KR102391138B1 - Drawing apparatus, and apparatus and method for manufacturing fibers and fibrous webs - Google Patents

Abstract

In order to provide a drawing device capable of stably producing a yarn of fineness while saving energy, which can efficiently apply a traction force to the yarn, in a passage having an inlet and an outlet of a yarn obtained by melt spinning a thermoplastic polymer, It is a stretching device for extending the thread by injecting an airflow from the outside to the inside of the running path of the thread, wherein the passage having an inlet and an outlet of the thread is a first airflow passage, an airflow injection port, a second airflow passage, a third airflow A passage and a fourth air flow passage are continuously provided in this order with respect to the thread running direction, and the following (i) to (iv) are satisfied. (i) The third airflow passage has a constant flow passage cross-sectional area with respect to the thread running direction. (ii) The flow passage cross-sectional area of the second air flow passage is smaller than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction. (iii) The flow passage cross-sectional area of the fourth air flow passage is larger than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction. (iv) the length L ₂ in the thread running direction of the second air flow passage, the length L ₃ in the thread running direction of the third air flow passage, and the length L ₄ in the thread running direction of the fourth air flow passage are the following relational expressions Satisfies. (L ₃ +L ₄ )/(L ₂ +L ₃ +L ₄ )≥0.6 L ₄ /(L ₂ +L ₃ +L ₄ )≤0.4

Description

Drawing apparatus, and apparatus and method for manufacturing fibers and fibrous webs

The present invention relates to a drawing apparatus, and an apparatus and method for producing fibers and fibrous webs using the same.

Conventionally, various researches and developments have been made on a method of stretching a thermoplastic polymer discharged from a spinneret in the form of yarn in the production of a nonwoven fabric, and are implemented with several device structures. As a general example, there is a stretching device for applying a tension to a yarn by supplying a high-speed gas from an upstream to a downstream direction of the yarn in a traveling path of a yarn discharged from a spinneret having a spinneret to make the yarn finer. A nonwoven fabric is continuously produced by fixing the yarn discharged from the stretching device to a collector.

More specifically, the extending|stretching apparatus in an open system is disclosed by patent document 1, for example. In Patent Document 1, in a passage in which 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 are formed, a gas outlet is provided for ejecting gas to form a gas flow in the suction direction. In addition, there has been proposed a stretching device in which a wide-end portion in which the passage width on the outlet side is wider than the passage width on the inlet side is provided between the gas injection port of the passage and the outlet. When this device is used, the amount of decrease in the speed 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 is reduced. By suppressing the deviation of the thread within the passage and increasing the air volume of the secondary gas flow, even if the flow rate of the primary gas flow is the same, the energy efficiency can be increased by increasing the spinning tension and spinning speed of the thread group.

In addition, Patent Document 2 discloses a stretching apparatus in which the space from the spinneret to the cooling chamber and the stretching apparatus is a closed system. In Patent Document 2, the connection between the cooling chamber and the stretching device is closed (closed system without inflow/outflow of air) to the periphery, and at least one diffuser (narrowing and widening of the flow path) is provided on the downstream side of the stretching device. formation) is proposed. By using this drawing device, the spinning speed of the filament can be increased, and a thinner filament can be obtained.

Japanese Patent Laid-Open No. 2002-371428 Japanese Patent Publication No. 3704522

However, in the stretching apparatus of Patent Document 1, from the viewpoint of reducing the resistance of the airflow in the passage of the stretching apparatus and the loss thereof, a region having a constant passage width between the gas injection port and the wide end is 1 to 10 times the passage width (implemented). It is said that it is preferable to provide in the range of an example passage length: 3-30 mm). That is, the idea of shortening the passage length (hereinafter referred to as passage x) in a region having a constant passage width and lengthening the passage length in a wide-end portion (hereinafter referred to as passage y) is disclosed. However, in such a configuration in which the passage x is short and the passage y is long, the traction force for stretching the group of yarns is not sufficiently obtained, and the spinning tension and the spinning speed of the group of yarns may decrease. Further, in the Example of Patent Document 1, the total length in the yarn running direction of the stretching device is 100 mm, and the section in which tension is applied to the yarn is configured to be short, and the traction force is proportional to the passage length, so that the yarn group is sufficiently drawn. In some cases, it is insufficient to obtain a spinning tension for manufacturing a filament of fineness.

Moreover, in the extending|stretching apparatus of patent document 2, since the narrowing part is provided in the middle of a flow path using the structure of a diffuser, pressure loss increases in a narrowing part, and sufficient gas cannot be supplied. Therefore, conditions of high wind speed cannot be obtained, and furthermore, it may become difficult to manufacture the filament of fineness. Further, in the apparatus of Patent Document 2, the cooling chamber and the stretching apparatus are closed systems, and the filament is drawn in the stretching apparatus using the air flow supplied from the cooling chamber. There is a limitation in the filament, and insufficient cooling of the filament may occur. Moreover, when manufacturing a yarn for a long time, filaments may accumulate in a narrowing part, and the weight nonuniformity per unit area of a sheet|seat may generate|occur|produce.

Therefore, it is an object of the present invention to provide a stretching device capable of efficiently producing a thread of fineness while saving energy, which can efficiently apply a traction force to the thread. Another object of the present invention is to provide an apparatus and method for producing fibers and fibrous webs using such a drawing apparatus.

This invention for achieving the said objective takes any of the following structures.

(1) In a passage having an inlet and an outlet of a thread obtained by melt spinning a thermoplastic polymer, it is a stretching device that stretches the thread by spraying an airflow from the outside to the inside of the running path of the thread, and the inlet and outlet of the thread The passage with Stretching device, characterized in that it satisfies.

(i) The third airflow passage has a constant flow passage cross-sectional area with respect to the thread running direction.

(ii) The flow passage cross-sectional area of the second air flow passage is smaller than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.

(iii) The flow passage cross-sectional area of the fourth air flow passage is larger than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.

(iv) the length L ₂ in the thread running direction of the second air flow passage, the length L ₃ in the thread running direction of the third air flow passage, and the length L ₄ in the thread running direction of the fourth air flow passage are the following relational expressions Satisfies.

(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 minimum flow path cross-sectional area H _2MIN of the second air flow passage, the flow passage cross-sectional area H ₃ of the third air flow passage, and the maximum flow passage cross-sectional area H _4MAX of the fourth air flow passage satisfy the following relational expression (1) Or the stretching apparatus according to (2).

1.05≤H ₃ /H _2MIN

1.05≤H _4MAX /H ₃

(4) the passage having the inlet and outlet of the thread is formed by a pair of opposing outer wall members, and the passage forming surface of one of the pair of outer wall members is formed from the second airflow passage with respect to the running direction of the thread. The stretching apparatus according to any one of (1) to (3), wherein a space up to the fourth airflow passage is formed in a continuous plane parallel to the thread running direction.

(5) A fiber manufacturing apparatus comprising a spinneret, a cooling device for the spun yarn, and a drawing device according to any one of (1) to (4) in this order in a yarn running direction.

(6) A fiber having a spinneret, a cooling device for the spun yarn, a drawing device according to any one of (1) to (4), and a conveyor for a fiber web with a net in this order in the yarn running direction. The manufacturing device of the web.

(7) After forming a yarn by melt-spinning a thermoplastic polymer from a spinneret, cooling and solidifying the yarn, the yarn is drawn by the drawing device according to any one of (1) to (4) above, production of a fiber Way.

(8) A method for producing a fibrous web, wherein the fibrous web is produced using the apparatus according to any one of (1) to (6).

Here, in the present invention, the term "passage" refers to an airflow passage formed by an outer wall member surrounding the outer side of the running path of the thread, in which the inlet and the outlet are open to the outside, and a first airflow passage, airflow that is continuous in the following order It is constituted by the nozzle, the second airflow passage, the third airflow passage, and the fourth airflow passage.

In the present invention, the term "inlet" refers to an opening which is disposed on the most upstream side in the thread running direction of the passage and opened to the outside. On the other hand, "outlet" means an opening which is arrange|positioned at the most downstream of the thread running direction of the said passage, and is opened to the outside. In addition, "upstream" means the side close to the spinneret in the main thread running direction in which the thermoplastic polymer discharged from the spinneret cools and solidifies and becomes a thread. On the other hand, "downstream" means the side far from the spinneret in the main thread running direction in which the thermoplastic polymer discharged from the spinneret cools and solidifies and becomes a thread.

In the present invention, the term "airflow injection port" refers to an opening provided in the passage through which gas is injected.

In the present invention, the term "first airflow passage" means between the inlet and the upstream end of the airflow injection port in the passage, and the "second airflow passage" refers to the third from the downstream end of the airflow injection port in the passage. It refers to the distance to the upstream end of the airflow passage. In addition, a "3rd airflow path" means the part which exists between a 2nd airflow path and a 4th airflow path among the said paths, and a flow path cross-section is constant with respect to the thread running direction. In addition, the "fourth airflow passage" means between the downstream end of the said 3rd airflow passage and the said outlet port among the said passages.

In the present invention, “minimum flow passage cross-sectional area H _2MIN of the second air flow passage” refers to the flow passage cross-sectional area at a position where the cross-sectional area in the direction perpendicular to the thread running direction is minimized among the second air flow passages. In addition, "the maximum flow path cross-sectional area H _4MAX of the fourth air flow passage” refers to the flow passage cross-sectional area at a position where the cross-sectional area in the direction perpendicular to the thread running direction is maximized among the fourth air flow passages. In addition, "the flow passage cross-sectional area H ₃ of the third air flow passage” refers to the flow passage cross-sectional area in a direction perpendicular to the thread running direction of the third air flow passage.

According to the stretching apparatus of the present invention, by making the section in which the traction force to the thread can be provided is relatively long, the amount of gas supplied can sufficiently express the traction effect of the thread in the stretching apparatus at least, and as a result, energy Stable driving is possible while saving money. Moreover, since the traction force can fully be expressed, the improvement of a spinning speed becomes possible, and it becomes possible also to obtain a yarn with a small single yarn fineness. And when a fiber web is manufactured from the fiber obtained in this way, it becomes possible to obtain a fiber web with a favorable texture with the reduction|decrease of single yarn fineness.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole schematic sectional drawing of the spinning apparatus provided with the extending|stretching apparatus which concerns on one Embodiment of this invention.
It is a schematic sectional drawing of the extending|stretching apparatus which shows one Embodiment of this invention.
It is a schematic sectional drawing of the extending|stretching apparatus which shows another embodiment of this invention.
It is a schematic sectional drawing of the extending|stretching apparatus which shows still another embodiment of this invention.
It is the value which measured the static pressure distribution in the passage in the extending|stretching apparatus which concerns on embodiment of this invention and a prior art.
It is a schematic sectional drawing for demonstrating the measuring method of the traction force of an extending|stretching apparatus.
It is a perspective view for demonstrating the measuring method of the static pressure in the passage of an extending|stretching apparatus.
It is a schematic sectional drawing of the extending|stretching apparatus which shows still another embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, the best embodiment of the extending|stretching apparatus of this invention is described in detail, referring drawings. 1 : is a general schematic longitudinal sectional view of the spinning apparatus provided with the extending|stretching apparatus which concerns on one Embodiment of this invention, and FIG. 2 is a schematic longitudinal sectional view of the extending|stretching apparatus used for FIG. 3, 4, and 8 are schematic longitudinal sectional views of another preferred embodiment of the stretching apparatus according to the present invention.

The stretching apparatus of the present invention is used, for example, in a nonwoven fabric production apparatus, which, as shown in Fig. 1, includes a spinneret 1, a cooling apparatus 19, a stretching apparatus 3, and a moving net. It is composed of a conveyor 4 and the like that collects fibers in a web shape. In addition, although not shown, a mechanism for thermally bonding the fiber web is provided on the downstream side of the conveyor 4 .

In such an apparatus, a thermoplastic polymer is melt-spun from a spinneret 1 , and the resulting yarn 2 is cooled by a cooling device 19 , and then stretched by applying tension by a stretching device 3 . The yarn 2 is then sprayed from the drawing device 3 onto the net of the conveyor 4 , and forms a web of fibers on the conveyor 4 . Here, as an area|region in which a thread travels in the extending|stretching apparatus 3, the very long rectangular area|region in the initiation direction (the paper depth direction of FIG. 1) is formed.

As shown in Fig. 2, the stretching device 3 has an air flow passage 9 sandwiched between the outer wall members 5 from the upstream side to the downstream side in the thread running direction, and the air flow passage 9 The upstream end has an inlet 14 through which the yarn flows, and the downstream end has an outlet 15 through which the yarn flows. The airflow passage 9 communicates with the 1st airflow passage 10 located on the downstream side of the thread running direction of the inlet 14, and the 1st airflow passage 10, and the airflow injection port 7 which injects an airflow to a thread. ) and the second air flow passage 11 located on the downstream side of the thread travel direction of the air flow injection port 7 , and the third air flow passage 12 located on the downstream side of the second air flow passage 11 in the yarn travel direction. ) and a fourth airflow passage 13 located on the downstream side of the third airflow passage 12 . The third air flow passage 12 has a constant flow passage cross-sectional area in a direction perpendicular to the yarn travel direction with respect to the yarn travel direction, and the second air flow passage 11 has a constant flow passage area compared to the third air flow passage 12 , compared with the third air flow passage 12 . The flow passage cross-sectional area in the direction perpendicular to the direction is small, and the fourth airflow passage 13 partially includes the outlet 15 through which the thread flows out, and compared with the third airflow passage 12 in the direction perpendicular to the thread running direction. The cross-sectional area of the flow path is large.

In the stretching apparatus 3 having the above configuration, the gas introduced into the buffer unit 6 of the air flow supply means is then injected into the air flow passage 9 from the air flow injection port 7 via the gas supply pipe. . And it passes through the 2nd airflow passage 11, the 3rd airflow passage 12, and the 4th airflow passage 13, and is discharged|emitted from the outlet 15 to the outside. According to the flow of the airflow, the thread introduced with the airflow from the inlet 14 passes through the inside of the airflow passage 9 and is discharged from the outlet 15 .

Here, in the extending|stretching apparatus 3 of this invention, the traction effect of a thread is fully expressed, the supply amount of gas is reduced, and the principle by which energy saving becomes possible is demonstrated. The stretching device 3 is generally also called an ejector, and by directly supplying a high-pressure compressed gas to the airflow passage 9, the thread is drawn and stretched. In that case, a compressor is separately required in that compressed gas is used, and the equipment cost is required accordingly, and also the service cost increases, which leads to an increase in the manufacturing cost. Therefore, in order to reduce the amount of compressed gas itself, it is important to most effectively express the traction force of the yarns in the stretching device 3, the traction force applied to the yarn in the stretching device is F, the constant is CF, and the density of the airflow. ρ, the wind speed of the airflow is w, the circumference length of the thread is c, and the length of the airflow passage is l. proportional

F=CFρw ² cl … (A)

Therefore, as a method of increasing the traction force F, it is considered to increase the wind speed w of the gas passing through the airflow passage 9 as much as possible. However, although 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 flow passage cross-sectional area), in reality, the pressure loss in the airflow passage 9 increases, and from the inlet 14 The amount of inflow gas is reduced. As a result, it was found that there is a limit to narrowing the gap between the airflow passages 9 (that is, reducing the flow passage cross-sectional area). Next, it is considered that increasing the supply amount of the gas supplied from the airflow injection port 7 is also an effective means for increasing the wind speed w of the gas.

Then, the present inventors paid attention to the length and clearance gap of the airflow passage 9, as a result of repeating earnest examination for the said subject solution. The present inventors have found that by optimizing them, the amount of gas flowing in from the inlet 14 can be increased, and as a result, the traction force F of the thread in the stretching device 3 can be increased. An important point thereof is the configuration of the second airflow passage 11, the third airflow passage 12, and the fourth airflow passage 13 from the airflow injection port downstream end 8 to the outlet 15, and relatively The length L ₂ of the second air flow passage 11, which has a cross-sectional area smaller than the flow passage cross-sectional area of the third air flow passage, while lengthening the length L ₃ of the third air flow passage 12 whose cross-sectional area is constant with respect to the thread running direction, and The length L ₄ of the fourth air flow passage 13 having a cross-sectional area larger than the flow passage cross-sectional area of the 3 air flow passage 12 is shortened.

Specifically, it is said that the following relationship is satisfied.

(i) The third airflow passage 12 has a constant flow passage cross-sectional area with respect to the thread running direction.

(ii) The flow passage cross-sectional area of the second air flow passage 11 is smaller than that of the third air flow passage 12, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.

(iii) The flow passage cross-sectional area of the fourth air flow passage 13 is larger than that of the third air flow passage 12, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.

(iv) the length L ₂ in the thread running direction of the second airflow passage 11 , the length L ₃ in the thread running direction of the third airflow passage 12 , and the length of the fourth airflow passage 13 in the thread running direction L ₄ satisfies the following relation.

(L ₃ +L ₄ )/(L ₂ +L ₃ +L ₄ )≥0.6

L ₄ /(L ₂ +L ₃ +L ₄ )≤0.4

First, by setting it as the structure of (ii) and (iii), the diffuser effect is expressed in the 2nd airflow passage 11 and the 4th airflow passage 13, and even if the gas becomes easy to travel in the airflow passage 9 As shown in FIG. 5 , since the static pressure in the airflow passage 9 is lowered, a pressure difference with the outside occurs, and the amount of inflow of the gas from the inlet 14 increases. Since the supply gas supplied from the airflow injection port 8 is combined with the inflow gas and supplied to the 2nd airflow passageway 11, the 2nd airflow passage 11 and the 3rd airflow passage 12 of the gas The wind speed w increases.

And by setting it as the structure of (i), (iv), the length of the thread running direction of the 3rd airflow passage 12 can be lengthened, maintaining the state in which the static pressure in the airflow passage 9 fell, and the 3rd It becomes possible to maintain a long high wind speed level of the airflow in the airflow passage 12 . Thereby, it becomes possible to express effectively the traction force F of a thread.

Here, when the flow passage cross-sectional area is larger than the third air flow passage 12 in the second air flow passage 11 or smaller than the third air flow passage in the fourth air flow passage, the static pressure in the gas passage 9 increases. Therefore, the pressure difference with the outside becomes small, and the inflow amount of the gas flowing in from the inlet 14 is reduced. In the worst case, the airflow passage 9 becomes higher pressure than the outside, and gas flows out from the inlet 14 in some cases. As a result, the wind speed w of the gas in the 3rd airflow passage 12 falls, and the traction force of a thread is not acquired.

When (L ₃ +L ₄ )/(L ₂ +L ₃ +L ₄ ) is less than 0.6, since the second airflow passage with a small flow passage cross-sectional area becomes longer, the static pressure in the airflow passage 9 increases, As the pressure difference with the outside becomes small, the inflow amount of the gas flowing in from the inlet 14 is reduced. In addition, when L ₄ /(L ₂ +L ₃ +L ₄ ) exceeds 0.4, the fourth airflow passage 13 in which the wind speed is lowered becomes longer, so that the section in which the traction force to the thread decreases becomes longer. You won't be able to get enough traction from the tide.

In addition, (L ₃ +L ₄ )/(L ₂ +L ₃ +L ₄ ) sufficiently secures a section with a large traction force for the thread (that is, the second airflow passage 11 with a high wind speed) to provide sufficient traction to the thread. In order to work, it is preferably 0.99 or less. In addition, L ₄ /(L ₂ +L ₃ +L ₄ ) sufficiently secures the section of the fourth airflow passage 13 , and stabilizes the flow in the fourth airflow passage 13 to sufficiently express the diffuser effect. For this reason, it is preferably 0.01 or more.

And the 2nd airflow passage 11 and the 4th airflow passage 13 each have a constant flow passage cross-sectional area toward the downstream side of the thread running direction in FIG. 2, but as shown in FIG. 3, the downstream side of the thread running direction You may increase it according to the direction. In this case, since the diffuser effect becomes easy to express in the 2nd airflow passage 11 and the 4th airflow passage 13, and the static pressure in the airflow passage 9 further falls, the gas which flows in from the inlet 14 It has the advantage of increasing the inflow of In addition, although it increases in a tapered shape in FIG. 3, it is not limited to this, You may increase in step shape. In addition, in FIG. 3, although you may increase over the full length of the 2nd airflow passage 11 and the 4th airflow passage 13, only a part may increase in taper shape as shown in FIG.

In addition, in the communication part of the 2nd airflow path 11 and the 3rd airflow path 12, and the communication part of the 3rd airflow path 12 and the 4th airflow path 13, the downstream of the thread running direction Although the flow passage cross-sectional area is enlarged, as shown in Fig. 2, the flow passage cross-sectional area may be expanded at once in those communicating portions, or as shown in Figs. 3 and 4, the second air flow passage 11 and the fourth air flow passage In (13), at least a portion in the vicinity of the communication portion with the third airflow passage 12 may be tapered, and the flow passage cross-sectional area may be gradually enlarged. Moreover, the structure in which these were combined may be sufficient. If the outer wall member 5 is formed so that the flow passage cross-sectional area is enlarged at once only in the communicating portion, there is an advantage of easy processing in manufacturing the outer wall member 5, and the outer wall member 5 is formed in a tapered shape in the vicinity of the communicating portion. When it is formed, it has the advantage that it becomes difficult to generate|occur|produce a turbulent vortex when gas passes, and it has the advantage of being able to suppress thread disturbance.

Next, the influence of the length of the thread running direction of the 2nd airflow passage 11, the 3rd airflow passage 12, and the 4th airflow passage 13 on the traction force is demonstrated in detail. In the stretching device 3 of the present invention, the length L 2 of the second air flow passage 11 in the thread travel direction, the length L ₃ of the _third air flow passage 12 in the yarn travel direction, and the fourth air flow passage 13 It is preferable that the sum (mm) of the length L ₄ in the thread running direction satisfies the following relational expression.

L ₂ +L ₃ +L ₄ ≥100

By setting it as this structure, it becomes possible to generate|occur|produce effectively the traction force of the above-mentioned thread. When the sum is less than 100 mm, the overall length of the second air flow passage 11, the third air flow passage 12, and the fourth air flow passage 13 is shortened, so that the length of pulling the thread is shortened, and the desired traction force is obtained. becomes difficult to obtain Further, since the distance between the outlet port 15 and the airflow injection port 7 is close, the pressure loss in the airflow passage decreases, and it becomes difficult to sufficiently obtain the diffuser effect by using the fourth airflow passage 13 . Therefore, it is preferable that it is a structure which satisfies the said relational expression, and that the said sum is 250 or more.

In addition, since the total length of the 2nd airflow passage 11, the 3rd airflow passage 12, and the 4th airflow passage 13 becomes long, the length which draws a thread becomes long, but the static pressure in the gas passage 9 is As it increases, the pressure difference with the outside becomes small, and the inflow amount of the gas flowing in from the inlet 14 is reduced. Therefore, it is preferable that the total length of the 2nd airflow passage 11, the 3rd airflow passage 12, and the 4th airflow passage 13 is 1500 mm or less, and it is more preferable that it is 1000 mm or less.

In addition, in the present invention, the minimum flow path cross-sectional area H _2MIN of the second air flow passage 11, the flow passage cross-sectional area H ₃ of the third air flow passage 12, and the maximum flow passage cross-sectional area H _4MAX of the fourth air flow passage 13 are the following It is desirable to satisfy the relational expression.

1.05≤H ₃ /H _2MIN

1.05≤H _4MAX /H ₃

By setting it as this structure, it becomes possible to generate|occur|produce the traction force of the above-mentioned thread more effectively. Here, when the ratio of the cross-sectional area of each flow passage is less than 1.05, it is said that the flow passage is not sufficiently expanded as it goes downstream with respect to the thread running direction when viewed as a whole of the air flow passage, and the diffuser effect in the air flow passage It is difficult to obtain enough In addition, in order to prevent the occurrence of disturbance in the flow and to more effectively express the diffuser effect, the ratio of the cross-sectional area of each flow path is preferably 3 or less.

Moreover, in this invention, as shown in FIG. 8, one passage formation surface of a pair of outer wall member 5 which forms an airflow passageway of the 2nd airflow passage 11 to the 4th airflow passage 13 It is preferable that it is formed in a continuous one plane parallel to the running thread direction so that the distance with the thread becomes constant with respect to the running thread direction between them. By setting it as this structure, the part where the flow path does not expand is continuously formed on one side of the thread in the 2nd airflow path 11 to the 4th airflow path 13, As a result, the airflow with little disturbance is continuous in the vicinity of the said part. It is formed, and it becomes possible to express the traction force with respect to the thread more efficiently.

Next, each member common to the extending|stretching apparatus 3 of embodiment of this invention shown to FIG.1, FIG.2, FIG.3, FIG.4, FIG.8, and the shape of each member are demonstrated in detail.

In the stretching apparatus 3 in the present invention, various materials such as metal, alloy, ceramics, and resin can be employed as the material of the outer wall member 5 . Among these, it is preferable that it is a metal from a viewpoint of intensity|strength and abrasion resistance.

As a cross-sectional shape of the direction perpendicular to the thread running direction of the airflow passage 9, various things, such as a circular shape and a rectangle, are employable. Among them, a rectangular shape is preferable from the viewpoint that the amount of compressed air to be used is relatively small, and fusion or abrasion between threads does not easily occur.

Since the length of the first airflow passage 10 in the thread running direction is shortened, the pressure loss in the passage is reduced and the amount of gas flowing in from the inlet 14 is increased, the length is preferably 100 mm or less. , it is more preferable to set it as 50 mm or less.

The cross-sectional area of the first airflow passage 10 in the vertical direction with respect to the running direction of the thread can be set in a range in which the thread can flow. Since the pressure loss in the first air flow passage 10 decreases and the amount of gas flowing in from the inlet 14 increases, the minimum cross-sectional area in the vertical direction with respect to the thread running direction of the second air flow passage 11 is It is preferable that it is wide, and it is more preferable that it is wider than the maximum cross-sectional area of the perpendicular|vertical direction with respect to the thread running direction of the 4th airflow passage 13. As shown in FIG.

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 fall of wind speed can be suppressed by setting it as 15 degrees or less. As a shape of a gas supply pipe|tube, it is preferable that the cross-sectional shape of the direction perpendicular|vertical with respect to the airflow direction among the said gas supply pipes is a rectangle. The cross-sectional area of the gas supply pipe may be constant with respect to the direction of the air flow in the gas supply pipe, or may be enlarged as it goes toward the air flow injection port 7, but the effect of the Laval nozzle in which the wind speed increases by adiabatic expansion in the sonic speed region is obtained. It is more preferable to expand toward the injection port 7 .

The airflow supplied to the thread from the airflow injection port 7 is preferable because air is the most economical, but mixed gas, steam, saturated steam, or heated steam may be used. In order to improve the traction force of a thread, it is preferable to select an airflow with a high density from the point that the density ρ of an airflow is also related like Formula (A) mentioned above. In addition, although room temperature is most economically preferable as for the temperature of an airflow, it is not limited to this. In addition, since the humidity of the airflow introduces the atmosphere, it is economically preferable not to control the humidity, but it is not limited to this, and, for example, it becomes possible to improve the traction force of the thread by supplying an airflow of high humidity.

The present invention is a very versatile invention, and can be applied in the production of all known fibrous webs. Therefore, it is not particularly limited depending on the polymer constituting the fibrous web. For example, if an example of the polymer which comprises a fiber web is given, polyester, polyamide, polyphenylene sulfide, polyolefin, polyethylene, polypropylene, etc. are mentioned. In addition, as long as the above-mentioned polymer does not impair the radiation stability, etc., matting agents such as titanium dioxide, silicon oxide, kaolin, color inhibitor, stabilizer, antioxidant, deodorant, flame retardant, yarn friction reducing agent, color pigment, surface modifier Various functional particles, such as, additives, such as an organic compound, may be contained, and copolymerization may be contained.

In addition, the polymer constituting the fibrous web may be composed of a single component or may be composed of multiple components, and in the case of multiple components, for example, a core-sheath, side-by-side configuration may be mentioned.

The cross-sectional shape of the fibers forming the fibrous web may be hollow or other shapes such as circles, triangles, and flats. In addition, the single yarn fineness of a fibrous web is not specifically limited. Although the number of single yarns of the fibrous web is not particularly limited, the greater the number of single yarns of the fibrous web, the clearer the difference from the prior art.

Next, a preferred embodiment for producing a spunbond nonwoven fabric comprising a fibrous web using the apparatus shown in Figs. 1 and 2 will be specifically described.

The apparatus shown in FIG. 1 WHEREIN: Polyolefin resin is melt-spun from the spinneret 1, for example. The spinning temperature at this time is preferably 200 to 270°C, more preferably 210 to 260°C, and still more preferably 220 to 250°C. By making the spinning temperature within the above range, it is possible to obtain a stable molten state and excellent spinning stability.

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 to the yarn with the cooling device 19, the yarn A method of natural cooling to ambient ambient temperature, a method of natural cooling by adjusting the distance between the spinneret 1 and the stretching device 3, etc. are mentioned. In addition, a method combining these methods may be employed. In addition, the cooling conditions may be appropriately adjusted and employed in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the ambient temperature, and the like.

The yarns cooled in the cooling device 19 are then stretched by applying tension by the stretching device 3 as described above, and sprayed onto the net of the conveyor 4 to form a web of fibers on the conveyor 4 . do.

It is preferable that the spinning speed when the extending|stretching apparatus 3 of this invention is used is 3,500-6,500 m/min, More preferably, it is 4,000-6,500 m/min, More preferably, it is 4,500-6,500 m/min. When the spinning speed is set to 3,500 to 6,500 m/min, high productivity is obtained, and the orientation and crystallization of the fibers proceeds to obtain long fibers of high strength. For this reason, the nonwoven fabric composed of high-strength fibers is also excellent in strength.

The drawing apparatus according to the present invention can be used not only for the production of a fibrous web, but also for the production of fibers used in medical and industrial applications. In that case, it is good to wind up the fiber obtained by spinning, cooling, and extending|stretching similarly to manufacture of the nonwoven fabric mentioned above on a bobbin etc.

<Example>

Hereinafter, the present invention will be described in more detail by way of Examples. In addition, the measuring method etc. of the characteristic value in an Example are as follows.

(1) Traction force (N):

6 shows a schematic diagram of a method for measuring the traction force. First, a No. 3 nylon degus (A-154 made by Yutaka Make) 17 of one single yarn is fixed to the tensiometer 16 (MODEL-RX-1 made by Aiko Engineering Co., Ltd.), and the airflow from the upper part of the stretching device 3 The degus 17 is hung into the passage 9, and the degus 17 is cut at the lowest point (outlet 15) of the airflow passage. And compressed air was supplied to the extending|stretching apparatus 3, and the tension|tensile_strength N generated at that time was measured with the tensiometer 16. As shown in FIG. This measurement was repeated 5 times, and the average value (N) was made into the traction force.

(2) Static pressure (kPa) inside the airflow passage:

As shown in FIG. 7, the state in which the pressure gauge (PG-100-102G manufactured by Copal Corporation) is hermetically connected to the static pressure measuring tool 18 which is a through hole drilled in the side wall member 20 of the airflow passage 9. The compressed air was supplied to the stretching device 3 at , and the gauge pressure (kPa) inside the air flow passage 9 was measured. In addition, the measurement height was made into the position of the downstream end part 8 of an airflow injection port. This measured value was employed 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 apparatus 3 in a state in which a pressure gauge (GS50-171-0.6MP manufactured by Nagano Keiki Co., Ltd.) is hermetically connected to the airflow supply part of the stretching apparatus 3, and the The gauge pressure (MPa) was measured. This measured value was employed as the supply pressure to the stretching apparatus.

(4) single fiber diameter (μm):

After towing and stretching in the stretching device, 10 small sample samples were randomly taken from the fiber web collected on the net, and a picture of the surface at 1000 times was taken with a microscope. The width of a total of 100 fibers, 10 each from the photograph of each sample, was measured, and their average value was adopted as the single-fiber fiber diameter.

(5) spinning speed (m/min):

From the diameter of the single fiber and the solid density of the resin to be used, the mass per 10,000 m in length was used as the single fiber fineness, and it was calculated by rounding off to two decimal places. From the single fiber fineness (dtex) and the discharge amount of the resin discharged from the single hole of the spinneret set in each condition (hereinafter abbreviated as the single hole discharge amount) (g/min), the spinning speed was calculated based on the following formula.

Spinning speed = (10000 x single hole discharge) / single fiber fineness.

[Example 1]

In the apparatus of the structure shown in FIG. 1, FIG. 2, the fiber web was manufactured as follows. In addition, the stretching device 3 has a rectangular cross section of the airflow passage 9 , the length L from the inlet 14 to the outlet 15 of the airflow passage 9 is 200 mm, and the length of the second airflow passage 11 . L ₂ was set to 50 mm, length L ₃ of the third air flow passage 12 was set to 50 mm, and length L ₄ of the fourth air flow passage 13 was set to 50 mm. Further, the gap W ₁ of the first air flow passage was 3 mm, the gap W ₂ of the second air flow passage was 3 mm, the gap W ₃ of the third air flow passage was 4 mm, and the gap W ₄ of the fourth air flow passage 13 was 5 mm. . The installation angle of the airflow supply pipe with respect to the airflow passage 9 was 15 degrees, and the width of the airflow supply pipe was 0.2 mm. In addition, 0.2 MPa of compressed air was supplied to the airflow supply part of the stretching apparatus 3 . As a result of measuring the traction force, as shown in Table 1, it was set to 37 mN. Further, the static pressure in the airflow passage 9 at the downstream end portion 8 of the airflow injection port was set to -6.3 kPa.

A polypropylene resin having a melt flow rate (MFR) of 35 g/10 min is melted in an extruder, and the resulting yarn is discharged from a rectangular spinneret 1 having a spinning temperature of 235° C. and a pore diameter of 0.30 mm at a single hole discharge rate of 0.56 g/min. After solidification by cooling in the cooling device 19, by supplying compressed air with a supply pressure of 0.20 MPa to the stretching device 3, it was pulled and stretched and collected on a moving net to obtain a fibrous web containing long polypropylene fibers. .

The obtained polypropylene long fiber had a single fiber diameter of 16.6 µm, and a spinning speed converted therefrom was 2,951 m/min.

[Example 2]

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 inlet 14 to the outlet 15 of the airflow passage 9 . 350 mm, the length L ₂ of the second air flow passage 11 is 100 mm, the length L ₃ of the third air flow passage 12 is 100 mm, and the length L ₄ of the fourth air flow passage 13 is 100 mm. 1 was the same.

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

The obtained polypropylene long fiber had a single fiber diameter of 16.1 µm, and a spinning speed converted therefrom was 3,043 m/min.

[Example 3]

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, and the length L from the inlet 14 to the outlet 15 of the airflow passage 9 140 mm, the length L ₂ of the second air flow passage 11 is 30 mm, the length L ₃ of the third air flow passage 12 is 30 mm, and the length L ₄ of the fourth air flow passage 13 is 30 mm. 1 was the same.

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

The obtained polypropylene long fibers had a single fiber diameter of 17.4 µm, and a spinning speed converted therefrom 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 a continuous one between the second air flow passage 11 and the fourth air flow passage 13 parallel to the running thread direction. As a pattern formed in the plane, it carried out similarly to Example 1 except having used the extending|stretching apparatus 3 as shown in FIG.

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

Characteristics of the obtained polypropylene long fibers were that the single-fiber fiber diameter was 16.3 µm, and the spinning speed converted therefrom was 3,005 m/min.

[Comparative Example 1]

As a pattern in which the second air flow passage is not enlarged, the gap W ₂ of the second air flow passage 11 is 4 mm, and the cross-sectional shape and cross-sectional area of the second air flow passage and the third air flow passage in FIG. 2 are the same. The same procedure as in Example 1 was carried out except for the above.

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

The obtained polypropylene long fiber had a single fiber diameter of 17.6 µm, and a spinning speed converted therefrom was 2,783 m/min.

[Comparative Example 2]

As a pattern in which the fourth air flow passage 13 is not expanded (that is, substantially no fourth air flow passage is provided), the gap W ₄ of the fourth air flow passage 13 is set to 4 mm, and the fourth air flow passage in FIG. It carried out similarly to Example 1 except having made the cross-sectional shape and cross-sectional area of the 3rd airflow passageway and the 4th airflow passageway become the same.

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

The obtained polypropylene long fiber had a single fiber diameter of 18.6 µm, and a spinning speed converted therefrom was 2,634 m/min.

[Comparative Example 3]

As a pattern in which the second air flow passage 11 is long with respect to the third air flow passage 12 and the fourth air flow passage 13, the length L from the inlet 14 to the outlet 15 of the air flow passage 9 is 200 mm , The length L ₂ of the second air flow passage 11 is 75 mm, the length L ₃ of the third air flow passage 12 is 25 mm, and the length L ₄ of the fourth air flow passage 13 is 50 mm. did the same

As a result of measuring the traction force, as shown in Table 1, it was set to 32 mN. Further, the static pressure in the airflow passage 9 at the downstream end portion 8 of the airflow injection port was set to -5.5 kPa. The obtained polypropylene long fibers had a single fiber diameter of 18.1 µm, and a spinning speed converted therefrom was 2,707 m/min.

[Comparative Example 4]

As a pattern in which the fourth air flow passage 13 is long with respect to the second air flow passage 11 and the third air flow passage 12, the length L from the inlet 14 to the outlet 15 of the air flow passage 9 is 200 mm , Example except that the length L ₂ of the second air flow passage 11 is 32.5 mm, the length L ₃ of the third air flow passage 12 is 32.5 mm, and the length L ₄ of the fourth air flow passage 13 is 75 mm. 1 was the same.

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

The obtained polypropylene long fibers had a single fiber diameter of 18.4 µm, and a spinning speed converted therefrom was 2,663 m/min.

The stretching apparatus of the present invention is not limited to stretching of yarns for nonwoven fabrics, and can also be applied to stretching of yarns for other uses, such as various woven and knitted fabrics.

1: spin detention
2: Sajo
3: Stretching device
4: Conveyor
5: External wall member
6: Buffer in the airflow supply
7: Airflow nozzle
8: the downstream end of the airflow nozzle
9: Airflow passage
10: first airflow passage
11: Second airflow passage
12: third airflow passage
13: fourth airflow passage
14: inlet
15: outlet
16: tensiometer
17: Degus
18: static pressure measuring sphere
19: cooling device
20: side wall member
90: passage forming surface

Claims (8)

In a passage having an inlet and an outlet of a thread obtained by melt spinning a thermoplastic polymer, a stretching device for stretching the thread by spraying an airflow from the outside to the inside of the running path of the thread, the thread having an inlet and an outlet The passage has a first airflow passage, an airflow injection port, a second airflow passage, a third airflow passage and a fourth airflow passage in this order with respect to the thread running direction, satisfying the following (i) to (iv) Characterized in that, the stretching device.
(i) The third airflow passage has a constant flow passage cross-sectional area with respect to the thread running direction.
(ii) The flow passage cross-sectional area of the second air flow passage is smaller than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.
(iii) The flow passage cross-sectional area of the fourth air flow passage is larger than that of the third air flow passage, and the flow passage cross-sectional area is constant and/or increasing with respect to the thread running direction.
(iv) the length L ₂ in the thread running direction of the second air flow passage, the length L ₃ in the thread running direction of the third air flow passage, and the length L ₄ in the thread running direction of the fourth air flow passage are the following relational expressions Satisfies.
(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 L ₂ and L ₃ and L ₄ satisfies the following relational expression.
L ₂ +L ₃ +L ₄ ≥100 The elongation according to claim 1, wherein the minimum flow path cross-sectional area H _2MIN of the second air flow passage, the flow passage cross-sectional area H ₃ of the third air flow passage, and the maximum flow passage cross-sectional area H _4MAX of the fourth air flow passage satisfy the following relational expressions Device.
1.05≤H ₃ /H _2MIN
1.05≤H _4MAX /H ₃ The second airflow according to claim 1, wherein the passage having an inlet and an outlet of a thread is formed by a pair of opposing outer wall members, and one passage forming surface of the pair of outer wall members is formed with respect to the thread running direction. The stretching apparatus in which a space from the cylinder to the fourth airflow passage is formed in a continuous single plane parallel to the thread running direction. A fiber manufacturing apparatus comprising a spinneret, a cooling device for the spun yarn, and the drawing device according to claim 1 in this order in a yarn running direction. An apparatus for producing a fibrous web, comprising a spinneret, a cooling device for the spun yarn, the drawing device according to claim 1 , and a conveyor for the fiber web provided with a net in this order in the yarn running direction. After forming a thread by melt-spinning a thermoplastic polymer from a spinneret, cooling and solidifying this thread, the manufacturing method of the fiber which draws the said thread with the extending|stretching apparatus in any one of Claims 1-4. A method for producing a fibrous web, wherein the fibrous web is produced using the apparatus according to claim 1 .

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