Note: Descriptions are shown in the official language in which they were submitted.
CA 02424127 2003-03-27
TITLE
APPLICATION OF A FLUOROCHEMICAL SOLUTION TO A FINISHED
FIBER
FIELD OF THE INVENTION
The invention relates to an application of finish
solution to yarn, and more particularly, to applying a
fluorochemical solution to a fiber or yarn after the
fiber manufacture or spinning process. The yarn can be
twisted, heat set or treated with any other type of
conventional fiber finishing treatment prior to
applying the fluorochemical solution using a roller
application.
BACKGROUND OF THE INVENTION
Flooring articles, such as carpets, that provide
good soil resistance, stain resistance and water
repellency are desired by designers and consumers. It
is known to use fluorochemical solutions to improve the
soil resistance, stain resistance and water repellant
features of flooring articles made from yarn. However,
conventional methods of applying fluorochemical
solutions to the yarn have normally taken place during
the process of manufacturing the fiber. For example,
in one method of manufacturing a fiber, the
fluorochemical finish or solution is applied to the
polymer during fiber spinning: after the quench zone
and prior to the feed-draw zone; or before winding the
yarn. Applying the fluorochemical at these locations in
the fiber manufacturing process created or compounded
fiber breakage or housekeeping problems in the process.
At the location between the quench zone and the feed-
draw zone, fiber breakage occurs because of the finish
deposits that accumulate on the spinning rolls. At the
location prior to winding in the fiber manufacturing
process, dripping of the finish solution occurs when
the fluorochemical solution is added at this location
leaving residue on the spinning process equipment
creating a housekeeping problem. The equipment must be
shut down for cleaning of the housekeeping problems and
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thus affects productivity. Because of these problems,
the present methods of applying fluorochemicals in the
fiber manufacturing process are undesirable. A method
that avoids the housekeeping and fiber breakage
problems described above is desirable.
The following disclosures may be relevant to
various aspects of the present invention and may be
briefly summarized as follows:
JP62 62-85080 to Ochi et al. discloses the
application of a fluorine-containing lubricant to short
fibers or filaments, especially to undrawn fibers, of
polyamide systems by well-known methods such as roller
coating, dipping, sprinkling, and is ideally for use as
the spinning lubricant when drawing.
JP-60-126375 to Toun et al discloses a readily
dyeable stain-proofing fiber. The readily dyeable fiber
is coated with a film of fluorine-based stain-proofing
agent containing a fluorine-based wetting agent. The
fluorine based stain-proofing agent was applied to the
finished product rather than to the finished fiber.
While it is known that finishes such as a tint
solution can be applied by spraying the solution
through spray nozzles onto a heat-set yarn, it was
found that fluorochemical solutions do not adhere to
the yarn or fiber surface when applied using a spraying
method. Furthermore, it is believed that an adequate
level of fluorochemical solution is not provided to the
fibers by spraying. It is desired to have a method for
applying fluorochemical solution to a multifilament
yarn or fiber so that the housekeeping concerns
associated with applying fluorochemical solution during
spinning are eliminated and the soil resistance, stain
resistance and water repellency of the ultimate
flooring article or other finished article is
optimized.
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SUMMARY OF THE INVENTION
Briefly stated and in accordance with one aspect
of the present invention, there is provided a method of
treating a finished fiber comprising the steps of:
a) manufacturing the finished fiber; and
b) applying a fluorochemical solution to the
finished fiber.
Pursuant to another aspect of the present
invention, there is provided an apparatus for treating
a finished fiber comprising: means for manufacturing a
finished fiber; and at least one roll that carries a
fluorochemical solution and contacts the finished fiber
having a fiber surface, the at least one roll being
rotatable applies the fluorochemical solution onto the
fiber surface as the at least one roll rotates.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the present invention will
become apparent as the following description and
example proceeds and upon reference to the drawing, in
which:
Figure 1 is a schematic illustration of an
embodiment of the present invention for application of
a fluorochemical finish to a heat set and twisted yarn
on heat setting equipment.
While the present invention will be described in
connection with an embodiment thereof, it will be
understood that it is not intended to limit the
invention to that embodiment. On the contrary, it is
intended to cover all alternatives, modifications, and
equivalents as may be included within the spirit and
scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION OF THE INVENTION
As used herein the following terms may be used for
interpretation of the claims and the specification:
The terms "yarn" and "fiber" refer interchangably
to a cohesive bundle of multiple filaments produced and
processed as one.
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The terms "finished multifilament yarn," "finished
fiber", and "finished yarn" are used interchangably to
refer to a synthetic single. or multifilament yarn upon
completion of manufacture by a fiber manufacturer
(e.g., DuPont or BASF) and otherwise ready to be
incorporated into a finished article such as a carpet
(e. g. by tufting, weaving or other means) or other
flooring article and apparel.
The term "mill" refers to the entity that creates
a finished article such as a flooring article (e. g.
carpet or rug) and apparel (e. g. socks, swimwear, etc.)
from the finished yarn.
The term "fluorochemical solution" or
"fluorochemical finish" refers to a fluorine based
solution (e. g. polymer containing perfluoro akyl
chains ) .
Reference is now made to the drawings, where the
showing is for the purpose of describing a preferred
embodiment of the invention and not for limiting same.
Figure 1 illustrates a process of the invention
using preferably dual finishing rolls to apply the
fluorochemical solution to the surface of the finished
fiber subsequent to the heat setting process. It is
believed that one roll can also be used to cover the
entire surface area of the finished fiber with
fluorochemical solution in the present invention.
The finished fiber is typically twisted and heat
set prior to the application of the fluorochemical
solution thereto, when the finished article is, for
ehample, a carpet, since these steps impart the
necessary body to be useful in carpet forming and the
ultimate use of the carpet. Additionally, since the
most common means of forming a carpet is Lay tufting,
and the most common type of multifilament fiber used is
white dyeable nylon, the finished yarn typically has
already been subjected to twisting and heat setting by
conventional means well known to fiber processors. The
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following example describes an embodiment of the
present invention shown by Figure 1.
Example
Process Apparatuse
Twisted yarn bundles 10 of 1245 denier DuPont
Antron" nylon fibers, having twelve ends, were sent
through a Superba Tunnel 20 (SuperbaTM Model SUTBP) at
a speed of 500 meters/minute. The yarn bundles were
coiled on a perforated SuperbaTM belt moving at a speed
of 15 meters/minute. The SuperbaTM Tunnel operated at
a temperature of 265°F. The twisted bundles of nylon
yarn 10 were heat set as they passed through the
SuperbaTM Tunnel 20. The heat set twisted nylon yarn
bundles, upon exit from the SuperbaTM Tunnel 20, were
straightened by passing over a series of rods (not
shown). The straightened fiber 11 was then transported
over two rollers 31, 32 en route to the winding area
55. The finish rolls, 40 and 50, had a diameter of
about 4.5 inches and a width of about b.25 inches. The
straightened fiber bundles 11 traveled past roller 33
and onto dual rolls 40, 50 rotating in the direction of
arrows 41, and 51, respectively. In this test, the
dual rolls 40, 50 were located a distance of about 10
inches, center to center, from each other on either
side of the straightened fiber bundles 11. The dual
rolls 40, 50 contacted opposite sides of the fibers
covering the entire surface area of the straightened
fiber bundles 11. The rotational speed of the dual
rolls 40, 50 was varied from 20 rpm (revolutions per
minute), 35 rpm, 45 rpm, 48 rpm, 55 rpm, 58 rpm and 84
rpm as shown by the attached tables. The
fluorochemical used was an anionic polyfluoronitrogen-
containing soil resist agent prepared according to US
Patent No. 5,580,645 using sodium alkyl sulfonates as
the surfactant to stabilize the emulsion, e.g., N130,
made by E. I. Du Pont de Nemours and Company, Inc. (A
detailed description of N130 is provided in US Patent
No. 5,948,980 and is incorporated herein by reference.)
CA 02424127 2003-03-27
The N130 fluorochemical was diluted with water at 5:1,
15:1 and 20:1 ratios to form the fluorochemical
solution used. (See Table I). (Note: By 5:1
concentration, it is meant five parts water to one part
of 1000 N130; for 15:1 concentration, it is meant 15
parts water to one part of 1000 N130 and so for other
concentration ratios used herein.) The fluorochemical
solution was applied via the finish rolls 40, 50. The
rolls 40, 50, are made of a ceramic material. The
fluorochemical solution was pumped from a finish tank
(not shown) into the finish pans 42 and 52 located just
under the finish rolls 40, 50, respectively. The finish
rolls 40,50 were lubricated with fluorochemical
solution from these pans by rolling the finish rolls
through the pans 42, 52 containing the fluorochemical
solution. The level of fluorochemical solution in the
pans 42, 52 was kept constant by allowing a small
amount of fluorochemical solution to overflow over the
edge of the pan and be caught and transferred back to
the finish tank. The straightened yarn bundles 11 were
run over the rolls 40, 50 as shown in the Figure 1,
allowing application of the fluorochemical solution or
finish on both sides of the yarn bundles 11. The yarn
bundles 12, now having fluorochemical solution applied
thereto, were transferred to a winding machine after
passing over roller 34, located about twenty (20)
meters from the rolls 40, 50 for adequate air drying.
Each bundle was separately wound on a tube (not shown).
The fluorine level (in ppm) was determined using
the DuPont Fluorine Analysis/Combustion Method. Briefly
described, this method involves measuring fluorine on
yarn. A weighed sample is burned in a flask containing
NaOH (sodium hydroxide) solution and the gases are
dissolved in the NaOH solution to form sodium fluoride.
The amount of fluorine in sodium fluoride solution is
measured using a pre-calibrated Fluoride Ion Activity
Electrode. Further details of the method are available
from DuPont, in Seaford, De under the Du Pont Test
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Method - TM 0371-86 called Fluorine Analysis/Combustion
Method.
Process Results:
The above process was used to determine the amount
of fluorine (ppm) that could be applied by the dual
rolls on the finished fibers. The results are shown in
Tables I-TV.
Each of the Samples in Table I, represent a fiber
bundle lot (meaning more than one fiber bundle with
fluorochemical solution applied after fiber
manufacture). The average fluorine level values of the
bundled finished fibers shown in the Tables reflect the
combined tubes or samples used in manufacturing a
finished product. Tables I - III, show that by varying
the roll speed of the dual rolls from 45 to 84 rpm at a
concentration of 20:1, the average fluorine values
ranged from 186 ppm to 537 ppm. Table I, Sample C,
showed an average fluorine value of 300 ppm at a
concentration of 15:1 with a roll speed of 45 rpm.
The roll speed and the fluorine concentration were
varied to determine if the process of the present
invention could provide desired fluorine concentration
on the finished fibers. For example, it is known that
the application of fluorochemical solution to fibers
provides desirable characteristics such as good soil
resistance, good stain resistance, and water
repellency. In order to achieve these desirable
characteristics, an average fluorine value of about 400
ppm (parts per million) to about 800 ppm is required on
the finished fibers. This desired average fluorine
value range was based upon the average fluorine ppm
range that achieved the best soil resistance, stain
resistance, and water repellency results when the
fluorochemical solution was applied during the spinning
operation. The results shown in Table IV show that
increasing the fluorine concentration to 5:1 and using
a roll speed of 35 rpm provides an average fluorine
value of 510 which is in the range desired
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(i.e.~400ppm- 800 ppm). As shown in Table IV, and
Tables I-III, the present invention contains
flexibility to achieve a variety of fluorine amounts on
the finished fibers.
The process of applying the fluorochemical
solution to the finished fiber avoids the housekeeping
and fiber breakage problems that occur when the
fluorochemical is applied during the fiber spinning
operation. Twisting the finished fiber prior to the
fluorochemical solution application is preferred, but
not required, because the twisting of the fiber
strengthens the fiber reducing fiber breakage problems.
Additionally, the roll application, preferably dual
roll application, is capable of supplying desired
amounts of fluorine to the finished fibers as shown by
Tables I-IV.
TABLE I:
Samples Concentration Roll Fluorine (ppm) Avg. of
of N-130 Speed Fluorine
( rpm) (ppm)
A 20:1 84 648, 428, 534 537
B 20:1 45 200, ~58, 189 216
C 15:1 45 231, 297, 370 300
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TABLE II:
Concentration of N-130 = 20:1
Roll speed = 48 rpm
Avg = 186 ppm Fluorine (F)
Tube Number F (ppm)
1 158
2 158
3 124
4 137
5 217
6 ~23
7 174
8 L 72
9 232
235
11 159
12 142
13 155
14 168
223
16 222
17 162
18 182
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EXAMPLE III:
Concentration of N-130 = 20:1
Speed = 58 rpm
Avg. - 285 ppm Fluorine
Tube Number F (ppm)
1 179
2 435
3 308
4 196
5 L32
6 203
7 412
8 218
9 338
10 289
11 211
12 2 67
13 358
14 244
252
16 247
17 314
18 435
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Example IV
Concentration of N130 = 5:1
Roll Speed (rpm) Fluorine (ppm) Average Fluorine
(Ppm)
20 260, 250 255
35 440,580 510
55 860, 1150 1005
The amount of fluorine applied to the fiber or
yarn bundles by the rolls was increased by increasing
the rotational speed of the finish rolls. It is
believed that a rotational speed of a single finish
roll in combination with the appropriate amount of
fluorochemical solution applied to the finish roll,
would enable the entire surface area of the finished
fiber to be covered using a single finish roll. Thus,
eliminating the need for two finish rolls to apply the
fluorochemical solution.
In another embodiment of the present invention, it
is not required that any heat setting or other treating
of the finished fiber occur for the enhanced properties
of the finished fiber to occur in the ultimate product.
These°enhanced properties include improved soil
resistance, stain resistance, and water repellency.
These improvements are of importance to manufacturers
and consumers of the finished product (e. g. carpets,
rugs, and apparel).
A novel element of the present invention is when
the application of the fluorochemical solution to the
finished fiber occurs. The fluorochemical solution is
applied after fiber manufacture, typically at a fiber
processor or carpet mill, and prior to the manufacture
of the finished article, (e. g. the carpet, socks,
swimwear), thereby avoiding the housekeeping and fiber
breakage problems of other methods. Additionally, the
present invention uses finishing rolls to apply the
fluorochemical solution rather than spraying the
finished fiber or finished article. The present
invention provides sufficient fluorine based solution
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to the fiber for better soil resistance, stain
resistance, and water repellency of the finished
article that spraying the fluorine based solution does
not accomplish due to lack of adherence of the fluorine
solution to the fiber. It is believed that any polymers
containing perfluoro akyl chains are applicable to the
finished fiber of the present invention as a
fluorochemical solution. Examples of applicable
fluorine based solutions are described in US Patent
Nos. 5,414,111, 5,411,766 and 4,517,376.
It is therefore apparent that there has been
provided in accordance with the present invention a
process for applying fluorochemical solution to a
finished fiber after manufacture of the fiber but prior
to manufacture of the finished product, e.g. a tufted
or woven carpet, socks, swimwear and other articles
made from the finished fiber. While this invention has
been described in conjunction with a specific
embodiment thereof, it is evident that many
alternatives, modifications, and variations will be
apparent to those skilled in the art. Accordingly, it
is intended to embrace all such alternatives,
modifications and variations that fall within the
spirit and broad scope of the appended claims.
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