JP6965922B2 - Stretching equipment, and fiber and fiber web manufacturing equipment and manufacturing methods - Google Patents

Description

The present invention relates to a drawing device, and a fiber and fiber web manufacturing device and manufacturing method using the stretching device.

Conventionally, in the production of non-woven fabrics, various studies and developments have been made on a method of stretching a thermoplastic polymer discharged in a thread shape from a spinneret, and the method has been carried out in several apparatus structures. Generally, in the traveling path of a yarn discharged from a spinneret having a spinning hole, tension is applied to the yarn by supplying a high-speed gas from the upstream to the downstream of the yarn, and the yarn is finely fiberized. There is a stretching device to make it. The non-woven fabric is continuously produced by fixing the yarn discharged from the drawing device to the collector.

More specifically, for example, a stretching device in an open system is disclosed in Patent Document 1. In Patent Document 1, gas is ejected into a passage formed by an inlet for sucking a group of threads extruded from a spinneret and an outlet for discharging a group of threads sucked from the inlet, and a gas flow in the suction direction. A stretching device is proposed in which a gas outlet for forming the gas is provided and a divergent portion is provided between the gas injection port of the passage and the outlet so that the width of the passage on the outlet side is wider than the width of the passage on the inlet side. Has been done. When this device is used, the velocity of the mixed flow of the gas flow (primary gas flow) generated by being supplied to the passage from the injection port and the gas flow (secondary gas flow) generated by being sucked into the passage from the inlet of the passage. The amount of decrease is reduced, the runout of the yarn in the passage is suppressed, and the air volume of the secondary gas flow is increased. Therefore, even if the flow rate of the primary gas flow is the same, the spinning tension and spinning of the yarn group It can increase speed and increase energy efficiency.

Further, Patent Document 2 discloses a drawing device in which the space from the spinneret to the cooling chamber and the drawing device is a closed system. In Patent Document 2, the connection between the cooling chamber and the stretching device is closed to the surroundings (a closed system with no inflow and outflow of air), and at least one diffuser (flow path narrowing) is provided on the downstream side of the stretching device. And widening) is proposed. By using this drawing device, the spinning speed of the filament can be increased and a finer filament can be obtained.

JP-A-2002-371428 Japanese Patent No. 3704522

However, in the stretching device of Patent Document 1, from the viewpoint of reducing the resistance of the air flow in the stretching device passage and the loss due to the resistance, a region having a constant passage width between the gas injection port and the divergent portion is formed between 1 to 10 of the passage width. It is said that it is preferable to provide it in the range of double (passage length of the embodiment: 3 to 30 mm). That is, the idea of shortening the passage length in the region where the passage width is constant (hereinafter referred to as the passage x) and increasing the passage length in the divergent portion (hereinafter referred to as the passage y) is disclosed. However, in such a configuration in which the passage x is short and the passage y is long, sufficient traction force for stretching the yarn group may not be obtained, and the spinning tension and spinning speed of the yarn group may decrease. be. Further, in the embodiment of Patent Document 1, the total length of the drawing device in the yarn traveling direction is 100 mm, and the section for applying tension to the yarn is short, and the traction force is proportional to the passage length. It may not be sufficient to stretch the yarns to obtain spinning tension to produce filaments of fineness.

Further, in the stretching apparatus of Patent Document 2, since the structure of the diffuser is used and the throttle is provided in the middle of the flow path, the pressure loss increases in the throttle portion and a sufficient gas cannot be supplied. Therefore, the condition of high wind speed cannot be obtained, and it may be difficult to produce a filament having a fine fineness. Further, in the apparatus of Patent Document 2, the cooling chamber and the stretching apparatus are sealed, and the filament is stretched in the stretching apparatus using the airflow supplied from the cooling chamber. Therefore, for the above reason, the cooling chamber is used. There is a limit to the amount of airflow that can be supplied, and insufficient cooling of the filament may occur. Further, when the yarn is manufactured for a long time, filaments may be deposited on the squeezed portion, and the sheet may have a basis weight unevenness.

Therefore, an object of the present invention is to provide a drawing device capable of efficiently producing a yarn having a fine fineness with energy saving, which can efficiently apply a traction force to the yarn. It is also an object of the present invention to provide a fiber and fiber web manufacturing device and a manufacturing method using such a stretching device.

The present invention for achieving the above object has any of the following configurations.
(1) In a passage having an inlet and an outlet of a yarn obtained by melt-spinning a thermoplastic polymer, an air flow is blown inward from the outside of the traveling path of the yarn to stretch the yarn. The stretching device, which has an inlet and an outlet for the yarn, has a first air passage, an air flow injection port, a second air passage, a third air passage, and a fourth air passage in the thread traveling direction. A stretching device that is continuously provided in this order and satisfies the following (i) to (iv).
(I) In the third airflow passage, the cross-sectional area of the flow path is constant with respect to the thread traveling direction.
(Ii) The second airflow passage has a flow path cross-sectional area smaller than that of the third airflow passage, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iii) The fourth airflow passage has a larger flow path cross-sectional area than the third airflow passage, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iv) the length L ₂ of the yarn running direction of the second air flow passage, the length of the third and the yarn running direction of the length L ₃ of the air flow passage, the yarn running direction of the fourth air flow path L ₄ satisfies the following relational expression.
(L ₃ + L ₄ ) / (L ₂ + L ₃ + L ₄ ) ≧ 0.6
L ₄ / (L ₂ + L ₃ + L ₄ ) ≤ 0.4
(2) The stretching apparatus according to (1), wherein the sum (mm) of _{L 2} and L ₃ and L _{4 satisfies the following relational expression.}
L ₂ + L ₃ + L ₄ ≧ 100
(3) The relationship between the minimum flow path cross-sectional area H _{2MIN of} the second air flow passage, the flow path cross-sectional area H _{3 of} the third air flow passage, and the maximum flow path cross-sectional area H _{4MAX of} the fourth air flow passage is as follows. The stretching device according to (1) or (2) above, which satisfies the formula.
1.05 ≤ H ₃ / H _2MIN
1.05 ≤ H _4MAX / H ₃
(4) The passage having the inlet and outlet of the yarn is formed from a pair of outer wall members facing each other, and one passage forming surface of the pair of outer wall members is from the second air passage in the thread traveling direction. The stretching device according to any one of (1) to (3) above, wherein the area up to the fourth airflow passage is formed by a continuous one plane parallel to the traveling direction of the yarn.
(5) A fiber manufacturing apparatus having a spinneret, a cooling device for spun yarn, and a drawing apparatus according to any one of (1) to (4) above in this order in the yarn traveling direction. ..
(6) A yarn traveling direction of a spinneret, a cooling device for spun yarn, a drawing device according to any one of (1) to (4) above, and a fiber web conveyor provided with a net. A fiber web manufacturing device that has in this order.
(7) A yarn is formed by melt-spinning a thermoplastic polymer from a spinneret, and after the yarn is cooled and solidified, the yarn is subjected to the drawing device according to any one of (1) to (4). A method for producing a fiber.
(8) A method for producing a fiber web, wherein the fiber web is produced using the apparatus according to any one of (1) to (6) above.

Here, in the present invention, the "passage" refers to an airflow passage in which the inflow port and the outflow port are open to the outside, formed by an outer wall member surrounding the outside of the traveling path of the thread, in the following order. It is composed of a continuous first airflow passage, an airflow injection port, a second airflow passage, a third airflow passage, and a fourth airflow passage.

In the present invention, the "inflow port" means an opening which is arranged on the most upstream side in the thread traveling direction of the passage and is open to the outside. On the other hand, the “outlet” refers to an opening that is arranged on the most downstream side in the thread traveling direction of the passage and is open to the outside. The term "upstream" refers to the side close to the spinneret in the main yarn running direction in which the thermoplastic polymer discharged from the spinneret is cooled and solidified to become a yarn. On the other hand, the “downstream” refers to the side far from the spinneret in the traveling direction of the main yarn, in which the thermoplastic polymer discharged from the spinneret is cooled and solidified to become a yarn.

In the present invention, the "airflow injection port" refers to an opening provided in the passage for injecting gas.

In the present invention, the "first airflow passage" refers to the passage from the inflow port to the upstream end of the airflow injection port, and the "second airflow passage" refers to the airflow in the passage. It refers to the area from the downstream end of the injection port to the upstream end of the third airflow passage. Further, the "third airflow passage" refers to a portion of the passage that exists between the second airflow passage and the fourth airflow passage and whose cross-sectional area of the flow path is constant with respect to the thread traveling direction. The "fourth airflow passage" refers to the passage from the downstream end of the third airflow passage to the outlet.

In the present invention, the "minimum flow path cross-sectional area H _{2MIN of} the second air flow passage" refers to the flow path break at the position where the cross-sectional area of the second air flow passage in the direction perpendicular to the traveling direction of the thread is the minimum. Refers to the area. Further, "maximum flow path cross-sectional area of _{the fourth air flow passage H 4MAX} " is the flow path cross-sectional area of the fourth air flow passage at the position where the cross-sectional area in the direction perpendicular to the traveling direction of the thread is maximum. To say. The "flow path cross-sectional area H _{3 of} the third air flow passage" means the flow path cross-sectional area of the third air flow passage in the direction perpendicular to the thread traveling direction.

According to the stretching apparatus of the present invention, by making the section to which the traction force can be applied to the yarn relatively long, the traction effect of the yarn in the stretching apparatus can be sufficiently exhibited even if the amount of gas supplied is small. As a result, stable operation with energy saving becomes possible. Further, since the traction force can be sufficiently exhibited, the spinning speed can be improved, and a yarn having a small single yarn fineness can be obtained. Then, when the fiber web is produced from the fibers thus obtained, it becomes possible to obtain a fiber web having a good texture as the single yarn fineness decreases.

It is an overall schematic sectional view of the spinning apparatus provided with the drawing apparatus which concerns on one Embodiment of this invention. It is the schematic sectional drawing of the stretching apparatus which shows one Embodiment of this invention. Another embodiment of the present invention is a schematic cross-sectional view of a stretching device. It is the schematic sectional drawing of the stretching apparatus which shows still another embodiment of this invention. It is a value which measured the static pressure distribution in a passage in the stretching apparatus which concerns on embodiment of this invention and the prior art. It is a schematic cross-sectional view for demonstrating the method of measuring the traction force of a stretching apparatus. It is a perspective view for demonstrating the method of measuring the static pressure in the passage of a stretching apparatus. It is the schematic sectional drawing of the stretching apparatus which shows still another embodiment of this invention.

Hereinafter, the best embodiment of the stretching device of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall schematic longitudinal sectional view of a spinning apparatus provided with a stretching apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic longitudinal sectional view of the drawing apparatus used in FIG. In addition, FIGS. 3, 4, and 8 are schematic vertical sectional views of another preferable form of the stretching apparatus according to the present invention.

The stretching device of the present invention is used, for example, in a non-woven fabric manufacturing device, and as shown in FIG. 1, the stretching device captures fibers in a web shape on a spinneret 1, a cooling device 19, a stretching device 3, and a moving net. It is composed of a collecting conveyor 4 and the like. Further, although not shown, a mechanism for heat-bonding the fiber web is also provided on the downstream side of the conveyor 4.

In such a device, a thermoplastic polymer is melt-spun from the spinneret 1, and the obtained yarn 2 is cooled by the cooling device 19 and then stretched by applying tension to the drawing device 3. The yarn 2 is then sprayed from the stretching device 3 onto the net of the conveyor 4 to form a fiber web on the conveyor 4. Here, as a region in which the yarn travels in the stretching device 3, a long rectangular region that is very long in the machine width direction (the paper surface depth direction in FIG. 1) is formed.

As shown in FIG. 2, the stretching device 3 has an airflow passage 9 sandwiched between outer wall members 5 from the upstream side to the downstream side in the thread traveling direction, and the upstream end portion of the airflow passage 9 is provided. Has an inflow port 14 into which the thread flows in, and an outflow port 15 in which the thread flows out at the downstream end. The airflow passages 9 communicate with the first airflow passage 10 located on the downstream side of the inflow port 14 in the thread traveling direction, the airflow injection port 7 that communicates with the first airflow passage 10 and blows the airflow onto the threads, and the airflow injection port. The second airflow passage 11 located on the downstream side in the thread traveling direction of No. 7, the third airflow passage 12 located on the downstream side in the thread traveling direction of the second airflow passage 11, and the downstream side of the third airflow passage 12. It is composed of a fourth airflow passage 13 located at. The third airflow passage 12 has a constant flow path cross-sectional area in the direction perpendicular to the thread traveling direction with respect to the thread traveling direction, and the second airflow passage 11 has a thread traveling direction as compared with the third airflow passage 12. The cross-sectional area of the flow path in the direction perpendicular to is small, and the fourth airflow passage 13 includes an outflow port 15 through which the yarn flows out, and is in a direction perpendicular to the running direction of the yarn as compared with the third airflow passage 12. The cross-sectional area of the flow path is large.

In the stretching device 3 having the above configuration, the gas introduced into the buffer portion 6 of the airflow supply means is subsequently injected into the inside of the airflow passage 9 from the airflow injection port 7 via the gas supply pipe. Then, it passes through the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13, and is discharged to the outside from the outflow port 15. According to the flow of the airflow, the threads flowing in from the inflow port 14 together with the airflow pass through the inside of the airflow passage 9 and are discharged from the outflow port 15.

Here, the principle that the drawing device 3 of the present invention can sufficiently exhibit the traction effect of the yarn, reduce the supply amount of gas, and save energy will be described. The stretching device 3 is also generally called an ejector, and pulls and stretches the yarn by directly supplying a high-pressure compressed gas to the airflow passage 9. At that time, since compressed gas is used, a compressor is required separately, and equipment costs are required accordingly, and utility costs increase, leading to an increase in manufacturing costs. Therefore, in order to reduce the amount of compressed gas used itself, it is important to most effectively express the traction force of the thread in the drawing device 3, but the traction force applied to the thread by the drawing device is F, a constant. Is CF, the airflow density is ρ, the airflow velocity is w, the circumference length of the thread is c, and the length of the airflow passage is l. It is proportional to the square of w and the length l of the airflow passage.
F = CFρw ² cl ・ ・ ・ (A)
Therefore, as a method of increasing the traction force F, it is conceivable to increase the wind speed w of the gas passing through the airflow passage 9 as much as possible. However, it is expected that the wind speed w of the gas increases by narrowing the gap of the airflow passage 9 (that is, reducing the cross-sectional area of the flow path), but in reality, the pressure loss of the airflow passage 9 increases and the inflow port increases. The inflow amount of the gas flowing in from 14 is reduced. As a result, it was found that there is a limit to narrowing the gap of the airflow passage 9 (that is, reducing the cross-sectional area of the flow passage). Next, increasing the supply amount of the gas supplied from the airflow injection port 7 is also considered to be an effective means for increasing the wind speed w of the gas, but of course, the amount of compressed air used is increased. This leads to an increase in manufacturing costs.

Therefore, the present inventors have focused on the length and the gap of the airflow passage 9 as a result of repeated studies for solving the above-mentioned problems. The present inventors have found that by optimizing these, the inflow amount of the gas flowing in from the inflow port 14 can be increased, and as a result, the traction force F of the yarn in the drawing device 3 can be increased. The important point is the configuration of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 from the downstream end 8 of the airflow injection port to the outflow port 15, and the relative flow paths. increasing the length L ₃ of the constant is the third airflow passage 12 with respect to the cross-sectional area of the yarn running direction, while the length of the second air flow passage 11 having a smaller cross sectional area than the flow path cross-sectional area of the third airflow passageway L _{2 and the length L 4} of the fourth air flow passage 13 having a cross-sectional area larger than the flow path cross-sectional area of the third air flow passage 12 are shortened.

Specifically, it means satisfying the following relationships.
(I) The third airflow passage 12 has a constant flow path cross-sectional area with respect to the thread traveling direction.
(Ii) The second airflow passage 11 has a flow path cross-sectional area smaller than that of the third airflow passage 12, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iii) The fourth airflow passage 13 has a flow path cross-sectional area larger than that of the third airflow passage 12, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iv) the yarn to the running direction of the length L _2, the length of the third and the yarn running direction of the length L ₃ of the air flow passage 12, the yarn running direction of the fourth air flow path 13 of the second air flow passage 11 L ₄ satisfies the following relational expression.
(L ₃ + L ₄ ) / (L ₂ + L ₃ + L ₄ ) ≧ 0.6
L ₄ / (L ₂ + L ₃ + L ₄ ) ≤ 0.4
First, by configuring (ii) and (iii), the diffuser effect is exhibited in the second airflow passage 11 and the fourth airflow passage 13, and the gas easily travels in the airflow passage 9, as shown in FIG. Since the static pressure in the airflow passage 9 decreases, a pressure difference from the outside occurs, and the inflow amount of gas from the inflow port 14 increases. Since the supply gas supplied from the airflow injection port 8 is combined with the inflow gas and supplied to the second airflow passage 11, the wind speed w of the gas in the second airflow passage 11 and the third airflow passage 12 increases. do.

Then, by adopting the configurations (i) and (iv), the length of the third airflow passage 12 in the thread traveling direction can be lengthened while maintaining the state in which the static pressure in the airflow passage 9 is lowered. , The high wind speed level of the airflow in the third airflow passage 12 can be maintained for a long time. This makes it possible to effectively develop the traction force F of the yarn.

Here, when the cross-sectional area of the flow path is larger than the third airflow passage 12 in the second airflow passage 11 or smaller than the third airflow passage in the fourth airflow passage, the static pressure in the gas passage 9 increases. Therefore, the pressure difference from the outside becomes small, and the inflow amount of the gas flowing in from the inflow port 14 decreases. In the worst case, the airflow passage 9 becomes higher pressure than the outside, and gas may flow out from the inflow port 14. As a result, the wind speed w of the gas in the third airflow passage 12 decreases, and the traction force of the yarn cannot be obtained.

When (L ₃ + L ₄ ) / (L ₂ + L ₃ + L ₄ ) is smaller than 0.6, the static pressure in the air flow passage 9 becomes longer due to the lengthening of the second air flow passage having a small flow path cross-sectional area. As the pressure increases, the pressure difference from the outside becomes smaller, and the inflow amount of the gas flowing in from the inflow port 14 decreases. Further, when L ₄ / (L ₂ + L ₃ + L ₄ ) exceeds 0.4, the fourth airflow passage 13 in which the wind speed decreases becomes longer, so that the section in which the traction force with respect to the yarn decreases becomes longer. , The traction force of the thread cannot be sufficiently obtained.

In addition, in (L ₃ + L ₄ ) / (L ₂ + L ₃ + L ₄ ), a section having a large traction force with respect to the yarn (that is, the second airflow passage 11 having a high wind speed) is sufficiently secured to sufficiently exert the traction force on the yarn. It is preferably 0.99 or less. Further, L ₄ / (L ₂ + L ₃ + L ₄ ) sufficiently secures a section of the fourth air flow passage 13, further stabilizes the flow in the fourth air flow passage 13, and sufficiently exerts the diffuser effect. In addition, it is preferably 0.01 or more.

The second airflow passage 11 and the fourth airflow passage 13 have a constant flow path cross-sectional area toward the downstream side in the thread traveling direction in FIG. 2, respectively, but as shown in FIG. 3, the thread traveling It may gradually increase toward the downstream side in the direction. In this case, the diffuser effect is likely to appear in the second airflow passage 11 and the fourth airflow passage 13, and the static pressure in the airflow passage 9 is further reduced, so that the inflow amount of the gas flowing in from the inflow port 14 increases. Has advantages. In FIG. 3, the taper is gradually increased, but the present invention is not limited to this, and the taper may be gradually increased. Further, in FIG. 3, the number may be gradually increased over the entire length of the second airflow passage 11 and the fourth airflow passage 13, but as shown in FIG. 4, only a part thereof may be gradually increased in a tapered shape.

Further, in the communication portion between the second airflow passage 11 and the third airflow passage 12 and the communication portion between the third airflow passage 12 and the fourth airflow passage 13, the cross-sectional area of the flow path on the downstream side in the thread traveling direction. However, as shown in FIG. 2, the flow path cross-sectional area may be expanded at once at the communication portions thereof, or as shown in FIGS. 3 and 4, the second airflow passage may be expanded. At least the portion of the 11 and the fourth airflow passage 13 near the communication portion with the third airflow passage 12 may be tapered so that the cross-sectional area of the flow passage gradually increases. Further, the configuration may be a combination of these. If the outer wall member 5 is formed so that the cross-sectional area of the flow path is expanded at once only in the communication portion, it has an advantage that it is easy to process in manufacturing the outer wall member 5, and it becomes tapered in the vicinity of the communication portion. When the outer wall member 5 is formed as described above, there is an advantage that a turbulent vortex is less likely to be generated when the gas passes through, and the thread turbulence can be suppressed.

Next, the influence of the lengths of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 in the thread traveling direction on the traction force will be described in detail. In stretching apparatus 3 of the present invention, the length of the yarn running direction of the second air flow passage 11 L ₂ and the yarn running direction of the length L ₃ of the third airflow passageway 12 yarn running direction of the fourth air flow passage 13 It is preferable that the sum (mm) of the length L _{4 and the length L 4 satisfies the following relational expression.}
L ₂ + L ₃ + L ₄ ≧ 100
With this configuration, it is possible to effectively generate the above-mentioned traction force of the yarn. When the sum is less than 100 mm, the total length of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 is shortened, so that the length of pulling the yarn is shortened and a desired traction force is obtained. It becomes difficult. Further, since the airflow outlet 15 and the airflow injection port 7 are close to each other, the pressure loss in the airflow passage is reduced, and it becomes difficult to sufficiently obtain the diffuser effect by using the fourth airflow passage 13. Therefore, it is preferable that the configuration satisfies the above relational expression, and further, the sum is 250 or more.

By increasing the total length of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13, the length of pulling the thread becomes longer, but the static pressure in the gas passage 9 increases. Therefore, the pressure difference from the outside becomes small, and the inflow amount of the gas flowing in from the inflow port 14 decreases. Therefore, the total length of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 is preferably 1500 mm or less, and more preferably 1000 mm or less.

Further, in the present invention, the minimum flow path cross-sectional area _{H 2MIN} of the second air flow passage 11, the flow path cross-sectional area _{H 3} of the third airflow passageway 12 and the maximum flow path cross-sectional area _{H 4MAX} fourth airflow passage 13 , It is preferable to satisfy the following relational expression.
1.05 ≤ H ₃ / H _2MIN
1.05 ≤ H _4MAX / H ₃
With this configuration, the above-mentioned traction force of the yarn can be generated more effectively. Here, when the ratio of the cross-sectional area of each flow path is less than 1.05, it means that the flow path is not sufficiently expanded toward the downstream side in the thread traveling direction as a whole. Therefore, it is difficult to obtain a sufficient diffuser effect in the airflow passage. In order to prevent turbulence in the flow and more effectively exhibit the diffuser effect, the ratio of the cross-sectional areas of each flow path is preferably 3 or less.

Further, in the present invention, one passage forming surface of the pair of outer wall members 5 forming the airflow passage is in the traveling thread direction between the second airflow passage 11 and the fourth airflow passage 13 as shown in FIG. It is preferable that the surface is formed in a continuous plane parallel to the running thread direction so that the distance from the thread is constant. With this configuration, a non-expanding portion of the flow path is continuously formed on one side of the thread in the second airflow passage 11 to the fourth airflow passage 13, and as a result, in the vicinity of the portion. An air flow with less turbulence is continuously formed, and it becomes possible to exert a traction force on the yarn more efficiently.

Next, each member common to the stretching apparatus 3 of the embodiment of the present invention shown in FIGS. 1, 2, 3, 4, and 8 and the shape of each member will be described in detail.

In the stretching device 3 of the present invention, various materials such as metal, alloy, ceramics, and resin can be adopted as the material of the outer wall member 5. Of these, metal is preferable from the viewpoint of strength and abrasion resistance.

As the cross-sectional shape of the airflow passage 9 in the direction perpendicular to the thread traveling direction, various shapes such as a round shape and a rectangular shape can be adopted. Of these, a rectangle is preferable from the viewpoint that the amount of compressed air used is relatively small and the yarns are less likely to be fused or scratched.

By shortening the length of the first airflow passage 10 in the thread traveling direction, the pressure loss in the flow path is reduced and the inflow amount of the gas flowing in from the inflow port 14 is increased, so that the length is 100 mm. It is more preferably 50 mm or less, and more preferably 50 mm or less.

The cross-sectional area of the first airflow passage 10 in the direction perpendicular to the thread traveling direction can be set within a range in which the thread can flow in. Since the pressure loss in the first airflow passage 10 decreases and the inflow amount of the gas flowing in from the inflow port 14 increases, the minimum cross-sectional area in the direction perpendicular to the thread traveling direction of the second airflow passage 11 is obtained. On the other hand, it is preferably wider, and more preferably wider than the maximum cross-sectional area in the direction perpendicular to the thread traveling direction of the fourth airflow passage 13.

The gas supply pipe connecting the buffer 6 and the airflow injection port 7 preferably has an angle of 30 ° or less with respect to the airflow passage 9 from the viewpoint of suppressing a decrease in the wind speed in the airflow passage 9. More preferably, the decrease in wind speed can be suppressed by setting the temperature to 15 ° or less. As for the shape of the gas supply pipe, it is preferable that the cross-sectional shape in the direction perpendicular to the airflow direction in the gas supply pipe is rectangular. Such a cross section may be expanded toward the airflow injection port 7 even if the cross-sectional area is constant with respect to the airflow direction in the gas supply pipe, but the effect of the Laval nozzle in which the wind speed increases due to adiabatic expansion in the sound velocity region is effective. It is more preferable to expand toward the airflow injection port 7 so as to be obtained.

The airflow supplied to the threads from the airflow injection port 7 is most economical and preferable, but may be a mixed gas, steam, saturated steam, or heated steam. In order to improve the traction force of the yarn, it is preferable to select an airflow having a high density because the density ρ of the airflow is also related as described in the above formula (A). Further, the temperature of the air flow is most economically preferable at room temperature, but the temperature is not limited to this. In addition, since the humidity of the airflow takes in the atmosphere, it is economically preferable not to control the humidity, but this is not the case. For example, by supplying a high humidity airflow, the traction force of the yarn is improved. It becomes possible to make it.

The present invention is an extremely versatile invention and can be applied to the production of all known fiber webs. Therefore, it is not particularly limited by the polymer constituting the fiber web. For example, polyester, polyamide, polyphenylene sulfide, polyolefin, polyethylene, polypropylene and the like can be mentioned as an example of the polymer constituting the fiber web. Further, in the above-mentioned polymer, a matting agent such as titanium dioxide, silicon oxide, kaolin, a color inhibitor, a stabilizer, an antioxidant, a deodorant, a flame retardant, and a thread friction are added to the above-mentioned polymer as long as the spinning stability is not impaired. Various functional particles such as a reducing agent, a coloring pigment, and a surface modifier, and additives such as an organic compound may be contained, and copolymerization may be contained.

Further, the polymer constituting the fiber web may be composed of a single component or a plurality of components, and in the case of a plurality of components, for example, a core sheath, a side-by-side structure, or the like may be mentioned.

The cross-sectional shape of the fibers forming the fiber web may be irregular such as round, triangular, flat, or hollow. Further, the single yarn fineness of the fiber web is not particularly limited. The number of single yarns of the fiber web is not particularly limited, but the larger the number of single yarns of the fiber web, the clearer the difference from the conventional technique.

Next, a preferred embodiment for producing a spunbonded nonwoven fabric made of a fiber web will be specifically described using the apparatus shown in FIGS. 1 and 2.

In the apparatus shown in FIG. 1, for example, a polyolefin resin is melt-spun from a spinneret 1. The spinning temperature at this time is preferably 200 to 270 ° C, more preferably 210 to 260 ° C, and even more preferably 220 to 250 ° C. By setting the spinning temperature within the above range, a stable molten state can be obtained and excellent spinning stability can be obtained.

The yarn 2 melt-spun from the spinneret 1 is then cooled by the cooling device 19, and as a specific cooling method, for example, a method of forcibly blowing cold air onto the yarn by the cooling device 19. , A method of naturally cooling at the ambient temperature around the yarn, a method of adjusting the distance between the spinneret 1 and the drawing device 3, and the like. It is also possible to adopt a method that combines these methods. The cooling conditions can be appropriately adjusted and adopted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the atmospheric temperature, and the like.

The yarn cooled by the cooling device 19 is then tensioned and stretched by the stretching device 3 as described above, and is sprayed onto the net of the conveyor 4 to form a fiber web on the conveyor 4.

The spinning speed when the stretching apparatus 3 of the present invention is used is preferably 3,500 to 6,500 m / min, more preferably 4,000 to 6,500 m / min, and even more preferably 4,. It is 500 to 6,500 m / min. By setting the spinning speed to 3,500 to 6,500 m / min, high productivity can be obtained, and the orientation and crystallization of the fibers proceed to obtain high-strength long fibers. Therefore, the non-woven fabric composed of high-strength fibers is also strongly excellent.

The stretching device according to the present invention can be used not only for producing fiber webs but also for producing fibers used in applications such as clothing and industry. In that case, the fibers obtained by spinning, cooling, and stretching may be wound around a bobbin or the like in the same manner as in the above-mentioned non-woven fabric production.

Hereinafter, the present invention will be described in more detail with reference to examples. The method for measuring the characteristic value in the examples is as follows.

(1) Traction force (N):
FIG. 6 shows a schematic diagram of a method for measuring traction force. First, a single yarn No. 3 nylon Tegs (A-154 manufactured by Yutaka Make Co., Ltd.) 17 is fixed to a tension meter 16 (MODEL-RX-1 manufactured by Aiko Engineering Co., Ltd.), and an air flow passage 9 is provided from the upper part of the stretching device 3. It is assumed that the Tegs 17 is hung inside and the Tegs 17 is cut at the lowest point (outlet 15) of the airflow passage. Then, compressed air was supplied to the stretching device 3, and the tension (N) generated at that time was measured with a tension meter 16. This measurement was repeated 5 times, and the average value (N) was used as the traction force.

(2) Static pressure (kPa) inside the airflow passage:
As shown in FIG. 7, a stretching device in a state where a pressure gauge (PG-100-102G manufactured by Copal Electronics Co., Ltd.) is hermetically connected to a static pressure measuring port 18 which is a through hole formed in a side wall member 20 of an airflow passage 9. Compressed air was supplied to No. 3, and the gauge pressure (kPa) inside the airflow passage 9 was measured. The measurement height was set to the position of the end portion 8 on the downstream side of the airflow injection port. This measured value was adopted as the static pressure inside the airflow passage.

(3) Supply pressure (MPa)
In a room at room temperature and normal humidity, compressed air is supplied to the stretching device 3 with a pressure gauge (GS50-171-0.6MP manufactured by Nagano Keiki Co., Ltd.) sealedly connected to the airflow supply section of the stretching device 3 to supply compressed air inside. The gauge pressure (MPa) was measured. This measured value was adopted as the supply pressure to the stretching device.

(4) Single fiber Fiber diameter (μm):
After being towed by a stretching device and stretched, 10 small piece samples were randomly collected from the fiber web collected on the net, and a surface photograph of 1000 times was taken with a microscope. The widths of a total of 100 fibers were measured, 10 from the photographs of each sample, and the average value thereof was adopted as the single fiber fiber diameter.

(5) Spinning speed (m / min):
It was calculated by rounding off the second decimal place with the mass per 10,000 m in length as the single fiber fineness from the above single fiber fiber diameter and the solid density of the resin used. Based on the single fiber fineness (dtex) and the discharge amount of the resin discharged from the single hole of the spinneret set under each condition (hereinafter, abbreviated as the single hole discharge amount) (g / min), based on the following formula. The spinning speed was calculated.
Spinning speed = (10000 x single hole discharge amount) / single fiber fineness.

[Example 1]
The fiber web was manufactured as follows by the apparatus having the configuration shown in FIGS. 1 and 2. The stretching device 3 has a rectangular cross section of the airflow passage 9, and the length L from the inflow port 14 to the outflow port 15 of the airflow passage 9 is 200 mm, the length L2 of the second airflow passage 11 is 50 mm, and the _second. 3 50 mm length _{L 3} of the air flow passage 12, the length _{L 4} of the fourth air flow passage 13 was set to 50 mm. Also, the gap _{W 1} of the first air flow passage 3 mm, and the gap _{W 2} of the second air flow passage 3 mm, 4 mm gap _{W 3} of the third airflow passageway, a gap _{W 4} of the fourth air flow passage 13 and 5 mm. The installation angle of the airflow supply pipe with respect to the airflow passage 9 was 15 °, and the width of the airflow supply pipe was 0.2 mm. Further, 0.2 MPa of compressed air was supplied to the airflow supply unit to the stretching device 3. As a result of measuring the traction force, it was 37 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −6.3 kPa.

A polypropylene resin having a melt flow rate (MFR) of 35 g / 10 minutes is melted by an extruder and spun from a rectangular spinneret 1 having a spinning temperature of 235 ° C. and a hole diameter of φ0.30 mm at a single hole discharge rate of 0.56 g / min. The obtained fibers are cooled and solidified by the cooling device 19, and then towed and stretched by supplying compressed air having a supply pressure of 0.20 MPa to the drawing device 3, and collected on a moving net to have a polypropylene length. A fiber web consisting of fibers was obtained.

The characteristics of the obtained polypropylene long fibers were that the single fiber fiber diameter was 16.6 μm, and the spinning speed converted from this was 2,951 m / min.

[Example 2]
As a pattern in which the total length of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 is long, the length L from the inflow port 14 to the outflow port 15 of the airflow passage 9 is 350 mm, and the second airflow passage The same as in Example 1 except that the length L _{2 of} 11 was 100 mm, the length L ₃ of the third air flow passage 12 was 100 mm, and the length L _{4 of the fourth air flow passage 13 was 100 mm.}

As a result of measuring the traction force, it was 40 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −5.5 kPa.

The characteristics of the obtained polypropylene long fibers were that the single fiber fiber diameter was 16.1 μm, and the spinning speed converted from this was 3,043 m / min.

[Example 3]
As a pattern in which the total length of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 is short, the length L from the inflow port 14 to the outflow port 15 of the airflow passage 9 is 140 mm, and the second airflow passage 11 The same as in Example 1 except that the length L ₂ of the third air flow passage 12 was 30 mm, the length L ₃ of the third air flow passage 12 was 30 mm, and the length L _{4 of the fourth air flow passage 13 was 30 mm.}

As a result of measuring the traction force, it was 35 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −7.2 kPa.

The characteristics of the obtained polypropylene filaments were that the single fiber fiber diameter was 17.4 μm, and the spinning speed converted from this was 2816 m / min.

[Example 4]
One passage forming surface of the pair of outer wall members 5 forming the air flow passage 9 is formed in a continuous one plane parallel to the traveling thread direction between the second air passage passage 11 and the fourth air flow passage 13. The pattern was the same as in Example 1 except that the stretching device 3 as shown in FIG. 8 was used.

As a result of measuring the traction force, it was 39 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −6.5 kPa.

The characteristics of the obtained polypropylene long fibers were that the single fiber fiber diameter was 16.3 μm, and the spinning speed converted from this was 3,005 m / min.

[Comparative Example 1]
As a pattern which does not expand the second airflow passage, the gap W ₂ of the second airflow passage 11 and 4 mm, the cross-sectional shape of the second air flow passage and the third air flow passage in FIG. 2, except that the cross-sectional area was set to the same The same as in Example 1.

As a result of measuring the traction force, it was 34 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −7.0 kPa.

The characteristics of the obtained polypropylene long fibers were that the single fiber fiber diameter was 17.6 μm, and the spinning speed converted from this was 2,783 m / min.

[Comparative Example 2]
Not larger fourth airflow channel 13 (i.e., not provided substantially fourth airflow passage) as a pattern, a gap W ₄ of the fourth air flow path 13 and 4 mm, the third air flow passage and the fourth air flow path in FIG. 2 The same as in Example 1 except that the cross-sectional shape and cross-sectional area of the above were the same.

As a result of measuring the traction force, it was 30 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −5.8 kPa.

The characteristics of the obtained polypropylene filaments were that the single fiber fiber diameter was 18.6 μm, and the spinning speed converted from this was 2,634 m / min.

[Comparative Example 3]
As a pattern in which the second airflow passage 11 is longer than the third airflow passage 12 and the fourth airflow passage 13, the length L from the inflow port 14 to the outflow port 15 of the airflow passage 9 is 200 mm, and the length of the second airflow passage 11 is 200 mm. The same as in Example 1 except that _{the length L 2} was 75 mm, the length L ₃ of the third air flow passage 12 was 25 mm, and the length L _{4 of the fourth air flow passage 13 was 50 mm.}

As a result of measuring the traction force, it was 32 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −5.5 kPa. The characteristics of the obtained polypropylene filaments were that the single fiber fiber diameter was 18.1 μm, and the spinning speed converted from this was 2,707 m / min.

[Comparative Example 4]
As a pattern in which the fourth airflow passage 13 is longer than the second airflow passage 11 and the third airflow passage 12, the length L from the inflow port 14 to the outflow port 15 of the airflow passage 9 is 200 mm, and the length of the second airflow passage 11 is 200 mm. The same as in Example 1 except that _{the length L 2} was 32.5 mm, the length L ₃ of the third air flow passage 12 was 32.5 mm, and the length L _{4 of the fourth air flow passage 13 was 75 mm.}

As a result of measuring the traction force, it was 31 mN as shown in Table 1. Further, the static pressure in the airflow passage 9 at the downstream end 8 of the airflow injection port was −6.6 kPa.

The characteristics of the obtained polypropylene long fibers were that the single fiber fiber diameter was 18.4 μm, and the spinning speed converted from this was 2,663 m / min.

The stretching device of the present invention can be applied not only to stretching yarns for non-woven fabrics but also to stretching yarns for other purposes such as various woven and knitted fabrics.

1: Spinning cap 2: Thread 3: Stretching device 4: Conveyor 5: Outer wall member 6: Airflow supply part buffer 7: Airflow injection port 8: Airflow injection port downstream end 9: Airflow passage 10: First airflow passage 11: 2nd airflow passage 12: 3rd airflow passage 13: 4th airflow passage
14: Inflow port 15: Outlet 16: Tension meter 17: Tegs 18: Static pressure measurement port 19: Cooling device 20: Side wall member 90: Passage forming surface

Claims (8)

A drawing device that stretches the yarn by blowing an inward airflow from the outside of the traveling path of the yarn in a passage having an inlet and an outlet of the yarn obtained by melt-spinning a thermoplastic polymer. The passage having the inlet and outlet of the yarn includes the first air passage, the air inlet, the second air passage, the third air passage, and the fourth air passage in this order with respect to the traveling direction of the yarn. A stretching device that is continuously provided and satisfies the following (i) to (iv).
(I) In the third airflow passage, the cross-sectional area of the flow path is constant with respect to the thread traveling direction.
(Ii) The second airflow passage has a flow path cross-sectional area smaller than that of the third airflow passage, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iii) The fourth airflow passage has a larger flow path cross-sectional area than the third airflow passage, and the flow path cross-sectional area is constant and / or gradually increases with respect to the thread traveling direction.
(Iv) the length L ₂ of the yarn running direction of the second air flow passage, the length of the third and the yarn running direction of the length L ₃ of the air flow passage, the yarn running direction of the fourth air flow path L ₄ satisfies the following relational expression.
(L ₃ + L ₄ ) / (L ₂ + L ₃ + L ₄ ) ≧ 0.6
L ₄ / (L ₂ + L ₃ + L ₄ ) ≤ 0.4 The stretching apparatus according to claim 1, wherein the sum (mm) of the L ₂ and the L ₃ and the L _{4 satisfies the following relational expression.}
L ₂ + L ₃ + L ₄ ≧ 100 The minimum flow path cross-sectional area H _{2MIN of} the second air flow passage, the flow path cross-sectional area H _{3 of} the third air flow passage, and the maximum flow path cross-sectional area H _{4MAX of} the fourth air flow passage satisfy the following relational expression. The stretching device according to claim 1 or 2.
1.05 ≤ H ₃ / H _2MIN
1.05 ≤ H _4MAX / H ₃ The passage having the inlet and outlet of the thread is formed of a pair of outer wall members facing each other, and one passage forming surface of the pair of outer wall members is formed from the second air passage to the fourth in the thread traveling direction. The stretching device according to any one of claims 1 to 3, wherein the space to the air flow passage is formed by a continuous one plane parallel to the thread traveling direction. A fiber manufacturing apparatus having a spinneret, a cooling device for spun yarn, and a drawing device according to any one of claims 1 to 4 in this order in the yarn traveling direction. A spinneret, a cooling device for spun yarn, a drawing device according to any one of claims 1 to 4, and a fiber web conveyor provided with a net are provided in this order in the yarn traveling direction. Textile web manufacturing equipment. A fiber in which a yarn is formed by melt-spinning a thermoplastic polymer from a spinneret, the yarn is cooled and solidified, and then the yarn is drawn by the drawing apparatus according to any one of claims 1 to 4. Production method. A method for producing a fiber web, wherein the fiber web is produced using the apparatus according to any one of claims 1 to 6.

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