Note: Descriptions are shown in the official language in which they were submitted.
C-14-54-0429
--1--
HEATSET PLIED YARNS AND
PROCESS FOR PRODUCING SAME
BACKGROUND OF THE INVENTION
A. Field o~ the Invention
This invention relates to a novel heatset, plied
yarn useful as pile in cut pile carpets and to a process
for producing such yarn.
As used herein the term "plied yarn" means a
yarn composed of two or more singles yarns which are plied
together and includes yarns formed with conventional
twisters or so called "cablers" as well as cabled yarns
formed by cabling two or more plied yarns with cable
twist. Each singles yarn is either a spun yarn or
continuous filament yarn which in turn may be either a
flat yarn or a textured yarn. Usually, for cut pile
applications each singles yarn is textured and has a total
denier ranging from about 500 to about 5000 (e.g. 1230-2640)
and each fiber thereo~ has a denier ranging from about 6 to
about 24. The term "textured yarn" as used herein means a
yarn having latent (undeveloped~ or actual ~developed) bulk.
The term "fiber" as used herein in~ludes both a fiber of
- continuous length (~ilamen~) and a fiber of s~aple length
(e.g. ~ilament cu~ into short lengths).
,~ ~
C-14-54-0429
--2--
B. Description of the Prior Art
Heatset, bulked, continuous filament yarns (BCF)
and spun yarns (staple) are conventionally used as pile in
cut pile carpet constructions (e.g. shag, saxony, frieze
and pin point plush). Cut pile is obtained by cutting the
loops of yarn in a tufted carpet. The cut pile consists of
individual short lengths of plied yarn (hereinafter referred
to as a tuft) each of which projects upwardly from the
surface of ~he carpet backing and terminates as a cut end.
The twist in cut pile tufts provides a rope-like contrast
between the individual tufts and, thereby, establishes an
identity between neighboring tufts, that is, the end of each
tuft is distinguishable from the ends of neighboring tufts.
This identity is commonly referred to as "endpoint
definition". Twist also preserves endpoint definition by
preventing neighboring tu~ts from becoming entangled which
gives a carpet an undesirable matted appearance. Addition-
ally, twist tends to make the tufts stand perpendicular to
the carpet backing. Twist is heatset (fixed) in the plied
yarn so that the tufts produced therefrom resist untwisting
during the construction and life of the carpet, i.e.,
retain good endpoint defintion.
In the typical ba~ch autoclave heatsetting
operation, which represents a majority of the commercial
heatsetting operations, a plied yarn having a latent bulk
is treated with steam at elevated temperatures while the
yarn is under low tension to develop bulk and set twist
in ~he yarn. The heatsetting operation relieves inherent
torque in the plied yarn which would otherwise cause it ~o
untwist and also fixes the shape of the singles yarns,
that is, causes the singles yarns ~o develop a permanent
helical (coiled) shape that locks them into thelr twisted
configuration Traditionally, the first step of the
heatsetting operation is to m~ke skeins from the plied yarn.
The skeins are normally tumbled in a tumbler where live
steam is circulated while the skeins are
6~
C-14-54-0429
--3--
tumbled for approximately 5 minutes. The skeins are then
removed from the tumbler, turned inside out, returned to
the t~bler and processed a second time through the steam
tumbling operation. The tumbling operation develops bulk
in the yarn and relaxes the yarn prior to the actual twist
setting steps. The tumbled skeins containing uniform
moisture are then carefully loaded on to a metal basket which
in turn is rolled into an autoclave. The autoclave is an
extremely large (and expensive) pressure vessel which is
automatically programmed to go through the heatsetting
cycle. A typical such cycle for setting textured plied
nylon yarn involves numerous steam treatments (e.g. five)
of the skeins under varying conditions of temperature,
pressure and time during which the autoclave is vacuum
extracted between each steam treatment~ After the autoclave
operation, the skeins are normally tumbled dry and then
allowed to come to equilibrium with atmospheric (ambient~ -
conditions. The skeins are then rewound into packages on
bobbins for tufting.
Recently, techniques have been developed for
continuously heatsetting plied yarns. According to one
such technique the yarn is slowly passed through a chamber
by means of a conveyor-type belt wherein the yarn is
exposed to a heated fluid (steam or air). According to
another technique the yarn is continuously passed through
two heated tubes wherein the bulk is developed in the
first tube and the yaxn is heatset and a false twist is
imparted thereto in the second tube. Such a technique is
described in U.S. 3,971,200.
The above-described prior art heatsetting
operations have several drawbacks. One drawback is that
the operations require considerable processing space.
Another drawback is that carpet tufts cut from the
resulting heatset yarns tend to untwist with time and
normal wear. The b~tch autoclave operation has additional
.
~9 g
C-14-54-0429
--4--
drawbacks such as not being capable of being run inline with
other operations and being time consuming and labor
intensified.
It is an object of the present invention to
provide a simple and relatively inexpensive process for
continuously heatsett:ing plied yarns which avoids the
above-mentioned drawbacks of the prior art heatsetting
operations.
Another object of the invention is to provide
cut-pile, the tufts of which are more resistant to un-
twisting (i.e. have superior end point definition).
SUMMARY OF THE INVENTION
The foregoing objects are accomplished by the
heatsetting process of the precent invention, comprising:
(1) passing a plied yarn at an overfeed of
from 10% to 40% into a first zone where at
least one jet of heated fluid is directed
laterally against the yarn at a velocity
sufficient to cause fibers of each singles
yarn to entangle with fibers of the other
singles yarn(s) at intervals along the
entire length of the yarn,
(2) passing said yarn rom said first zone through
a second zone where the yarn is in contact
with a hea~ed fluid, wherein the residence
time of the yarn and the temperature of said
heated fluid in said second zone are correlated
to set the twist in said plied yarn, and
(33 thereafter cooling the resulting heatset
plied yarn.
g~
~-14-54-0429
--5--
Preferably, the process is carried out by
continuously passing a plied yarn through a single device
wherein the fibers of each singles yarn are first entangled
with fibers of the other singles yarn(s) (first zone) and
then the yarn is heatset (second zone) using superheated
steam as the heated fluid. The yarn passes from the device
into ambient air where it is cooled. While tangling devices
which are commercially available and/or described in the
literature may be suitably used in carrying out the process
of this invention,slight modification of such tangling
devices may be required, for example, lengthening of the
device may be req~ired in order to provide for sufficient
residence time of the yarn in the second zone (i.e. the
heatsetting zone). While it is preferred to use steam and
particularly superheated steam as the heated fluid in
carrying out the process, heated air or some other heated
fluid such as heated nitrogen or carbon dioxide can also
be effectively used. If desired, the process of this
invention may be conveniently coupled inline with other
yarn processing operations, such as downstream from a
twister or cabler.
The resulting heatset plied yarn is characterized
in that fibers of each of its singles yarns are entangled
with fibers of the other single yarn(s) at intervals
along the entire length of the yarn thereby enhancing the
resistance of the yarn to untwist. The entanglements act
as mechanical bonds which lock the singles yarns together
and help prevent them from untwisting during the
construction and life of cut pile carpet. While the
entanglements are not generally visible or noticeable by
merely viewing the heatset yarn, they may be seen by
6~g
C-14-54-0429
--6--
untwisting the plied yarn. I~hen compared to corresponding
yarns heatset by the conventional batch autoclave heatsetting
process, the resulting heatset plied yarn also has improved
dyeing characteristics and, in particular, improved dye
uniformity and resistant to color fading in the presence
of ozone. It is believed that the improvements are due
at least in part to the act that in the process of this
invention the yarn is subjected to steam for a relatively
short period of time ~e.g. less than a second) as compared
1~ to the batch autoclave process where the yarn is subjected
to steam for ~uch longer periods of time.
Cut pile carpets constructed from plied yarns
heatset by the process of this invention have improved
endpoint definition and improved tuft rigidity. Tuft
rigidity is the abili~y o the tufts to stand perpendicular
to the carpet backing after repeated cycles of compressive
forces (load/no load), such as those encountered in the
normal traffic patte-rns of a carpet.
BRIEF D~.SCRIPTION OF THE DRAWING
FIGURE 1 is a schematic representation of a
preferred embodiment of a device suitable for use in carry-
ing out the heatsetting process of this invention.
FIGURE 2 represents an enlarged lateral section
" taken along line 2-2 in FIGURE 1 and shows internal
structural fea~ures of one embodiment of a device.
FIGURE 3 is a quarter section in perspective of
a preferred embodiment of a forwarding jet suitable for use
in the process of the invention.
~-14-54-0429
--7--
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process of this invention is particularly
useful in heatsetting plied yarns that are intended for
use in the construction of cut pile carpets. Typically,
such yarns are plied yarns composed of two or three singles
yarns (usually two) which may be composed of polymeric
fibers of materials such as polyamides, polyesters,
polyolefins and polyacrylonitrile copolymers. The denier
of the singles yarns is normally in the range of 1230 to
2460 with the fibers thereof each having a denier ranging
from about 6 to about 24, although deniers outside these
denier ranges could also be used. For most cut pile.
applications BCF singles yarns should each have a latent
bulk of at least 15% and preerably in the range of 18 to
35%. The term "% Bulk" as used herein is determined by
the formula:
Ll-L2
~ Bulk = L x 100
where Ll is the length of a sample of yarn before development
of its latent bulk and L2 is the length of the same sample
of yarn after being subjected to 180C. dry heat for five
(5) minutes followed by cooling at ambient temperature for
one minute. The yarn sample lengths (Ll and L2) are
measured with the sample being maintained in a vertical
position by means of a clamp attached to the upper end of
the yarn and a suitable support and a weight of 0.0009
grams per denier (gpd) attached to the lower end of the
yarn, with the measurements being made 90 seconds after
being subjected to 180C. dry hea~. The ~hermal shrinkage
(TS) of the bulked yarn can be calculated by the formula
Ll-L3
~/O TS = L - x 100 where Ll has the same meaning as above
C-14-54-0429
--8--
and L3 is the length of the yarn (L2) after it has been
additionally stressed at 0.8 gpd. The latent bulk is
developed under the heatsetting conditions used in carrying
out the process of this invention.
The manner in which latent bulk is imparted to
the singles yarns is not a critical part of this invention.
Accordingly, latent bulk may be imparted to the singles
yarns by any suitable means, for example, by spinning
techniques or mechanical texturing techniques, such as,
by gear crimping, jet crimping or stuffer-box crimping.
Two or more singles yarns are plied to provide
the plied feed yarn. The singles yarns may be plied by
means of commercially available apparatus specifically
designed for this purpose. From the standpoint of
economics recently developed apparatus referred to in the
industry as "cablers" are preferred. To achieve a plied
yarn of good appearance, the same physical conditions should
be applied to each of the singles yarns, otherwise, a
cork-screw effect will result, for example, the singles yarns
should be of the same count and twist, the direction of
twist should be the same for each and the tension in the yarns
should be equal.
In a preferred embodiment of the process of the
invention, disclosed in FIGURE 1, a plied yarn having latent
bulk (i.e. ~eed yarn 1) is taken from a suitable supply
source (e.g. from a cabler) and passed between driven roll
2 and its associated idler cot roll 3, through forwarding
jet/heat chamber device 4, between driven roll 5 and its
associated idler cot roll 6 and, finally, is wound up on
bobbin 7 (by means of a winder~ not shown) to form a package
8 of heatset, bulked, plied yarn. Roll 2 is driven at a
higher peripheral speed than roll 5 to pro~ide a 10 to 40%
overfeed. The length of device 4 normally will range from
C-14-54-04Z9
_g_
10 cm to 25 cm although the device may be of a longer or
shorter length, if desired. For any given device the
residence time of the plied feed yarn in the device and
the temperature of the steam are correIated to suficiently
set the twlst in the yarn. Under such conditions any
latent bulk in the yarn will also be developed. It is
desirable to use superheated steam so as to avoid un-
necessary wetting of the yarn which can lead to handling
difficulties.
It will be appreciated that, if desired, the
entire embodiment shown in FIGURE 1 could be inverted so
that yarn instead of traveling in a downward direction
would travel in an upward direction, in which case, rolls
2 and 3 would be at the bottom, bobbin 7 (and rolls 5 and
6~ would be at the top~ and device 4 would be inverted
and between rolls 2 and 3 and rolls 5 and 6.
The structure and function of the forwarding
jet/heat chamber device 4 can be better understood by
reference to FIGURE 2 which represents a longitudinal
section along line 2-2 of FIGURE 1. The device is
comprised of a body assembly and a replaceable jet nozzle
9 defining a first zone. The body has an outer shell 10
than can be cylindrical or have a square, rectangular or
other cross section for convenience in fitting into existing
2S equipment. Disposed coaY.ially with the axis of outer shell
10 is an inner cylinder 11 defining a second zone that is
open at its yarn outlet end which projects beyond the end
of the shell and is closed at i~s yarn inlet end by the
cylindrical end piece 12 that is integral with inlet end
shell closure 13. The outlet end of the shell is closed
by end piece 14 that ma~es agains~ the outside of inner
cylinder 11. All junctions or contact surfaces between
end closures and the shell and tube are welded or otherwise
6~ ~
C-14-54-0429
-10 -
sealed to form strong leak-proof joints. In analogy with
shell~and-tube heat exchangers, the open annular volume
formed between ~he outer wall of the inner cylinder and the
inner wall of the shell may be referred to as the "shell
side," and the interior volume of the inner cylinder may be
designated "tube side." Nipple or hal coupling 15 opens
into the shell side to provide an inlet for steam.
Optionally, nipple or half coupling 16 opens into the shell side
to provide a condensate drain connected to a steam trap
(not shown~. An externally threaded rod 17 welded to the
shell provides convenient means for attaching the device 4
to a supporting bracket or to a machine frame.
Cylindrical opening 18 concentric with the axis
of the inner cylinder is formed through the inlet end closure
13. The diameter of the central opening is abruptly reduced
about half way along the axis of the end closure to provide
an annular shoulder 19 that supports jet nozzle 9. The
central opening flares to form a diverging frust~conical
surface 20 into the tube side. A plurality of radial
ports 21 pass through the wall o~ the end piece, forming
passages for steam from the shell side to the tube side.
Removable jet nozzle 9 makes a snug fit into the end piece
opening and bears against a sealing-ring gasket of soft
metal, such as aluminum, suppor~ed by shoulder 19. A
sealing-ring gasket of similar material is placed at the
upper end of the noæzle, the two gaskets and nozzle being
compressed into tight engagement by a follower ring or
gland 22 held firmly in place by cap screws 23.
The structure uf a ~ypical jet nozzle 9 is shown
in the perspec~ive view of FIGU~E 3 which shows that the
axial passage for receiving the yarn undergoing treatment
is comprised of a ~onverging frusto-conical inlet 24 that
C-14-54-0429
-11 -
joins a short cylindrical bore 25 which at its lower end
joins a diverging frusto-conical outlet section 26. Along
a major portion of the length of the nozzle its outside
diameter is reduced to provide a circumferential channel
27 that registers with radial ports 21 of the body assembly
shown in FIGURE 2 The outer edge of the upper end of the
nozzle forms an external conical surface to aid in the
centering and sealing of the upper ring gasket.
A~ least one conduit 28 through which a heated
fluid (e.g. steam) passes connects circumferential channel
27 with inner bore 25. Preferably, a plurality of conduits
28 spaced apart along the axis of the jet and spaced
circumferentially about the a~is, connect circumferential
channel 27 with the inner bore 25. As indicated, for ease
of fabrication, the conduits may have an enlarged entrance
counterbore which conv~rges to a small exit through the
wall of the central bore. The axis of the conduits 28 may
be normal to the axis of the central bore of the jet but
preferably are angled such that an appreciable component of
the steam velocity is directed along the axis of the central
bore. If the direction of movement of the yarn is taken
as the positive direction of the central axis of the bore,
then the axis of the conduits are preferably at an obtuse
angle of 100-175 with respect ~o the central axis of the
bore. The actual diameter of the central bore depends,
of course, upon the size of the yarn being treated. The
cone angles or angles of con~ergence and divergence of the
frusto-conical inlet and outlet sections, respectively, of
the jet nozzle can be equal or unequal. However, to avoid
undesirable turbulence, the divergence angle of the outlet
section is made equal to or less than the divergence angle
of the upper end closure of the device (surface 20 in
FIGURE 2). The cone angles for both converging and diverg-
ing section~ should be within the range of about 15U_95O.
2 ~
C-14-54-0429
-12-
A particularly preferred jet nozzle 9 is that
described in U.S. Patent 3,609,834 to Lamb et al. The jet
nozzle described in this patent differs from that shown
in FIGURE 3 mainly in that it has removable parts (waffers)
which it together to provide yarn passage 24, 25, upper
portion of 26 and conduits 28. This permits for easily
and quickly changing the number size and angle of conduits
28 and also simplifies the manufacture of jet nozzle.
As indicated by numeral 29 in FIGURES 1 and 2,
a metal duct having an open front is mounted directly to
or beyond the outlet end of device 4. Suction line 30
(FIGURE 2) is connected to the duct so that volatile
componen~s or moisture escaping from the outlet of the
device are drawn away from the operating area. When super-
heated steam is used, the steam is withdrawn from the yarnthrough line 30 before any substantial amount thereof is
cooled and converted from superheated (i.e. dry steam) to
saturated (i.e. wet~ steam. Wet steam if in contact with
the yarn will cause the yarn to become damp which-in turn
causes processing difficulties. The suction or vacuum
source connected to line 30 can be the inlet side of a
common air blower with a condenser and condensate trap
upstream of the blower. A water-actuated aspirator or a
low efficienc~ steam jet squelched with water are very
ùseful suction sources, particularly when steam is the
active fluid in the device.
Whileany inert heated fluid may be used in practicing
the present invention~ superheated steam is preferred.
Steam temperatures and pressures which may be used in
providing superheated steam are pubIished in the literature,
such as7 in the "Handbook of Chemistry and Physics".
Although the ~emperature of the steam has some influence
on the tangling of the fibers, its influence is insignificant
in comparison to that of the pressure of the steam.
4~ ~
C-14-54-0429
-13-
Superheated steam or other suitable heated fluid
is directed t'nrough conduit(s) 28 against the plied yarn
at a velocity sufficient to cause fibers of each singles
yarn to entangle with fibers of the other singles yarn(s)
at intervals along the entire length of the yarn. It will
be appreciated that the ~requency of the intervals and the
strength of the entangl'ements imparted to the yarn increases
as the velocity at which the heated fluid strikes the yarn
increases. It will also be'appreciated that as the
frequency of the intervals and the strength of the entangle-
men~s increase, the resulting yarn becomes more resistant
to untwisting. The following test is used to measure the
yarns resistance to untwisting:
The plies of a sample of ~arn measuring
at least 12.5 inches (31.75 cm) in length
are separated from one another at one
end thereof for a distance of 0.5 inch
(1.27 cm). With the length of the yarn
sample in a vertical position and the
separated ply ends entending upwardly,
a clamp is attached to each separated
ply end. A pulling tension is then
exerted on each clamp (i.e. ply end)
- sufficient to move it away from the
vertical yarn length at a constant
rate of 1.25 inches (3.175 cm) per
second in a direction that is perpendicular
to the vertical yarn length and that
produces no lateral movement of th~ vertical
yarn length at the point where the plies
are being separated from one another (i.e.
the clamps are moved in opposing directions
and the angles defined by adjacent ply ends
C-14-54-0429
-14-
are equal -- two ply ends define two
angles each of 180, three ply ends
define three angles each of 120, etc.).
The same pulling tension will be'exerted
in each ply end. As the ply ends are
moved away from the'vertical yarn length,
the yarn length is decreasing in length
at the rate of 1.25 inehes per second
; and is rotating about i~s length. The
pulling tension required to move each
clamp (i.e. ply end) away from the
vertical yarn length a~ the rate of 1.25
inches per se~ond is continually recorded
on a chaxt. However, in carrying out the
test, the clamps and means for moving same
are adjusted so that the pulling tension
exerted on each ply end will not exceed
40 grams. In the event that during the
test movement of the clamps stops (i.e.
a pulling tension of 40 grams fails to separate
the ply ends from one ano~her due to the
presence of entangled fibers), the
entang7ements holding the plies together
are cut (such as with scissors) one at a
time while maintaining a pulling tension
of 40 grams until the clamps are once
again i~ motion ~i.e. once again moving
away from the'ver~ical yarn length at
a rate of 1.25 inches per second with a
pulling tension of 40 grams or less).
Such an event is referred to as a "s~op".
Care should be taken to keep the yarn
sample from snarling at the point where
the plies are separated from one another,
~uch as, by gently holding the sa~ple
C-14-54-0429
-15-
between the thumb and index finger just
below the point where the ply ends are
being separated from one another. How-
ever, the yarn length must not be held
so tightly that the yarn is no longer
ree to rotate. Each tîme the clamps
stop (i.e. a stop occurs) the foregoing
procedure is repeated until the yarn
sample is pulled apart. The number of
stops is recorded and expressed in terms
of stops per foot (30.48 cm) of yarn sample
length. The average pulling tension between
stops is de~ermined from the above-mentioned
chart.
Preferably, the heated fluid is directed through
conduit(s) 28 against the yarn at a velocity sufficient to
provide a plied yarn having on the average at least one
stop per foot of yarn length and an average pulling tension
of at least 10 grams and preferably at least 20 grams. Most
preferably for carpet pile applications, the velocity of
the heated 1uid is sufficient to provide a plied yarn having
from 4 to 20 stops per foot of yarn length with 7-15 being
particularly preferred and an average pulling tension of
at least 10 grams with 20 grams being particularly preferred.
(As the stops per foot of yarn length increase, the yarn
becomes increasingly ~arsh to the touch, decreases in
diameter, and increases in its resistance to untwisting.)
For purposes of comparison a two-ply 1850 denier
nylon 66 BCF yarn when heatset by the conventional batch
autoclave process contains no stop5 and has an average pulling
tension of from 3 to 5 grams. A corresponding plied yarn
formed from spun singles yarns (staple) contains an occasional
stop and also has an average pulling tension of 3-5 grams.
It will be appreciated that in ~he case of yarns heatset
~?.~649gr
C-14-54-0~29
-16-
by the process of this invention the pulling tension will
vary along the yarn length since the strength and frequency
of the entanglements varies. On the other hand, in the
case of a plied yarn heatset by the conventional autoclave
process, there is very little variation in the pulling
tension along the length of the yarn since the yarn does
not have entanglements.
The following examples are given to fur~her
illustrate the invention. In the examples a forwarding
jet/heat chamber device substantially as shown in FIGURES 1
and 2 and ~ jet noæzle substantially as shown in FIÇURE 5
of U.S. Patent 3,609,834 were used.
The device had an outer shell comprised of standard
2.5 inch (6.3 cm) pipe that projected 0.5 inch (1.27 cm)
beyond the outlet end of ~he shell. The inlet end piece,
integral with inner cylinder end closure was bored to a
diameter of 0.75 inch (1.9 cm) with shoulder spaced 0.671
inch (1.7 cm) from the top; the portion of this bore below
the shoulder diverge at a 90 cone angle with the length
of the shoulder being 0.656 inch (1.66 cm).
The overall outside diameter of the jet nozzle
was 0.75 inch and the overall length was 1.327 inch (3.37 cm).
The nozzle con~ained 3 removable waffers as shown in FIGURE 5
of U.S. Patent 3,609,834. The converging inlet of the
nozzle had a 50 cone angle and converged to a bore diameter
of O.078 inch (2 mm). The bore then diverged at a 15 cone
angle and joined the diverging outlet having a 90 cone
angle. The center waffer had one slot and the top waffer
two slots (conduits) each drilled through the wall of the
bore at an angle of 140 with respect to the axis of the
bore. The slots in the top waffer were spaced 0.050 inch
(1.3 mm) on center and the slot in the center waffer was
spaced opposite and equidistant from the slots in the top
C-14-54-0429
-17-
waffer. The slots in the top waffer each had a depth of
O.040 inch (1.02 mm) and a width of 0.012 inch (0.30 mm).
The slot in the center waffer each had a depth of 0.030
inch (0.76 mm) and a width of 0.020 inch (0.51 mm). The
nozzle was locked into the body assembly by means of the
follower ring and two aluminum ring gaskets as shown in
FIG~RE 2.
The device was mounted about 12 inches (30.48 cm)
from a driven feed roll-cot- roll combination on a vertical
frame in a position inverted from that shown in FIGURE 1.
A similar roll combination was located about 10 inches
(25.4 cm) above the device and a winder was located below
this roll combination~ The lower coupling of the device
was connected to a supply of superheated steam by means of
pipe with a pressure gauge and steam pressure regulator
immediately upstream. The upper coupling was plugged. The
device was thermally insulated with standard-thickness
magnesia pipe covering and wrapped with seamed asbestos
cloth. The follower ring was left uninsulated and exposed
so that the jet nozzle could be easily removed and replaced.
Two funnel-mouthed alurninum ducts,one below and one above
the device,were each connected to a vacuum source to draw
away fumes from the operating area.
EXAMPLES 1-9
Two bulked continuous filament (BCF) nylon 66
(polyhexamethylene adipamide) singles yarns each having 95
filaments and a total denier of about 1850 were plied on a
commercial cabling apparatus to provide a 3888 denier, 2
ply S-twist, BCF nylon 66 yarn with zero twist inserted
in the singles yarns and 2.5 turns per inch (tpi) or 9.8
turns per decimeter (tpd~ S-twist inserted in the ply.
Samples of the yarn were processed under va~rious sets of
C-14-54-042g
-18-
conditions. In processing the yarn samples, the yarn was
threaded through the apparatus as shown in FIGURE 1 and
collected onto a bobbin. The denier, % bulk, thermal
shrinkage,and tangle between plies were measured
on each processed yarn sample and are given in the following
table along with the conditions under which each yarn
sample was processed.
s ~f~6'~
C-14- 54-0429
-19 -
~o
h u~
O o o o o o o o O
OA~ ~ A~ A\ A\ A\ A\ A~ A~
~ C
E~
~_
C~ ~ C`l 1~ ~ ~ O
O O ~
_1 ~1
_l O
~.~,v
E~ ,~ o ~ ~ o o o c~
U~
:~1~ c~ O ~;t a\ ~) it o\ ~I o 1`
~1 1 0 a ) ~ ~D O ~1 1~ ~) ~ ~O
C~
~ O ~ I` O
O ~1 ,_1 C`l C~l::: I
4~ \O~
~, e
E~ e v r~
E~ o o ~ cA o o
C~l ~ O O~
E3 ~
o
~ ~ ~ ~7 ~
.
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C-14-54-0429
-20-
E~AMPLE 10
This example illustrates the exceptional
appearance and performance characteristics of carpets
constructed from heatset plied yarns of the present
invention.
1300 denier, 68 filament, 2 ply S-twist bulked,
continuous filament (BCF) nylon 66 yarn having 3.0 turns per
inch (tpi) or 11.8 turns per decimeter (tpd) Z-twist inserted
in the singles yarns and 3.0 tpi S-twist inserted in the
ply was heatset using the procedure described in Example 1
and a steam pressure of 58 psig (17.58 Kg/cm ), ~ steam
temperature of 250C. and an overfeed of 20%. The resulting
heatset yarn (Test yarn) was tufted into a saxony construction
(Test carpet) at 30 ozjyd2 (1.02 kg/m2) pile weight, 7/8
inch (2.2 cm) pile height in Typar R primary backing.
A 1230 denier, 68 filament, 2 ply S-twist BCF
nylon 66 yarn (Control yarn) with 3.0 tpi Z-twist inserted
in-the singles yarns and 2.75 tpi (10.8 tpd) S-twist inserted
in the ply was heatset and its bulk developed by the
conventional batch autoclave heatsetting process (i.e. steam
tumbled in skein form and then heatset in an autoclave). This
yarn was tufted into a saxony construction (Control carpet)
identical to that of the Test carpet.
Each carpet was beck dyed to a gold shade using
disperse dyes. A secondary backing of polypropylene was
- then applied to each carpet. Each carpet was then ~ip
sheared.
As compared to the Control carpet, the Test carpet
was of a cleaner and clearer appearance and had noticeably
better tuft erection, endpoin~ definition and tuft definition.
Each tuft of the Test carpet was individually visible.
C-14-54-0429
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The performance of samplPs of both carpets (Test
and Control carpets) was assessed under identical
conditions. A sample of each carpet was su`bjected to the
"Tetrapod Walker Carpet Test". This test is designed to
predict wear performance of carpets in terms of change in
appearance due to tuft or pile compaction. In the test a
drum is lined with carpet sample with the pile facing inward.
The sample measures 8.75 inches (22.23 cm~ by 24.75 inches
(62.87 cm) cut the long dimension parallel to the tufted
rolls and is conditioned at least 12 hours at 21 + 1C.
and 65% relative humidity ~ 2%. The inside surface of the
drum corresponds to that of the sample surface. An
equiangular tetrapod having rub~er feet and weighing 1.1 kg
is placed inside the drum. The drum is rotated at the rate
of 60 rpm about its cyrindrical axis, thereby causing the
tetrapod to ~umble or walk on the carpet pile. The carpet
samples were examined after being exposed to 10,000; 25,000
and 50,000 revolutions of the drum. Even after 50,000
revolutions, ~he Test carpet sample had a good appearance
and good color retention; no traffic lane was evident and
the carpet had good body. On the other hand, the Control
carpet sample had a matted appearance after 10,000
revolutions. Also, the Test carpet exhibited better
retention of endpoint definition and tuft rigidity than did
the Control carpet.
In another test a sample of each carpet was placed
on a floor in a high school in Decatur, Alabama. After
20,000 traffics on each sample, each sample was steamed
cleaned. Again, the Test carpet exhibited better retention
of endpoint definition and tuft rigidity after the traffics
and after the steam cleaning than did the Control carpet.
The Control carpet appeared mat~ed. In this test a traffic
is one person walking across the carpet sample. Even after
50~000 traffics, a sample of the Test carpet appeared almost
like new and s~ill possessed good endpoint definition and
tuft rigidity.
C-14-54-0429
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E~AMPLE 11
This example demonstxates that heatset plied yarns
of the present invention, when dyed, have improved
resistance to color fading in the presence of ozone as
compared to corresponding yarns which have been heatset by
the conventional batch autoclave process.
1230 denier, 68 filament, 2 ply S-twist BCF nylon
66 yarn with 3.5 tpi of Z-twist inserted in the singles and
3.5 tpi of S-twist inserted in the ply was heatset in the
same manner as the test yarn described in Example 2. This
yarn was tufted into a tip sheared, saxony construction
(Test carpet) at 27.6 oz/yd2 (0.937 kgtm2) pile weight, 7/8
inch (2.2 cm) pile height in Typar R primary backing.
A 1230, 68 ilament, 2 ply S-twist BCF nylon 66
yarn with 2.5 tpi (8.B tpd) Z-twist inserted in the singles
and 2.75 tpi (10.8 tpd) S-twist inserted in the ply was
heatset and its bul.k developed by the conventional batch
autoclave heatsetting process (i.e. steam tumbled in skein
form in an autoclave at 132.2C.). This yarn was tufted
into a saxony construction (Control carpet3 identical to
that o~ the above Test carpet.
A sample of each carpet was beck dyed with one
of six commercially used disperse dye shades. After a
secondary backing of polypropylene was then applied to the
dyed carpet samples with latex, the pile was tip sheared.
- The color fading of each dyed carpet sample was measured
after three ozone cycles by AATCC Test Method 129-1968 which
expresses fading as a relative Gray Scale value ranging
from 1 to 5 with 5 being the least faded and 1 being the
most faded. The results o the testing are given in the
following table.
C-14-54-0429
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TABLE II
Carpe_ Sample Gray Scale Number
.1. Light Blue
Test 3 1/2
Control 3
2. Beige
Test 3
Control 2 1/2
3. Spring Green
Test 2 1/2
Control 2
4. Kentucky Green
Test 3
Control 2 l/2
5. Rust
Test 2 1/2
Control 2.
The results in Table II show that disperse dyed
carpets prepared from heatset yarns of`the present invention
have improved resistance against fading in the presence of
ozone. A difference of 1/2 Grade Scale is generally recognized
in the trade as bein~ significant.
EX~LE 12
A 2.5 cotton count, 2 ply S-twist nylon 66 spun
yarn with 4.5 tpi (17.7 tpd) of Z-twist inserted in the
singles and 3 tpi (11.8 tpd) of S-twist inserted in the
ply was heatset according to the present invention using
the same procedure and conditions that were used in heat-
set~ing the yarn described in Example 1 and a steam pressure
of 120 psig tl7.58 kg/m2), a steam temperature of 250C. and
an overfeed of ~0%. The individual singles yarns were
composed of fibers having a staple length of 7.5 inches
(19.05 cm) each of which contained 8-10 crimps per inch
(3.15-3.94 crimps per cm). The resulting heatset yarn
was tufted into a plush construction of acceptable
appearance.
