JPS609135B2 - Clamp-type false twisting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the processing of synthetic fiber yarns, and in particular to a false twisting method for crimping.

A false twisting spindle is currently widely used as a false twisting device.

However, the practical upper limit of the processing speed by the spindle is usually 100 m/min to 150 m/min in terms of yarn traveling speed, and if the speed is higher than this, troubles such as generation of a large amount of fuzz and yarn breakage occur. In addition, with the spindle method, the pull-out tension must be greater than the tension in the twisting area;
When the drawing tension increases, the occurrence of fluff increases rapidly, making it impossible to obtain a winding yarn of good quality. In addition to these spindles, various friction false twisting devices have been proposed. As one type of conventional friction false twisting device, a device is known in which yarn is passed through it so as to come into contact with a friction rotating body having a surface with a large coefficient of friction, and the yarn is twisted by the friction rotating body.
Such a surface friction false twisting device can achieve a high processing speed compared to a spindle. However, as the processing speed increased, yarn breakage increased, and there was a tendency for workability to decrease and fuzz to increase. In particular, in the false twisting of polyester filaments, the occurrence of fuzz and a decrease in strength were remarkable. In addition, in the frictional false-twisting method, combustion is normally performed by the frictional force between the yarn and a high-friction body, so a certain amount of tension is required for twisting, which is different from that seen in the false-twisting method using a spindle. Compared to winding the thread around the pin once to ensure proper twisting, the twisting efficiency is poor, and stick slip occurs easily between the thread and the high-friction object, resulting in uneven twisting and unresolved twisting. This will make it easier for twisting to occur. At the same time, the tension on the untwisting side also increases as the processing speed (travel speed of the yarn) increases, which causes problems in productivity and quality, such as the generation of fluff and yarn breakage, so it is difficult to use in practical processing. The speed limit is about 500 to 600 meters per minute. Furthermore, the number of twists was estimated by either grabbing the yarn while it was running and measuring the actual number of burns, or by referring to the pre-determined correlation between the actual number of twists and the twisting tension. , it is difficult to accurately manage the number of twists. As a different type of conventional friction false twisting device, two rotating disks having an annular convex portion on their circumferences are brought into contact with each other facing each other with their central axes offset, and yarn is passed through the contact portion to perform the false twisting process. It is a device that performs However, with this type of device, a relatively large amount of pressure is required between the discs in order to reliably nip the yarn between the discs, and the surface of the convex part of the discs is easily worn, making it difficult to achieve stable false twisting. was difficult. As another method, it has been considered to perform false twisting by intersecting twisting bands consisting of two endless belts and sandwiching the yarn between them.

However, in this case, when the twisting bands made of high friction bodies used in conventional friction false twisting were run in contact with each other, the surfaces would rapidly wear out, making it impractical. Therefore, in order to prevent wear, it was considered to bring the twisted bands very close to each other, but not to make them actively contact each other, so as to hold the threads together. However, if the object is thick like a rope, it can be stably twisted, but the yarn that can be subjected to false twisting is 0.01 to 1
．． It was difficult to hold it stably because it was extremely thin, on the order of a rib. The present invention enables stable pinning by actively pressing two endless belts and passing yarn between them, and is the first to successfully put false twisting into practical use using the holder method.

The main object of the present invention is to provide a clamping type false-twisting method that can perform false-twisting at high speed. Another object of the present invention is to provide a clamping type temporary combustion method that clamps the yarn and simultaneously provides twisting and feeding effects.

Still another object of the present invention is to provide a holding type false-twisting method that can stably perform false-twisting over a long period of time.

The clamp-type false twisting method according to the invention comprises at least two inorganic belts having a relatively 4.0 mm surface friction coefficient, both belts running intersectingly at an angle and at the point where they intersect. The yarn is passed between the contact surfaces of the belts through an angular region between the directions of travel of the belts, so that the yarn is It is held by both belts and is twisted and fed simultaneously as the belts run.

The present invention will be described with reference to FIG. 1. A false twisting device 1 includes flat endless belts 2 and 3 made of synthetic rubber, for example, which are arranged to cross each other at an angle of 8. 2 and 3 are supported by pulleys 4 and 5 and 6 and 7, respectively, and are driven by drive pulleys 8 and 9 in the direction of the arrow.

As shown in FIG. 2, the inorganic belts 2 and 3 are actively pressed at the intersection, and their surfaces are in planar contact with each other, as they travel in different directions at the same speed. The yarn 10' is heated by a heater (not shown) upstream of the false twisting device 1, passes through the inlet side guide 11, passes through the region of angle 8 between the directions of travel of the endless belts 2 and 3, and passes through the contact intersection surface 12. There, the fuel is temporarily combusted while being held by both belts 2 and 3, and then sent out and taken out via the exit side guide 13. As shown in FIG. 1, the traveling direction of the endless belts 2 and 3 is at an angle of 4 mm from 900 with respect to the traveling direction of the yarn 10.
The belts 2, 3 not only twist the yarn 10, but also provide a pulling action to the yarn 10. That is, if the running speed of the belt 2 is V and the angle between the belt 2 and the yarn 10 is 8, the feed speed V2 given to the yarn 10 by the belt 2 is V2:
V, cos8.

The same applies to the belt 3. As will be described later, the false twisting device 1 can be configured to be able to change the angle between the yarn 10 and the belts 2 and 3, and by changing this angle to a desired value,
The feeding speed of the yarn 10 can also be changed to a desired value. Here, the angle a,,82 between the belts 2, 3 and the yarn 10 is
It is most preferable to adjust it to 82 from the viewpoint of yarn feeding stability. Figure 3 shows the surface speed V of belts 2 and 3.
, (skin/min) and the thread feeding speed V2 (strip/min) inevitably generated by the belt, with respect to the angle between the belt and the thread. In this way, in the false twisting method according to the present invention, the yarn 10 is fed while being held between the belts 2 and 3, so that the feeding speed V
2 and the processing speed V determined by the upstream supply roller and the downstream take-up roller of the preliminary combustion device 1, that is, by adjusting it so that V2=V, the yarn 10 can be false-twisted without any difficulty. This makes it possible to perform ultra-high speed processing, such as false twisting at yarn speeds of 80 to 1000 m/min, without damaging the yarn. In addition, in the false twisting method of the present invention, since the yarn is heated while being carefully attached, unlike the conventional friction false twisting method using contact friction, in which the number of false twists cannot be accurately determined, the number of false twists can be determined as follows. It can be predicted accurately from a theoretical formula such as That is, in the false twisting device of the present invention shown in FIG. 1, the surface speed of the twisting belts 2 and 3 is V, the delivery speed from the false twisting device is V2, and the horizontal The twisting speed acting in the direction is V3, the angle between twisting belts 2 and 3 is 8, and the angle between yarn 10 and each belt 2 and 3 is 8.
,,82 is a, :82=vine, the following relationship holds true.

8 V2=V, cos…”m V3=V・Sin number…■ Also, the cross-sectional area of the thread in the denier method is r2=de×10-6/0.9×p (ground), but de:
Denier r: Yarn radius p: Specific gravity, so rearranging this equation, r=5.95
× 10-4 × Zomatofu (Shu) Furthermore, if this is expressed in diameter, D 1, 19 × 10-5 × Node/p (Desk) ■
The number of rotations of the yarn grain when the yarn is rotated by the running of the twisting belt, Yr. p. m. is expressed by the following formula.

V3-V. SingYrpm:;6 xl. 1
9xl.

-5x value within.・・・． ...'41, the number of twists per 1 is N: Equal: tangX. ．． ．． ．． ．． ．． [5, Shore x 1.
19xlo-5x The angle of the twisted belt expressed in J-bushi is 8
By changing , the number of false twists changes.

To try to find the number of false twists for each material, refer to Table 1 below. Table 1 Materials (Specific gravity) Temporary grandchild number (T no M) t
ana/2 polyester 1.38 31423×〉d
e-tana/2 nylon 1.14 285
60×〉detana/2 acrylic 1.17
28933×Tanao 2 diacetate 1.3
2 30732 The changes are shown in a graph as shown in Figure 4.

As described above, according to the temporary combustion method according to the present invention, the number of temporary combustion can be managed accurately as in the spindle method.

In the false twisting method of the present invention, in which two twisting members are brought into contact and the yarn is propagated in different directions in a ball-held state, wear of the twisting members becomes a problem.

Wear largely depends on the contact pressure between the twisted members and the coefficient of friction. When the present inventor uses an endless belt as a twisting member, the surface of the endless belt has flexibility that can be displaced to some extent in a direction perpendicular to the surface, and exhibits elasticity against a force perpendicular to the surface. Therefore, it has been found that a sufficient narrowing effect can be obtained even at a relatively small bush pressure, for example, 300 tare or less, or even 100 tare or less.

Furthermore, in conventional friction false twisting devices, twisting members with a large surface friction coefficient were generally used to enhance the twisting effect, but the present inventor found that conversely, it is preferable to use a twisting member with a relatively small surface friction coefficient. Ta. In other words, if a high-friction material is used on the surface of a twisted belt, heat will be generated as the belt moves, and the surface will become excessively sticky, causing the belt to not move smoothly and risk coming off the pulleys. . From this point of view, the coefficient of friction between the surfaces of the false twisted belt used in the present invention is preferably <0.5, particularly preferably 0.1 <0.4, and more preferably 0.5. ．．
It has been found that 0.3 is preferable. Figure 5 shows a support mechanism 20 that supports the twisted belt shown in Figure 1.
In this explanatory diagram, the support mechanism for the twisted belt 2 and the support mechanism for the twisted belt 3 shown in FIG. 1 have the same or equivalent structure, so in FIG. Only those that are included are shown.

The rotation shaft of the pulley 4 is supported by a bearing 22 provided on the support base 21, and the rotation shaft of the pulley 5 is supported by a bearing 23 provided on the support base 21. This bearing 23
The support stand 2 is installed so that the tension of the twisted belt 2 can be adjusted.
It is movably provided on the top surface of 1. The support base 21 has an arc-shaped guide hole 25 centered on the center 24 of the intersecting surface 12.
, a bolt 27 is installed as a shield on the fixed frame 26,
The tip thereof loosely passes through the guide hole 25, and a nut 28 is screwed thereto. Further, the support base 21 has a pointer 29, and the fixed frame 26 has a scale 30 corresponding to the pointer 29. That is, by tightening the nut 28 to the bolt 27, the support body 21 is maintained fixed to the fixed frame 26, but when the nut 28 is loosened, the support base 21 is moved within the range of the guide hole 25 with respect to the fixed frame 26. Therefore, when it becomes necessary to change or adjust the introduction angle 82 of the thread 1, for example, when it becomes necessary to change the introduction angle 82 to 4°, loosen the nut 28 and move it to the center 24 of the intersecting plane 12. Rotate the support base 21 clockwise around the center, and when the pointer 29 comes to a predetermined position by looking at the scale 30, firmly tighten the nut 28 on the bolt 27 at that position to tighten the support base 21. The desk may be fixed to the fixed frame 26. In FIG. 5, a part of this state is shown by a chain double-dashed line. If it becomes necessary to increase 02', the support base 21 may be rotated counterclockwise in the same manner as described above. According to the false twisting method of the present invention, since the yarn is held between the twisting belts 2 and 3, the temporary twisting tension T, (the tension upstream from the nipping point 5
and the scale twisting tension T2 (tension downstream from the clamping point) is T. <T2
However, it is also possible to set T,=L,T,>T2.

That is, in the conventional false-twisting method, the yarn is pulled by a thread winding roll or the like and sent out from the false-twisting device. <T2. However, in the false twisting method of the present invention, since the belt applies a feeding action to the yarn, by selecting the processing speed V (yarn feeding speed) as shown in FIG.
The relationship can be varied over a wide range. In other words, Figure 6 shows the temporary lacquer tension T, (grams) when the processing speed V is varied while the speed V2 of the feeding action necessarily generated by the twisting belt is maintained constant at V2 = 750/min. The relationship between T2 and untwisting tension T2 is shown. In this way, the magnitude of the untwisting tension and the false twisting tension can be changed from positive to reverse, which has the effect of providing variety in the appearance of the false yarn, and even at ultra-high speeds. The operability is extremely good, and even in the processing of polyester, no fuzz is observed at all, and the effect is extremely large.

In particular, when T2/T, >1, that is, T2>T, the yarn is pulled between the nip point of the false-twisting belt and the pull-out roller, so fuzz is likely to occur, but when T2/T, Mi1, The occurrence of fuzz is almost completely zero when using strong polyester, nylon, etc., and extremely low even when using low-strength materials such as acetate.

Furthermore, if T2/T, > 1, the bundle of filaments formed by the false-twisting belt will be pulled downstream of the false-twisting belt and break apart into individual filaments, unless they are fused by heating at a considerably high temperature. In the case of T2/T, SI, the filaments remain twisted in an east-centered manner, so a unique crimped yarn with east-centering properties can be obtained. Next, specific examples according to the present invention are as follows.

The materials used were representative synthetic fibers such as polyester, acrylic, and nylon, particularly acetate, which has the lowest strength. When each fiber is processed under the conditions shown in the table below, a crimped yarn with an east-gathering appearance can be easily obtained, and compared to conventional crimped yarns, it has a spun-like appearance, but can be used at high speeds. Moreover, the effect obtained with almost no fuzz was confirmed. Example 1 Next, T. An example under the condition of <T2 is shown.

As is clear from the above examples, in order to suppress the occurrence of fluff, it is preferable that T2/T be 2.0, and it is particularly preferable that T2/T be ≦1.0. -
It is preferable that oo5<voice≦・-o.

Next, in terms of false twisting, the difference in structure is that the belts are in active contact as in the present invention, and passive contact or no contact as in previous attempts.
I will explain why this causes an extremely large difference in effectiveness. In other words, the yarn to be subjected to false twisting is extremely thin. For example, in the case of a 75 denier thread, the diameter is approximately 0.088 mm, so any slight change in the way the thread is held will affect the twisting state and cause variations in the twist. . Conventionally, attempts have been made to apply tension to both belts so that the belts do not come into contact with each other, or to sandwich the yarn with only slight contact. Looseness occurs in the belt, causing slight waving motion on the belt surface during running.

When this minute wave motion occurs, it affects the state in which the yarn is held and causes variations in the twist, which is fatal to the false twisting process. For this reason, practical false twisting has not been possible until now with false twisting devices that do not actively contact the belt. This point will be further explained using an experimental example conducted by the present inventor. The experimental apparatus was installed as shown in FIG.

The inorganic belt 2 has pulleys 34 and 35 provided on the base 31.
is supported by The inorganic belt 33 is supported by pulleys 36 and 37 installed on a support 39 that is slidably combined with a guide 38 on the base 31', and the endless belts 32 and 33 cross each other with their surfaces facing each other. It is arranged so that A guide hole 40 with a female thread is provided in the center of the side surface of the support stand 39, and the guide hole 401 is connected to the support frame 4.
A guide bolt 42 rotatably supported by 1 and threaded around the periphery is inserted. When this guide bolt 42 is rotated, the support base 39 is slid to the left in the figure. As a result, the belt 33 can approach and leave the belt 32 supported by the fixed pulleys 34 and 35 in a direction perpendicular to the belt cross contact surface, and the belts 32 and 3 can
3 can be pressed together and pushed into each other to the desired depth. Diameter of drive pulleys 34, 36...
・Diameter of 54 kite driven pulleys 35, 37 .... Distance between uneven side pulleys 34 and 35 and interval between 36 and 37
...53 side belts 32, 33: Material
Synthetic rubber thickness 1 sail width
12 Working circumference length 25 Speed of the belts 32, 33 9.2 m/min Intersection angle of the belts 32, 33 8 = 120 o thread distance (peripheral speed of the delivery roller) 400/ministOF (
Overfeed) -0.8% WindOF
(〃) 15% yarn: polyester drawn yarn 7We/36 (approximately 0.0 diameter side) The contact state of the belts 32 and 33, that is, the pushing amount, was changed, and the number of false twists per 1 at that time (T /M) was investigated.

Here, the number of false twists (T/M) is calculated as follows:
X Fortress To: Finishes the running thread in a twisted state.

(Skin) Number of untwists when caught and decomposed So: The twisted yarn is cut to the desired length.

(The skin) is grabbed, decombusted, and returned to a non-twisted state.The length and amount of pushing is the state where the belts 32 and 33 in a stationary state are on the border between touching and separating, that is, the belts are barely touching each other. The support stand 39 slides in FIG. 7 with the state set to zero.
The distance traveled in the direction of the belt 32 was measured.

The amount of belt push-in will therefore represent the sum of the push-in depths of both belts 32 and 33. The experiment started with the belt being pushed in until just before it came off the pulley, and the amount of pushing was gradually reduced, and the number of false twists at each time was tested 10 times.

The results are shown in Table 3 and the average false twist number graph in FIG. In addition, in Table 3, the fluctuation rate is the average of the absolute value lx - xnl of the difference between the average value x of the number of false twists and each number xn of false twists, that is, the life
is. IX-Xnl, divided by the average value x and multiplied by 100.

Table 3 As shown in this result, when the thread thickness is approximately 0.088 ribs in diameter, stable twisting occurs when the belts are pushed into each other by 0.5 ribs or more, that is, when they are pressed together sufficiently. It has been shown that when the belt is applied but the belt is not pushed in enough, the twist varies widely and the number of twists decreases rapidly.

Furthermore, it has been shown that when the distance between the belts is 0, that is, they are barely in contact with each other, almost no twist is applied, and the variation in twist is very large. Furthermore, even when the belts are spaced 0.04 skin apart from each other, that is, with a spacing of 0.04 ribs, there is barely enough twist, but the number of twists is extremely low and it is clear that it cannot be put to practical use. Dew. In this way, it is impossible to actually perform false twisting by placing the belts very close to each other and sandwiching the yarn, or by sandwiching the yarn so that they are almost in contact with each other. It is clear from this experimental example that this cannot be done. In other words, the structural difference between whether the belts are pressed together or not is easily seen as a mechanical difference, but as mentioned above, this point means a decisive difference in the false twisting process. This will be clear from the experimental examples.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus according to the invention. FIG. 2 is an enlarged sectional view taken along line 0-0 in FIG.
FIG. 3 is a graph showing the relationship between the running speed V of the twisting belt and the feeding effect V2 exerted on the yarn. FIG. 4 is a graph showing the relationship between the angle between the twisted belts and the number N of twisted belts. FIG. 5 is a diagram showing an example of a support structure for the twisted belt shown in FIG. 1. FIG. 6 is a graph showing the relationship between yarn supply speed V and yarn tension. FIG. 7 shows an apparatus according to the invention for testing the amount of belt push-in. FIG. 8 is a graph showing the relationship between the belt pushing amount and the number of false twists.
Explanation of symbols, 1... false twisting device, 2, 3... endless belt,
4, 5, 6, 7... Pulley, 8, 9... Drive pulley, 10... Yarn. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. At least two running twisted bands are crossed at a certain angle, both twisted bands are actively pressed, and at least one yarn is passed through the intersecting plane, and both twisted bands are are arranged so that they are in contact with the yarn and also in surface contact with each other on both sides of the yarn, thereby giving a feeding action at the same time as the yarn is being twisted with both twisting bands clamped and pressed, and the clamping point is A false twisting tension T_1 applied to the yarn further upstream and an untwisting tension T_1 applied to the yarn downstream from the nipping point.
2 is a false twisting method in which the yarn feeding speed is selected relative to the feeding speed inevitably generated by the belt so that T_2/T_1≦1.0. 2 False twisting tension T_1 and untwisting tension T_2 are 0.005≦T
The false twisting method according to claim 1, wherein _2/T_1≦1.0.