JP2003286648A - Method and machine for producing web with unidirectionally arranged filaments - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a web with more highly unidirectionally arranged filaments. <P>SOLUTION: A web production machine comprises a melt blow die 3 parallel arranged with many nozzles 2 via which a molten polymer is extruded as filaments 4 and a conveyor 1 for collecting the filaments 4 extruded via the nozzles 2 and conveying them, wherein the melt blow die 3 is equipped with slits 6a and 6b jetting hot air from both sides of the filaments 4 for slitting them extruded from the nozzles 2. The jetting levels of the hot air from the slits 6a and 6b are altered so as to alternately repeat such a state that the jetting level of one of the slits 6a and 6b is greater than that of the other and vice versa. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a web in which filaments are arranged in one direction and an apparatus for producing the web.

[0002]

2. Description of the Related Art Nonwoven fabrics are produced by forming a web from a filament group spun from a polymer and immediately adhering the filaments to each other. The spunbond method, the melt blow method, the flash spinning method (hereinafter, these production methods are broadly defined as spunbond). Method, and the nonwoven fabric produced by these production methods is called a spunbond nonwoven fabric in a broad sense). Spunbond nonwoven fabrics in a broad sense are the mainstream of nonwoven fabrics because they are excellent in economy and mass productivity.

[0003] Conventional spunbonded nonwoven fabrics in a broad sense are random nonwoven fabrics in which filaments are arranged in random directions, so that they often have low strength and lack dimensional stability. Therefore, various proposals have been made to improve the arrayability of filaments.

For example, as a method for vertically arranging filaments, Japanese Patent Publication No. 60-25541 discloses a method for highly arranging filaments in one direction by inclining a conveyor with respect to the ejection direction of the filaments. Has been done. Further, in Japanese Patent Application Laid-Open No. 7-3604, the filaments ejected together with the air flow are deposited on a breathable conveyor, and an air flow blocking means is provided on the back side of the conveyor to control the air flow to remove the filaments. It describes a method of spreading in the longitudinal direction to improve the alignment property. On the other hand, as a method of arranging the filaments in the lateral direction, Japanese Patent Publication No. 3-36958 and Japanese Patent No. 1992584 disclose a plurality of air jets around the spinning nozzle, each having a circumferential component of the nozzle. One spray nozzle is arranged, and two second spray nozzles are arranged outside the first spray nozzle so as to collide with each other in a direction parallel to the web conveying direction. A method is disclosed in which the filaments are arranged in the lateral direction by rotating the filaments in a spiral shape with a nozzle and then spreading the filament in the lateral direction with a second spray nozzle. Further, Japanese Patent No. 2612203 discloses a method of arranging filaments laterally by devising a conveyor.

[0005]

With the recent development of the non-woven fabric industry, the range of application of non-woven fabrics is rapidly expanding, and non-woven fabrics are required to have further strength and dimensional stability. Generally, it is most effective to draw a filament in order to improve the strength and dimensional stability of the nonwoven fabric. A simple method for stretching the filament is to stretch the web in the filament arrangement direction in the state where the web is deposited on the conveyor. However, if the filaments are not aligned in one direction before the web is stretched, even if the web is stretched, the spacing between the filaments will only widen and the probability that the filaments will be substantially stretched will decrease. And the dimensional stability cannot be obtained. In the conventional method for producing a non-woven fabric, the degree of highly arranging the filaments is insufficient, and it has been difficult to produce a non-woven fabric having high strength and dimensional stability as required in recent years. That is, in order to produce a nonwoven fabric having higher strength and dimensional stability, it is required that the filaments are more highly unidirectionally arranged in the web.

[0006] Therefore, an object of the present invention is to provide a method and an apparatus for producing a web, in which filaments can be more highly aligned in one direction.

[0007]

In order to achieve the above object, the first aspect of the method for producing a web of the present invention is a plurality of nozzles arranged in parallel and extruding a molten polymer as filaments, respectively, and a plurality of nozzles extruding from the nozzles. And a spinning means having a pair of hot air jet nozzles for jetting hot air from both sides to the filament extruded from the nozzle to thin the filament, and the filament extruded from the plurality of nozzles is collected and conveyed. A method of manufacturing a web using a conveyor, the step of extruding a filament from the nozzle, the amount of hot air jetted on both sides of the filament by the hot air jet nozzle,
And a step of changing such that a state where the injection amount from one side is larger than the injection amount from the other side and a state where the injection amount from the other side is larger than the injection amount from one side are alternately repeated.

A second aspect of the method for producing a web of the present invention is a spinning means having a plurality of nozzles arranged in parallel and each of which extrudes a molten polymer as a filament, and the filaments extruded from the plurality of nozzles are collected. A method of manufacturing a web using a conveyor to convey, a step of extruding a filament from the nozzle, a step of ejecting a fluid from both sides of the filament extruded from the nozzle, the injection amount from one There is a step of changing the injection amount of the fluid such that a state in which the injection amount from the other is larger and a state in which the injection amount from the other is larger than the injection amount from one are alternately repeated.

A first aspect of the apparatus for producing a web of the present invention comprises a plurality of nozzles arranged in parallel and each extruding a molten polymer as a filament, and a nozzle extruded from the nozzle for thinning the filament extruded from the nozzle. The spinning filament having a pair of hot air jet nozzles for jetting hot air from both sides of the filament, and a conveyor for collecting and transporting the filament extruded from the nozzle, both sides of the filament from the hot air jet nozzle The state in which the injection amount of the hot air injected into is larger than the injection amount from the other and the state in which the injection amount from the other is larger than the injection amount from one are alternately repeated. Be changed.

A second aspect of the web manufacturing apparatus of the present invention is a spinning means having a plurality of nozzles arranged in parallel and each of which extrudes a molten polymer as a filament, and the filament extruded from the nozzle is collected and conveyed. Conveyor and a pair of fluid ejecting means for ejecting fluid from both sides of the filament extruded from the nozzle, the state in which the injection amount from one is larger than the injection amount from the other, the injection amount from the other A fluid ejecting unit that changes the fluid ejection amount so that the state in which the ejection amount from one side is larger than the state in which the ejection amount is larger is alternately repeated.

According to the present invention, the filament extruded from the nozzle is collected on the conveyor and conveyed as it is to form a web. Here, the fluid extruded from both sides of the filament extruded from the nozzle. The fluid ejected from both sides of the filament is changed in such a manner that the ejected amount thereof is larger than the ejected amount of the other and the opposite state is alternately repeated. The direction of ejection is periodically changed according to the change of the injection amount of the fluid. As a result, the filaments are collected on the conveyor while being shaken in one direction, so that a web in which the filaments are highly aligned in one direction is obtained.

As the fluid jetted from both sides of the filament, it is also possible to use hot air jetted to thin the filament extruded from the nozzle. In this case, the hot air jet nozzle for jetting hot air is often already incorporated in the spinning means, and it is not necessary to install another structure in the spinning space below the spinning means, so that the device configuration is simplified, In addition, workability during maintenance of the spinning means does not deteriorate. Further, when the fluid jetting means for shaking the filament is provided separately from the hot air jetting nozzle, the fluid jetting means has a function of assisting the thinning of the filament by jetting hot air from the hot air jetting nozzle. Further, the fluid for shaking the filament may be water in the form of mist for cooling the filament between the spinning means and the conveyor. As a result, the filament is rapidly cooled and the crystallinity of the filament can be reduced, which is advantageous when the web is stretched in a later step.

In the present invention, the "longitudinal direction" used to describe the filament arrangement direction, the drawing direction, etc.
It means a machine direction in producing a web or a nonwoven fabric, that is, a feeding direction of the web or the nonwoven fabric, and "transverse direction" means a direction perpendicular to the machine direction, that is, a width direction of the web or the nonwoven fabric.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic front view of an apparatus for producing a web by a melt-blowing method, which is an embodiment of the present invention. The apparatus shown in FIG. 1 is for producing a web 8 in which filaments 4 are arranged in a longitudinal direction.
It has a melt blow die 3 for spinning and a conveyor 1 for collecting and transporting the spun filament 4. In FIG. 1, the melt blow die 3 is shown in cross section so that the internal structure can be seen.

The melt blow die 3 has a large number of nozzles 2 arranged in parallel at the tip (lower end) thereof in a direction parallel to the width direction of the conveyor 1. Gear pump (not shown)
A large number of filaments 4 are formed in the width direction of the conveyor 1 by continuously extruding the molten resin sent from the nozzles 2. On both sides of the nozzle 2 of the melt blow die 3, more specifically, in the direction perpendicular to the plane passing through the center line of each nozzle 2, on both sides of the nozzle 2 along the width direction of the melt blow die 3 (width direction of the conveyor 1), respectively. Slits 6a and 6b are provided at the tip of the melt blow die 3 and are formed. Each slit 6a, 6b communicates with an air reservoir 5a, 5b provided inside the melt blow die 3, respectively. The high-pressure air heated above the melting point of the resin as the raw material of the filament 4 is fed into the air reservoirs 5a and 5b, and the high-pressure air fed into the air reservoirs 5a and 5b is fed into the slits 6a,
The hot air is blown from 6b toward the filament 4.

The filament 4 extruded from the nozzle 2 is maintained in a molten state by the hot air blown from the slits 6a, 6b, and the filament 4 is caused by the frictional force with the hot air.
Tension is applied to the filament 4, and the filament 4 is thinned. The structure of the above melt blow die 3 is the same as that of a die used in a usual melt blow method. The temperature of the hot air is set to 80 ° C. or higher, preferably 120 ° C. or higher than the spinning temperature of the filament 4.

In the method of spinning the filament 4 using the melt blow die 3, the filament 4 immediately after being extruded from the nozzle 2 is increased by raising the temperature of hot air.
Since the temperature of 1 can be made sufficiently higher than the melting point of the filament 4, the crystallinity of the filament 4 can be reduced.

The conveyor 1 is arranged below the melt blow die 3. The conveyor 1 is wound around a conveyor roller 1a and other rollers that are rotated by a drive source (not shown). The rotation of these rollers causes the conveyor 1
The web 8 obtained by driving the filaments 4 extruded from the nozzles 2 on the conveyor 1 by driving
Are conveyed from the left side to the right side in FIG.

In the usual melt blow method, each slit 6
Hot air is jetted simultaneously from a and 6b with the same jet amount. However, in the present embodiment, the injection amount of hot air from each slit 6a, 6b is variable, and the injection amount from one slit 6a is larger than the injection amount from the other slit 6b, and vice versa. The injection amount of hot air is alternately changed so that is switched alternately. The state in which the other injection amount is larger than the one injection amount means that each slit 6
It suffices that there is a difference between the injection amounts from a and 6b, and this includes not only changing the strength of the injection amount but also changing the presence or absence of injection.

Regarding an example of the spinning operation by the melt blow die 3 of the present embodiment, the case where the injection amount of hot air from each slit 6a, 6b is variable in two stages of the presence or absence of injection is shown in FIG. This will be described with reference to a) to (c). First, in the state shown in FIG. 2A, hot air is jetted only from the slit 6b on the right side, whereby the filament 4 is swung to the left side and pushed out from the nozzle 2. Next, as shown in FIG. 2 (b), the hot air blowing from the right slit 6b is stopped, and the hot air is jetted only from the left slit 6a. Then, this time, the filament 4 is swung to the right side by the hot air from the slit 6a on the left side. Next, as shown in FIG. 2C, when the hot air jet from the left slit 6a is stopped and the hot air is jetted only from the right slit 6b, the filament 4 is swung to the left side again.

In the above description, the hot air blown from each of the slits 6a and 6b has been described as an example controlled by the presence or absence of the jet. However, when one is strongly jetted, the other is weakly jetted. The filament 4 exhibits the same behavior even when the strength is alternately repeated.

As described above, by alternately changing the injection amount of hot air from the slits 6a and 6b, the filament 4 is periodically swung in the conveying direction of the conveyor 1, that is, in the vertical direction, as shown in FIG. , Being collected on the conveyor 1 while being folded. Therefore, it is possible to improve the arranging property of the filaments 4 on the conveyor 1 in the vertical direction and increase the folding width S of the filaments 4 on the conveyor 1. The arrangement of such filaments 4 is effective in improving the strength of the web 8 in the longitudinal direction.

Further, in this embodiment, the hot air blown to thin the filament 4 is used.
Therefore, it is not necessary to provide an extra structure in the spinning space below the melt blow die 3. For this reason,
The turbulence of the air flow due to the structure does not occur, and stable spinning can be performed. Further, since there is no extra structure below the melt blow die 3, the workability below the nozzle 2 during maintenance of the melt blow die 3 does not deteriorate.

The deflection width of the filament 4 is determined by the slit 6
It depends on the difference in the amount of hot air jetted from a and 6b and the inclination angle θ of the slits 6a and 6b with respect to the center line of the nozzle 2.
The greater the difference in the amount of hot air jetted, the greater the deflection width of the filament 4. Further, the larger the tilt angle θ of the slits 6a and 6b, the larger the swing width of the filament 4.
However, when an attempt is made to increase the deflection width of the filament 4, the orientation of the filament 4 changes greatly immediately below the nozzle 2, and thus the extrusion of the filament 4 from the nozzle 2 may become unstable. The inclination angle θ of the slits 6a and 6b is preferably in the range of 20 ° to 40 °. Further, in order to shake the filament 4 in the right and left in a well-balanced manner, it is preferable that the difference in the injection amount of hot air from the slits 6a and 6b be equal and the inclination angles θ of the slits 6a and 6b be equal.

Although FIG. 1 shows an apparatus for producing the web 8 in which the filaments 4 are arranged in the longitudinal direction, the web 8 in which the filaments 4 are arranged in the lateral direction can be obtained by changing the arrangement of the melt blow die 3. It can also be manufactured. FIG. 3 shows an example of an apparatus for manufacturing a web in which filaments are arranged in the lateral direction. In FIG. 3, (a) is a front view and (b) is a side view. Further, in FIG. 3, the arrangement of the melt blow die is only different from that in FIG. 1, and therefore the same components as those in FIG. 1 are designated by the same reference numerals as those in FIG.

As shown in FIG. 3, in order to arrange the filaments 4 in the lateral direction, the melt blow dies 3 are arranged so that the row direction of the nozzles 2 thereof is parallel to the conveying direction of the web 8 by the conveyor 1. . Then, the hot air jets from the slits 6a and 6b are alternately controlled as in the case of FIG. Thereby, the filaments 4 extruded from the nozzles 2 are collected on the conveyor 1 while being shaken in the lateral direction, and the web 8 in which the arrangement of the filaments 4 in the lateral direction is improved can be obtained.

In the arrangement shown in FIG. 1, the width of the web 8 depends on the arrangement width of the nozzles 2, but in the arrangement shown in FIG.
The width of the web 8 depends on the deflection width S of the filament 4.
Therefore, in the arrangement shown in FIG. 2, the width of the web 8 can be freely changed by appropriately setting the deflection width S of the filament 4.

By the way, in the usual melt blow spinning,
Since the filament collides with the conveyor linearly with the hot air, the time required to reach the conveyor, that is, the cooling time is short. Further, if the distance between the nozzle and the conveyor is made too large, the formation of the web (partial uniformity of basis weight) becomes poor. Therefore, in normal melt blown spinning, the distance between the nozzle and the conveyor is about 300 mm. On the other hand, according to the present invention, since the deflection width S of the filament 4 becomes large, the time until the filament 4 reaches the conveyor 1 becomes long, and the distance between the melt blow die 3 and the conveyor 1 does not have to be increased. The filament 4 can be cooled well. Further, although the reason is not always clear, it has been clarified as a result of the experiment that the formation of the web 8 is rather good.

In the above-mentioned example, the hot air for thinning the filament 4 is used to shake the filament 4. However, in addition to the hot air for thinning the filament 4, air is jetted to the filament 4. However, the filament 4 can be shaken accordingly.

FIG. 4 shows an example of a spinning device equipped with an air jet nozzle used to shake a filament. Figure 4
The spinning device shown in FIG. 1 is a spinning device by the melt blow method similar to that in FIG. 1. Therefore, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

As shown in FIG. 4, the melt blow die 3
A pair of air injection nozzles 9a and 9b are disposed below the. The air injection nozzles 9a and 9b are arranged so as to face each other with the filament 4 extruded from the nozzle 2 interposed therebetween, and are configured to alternately change the injection amount of air. As a result, the filaments 4 are periodically shaken, and as a result, the filaments 4 are folded in a state of being arranged in one direction and collected on a conveyor (not shown). Therefore, by appropriately setting the relative positional relationship between the spinning device and the conveyor shown in FIG. 4, it is possible to manufacture a web in which the filaments 4 are arranged in the longitudinal direction, or a web in which the filaments 4 are arranged in the lateral direction. Can also be manufactured.

The air injection nozzles 9a and 9b are different from the slits 6a and 6b provided in the melt blow die 3,
Since the installation position and the air ejection direction can be arbitrarily set, the filament 4 can be swung with high reliability. In addition, the air jet nozzles 9a and 9b also have a function of assisting the thinning of the filament 4 by the hot air jetted from the slits 6a and 6b.

In the configuration shown in FIG. 4, the air injection nozzle 9
Since the filament 4 is swung by air injection from a and 9b, hot air is simultaneously injected from the slits 6a and 6b as in the usual melt blow method. However, in order to assist the deflection of the filament 4 by the air injection nozzles 9a and 9b, the injection amount of hot air from the slits 6a and 6b may be controlled in synchronization with the air injection from the air injection nozzles 9a and 9b.

The width of the air injection nozzles 9a, 9b is preferably larger than the width of the filament group spun by the melt blow die 3. Air injection nozzles 9a, 9
If the width b is equal to or smaller than the width of the filament group, a force having a component other than the direction in which the air jet nozzles 9a and 9b face each other acts on the filament 4 at both ends of the filament group. There is a risk that the alignment will be insufficient. Further, in order to shake the filament 4 to the left and right in a well-balanced manner, the air injection nozzles 9a, 9a
It is preferable that b are installed at the same distance from the center line of the nozzle 2 and at the same height.

The present invention has been described with reference to some typical examples. Hereinafter, examples of filaments, spinning means, and other additional components applicable to the present invention will be described.

<Filament> As the polymer suitable for the filament used in the present invention, polyethylene,
Thermoplastic resins such as polypropylene, polyester, polyamide, polyvinyl chloride resin, polyurethane, fluorine resin and modified resins thereof can be used. Further, a resin produced by a wet or dry spinning device such as polyvinyl alcohol resin or polyacrylonitrile resin can also be used.

The filament in the present invention is a long fiber filament. Generally, a filament filament has an average length of more than 100 mm, and a filament spun continuously as in the present invention is included in the filament filament. Further, if the diameter of the filament immediately after spinning is 50 μm or more, the filament is rigid and the entanglement becomes insufficient. Therefore, the diameter of the filament used in the present invention is preferably 30 μm or less, more preferably 2 μm or less.
It is 5 μm or less. If a particularly strong web is desired, it is desirable to stretch the web in the transverse direction after spinning the web. In that case, the diameter of the filament after drawing is 5μ
It is preferably m or more. The diameter and length of the filament were measured from a magnified micrograph, and the length was 3
The average value of 0 pieces and the diameter of 100 pieces are shown.

<Spinning Means> As the filament spinning means, the melt-blowing method, which is a spunbond method in a broad sense, has been described, but an example using the spunbond method in a narrow sense will be described below.

FIG. 5 is a schematic sectional view of a web manufacturing apparatus using a spunbond method in a narrow sense as seen from the front. In ordinary spunbond spinning, a spunbond die 2 having a large number of spinning holes arranged in parallel in the width direction of the conveyor 21.
A large number of filaments 24 spun from 3 are sucked by the air 26 by the ejector 25, and are collected on the conveyor 21 along with the high-speed airflow which is the air 26 accelerated by the nozzle 25a of the ejector 25. Conveyor 21
Is driven by a conveyor roller (not shown) to convey the filament 24 from the left side to the right side in the drawing.

Below the ejector 25, a pair of air injection nozzles 29a and 29b are provided from the nozzle 25a to the air 26.
The filaments 24 discharged together with the filaments 24 are arranged to face each other. The air injection nozzles 29a and 29b are the same as those shown in FIG. 4, and the filament 24 is periodically swung in the conveying direction of the conveyor 21 by alternately changing the injection amount of air. As a result, the filament 24 is folded in the vertical direction while being conveyed to the conveyor 2.
A web 28 is obtained on which the filaments 24 are vertically aligned.

Further, as in the case of the melt blow method described above, the spun bond die 23 and the air jet nozzle 2 are used.
By arranging 9a and 29b in parallel with the conveyance direction of the web 28 by the conveyor 21, the web 28 in which the filaments 24 are arranged in the lateral direction can be manufactured.

When the spinning means is the spunbond method or the flash spinning method in a narrow sense, the crystallization of the filament may have already been carried out. Even in such a case, the arrangement of the filament is remarkably improved. It is possible to obtain a strong web in the filament arrangement direction.

<Additional Components> The obtained web is
Although it can be used as it is, the filament arrangement can be further improved by stretching in the filament arrangement direction. Therefore, it is preferable to add a stretching device for stretching the web in the filament arrangement direction. At this time, the better the alignment of the filaments, the higher the probability that the filaments will be substantially stretched when the web is stretched, and the higher the strength of the final stretched web. If the arrangement of filaments is not good, even if the web is stretched, the folded structure of the filaments and the spacing between the filaments are widened, and the probability that the filaments are substantially stretched becomes low, and sufficient strength after stretching cannot be obtained. Further, by arranging the filaments in a highly unidirectional manner at the web stage, it is possible to prevent the filaments from breaking during stretching.

A web having filaments arranged in the machine direction is stretched in the machine direction. To stretch the web in the machine direction,
In some cases, the stretching may be performed in one stage, but a multi-stage stretching method is mainly used. In the multi-stage stretching method, the first stage stretching is performed as a preliminary stretching immediately after spinning, and the subsequent second and subsequent stretching is performed as a main stretching. Among them, it is particularly preferable to use the proximity stretching method for the first stage of multi-stage stretching.

Proximity stretching is a method in which a web is stretched by a difference in surface speed between two adjacent rolls, and stretching is performed while maintaining a short distance between stretchings (distance from starting point to ending point of stretching). It is desirable that the distance between stretching is 100 mm or less. In particular, even if the filaments are arranged in the longitudinal direction as a whole and are individually bent to some extent, it is possible to keep the distance between stretching as short as possible.
It is important for effectively drawing individual filaments.
The heat in the proximity stretching is usually given by heating a roll for stretching, and the stretching point is supplementarily heated by hot air or infrared rays. Further, hot water, steam, or the like can be used as a heat source for the proximity drawing.

On the other hand, in the multi-stage stretching, not only proximity stretching but also various means used for ordinary web stretching can be applied to the second and subsequent stretching. For example, stretching methods such as roll stretching, hot water stretching, steam stretching, hot plate stretching, and roll rolling may be used. Proximity drawing is not always necessary because individual filaments have already been lengthened in the machine direction in the first drawing.

On the other hand, a web having filaments arranged in the transverse direction is stretched in the transverse direction. As a means for stretching the web in the transverse direction, for example, a tenter type transverse stretching device used for biaxial stretching of a film or Japanese Patent Publication No. 3-369.
No. 48, a pulley type lateral stretching device, or a groove roller type lateral stretching for laterally stretching the web by sandwiching the web with two grooved rollers each having a groove along the circumferential direction. A device can be used. Among these stretching devices, the pulley type lateral stretching device is an inexpensive and simple method, and since the stretching ratio can be freely changed and high-strength stretching is also possible, the lateral stretching used in the present invention. Most suitable as a device.

When it is desired to make the width of the stretched web very large, a temperature higher than the normal stretching temperature (5% in the case of polyester is used) before the transverse stretching at the normal stretching temperature.
-10 ° C higher temperature, 20-30 for polypropylene
It is effective to carry out pre-stretching at a temperature higher by ℃. As the transverse stretching device in that case, the above stretching device can be used.

In the stretching of the web, the web before stretching is lightly embossed, and then stretched, whereby the stretching ratio can be increased, the strength after stretching can be improved, and troubles such as stretch breakage can be caused. It is possible to perform stable stretching with less. In this case, the embossed pattern is preferably a pattern having directivity in a direction perpendicular to the stretching direction. The embossing temperature is preferably lower than the stretching temperature + 5 ° C. If the embossing pressure is too high, it damages the filament of the web and causes stretching breakage. Therefore, the linear pressure is preferably in the range of 3 N / cm to 50 N / cm, more preferably in the range of 8 N / cm to 30 N / cm, and most preferably. The range is preferably 10 N / cm to 25 N / cm. In the case of the embossing roller, the web is not uniformly pressed by the embossing roller over the entire width, and the embossing pressure does not apply to each embossing point. However, in the embossing performed here, the embossing pressure is sufficiently small and does not need to be calculated exactly. Therefore, the embossing pressure is the same as the normal linear pressure. It is defined by force (N) / embossing roller width (cm).

The draw ratio of the web varies depending on the type of polymer of the filaments constituting the web, the web spinning means, and the intended strength and elongation in the longitudinal and transverse directions. However, no matter which kind or means is used, a draw ratio that can achieve the high alignment property and high strength of the web which is the object of the present invention is selected.

The draw ratio is defined by the following formula by the marks placed on the web before drawing at regular intervals in the drawing direction. Draw ratio = [length between marks after drawing] / [length between marks before drawing] The draw ratio as used herein is not necessarily one filament 1 as in the case of drawing a normal long fiber filament yarn. It does not mean the draw ratio of the book.

As described above, the web can be stretched in the filament arranging direction to further improve the filament arranging property. However, when the crystallinity of the filament is large, the filament has no elongation and the stretching tension becomes high, so that it may be difficult to perform post-stretching at a high ratio. When high-strength post-stretching is desired, it is effective to reduce the crystallinity of the filament by cooling the filament just below the nozzle. The most effective means is to spray atomized water into the hot air for thinning the spun filaments between the spinning device and the conveyor, and to include the atomized liquid in the hot air. .

Therefore, when a mechanism for spraying mist-like water is provided, the filament can be shaken by utilizing this mechanism. FIG. 6 shows a schematic configuration diagram of a spinning device in which a filament is shaken by a spray nozzle that sprays mist-like water. In the spinning device shown in FIG. 4, a pair of spray nozzles 39 a, 39 is provided below the melt blow die 33.
b is arranged. The spray nozzles 39a and 39b are
Extruded from the nozzle 32 of the melt blow die 33,
In order to cool the filament 34 thinned by the hot air jetted from the slits 36a and 36b, mist-like water is sprayed toward the filament 34. The spray nozzles 39a and 39b are arranged similarly to the air injection nozzles 9a and 9b shown in FIG. 4, and the amount of water sprayed is controlled in the same manner as the air injection from the air injection nozzles 9a and 9b. As a result, the filaments 34 are periodically shaken, and as a result, the filaments 34 are folded in a state of being arranged in one direction and collected on a conveyor (not shown). Therefore, by appropriately setting the relative positional relationship between the spinning device and the conveyor shown in FIG. 6, it is possible to manufacture a web in which the filaments 34 are arranged in the longitudinal direction, or a web in which the filaments 34 are arranged in the lateral direction. Can also be manufactured.

When the atomized liquid is sprayed from the spray nozzles 39a and 39b to cool the filament 34, the atomized liquid is given a property such as so-called spinning / drawing oil agent such as extensibility and electrostatic removal. The addition of an oil agent that can be added is also effective in improving the subsequent stretchability, reducing the fluff, and further improving the strength and elongation after stretching. The fluid sprayed from the spray nozzles 39a and 39b does not necessarily need to contain water as long as it can cool the filament, and may be cold air.

The web obtained by the present invention has excellent tensile strength and dimensional stability, and can be used as a raw material web for a nonwoven fabric or a cross-woven fabric which requires strength in one direction. Further, the web according to the present invention can be used as it is as a web that requires strength in one direction, and also for reinforcing the strength in the lateral direction of paper, nonwoven fabric, cloth, film, etc.
It can also be used by laminating them. Further, the stretched web according to the present invention has good gloss, and can be used as a packaging material or the like utilizing the gloss.

[0057]

As described above, according to the present invention, the fluid is ejected from both sides of the filament extruded from the nozzle, the ejection amount of the fluid is changed, and the filament is shaken to arrange the filaments. Improve
A web having excellent strength and dimensional stability in the filament arrangement direction can be manufactured. In particular, in the case of ejecting hot air from both sides of the filament in order to thin the filament extruded from the nozzle,
By changing the injection amount of this hot air, the device configuration becomes simple. Further, by cooling the filament by using the fluid for shaking the filament, it is possible to improve the stretchability in stretching the web.

[Brief description of drawings]

FIG. 1 is a front view of a web manufacturing apparatus according to an embodiment of the present invention for manufacturing a web in which filaments are vertically aligned.

FIG. 2 is a diagram illustrating a hot air jetting operation from a slit of the melt blow die shown in FIG.

FIG. 3 is a view of a web manufacturing apparatus according to another embodiment of the present invention for manufacturing a web in which filaments are arranged in a lateral direction, FIG. 3 (a) is a front view, and FIG. A side view is shown.

FIG. 4 is a view of an example of a spinning device provided with an air injection nozzle for shaking a filament.

FIG. 5 is a diagram showing a sectional configuration of a web manufacturing apparatus using a spunbond method in a narrow sense to which the present invention is applied.

FIG. 6 is a diagram of an example of a spinning apparatus that uses a spray nozzle for cooling a filament to shake the filament.

[Explanation of symbols]

1,21 conveyor 1a Conveyor roller 2,32 nozzles 3,33 Melt blow die 4,24,34 filament 6a, 6b, 36a, 36b slits 8,28 Web 9a, 9b, 29a, 29b Air injection nozzle 23 Spunbond Dice 25 ejectors 25a nozzle 39a, 39b Spray nozzle

Claims (6)

[Claims] 1. A plurality of nozzles arranged in parallel and each extruding a molten polymer as a filament, and a pair of jetting hot air from both sides to the filament extruded from the nozzle in order to thin the filament extruded from the nozzle. A method for producing a web using a spinning means having a hot air jet nozzle, and a conveyor for collecting and transporting filaments extruded from the plurality of nozzles, the step of extruding filaments from the nozzles, and the hot air The amount of hot air jetted to both sides of the filament by the jet nozzle is divided into a state in which the jet amount from one is larger than the jet amount from the other and a state in which the jet amount from the other is larger than the jet amount from one. A method of manufacturing a web, the method including changing the shape of the web so that the web is alternately repeated. 2. A method for producing a web using a spinning means having a plurality of nozzles which are arranged in parallel and each of which extrudes a molten polymer as a filament, and a conveyor which collects and conveys the filament extruded from the plurality of nozzles. The step of extruding a filament from the nozzle, the step of ejecting fluid from both sides of the filament extruded from the nozzle, the state in which the injection amount from one is larger than the injection amount from the other, the other And a step of changing the injection amount of the fluid so that a state in which the injection amount from is larger than the injection amount from one side is alternately repeated. 3. A plurality of nozzles arranged in parallel and each extruding a molten polymer as a filament, and a pair of jetting hot air from both sides to the filament extruded from the nozzle in order to thin the filament extruded from the nozzle. A spinning means having a hot air jet nozzle, and a conveyor that collects and conveys the filament extruded from the nozzle, and the amount of hot air jetted from the hot air jet nozzle to both sides of the filament is from one side. The apparatus for manufacturing a web is changed such that a state in which the injection amount of is larger than the injection amount from the other and a state in which the injection amount from the other is larger than the injection amount from one are alternately repeated. 4. A spinning means having a plurality of nozzles arranged in parallel and each extruding a molten polymer as a filament, a conveyor for collecting and conveying the filament extruded from the nozzle, and a filament extruded from the nozzle. A pair of fluid ejecting means for ejecting fluid from both sides, wherein a state in which the injection amount from one is larger than the injection amount from the other and a state in which the injection amount from the other is larger than the injection amount from one alternate And a fluid ejecting unit in which the amount of fluid ejected is changed. 5. The spinning means comprises hot air jetting means for jetting hot air to the filaments extruded from the nozzles in order to thin the filaments extruded from the nozzles, and the fluid jetting means comprises the spinning The web manufacturing apparatus according to claim 4, which is an air injection nozzle for injecting air between a means and the conveyor. 6. The web manufacturing apparatus according to claim 4, wherein the fluid jetting means is a spray nozzle that sprays mist-like water to cool the filament between the spinning means and the conveyor.