JPS6235498B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a yarn opening nozzle,
More specifically, the present invention relates to a yarn opening nozzle that makes it possible to produce processed yarn with excellent bulkiness when bulking synthetic fiber multifilament yarn using a high-speed fluid. As methods for bulking synthetic fiber multifilament yarns, false twisting and fluid processing are generally widely used. The false twisting method uses a spindle method or a friction method to give yarn a false twist, then heat-treats it, cools it, and then untwists it.The feature of this method is that a processed yarn with excellent bulk can be obtained. Therefore, although the processed yarn is used for applications requiring high bulkiness, the actual processing speed is limited to about 1000 m/min at most due to speed constraints of the false twisting device. On the other hand, the fluid processing method uses unheated or heated high-speed fluid to loop the yarn.
They provide bulkiness by providing tangles, transporting the threads at high speed and causing them to collide with obstacles (porous collision surfaces such as wire mesh), or pushing the threads into narrow rooms. Fluid processing methods, especially methods in which the yarn is transported at high speed by fluid and collides with obstacles, or are pushed into a narrow room to obtain bulky yarn, can be processed at high speeds that exceed the false twisting speed. , is attracting particular attention as a means for continuous spinning, drawing, and bulking processing of synthetic fibers. However, there is a problem in that bulky yarns obtained by fluid processing still have insufficient bulkiness compared to false twisted yarns. FIG. 1 is a schematic diagram showing an example of a fluid processing device, in which a yarn a supplied by a supply roller 1 is conveyed through a yarn guide hole 2 by jetting a high-temperature, high-pressure fluid b from a jet hole 3. heated, thread passage 4
The injected high-speed fluid is forced into the retention chamber 5 through the exhaust hole 6 and is discharged from the exhaust hole 6. The retained yarn is pushed out to the rear of the processing device by the pressure from the rear caused by the jetted fluid, and is kept at a temperature for a certain period of time and set. The yarn that is further pushed out backwards and reaches the cooling chamber 7 is cooled by the low-temperature fluid c, and then passed to the take-up roller 8.
It will be taken over by. FIG. 2 shows an example of a conventionally used nozzle, in which the yarn passage 4 is flared at the end in order to increase the fluid velocity and increase the yarn carrying capacity.
Fig. 3 shows an expansion chamber 9 provided for opening the yarn, and Fig. 4 shows a discharge hole 1 provided to discharge part of the fluid from the expansion chamber 9 in order to increase the opening effect.
0 is set. Although these conventionally used nozzles have the ability to transport yarn or spread yarn, they do not have the ability to give structural differences that govern bulkiness, that is, fine fiber structural differences in the length direction of single yarns or between single yarns. No, but very few if any. Therefore, when bulking yarn is processed using these nozzles, the resulting bulky yarn is mainly crimp-like when pushed into the pushing chamber, and the crimp pitch is coarse and bulky. It's not something I'm satisfied with. Therefore, as a means to narrow the crimp pitch using a conventional nozzle, the fluid temperature is set to the melting temperature of the synthetic fiber yarn or higher, and heating unevenness of the yarn is utilized to make the crimp pitch thinner. The method of creating fine fiber structure differences between yarns is said to be effective, but on the other hand, many dyeing spots occur due to temperature control of high-temperature heating fluid, uneven yarn running, or yarn unevenness when used, making it impractical. poor. The inventors of the present invention conducted extensive research in an attempt to provide an excellent bulky yarn using a fluid processing method. As a result, the nozzle structure was designed to run the yarn in a state of minute vibration in order to prevent the yarn from shifting while traveling through the nozzle passage. Through ingenuity, he achieved his goal. That is, the present invention includes an expansion chamber 9 connected to the downstream side of a yarn guide hole 2 having a fluid injection hole 3 opened so as to give a propulsion force to the yarn, and a yarn passage 4 extending through the center of the expansion chamber to the end of the nozzle. A yarn opening nozzle characterized in that the expansion chamber 9 and the yarn passage 4 are connected to each other by a detour passage 11 provided at a symmetrical position across the yarn passage. . The present invention will be explained in detail using figures. FIG. 5 shows an example of the yarn opening nozzle of the present invention. The yarn a is introduced through the yarn guide hole 2, is suctioned and transported by the injection of high-temperature, high-pressure fluid b from the injection hole 3, and is opened in the expansion chamber 9 connected to the downstream part of the yarn guide hole 2, before reaching the end of the nozzle. In this case, in the present invention, the expansion chamber 9 and the yarn passage 4 are connected by a detour passage 11 provided symmetrically with the yarn passage 4 in between. Fine vibrations are caused in the yarn to generate fine fiber structure differences in the length direction of the yarn or between single yarns. Here, the principle of applying vibration to the yarn, which is a feature of the present invention, will be explained. Normally, in a symmetrical nozzle other than a nozzle intended for eccentricity, theoretically the yarn runs without deviation, but
In practice, the nozzle machining accuracy or the thread becomes a disturbance factor, causing uneven running of the thread. The yarn opening nozzle of the present invention is no exception to this. However, the yarn opening nozzle of the present invention opens the running yarn symmetrically by providing fluid detour passages at symmetrical positions across the yarn passage, thereby causing the running yarn to be biased against the wall surface of the yarn passage. It is designed to give vibration to the yarn. In other words, when the yarn approaches the A side of the bypass passage that opens in the yarn passage for some reason, the fluid pressure in the bypass passage on the A side increases, and conversely, the pressure on the B side decreases, and the amount of fluid ejected from the B side decreases. and the flow rate increases. Therefore, each time the dynamic pressure on the A side increases and the static pressure on the B side decreases, the yarn moves to the B side. next,
The yarn that has moved to the B side moves to the A side by the same action as when it approaches the A side, and this operation is repeated at a high speed so that the yarn runs while causing high-speed vibration. Furthermore, the yarn subjected to high-speed vibration causes distortion of the fiber structure due to the vibration, resulting in minute differences in the fiber structure in the length direction of the yarn single yarn or between single yarns. In this way, yarns with fine fiber structure differences in the length direction or between single yarns are usually caused by colliding with an obstacle installed at the rear of the nozzle or being pushed into a narrow room. A processed yarn with excellent bulkiness and a thin crimp pitch can be obtained. In the present invention, the effect is sufficient if there is one detour passage at a symmetrical position across the yarn passage, but two or more detour passages may be provided. There is no particular restriction on the upper limit of the number of detour paths, and it may be taken into consideration from the nozzle construction aspect. Further, it is desirable that the aperture angle α of the detour passage to the yarn passage is 20 to 80 degrees, and if it is less than 20 degrees or more than 80 degrees, the effect of the present invention will be reduced. In addition, a bypass thin tube 1 is further inserted between the detour passages.
2, the pressure response between the bypass passages can be accelerated and the effects of the present invention can be further increased. The shape of the thread passage in the present invention may be straight, but the effect will be further enhanced if it is flared at the end. It is desirable that the spread angle β of the end spread shape is 30° or less. In the present invention, if a flow rate adjustment valve is provided in each of the detour passages, it is easy to adjust the amount of fluid flowing through the detour passages or the difference in flow rate between the detour passages caused by problems in machining accuracy. On the other hand, in the present invention, the fluid injection hole, the thread guide hole,
The expansion chamber, the thread passage, and the detour passage may be circular, but they are particularly easy to work with if they are rectangular. In addition, in the present invention, a portion of the fluid flows out from the expansion chamber through the detour passage in a direction substantially perpendicular to the yarn traveling direction, thereby further enhancing the yarn opening effect in the expansion chamber. However, even if the expansion chamber is provided with a fluid discharge hole together with a detour passage hole, the effects of the present invention will not be particularly diminished. The present invention will be explained in detail by way of examples. Examples 1 to 7, Comparative Examples 1 to 5 150 denier 30 filament polyethylene terephthalate fiber yarn containing 0.3% by weight of titanium oxide was fed to the nozzle, the air pressure, and the temperature of the feed roller by changing the air temperature using the apparatus shown in Figure 1.
Bulking was carried out at 200° C. and a processing speed of 1500 m/min to obtain bulky processed yarns shown in Table 1. All the nozzles used had two fluid jet angles of 25° with respect to the thread guide hole at target positions, and the fluid jet amount was at an air pressure of 1.5 kg/cm ² and an air temperature of 240°C.
It was created so that it would be 2Nm ³ /hour. Other specifications are as follows. (i) Cross section: rectangular (ii) Nozzle length: 60mm (iii) Thread guide hole 2 Entrance: 2.5mm x 2.5mm, end: 1.5mm
mm×1.5mm (iv) Detour passage 11 1.8mm×1.5mm (v) Yarn passage 4mm×2.5mm (vi) Expansion chamber 9 13mm×4mm, bottom angle...115° In addition, crimp rate, number of crimp threads The measurements of staining and staining spots were carried out by the following methods. (i) Crimp rate Processed yarn is made into a skein shape to approximately 3000 denier, then a load equivalent to 0.2 g/denier and 0.002 g/denier is applied to the skein, and the length (l) is measured after 1 minute has elapsed. ₀ ). Furthermore, after removing a load of 0.2 g/denier and processing in boiling water for 20 minutes, it was left in a free state.
Air dry for 24 hours. 0.2 again after air drying
Loads equivalent to g/denier and 0.002 g/denier are applied, and the length (l ₁ ) is measured after 1 minute has elapsed. Immediately, the load equivalent to 0.2 g/denier is removed, and the length (l ₂ ) after one minute has passed is measured and calculated using the following formula. Crimp rate (%) = l ₁ - l ₂ / l ₀ × 100 (ii) Number of crimps 20 single fibers of the yarn whose crimp rate was measured were arbitrarily taken out, and 0.2 g/denier was added to each single fiber. After applying a considerable load and marking a length of 1 inch, the number of free and uncrimped ridges is measured and the average value is calculated. (iii) Dyeing spots are determined by the following method: The processed yarn is knitted using a 24-gauge 1-feeder circular knitting machine, and 4% by weight of Eastman Polyester Blue GFL dye manufactured by Eastman Kodatsu Co., Ltd. is added to the knitted fabric in a bath. Stain with a ratio of 1:50. The dyeing time was such that the knitted fabric was placed at room temperature, the solution was stirred and the temperature was raised to 100°C under normal pressure for 20 minutes, and then the dyeing was continued at 100°C for 60 minutes. After washing, dehydrating, and drying while gradually lowering the temperature, visual appearance was evaluated by five experts.

[Table] As is clear from the above examples, according to the present invention, not only the bulkiness of the processed yarn is improved, but also the dyeing unevenness of the processed yarn is reduced even when the air temperature is increased. This is because by vibrating the yarn at high speed, which is the principle of the present invention, it is impossible to judge staining spots with the naked eye due to the extremely minute fiber structure differences in the length direction of the yarn or between single yarns. It is. The yarn opening nozzle of the present invention is capable of processing not only polyethylene terephthalate as shown in the examples, but also other polyester fibers and all kinds of thermoplastic synthetic fibers such as polyamide fibers. It can also be used if the supplied fiber yarn already has latent crimp ability or actual crimp ability.

[Brief explanation of the drawing]

Figure 1 shows a fluid bulk processing device for synthetic fiber yarn.
Schematic diagrams showing examples, FIGS. 2, 3, and 4 are vertical sectional views of conventional nozzles, and FIGS. 5, 6, and 7.
The figure is a longitudinal sectional view showing an example of the yarn opening nozzle of the present invention. 2... Yarn guide hole, 3... Fluid injection hole, 4... Yarn passage, 9... Expansion chamber, 11... Detour passage.

Claims (1)

[Scope of Claims] 1. An expansion chamber 9 connected to the downstream part of the yarn guide hole 2, which has a fluid injection hole 3 opened so as to give a propulsive force to the yarn, and an expansion chamber 9 that passes through the center of the expansion chamber and extends to the end of the nozzle. In a nozzle equipped with a yarn passage 4, the expansion chamber 9 and the yarn passage 4 are connected to each other by a detour passage 11 provided at a symmetrical position with the yarn passage sandwiched therebetween. Opening nozzle. 2. Claim 1, in which two or more detour passages are provided at symmetrical positions across the yarn passage.
Yarn opening nozzle described in Section 1. 3. The yarn opening nozzle according to claim 1 or 2, wherein the detour passages are further connected by a bypass capillary. 4. The yarn opening nozzle according to claim 1, 2 or 3, wherein each of the detour passages is provided with a flow rate regulating valve. 5. The yarn opening nozzle according to claim 1, wherein the yarn passage is provided in a shape that widens toward the end of the nozzle. 6. The yarn opening nozzle according to claim 1, wherein the fluid injection hole, the yarn guide hole, the expansion chamber, the yarn passage, and the detour passage are substantially rectangular.