared with 3-void comparison fibers
35 (crimped to similar levels of crimp, providing similar levels of blllkin~ , as
described above, as given for Sample B and for Sample D in TABLE B), of the
same denier and which were made similarly, except for using a capillary without
any extra orifice 60, i.e., a capillary as described and illustrated in Fig. 2 of
CA 0223394~ l998-04-02
W O 97/1389~ PCTrUS95/12799
aforesaid U.S. Patent No. 5,458,971. These co~ ison fibers are shown in
Figures 12 and 13, and their cross-sections are similar to those of the invention,
except that they contain no fiber identification marker, i.e., there are no
protuberances that act as identifier marks as shown in Figures 10 and 11.
Sample A (identified fibers) and Sample B (comparison fibers) were
crimped to similar crimp levels of about 4.5 crimps per inch (CPI), and to a Crimp
Index (CHI) of about 7. Table B shows that the TBRM data measured for such
Samples are very similar, so much so that, when the data points are plotted on agraph, as shown in Figure 14, Curves A and B are extremely close together.
10 Similarly, Sample C (identified fibers) and Sample D (conventional fibers) were
crimped to similar crimp levels of about 7.5 crimps per inch (CPI), and to a
similar Crimp Index (CHI) of about 11, and give similar TBRM results (see Table
B and Figure 14). In other words, when these two types of fibers are crimped to
similar crimp levels (similar CPI and CHI), the resulting blllkin~ of the fibers (as
15 measured by TBRM) is virtually incli~tinguishable, despite the differences in their
cross-sections, which are visible in magnified photographs, as shown in Figures
10 to 13.
T~RT F B
Pressllre He;~ht (inches) under such Pressnre
(psi) S~m~rle A S~n~rle B Sample C S~mple D
0.001 5.873 5.925 5.46 5.419
0.005 4.412 4.419 3.932 4.006
0.010 3.497 3.473 3.208 3.251
0.040 1.694 1.643 1.952 1.972
0.20 0.535 0.550 0.861 0.861
In all the above co.llL,~u~Li~e tests, where the b-llkin~ of fiberfill
30 comprising identifier fibers of the invention was co~ alcd with the blllkines~ of
fiberfi11 comprising fibers of similar cross-section except that all voids were clear
(i.e., without identifier), the crimping of each set of fibers that were compared was
carried out in the same stuffer-box machine under the same conditions (using thesame velocity, tclll~claLwc profile and ~l~.7~:iWeS). Figure 15 is a m~gnified
35 photograph of crimped 4-void fibers according to the invention, showing some 4-
void cross-sections somewhat similarly to those in the (m~Enified) photographs in
Figs. 1, 4, and 5, except that more of the fiber can be seen so this photograph can
show that these fibers have indeed been crimped conventionally, using such a
CA 0223394~ l998-04-02
W O 97/1389S PCTrUS95/12799
stuffer-box. Similarly, Figure 16 is a (m~gnified) photograph like that in Figure
15, except of crimped 3-void fibers according to the invention.
The multi-void fibers of the invention may be processed into products
such as batts and fiberballs (sometimes referred to as clusters) and further
S processed into pillows, filled apparel, comforters, cushions and like bedding and
fi-rni~hin~ mz~t~ri~l, as disclosed in the art, including that specifically mentioned
herein, and art such as LeVan U. S. Patent Nos. 3,510,888, and 4,999,232, and
various Marcus patents, including U. S. PatentNos. 4,618,531, 4,783,364,
4,794,038, 4,818,599, 4,940,502, and 5,169,580, and U. S. Patent No . 5,088,140
(Belcher et al). Although, hitherto, most fiberfill has comprised cut fiber, such as
has been disclosed above, there has been growing commercial interest in using
deregistered tows of continuous fil~ment~ as fiberfill, as disclosed for example by
Watson in U. S. Patent Nos. 3,952,134 and 3,328,850. Accordingly, application
of the invention to fiberfill in the form of deregistered tows of continuous
fil~ment~ is also contemplated herein, and the invention is not confined to cut
fibers nor to fiberfill comprising such cut fibers. Additionally, as well understood
in the art, it has been commonplace to mix or blend fibers for use as filling
material. Accordingly, it is contemplated that fiberfill according to the invention
may consist e~sçnti~lly entirely of identifier fibers according to the invention, or
these identifier fibers may be mixed witn other fibers, thus, the fiberfill filling
m~t~ri~l may be identified by all or a portion of its fibers being such i~entifil~r
fibers. Reference is made in this regard to my copending application No.
(DP-4711-D), being filed simultaneously herewith, the disclosures of which is
hereby expressly included herein by reference, and which solves the problem of
identifying and differe~ti~ting hollow filling fibers (cont~ining a single
continuous void throughout their fiber length) and fiberfill comprising such filling
fibers. Fiberfill, as is well understood by those skilled in the art, is shorthand for
fiberfill filling material, or more shortly fiberfillin~ material, and refers to a bulky
mass of fibers used to fill articles, such as pillows, cushions and other filrni~hin~
m~tt~ri~l~, including other bedding materials, such as sleeping bags, mattress pads,
quilts, comforters, duvets and the like, and in apparel, such as parkas and other
in~ul~tt-cl articles of apparel, whether quilted or not. Crimp is an important
ch~r~cteristic and provides the bulk that is an e~çnti~l requirement for fiberfill.
Generally, the fibers are crimped by mechanical means, usually in a stuffer-box
crimper, as described, for example, in Halm et al. in USP 5,112,684. Crimp can
also be provided by other means, such as asymmetric qu~nching or using
bicomponent fil~m~-nt~ as reported, for example, by Marcus in USP 4,618,531 and
CA 02233945 1998-04-02
W O 97/13895 PCTrUS95/12799
in USP 4,794,038, and in the literature referred to therein, so as to provide "spiral
crimp". All this is well understood by those skilled in this art.
-
