Note: Descriptions are shown in the official language in which they were submitted.
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001 -1-
002 BOllNCE CRIMP TEXTURIZING PROCESS AND APPARATUS
004 BACKS~ROUND OF THE INVENTION
005 1. Field of the Invention
006 This invention relates to an improved method and
007 apparatus for bounce crimp texturizing yarn. In a further
008 aspect this invention relates to an accumulatorless bounce
009 crimp process and apparatus wherein relative yarn tension is
010 sensed and yarn tension adjusted to prevent yarn tangling and
011 yarn crimp straightening.
012 2. The Prior Art
013 Synthetic tnermoplastic yarn materials are produced
014 as a nunber of continuous, straight, smooth filaments. Such
015 yarns have little bulk, and their utility in textile applica-
016 tions is thus rather limited.
01? In order to enhance the bulk and texture of synthetic
018 yarns, a variety of crimping processes have been used in the
019 pas~:. One- common technique which has been used for thermo-
020 plastic yarns is to bend the yarn filaments and heat the yarn
021 while the filaments are in bent or crimped configurations,
022 commonly referred to as false twist texturizing. Another type
023 of texturizing is fluidized texturizing such as, for example,
024 described in ~.S. Patent 2,869,967.
025 An especially good texturizing technique, in terras of
026 yielding a high-bulked yarn, is known as "rebound" or "bounce
027 crimping". Bounce crimping entail~ hurling yarn, propelled by
028 a heated fluid through a jet, in a continuous stream-like flow
029 against a foraminous surface upon which the yarn impinges and
030 from which the yarn instantaneously rebounds or bounces. The
û31 impact of the yarn upon the foraminous surfa~e axially buckles
032 and crimps individual filaments of the yarn while the heated
033 fluid passes through the foraminous surface. The texturized
034 yarn progresses without tension and substantially by rebound
035 inertia away from the crimping zone and, in the prior art
036 process, is guided to a collection station where the yarn is
037 heated and then cooled to heat-set the crimp prior to winding
038 upon a storage spool.
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001 -2-
002 Thermoplastic yarn texturized by the foregoing bounce
003 crimping process possesses, inter alia, exceptional covering
004 capability and a high degree of resiliency; note U.S. Patent
005 3,686,848.
006 The basic process and apparatus for practicing the
007 bounce crimp texturizing process is described by Clarkson in
008 U.S. Patent 3,665,567. Eriefly, the Clarkson processs entails
009 feeding a yarn through an elongate slender tube by a jet of
010 steam and hurling the yarn longitudinally against a foraminous
011 screen causing it to buckle in a random manner and bounce away
012 in a random array. The yarn is thereby crimped or texturized
013 and freely rebounds laterally through a passage from which it
014 drops down to a receiver for heat-setting. The steam primarily
01~ passes through the foraminous screen and is collected.
016 Although, bounce crimping produces a particularly
017 desirable produçt, the process has certain sensitivities. Thus-
018 in order to properly conduct bounce crimping, it is Lmportant
019 that the yarn is rebounded from the screen and discharged from
020 the bounce crimper under essentially no tension. The yarn
021 cannot be pulled from the bounce crimper, since tension on the
022 yarn at this point could pull the crimp from the yarn and could
023 also cause the foraminous screen to be bypassed.
024 Various improvements in bounce crimp texturizing
025 processes and apparatus are described in U.S. Patents
026 3,859,696, 3,859,S97 and 3,887,971. All of the apparatus and
027 processes described in these patents and in U.S. Patent
028 3,665,567 are characterized by the use of a J-tube type yarn
029 accumulator wherein the yarn is accumulated (piled) and heat-
030 treated (heat-set and cooled). In U.S. Patent 3,879,819, the
031 J-tube is provided with a photo-cell light sensing means for
032 maintaining a contain height (pile) of yarn in the J-tube by
033 regulating the yarn wind-up speed in response to the sensing
034 means.
035 The J-tube accumulator was used by the prior art to
036 heat-set the crimp on the yarn and to ensure that the yarn
037 rebounded from the bounce crimp screen in a tensionless state
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by permitting the yarn to free fall into the J-tube accumu-
lator. Subsequently, the J-tube was primarily used only
for the second purpose. However, in accumulating or piling
the yarn, tangles were fo~md to occur, resulting in localized
pulling on the yarn as it was wound up, thus causing the
crimp to be pulled out of random segments of the yarn and/or
the yarn to break. The frequency of these breaks necessitated
an increase in the number of operators required to operate
or monitor a given number of texturizing machines and re-
thread the yarn when breaks occur.
Also, where low-denier yarns ~e.g., about 500 denier
or less) are used, the problem is magnified such that accumu-
lator systems cannot be efficiently used. This magnification
is believed caused by the fact that the lower the denier,
the more loops or coils that are in contact with each other
in the accumulator. Hence, the more contact the more chance
there is for filaments of the various loops to tangle with
each other. This increased contact, coupled with the lower
weight of the loops or coils, substantially increases the
likelihood of the loops being pulled out of the accumulator,
resulting in increased piling and tangles, etc.
SUMMARY OF THE INVENTION
The present invention provides a felicitous method
and apparatus for bounce crimp texturizing yarn wherein the
yarn issuing from the bounce crimper is collected without
tensioning the yarn in the critical area (i.e., the freshly
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001 -4~
002 texturized yarn is discharged from the bounce crimper in an
003 essentially tensionless state) and which eliminates inter-
004 mediate yarn accumulation (piling). By eliminating inter-
005 mediate yarn accumulation the present invention eliminates the
006 tangling problems associated with such yarn accumulation and
007 very substantially reduces yarn breaks and localized segments
008 of straightened yarn and facilitates the use of high yarn
009 speeds (e.g., 5200 feet per minute).
010 In one embodiment the invention comprises an
011 accumulatorless process for bounce crimp texturizing yarn which
012 comprises supplying a yarn to a bounce crimper wherein said
013 yarn is bounce crimp texturized, winding said yarn on a
014 rotating winder spindle, preferably laterally offset from said
015 bounce crimper; sensing the tension on said texturized yarn at
016 a po~ition between said. bounce crimper and said wind-up means
017 and.decreasing the wind-up speed of said texturized.yarn when,
018 and: during the time, said. tension exceeds a predetermined
019 value; and increasing the wind-up speed of said yarn when, and
020 during the time, the sensed tension is equal to or less than
021 said predetermined value.
022 Another embodiment of the in~ention comprises a
023 bounce crimp texturizing apparatu comprising a bounce crimp
024 texturizer; means for supplying yarn to said texturizer, wind-
025 up~means for collecting the texturi3ed yarn; tension sensing
- 026 mean for sensing the relative tension on said yarn at a
027 lo~ation between said bounce crimp texturizer and said wind-up
028 means; controller means operatively connected to said tension
029 sensing means and a means for adjusting the rate of yarn
030 take-up,. for controlling the rate of yarn take-up in response
031 to said sensed tension whereby the rate of yarn wind-up is
032 decreased when, and so long as, the yarn tension sensed by said
033 tension sensing means exceeds a predetermined value and
034 increased when, and so long as, the tension sensed by said
035 slack sensing means is equal to or less than said predetermined
03~ value.
037 A further embodiment of the pro~esses and apparatus
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002 comprises the adapta~ion of the aforedescribed processes and
003 apparatus to the production of conjugate and novelty yarns.
004 This is accomplished by feeding two or more yarns to the bounce
00S crimp texturizer.
006 In one preferred embodiment of the above processes
007 and apparatus, relative tension is sensed by sensing the
008 relative tightness of the yarn and in another preferred embodi-
009 ment by sensing the relative slack of the yarn.
010 BRIEF DESCRIP$ION OF THE DRAWING
.
011 The drawings represent preferred non-limiting embodi-
012 ments of the process and apparatus of the invention, wherein
013 like reference numerals refer to like parts, wherein:
014 FIG. l is a schematic elevation reprssenting a yarn
015 processing system and apparatus according to the invention;
0l6 FIG. 2 is a section view of FIG. l along line 2-2;
011- FIG. 2A i5 a section view corresponding to FIG. 2 but
018 wherein the photosensing means have been repositioned to sense
0l9 yarn slack.~
020 FIG. 3 is a schematic elevation representing an
021 adaptation of the yarn processing system and apparatus shown in
022 FIG. l to the production of conjugate and novelty yarns.
023 F~RT~ER DESCRIPTIO~ OF T~E
024 INVENTION A~D PREFERRED EMBODIMENTS
025 The present invention is applicable--to thermoplastic
026 yarns and deniers which can be bounce cromp texturized. Such
027 thermoplastic- yarns include, for example, nylon yar~s, e.g.,
028 nylon 66, nylon 6, polyolefin yarns, e.g., polypropylene,
029 combination yarns such as combinations of nylon and
030 polypropylene; and the like. The drawn yarn fed to the
031 texturizer typically has ~ denier in the range of about from
032 l00 to 5000.
033 Referring now to FIG. l of the drawings, a preferred
034 non~limiting embodiment of the invention will be described.
035 The overall yarn processing apparatus typically
036 comprises a panel board or frame 20 upon which the various
037 operative components of the apparatus, described hereinbelow,
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001 -6-
002 are mounted. Undrawn thermoplastic yarn 1 (e.g., polypro-
003 pylene, nylon 66, etc.) is fed from a supply package of yarn,
004 not shown, to a first driven godet roller 3 with skewed
005 separator roll 2 and then to a second driven godet roller 5
006 with skewed separator roll 4. Godet rolls 3 and 5 can be and
007 typically are heated. Rolls 4 and 5 advance the yarns at a
008 much greater speed than the rolls 2 and 3, thereby drawing the
009 yarn. For example, ~sing nylon 66, rolls 4 and 5 are typically
010 operated at a peripheral speed in the range of about from 3 to
011 3.6 times that of rolls 2 and 3, thereby effecting about a 3 to
012 3.6 draw in the nylon 66 yarn. Using nylon 66, godet rolls 3
013 and 5 are typically operated at temperatures in the range of
014 about from 275F to 325F. Using polypropylene, rolls 4 and 5
015 are typically operated at peripheral speeds in the range of
016 about 2.7 to 3.1 times that of rolls 2 and 3, thereby effecting
017 about a 2.7 to 3.1 draw~ in the polypropylene yarn, and godet
018 rolls 3 and 5 are typically operated at temperatures in the
019 range of about from 222F to 275F.
020 Yarn 1 is fed from the draw rolls via roll 4 to
021 bounce crimp texturizer 6, typically at speeds in the range of
022 about 3000 to 5000 fpm.
023 A fluid such as steam or heated air is fed to the
024 bounce crimper 6 through line 7. In the bounce crimper, a jet
025 o fluid causes the yarn to be hurled against a screen (not
026 shown) in the interior of the texturizing jet. From thare, the
027 yarns rebounds out through outlet tube 8 in a substantially
028 tensionless state. Yarn 1 leaves bounce crimper outlet tube 8
029 at a speed about 5 to 15% less than the feed speed due to the
030 shortening of the yarn caused by crimping and loop-to-loop
031 compaction, and is ultimately collected on yarn package 16 at
032 over-all average speeds of about 5-10% less than the feed speed
033 due to the retained crimping (but substantial removal of the
034 loop-to-loop compaction).
035 The present invention does not alter the operation of
036 the bounce crimper and thus the bounce crimper can be operated
037 in the usual manner. Suitable bounce crimp texturizers and
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their method of operation are, for exampleJ described in U.S. Patents
3,859,696; 3,859,697; 3,879,819 and 3,887,971.
Yarn 1 leaves outlet tube 8 in a loosely compacted state,
and at this point has a diameter generally approaching or approximat-
ing the internal diameter of the outlet tube 8.
Yarn l then falls into J-tube 9 wh;ch~ guides the yarn past
the sensing device 10. No yarn accumulation occurs in the J-tube and
its use merely represents an adaptation of existing conventional
equipment. Other guide means could also be used in place of or in
addition to the J-tube (e.g., idler rollers and/or guide plates).
Also, the J-tube can be provided with idler rolls to minimize yarn
contact with the walls of the J-tube.
Yarn l leaves the J-tube and passes over idler roll 11 then
through electromag~ttic disc tensîoner 12 and then over idler roll 13
and compensator ar~ roller 14a and is wound to wind up on package 16
driven by driving roller 15.
Referring to FIG. 2 the tension sensing means will now be
described. The tension sensing means is shown as a combined light
source and light receiving means 10a and a slightly tilted reflecting
surface 10b positioned within J-tube 9 in generally diametrically
opposed relationship on opposite sides and generally above the base
path of yarn 1 (shown somewhat enlarged to facilitate illustration).
(The term "base path" generally refers to the path that the yarn would
normally take when taken-up at speeds about 5-15% less than the speed
at which the yarn (or core yarns in the case of novelty yarns) in fed
to the bounce crimper). As the tension on yarn 1 increases, the yarn
is tightened and path of yarn 1 rises, eventually preventing light
from being received by the light receiving (sensing~ meansO ~hen light
is not received by ~he light sensing means 10a, the light sensing means
activates controller 17 (FIG. 1~ which decreases the rate or speed of
yarn take-up of yarn 1 on package 16; for example, by directly reducing
the speed of driving roller 15 or by activating electromagnetic
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disc tensioner 12. This in turn reduces the tightness of yarn 1 and
lowers the path of yarn 1 until it no longer prevents the receipt of
light by light sensing means lOa. When light is received by light sens-
ing means lOa, it in turn activates controller 17 to increase the wind-
up speed thereby increasing tension, thus increas;ng yarn tightness
and again raising the path of yarn until it prevents the receipt of
light by light sensing means lOa, thus repeating the cycle. Accordinglys
the steady state is seldom reached and generally there is a more or less
constant cycling (increases and decreases~ of the yarn take-up speed.
Referring again to FIG. 1, two means of controlling the rate
of yarn take-up are shown; though typically, and preferably, in actual
practice only one method of take-up control will be used. In the first
method controller 17 directly controls the speed of driving roll 15,
for example, by utilizing a conventional D.C. motor and-a speed control
relay. The driving roll motor oscillates between a high and low speed
setting in accordance with the command given by controller 17. In
actual practice it seldom, if ever, reaches the high or low speed
setting because the command is rapidly changed as the photocell is
blocked and unblocked. The present speed settings will vary with the
particular yarn material and denier but typically high wind-up speed
setting of about from 2000 to 5000 fpm and slow speed setting of about
from 1400 to 4500 fpm can be used. The variation in speed selected
between the high setting and low setting will be a function of the
particular system and the rapidity of response desired.
In the second control system illustrated in FIG. 1, yarn
take-up speed can also be controlled by an electromagnetic disc
tensioner and compensator arm system. (The compensator arm system is
a conventional method of changing yarn take-up speed.) In the present
system, when the yarn 1 blocks light from light receiving means lOa, it
activates controller 17 which in turn activates electromagnetic disc
tensioner 12 which causes disc 12a to be lightly pressed against yarn
1, thereby
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001 -'9-
002 increasing the tension on yarn 1 between the tensioner 12 and
003 package 16. This causes compensator arm 14 to rotate about
004 pivot point 14b in a clockwise direction causing the rate of
005 yarn take-up to increase and ultimately lowering the path of
006 yarn 1 so that light is no longer blocked from the light
007 sensing means. The light sensing means then deactivates
008 controller 17 which in turn deactivates electromagnetic disc
009 tensioner 12. Thus, decreasing the yarn tension acting on the
010 compensator arm. Spring 14c then causes the compensator arm to
011 rotate in a counterclockwide direction, which cau es the rate
012 of yarn takeup to decrease until yarn 1 again blocks light from
013 light source means lOa, thus repeatiny the cycle. Where it is
014 desired to rely on the motor speed control discussed above,
015 tensioner 12 can be deactivated and the position of compensator
016 arm 14 ~ixed so that it will not vary with yarn speed and
OI7 interfere with proper operation of the control system.
018 Referring to FIG. 2A, an embodiment of the invention
019 is illustrated wherein the light source and sensing means are
020 positioned below th~ general path of yarn 1 (again shown
021 enlarged to facilitate illustration), so in this instance,
022 light is blocked from the light sensing means when yarn
023 tension, as measured by slack, decreases to a predetermined
024 value. Also in FIG. 2A a separate light source means and light
025 receiver means have been used in place of the combined light
026 source and receiving means and reflecting surface used in FIG.
027 2, for purposes of illustration. In this figure, light source
028 means lOc and light receiving means lOd are positioned
029 generally diametrically opposed on opposite sides of the slack
030 path of yarn 1 and below the selected base path of yarn 1. As
031 slack on yarn 1 increases ~or yarn tightness is decreased), its
032 path through J-tube 9 is lowered until eventually yarn 1 blocks
033 the receipt of light by light receiving means lOd. When this
034 occurs controller 17 (FIG. 1) is activated causing the rate of
035 yarn take-up of yarn 1 to be increased. When light i5 again
036 received by light receiving means lOd, controller 17 (FIG. 1)
037 is activated causing the yarn take-up speed to be reduced. The
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001 -10-
002 operation of this embodiment is the same as described above
003 with respect to FIGS. 1 and 2 with the exception that here the
304 rate of yarn take-up is increased when light is blocked from
005 the light sensing means and decreased when it is received. And
006 again, as with the embodiment described in FIGS. 1 and 2 in
007 actual operation, there will generally be a more or less
008 constant cycling of the rate of yarn take-up.
009 Also, although reflecting means and a combined light
010 source and receiving means have been used in one instance and a
011 separated light source means and receiving means in the other,
012 it should be appreciated that either light sensing system could
013 be used in either instance or other suitable light sensing or
014 photocell systems could be used as well as other systems for
OlS sensing yarn tension. Also, although the optimum vertical
016 position of the light sensing system relative to the lateral
017 base path of the yarn will vary with the process and apparatus
018 details of th~ system, typically the light sensing system is
019 positioned about from 5 to 50 ~m, preferably 10 to 30 mm above
020 or below the base path of the yarn.
021 As is readily apparent, by routine adjustment of the
022 high and low yarn take-up rates and the sensing system, the
023 present inv~ntion ensures that freshly texturized yarn is
024 discharged from the bounce crimper in an essentially tension-
025 less state and eliminates yarn piling and tangles.
026 Referring to FIG. 3, an embodiment of the invention
027 is shown for preparing conjugate and novelty yarns.
028 Fluidized jet and especially bounce crimp crimpers
029 are particularly applicable to the formation of conjugate and
030 novelty yarns because they produce a greater initial separation
031 of the respective yarn fibers and subsequent intertwining of
032 the fibers of the respective yarns. Thus by simultaneously
033 passing two or more yarns through the same bounce crimping
034 means, a conjugate yarn is formed wherein the fibers of the
035 respective yarns are intertwined. If one of the yarns is fed
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001
002 to the bounce criping unit at a slower rate of speed than the
003 other yarns, the faster fed yarns will loop around the slower
004 fed yarn, thus forming an outer yarn effect. The outer yarns
005 are generally referred to as the "effect yarns", whereas the
006 inner yarn is referred to as the "core yarnn. The relative
007 amount of looping of the effect yarns per unit length of the
008 slower fed yarn (i.e., core yarn) will, of course,-depend upon
009 the relative feed speeds of the core yarn and the effect yarns.
010 Because of the crimping and yarn compaction,
011 occurring in the crimping mean~, the novelty yarn will leave
012 the crimping means at a speed about 5 to 15% slower than the
013 speed at which the core yarn was fed to the crimping means.
014 Typically core yarn feed speeds in the range of about from 200
015 to 400 fpm and effect yarn to core yarn feed rate ratios up to
016 about 100:1, can be used. Also, by varying the relative feed
017 rates of the effec~ yarn, or yarns, to the core yarn, slub yarn
018 effects can be obtained.
019- All of the yarns can also be fed to the crimper at
020 about the same rate of speed in which case the resulting yarn
021 will be an intertwined composite o~ the respective yarns;
022 commonly referred to as a conjugate yarn.
023 Returning now to FIG. 3, the operation of the
024 apparatus shown in this figure is the same as described herein-
025 above, with respect to FIGS. 1-3 with the exception that two
026 yarns are fed to the-bounce crimper. Thus, undrawn thermo-
027 plastic yarn 1 is fed from a supply package of yarn (not shown)
028 to a first driver godet roller 3 with skewed separator roll 2
029 and then to a second driven godet roller 5 with skewed
030 separator roll 4. Godet rolls 3 and 5 can be and typically are
031 heated. Rolls 4 and 5 advance yarn l at a much greater speed
032 than the rolls 2 and 3, as already explained with respect to
033 ~IG. l, thereby drawing yarn l. Yarn l is then fed to bounce
034 crimper 6.
035 A predrawn multi-filament yarn la is fed from a
036 supply packup (not shown) to a driven godet roll l3 and about a
037 skewed separator roll 18a and roll 19 to bounce crimper 6,
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001 -12-
002 simultaneously with yarn 1. 8Oth yarns can be fed at the same
003 rate, in which case the texturized yarn product will be a
004 conjugate yarn, or at different rates in which case the slower
005 fed yarn will form the core yarn and the faster fed yarn will
006 form the effect yarn. Where novelty yarns are desired,
007 overfeed effect yarn:core yarn ratios as high as 100:1, or
008 higher can be used but typically will be in the range of about
009 from 3:1 to 50:1.
010 The respective yarns are crimped, intertwined by the
011 action of bounce crimper 6 and issued therefrom as a single com-
012 bined yarn lb. The details of the remaining components-shown
013 in FIG. 3 and the operation thereof are the same as described
014 hereinabove with respect to FIGS. 1, 2, and will not be
015 repeated. Also, although, as shown, light sensing me~ns 10 is
016 positioned above the general yarn path, it should be
017 appreciated that the embodiment, described with respect to FIG.
018 2A could also be practiced with respect to this embodiment.
019 Yarns 1 and la can be of the same or different
020 thermoplastic materials and can have like or different deniers.
021 Also, although for ease of illustration only two yarns have
022 been ~hown per texturizing unit it should be appreciated that
023 more than two yarns could be used, for example 3 to 8 yarns,
024 depending on the size of the bounce crimper and the denier of
025 the yarns.
026 Obviously, many modifications and variations of the
027 --- invention, described hereinabove and below in the claims, can
C28 be made without departing from the essence and scope thereof.
