WO2017170241A1

WO2017170241A1 - Non-woven fabric manufacturing device, non-woven fabric manufacturing method, and non-woven fabric

Info

Publication number: WO2017170241A1
Application number: PCT/JP2017/012062
Authority: WO
Inventors: 翔一 ▲高▼久; 鈴木　健一; 尚佑國本; 敦之川田; 喬之田中
Original assignee: 三井化学株式会社
Priority date: 2016-03-30
Filing date: 2017-03-24
Publication date: 2017-10-05
Also published as: CN108884618B; MY194230A; DK3438339T3; EP3438339B1; JP2020073749A; JPWO2017170241A1; JP2022010113A; EP3438339A4; US20190106821A1; KR20180117183A; EP3438339A1; CN108884618A

Abstract

In a scattering part of a non-woven manufacturing device, a scattering space is provided between a spray nozzle and a travelling belt of a collector, the openings of auxiliary nozzles are positioned next to the opening of the spray nozzle, and the auxiliary nozzles spray air from the opening. The spray nozzle sprays, together with air, a plurality of filaments towards the travelling belt. The air sprayed from the spray nozzle forms a transportation flow flowing so as to gradually spread in the scattering space, and the plurality of filaments are transported towards the travelling belt while being caused to scatter by the transportation flow and collected. The air sprayed from the auxiliary nozzles flows, around the transportation flow and along the airflow, and inhibits the air in the scattering space from entering the transportation flow.

Description

Nonwoven fabric manufacturing apparatus, nonwoven fabric manufacturing method, and nonwoven fabric

The present invention relates to a nonwoven fabric manufacturing apparatus, a nonwoven fabric manufacturing method, and a nonwoven fabric.

Non-woven fabrics such as spunbonded non-woven fabrics are widely used for medical, hygiene materials, civil engineering materials and packaging materials. Spunbond nonwoven fabric is collected and deposited while being diffused on the collection medium after the cooling treatment using the cooling air and the drawing treatment using the drawing air are performed on the filaments obtained by melt spinning the thermoplastic resin. Manufactured from the web obtained in

In Document 1 (Japanese Patent No. 2556953), a horizontal cross section in a rectangular shape is formed into a rectangular shape, and a stepped depression is formed in a wall body at a discharge port connected to a cooling chamber and a cooling chamber which is gradually reduced in cross section in the filament running direction. An apparatus for producing a spun fiber strip from an aerodynamically stretched synthetic resin filament having a stretch nozzle formed with a portion and a fiber placement device connected to the stretch nozzle is disclosed. The fiber placement device of this document 1 has a rectangular cross section in the horizontal direction, and has a form of a jet pump having a venturi-shaped basin in the vertical direction and a diffuser outlet. The amount of air sucked from the free air suction port is adjusted by an intake pipe facing the diffuser outlet with the belt interposed therebetween.

Document 2 (Japanese Patent No. 3135498) has a nozzle plate having a large number of nozzles, a processing shaft, a transport unit, and a transport conveyor. Processing air is introduced into the processing shaft and the transport unit, and the nozzle holes of the nozzle plate Endless fibers are fed from the end and are fed into the processing shaft by discharge movement toward the conveyor as endless fiber groups in the form of a mixture of air and fibers, and the transport unit follows the central inflow conduit for the endless fiber groups and this A spine fleece from a thermoplastic endless fiber having a diffuser conduit extending to the conveyor, forcing a discharge motion and an overlapping fleece forming motion, both conduits extending in a direction transverse to the direction of travel of the conveyor belt An apparatus for manufacturing a web is disclosed. In this document 2, an introduction conduit and / or a diffuser conduit is used for mixing air and fibers, and a flow slit for additionally introducing air into a conduit extending across the width of the conduit and across the direction of travel of the conveyor belt. Aerodynamic equal distribution device in the form of an outflow slit for discharging air from the conduit and in addition to the flow of air to be additionally fed and the flow of air to be discharged during the mixing of air and fibers Is controlled or adjusted for the purpose of influencing the equal distribution of fibers. In Patent Document 2, the inner surface of the inflow conduit and / or the diffuser conduit includes an obstruction member in the vicinity of the surface in the longitudinal section of the conduit, and a spiral region is formed rearward with respect to the flow direction.

Document 3 (Japanese Patent No. 5094588) is provided with a spinneret for forming a filament as an apparatus for producing a spunbond formed from a filament, and cooling for supplying processing air for cooling the filament downstream of the spinneret. A drawing unit for drawing the filament is connected to the cooling chamber, the connection region between the cooling chamber and the drawing unit is closed, and the drawing unit has a passage wall on at least part of the length of the drawing passage. In the drawing unit, additional air is injected into the drawing passage at the upstream end of the branch drawing passage portion so that the filament bundle is widely formed in the machine direction, and the filaments of the spunbond web An apparatus is described which is provided with a deposition apparatus for depositing. Reference 3 also describes that there is a sedimentation unit downstream of the stretching unit, the deposition unit consists of an upstream diffuser and an adjacent downstream diffuser, and an ambient air inlet slit is provided between the upstream diffuser and the downstream diffuser. .

By the way, there are uniformity and strength as important characteristics related to the quality of the nonwoven fabric. For example, the document 2 aims to obtain a nonwoven fabric with a uniform mesh size, but a nonwoven fabric with high uniformity may have insufficient filament entanglement and lower strength.

The present invention has been made in view of the above-described facts, and an object of the present invention is to provide a nonwoven fabric manufacturing apparatus, a nonwoven fabric manufacturing method, and a nonwoven fabric that can improve uniformity while suppressing a decrease in strength of the nonwoven fabric.

Specific means for achieving the above object includes the following aspects.
According to a first aspect of the present invention, there is provided a collection unit that collects a filament ejected toward a collection medium on the collection medium, and air that is supplied together with the filament that is collected on the collection medium. A main nozzle that is ejected toward the collection medium, and the filament is diffused by an airflow that flows while diffusing air that is ejected from the main nozzle together with the filament. A non-woven fabric manufacturing apparatus comprising: a diffusing portion including a diffusing space; and an airflow generating means for generating an airflow in close proximity to the airflow around the airflow of air injected from the main nozzle into the diffusing space. .

In the second aspect, the air ejected from the main nozzle together with the filament is diffused between the main nozzle from which air is ejected together with the filament and the collection medium that collects the filament ejected from the main nozzle. While providing a diffusion space in which the filament is diffused by the flowing air flow, and generating an air flow in close proximity to the air flow around the air flow of air blown from the main nozzle to the diffusion space by the air flow generation means, A method for producing a nonwoven fabric, comprising: ejecting the filament together with air from the main nozzle toward the collection medium, and collecting and depositing the filament diffused in the diffusion space on the collection medium. .

In the first aspect and the second aspect, a filament is spun from a molten resin or the like, a spinning section (spinning process) for leading out a plurality of filaments, and a plurality of filaments introduced from the spinning section are cooled with air. A cooling section (cooling process) for cooling by the above, a stretching section (stretching process) for stretching the cooled filaments by stretching air, and a collecting section (collecting and depositing the plurality of stretched filaments to generate a web) A non-woven fabric is produced from the collected web. The manufacturing apparatus also includes a diffusion unit (diffusion process) that ejects the plurality of filaments introduced from the stretching unit toward the collection unit while diffusing the plurality of filaments.

The diffusion unit includes a main nozzle and a diffusion space provided between the main nozzle and the collection medium of the collection unit. The diffusion space in the first and second aspects is preferably a space that can naturally diffuse without hindering the diffusion of the airflow from the air ejected from the main nozzle. The diffusion space may be surrounded by the partition wall, but when surrounded by the partition wall, the partition wall may be provided away from the air flow so as not to affect the air flow caused by the air ejected from the main nozzle. A plurality of filaments are arranged along the machine width direction, and the main nozzle has a long slit shape along the machine width direction.

Thereby, the air ejected from the main nozzle becomes an air flow (jet) flowing to the collection medium while gradually expanding along the machine direction in the diffusion space. The plurality of filaments ejected from the main nozzle together with air are collected in the collection medium by the filaments being diffused in the machine direction by the airflow formed in the diffusion space.

Here, the diffusing section is provided with an airflow generating means, and an airflow is generated in the vicinity of the airflow around the airflow generated by the air blown from the main nozzle by the airflow generating means, and close to the airflow of the main nozzle. The air flowing in the diffusion space suppresses the air (air) in the diffusion space from entering the air flow caused by the air ejected from the main nozzle together with the plurality of filaments. The air flow jetted from the main nozzle has a flow velocity fluctuation inside, but an area in which the flow velocity fluctuation is larger than the surroundings is caused by the entry of air in the diffusion space. On the other hand, the air in the diffusion space enters the airflow generated by the air ejected from the main nozzle by generating an airflow that is close to the airflow around the airflow generated by the air ejected from the main nozzle. The region where the flow velocity fluctuation is larger than the surrounding area is narrowed, or the flow velocity fluctuation magnitude in the region where the flow velocity fluctuation is larger than the surrounding area is suppressed.

Each filament has a region where the flow velocity fluctuation is larger than the surrounding area, and the larger the flow velocity fluctuation in the region, the more the filaments are entangled and the bundle of filaments is generated, resulting in a decrease in uniformity. By suppressing the magnitude of the flow rate fluctuation, the occurrence of bundles of filaments can be suppressed and the uniformity can be improved.

Further, in the third aspect, it is preferable that the airflow generation means includes a sub nozzle that ejects air into the diffusion space. In the fourth aspect, the airflow generation means includes a sub nozzle that has an opening arranged alongside the opening of the main nozzle and ejects air to the diffusion space.

In the third aspect and the fourth aspect, there is provided a sub nozzle in which an opening is arranged side by side with the opening of the main nozzle, and the air ejected from the sub nozzle causes the air around the air flow by the air ejected from the main nozzle. Creates an airflow along the airflow.

Thereby, since the air in the diffusion space is prevented from entering the air flow by the air ejected from the main nozzle, the uniformity of the nonwoven fabric can be easily improved.

Further, in the fifth aspect, in the third and fourth aspects, the sub nozzle is provided on the machine direction side of the main nozzle and on the opposite side to the machine direction.

In the fifth aspect, the sub nozzle is provided on each of the machine direction side and the machine direction side with respect to the main nozzle. As a result, the air in the diffusion space is prevented from entering from the machine direction side and the opposite side to the machine direction with respect to the air flow jetted from the main nozzle, so that the air is jetted from the main nozzle. An increase in air flow rate fluctuation is effectively suppressed.

The sixth aspect may be any one of the third to fifth aspects, wherein the flow velocity of the air ejected from the sub nozzle may be equal to or lower than the flow velocity of the air ejected from the main nozzle. The seventh aspect is more preferably the sixth aspect, wherein the flow velocity of the air ejected from the sub nozzle is 1/10 or more of the flow velocity of the air ejected from the main nozzle.

Each of the first to seventh aspects is a nonwoven fabric that is improved in uniformity while suppressing a decrease in strength, and is stretched 5% in the machine direction relative to the strength when stretched 5% in the direction perpendicular to the machine direction. It is suitable for obtaining a nonwoven fabric having a strength ratio of 2.0 or less.
Each of the first to seventh aspects is suitable for producing a nonwoven fabric having a maximum strength when stretched in the machine direction of 35.0 (N / 25 mm) or more. Further, in each of the first to seventh aspects, the maximum strength when stretched in the machine direction of the produced nonwoven fabric is more preferably 37.5 (N / 25 mm) or more, and further preferably 40. 0.0 (N / 25 mm), most preferably 42.5 (N / 25 mm).
Furthermore, each of the first to seventh aspects is suitable for producing a nonwoven fabric having a basis weight variation (%) of preferably 3.0% or less, more preferably 2.5% or less.

According to the embodiment of the present specification, there is an effect that a non-woven fabric with improved uniformity can be obtained while suppressing a decrease in strength.

It is a schematic block diagram of the manufacturing apparatus which concerns on this Embodiment. It is a schematic block diagram which shows a spreading | diffusion part. It is a distribution map which shows an example of the simulation result of the flow-velocity fluctuation | variation in this Embodiment. It is a distribution map which shows an example of the simulation result of the flow velocity fluctuation | variation in contrast. It is a graph which shows the comparison of the manufacturing conditions and physical property which concern on an Example.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, the principal part of the manufacturing apparatus 10 of the nonwoven fabric which concerns on this Embodiment is shown. The manufacturing apparatus 10 according to the present embodiment is used for manufacturing a spunbonded nonwoven fabric. In the following description, an MD (machine direction) direction indicates a machine direction (machine flow direction), and an UP direction indicates an upper direction. Further, in the following description, a direction (direction perpendicular to the machine direction) orthogonal to each of the MD direction and the UP direction is expressed as a CD (cross machine direction) direction (machine width direction, not shown).

The manufacturing apparatus 10 includes a spinning unit 12 that generates a filament by spinning a molten resin in which a thermoplastic resin used for a spunbond nonwoven fabric is melted, a cooling unit 14 that performs a cooling process on the spun filament, and a filament. And a stretching section 16 for performing a stretching process. Moreover, the manufacturing apparatus 10 collects the filaments that have been subjected to the cooling treatment and the stretching treatment, and ejects the plurality of filaments toward the collection unit 18 that obtains a web to be a nonwoven fabric and the collection unit 18. A diffusion unit 20 is provided.

The spinning unit 12 includes a spinneret 22 in which a plurality of spinning nozzles are arranged, and a molten resin introduction tube 24 is connected to the spinneret 22. The spinning unit 12 generates a filament by spinning the molten resin introduced into the spinneret 22 through the molten resin introduction tube 24 using a spinning nozzle. Further, the spinning unit 12 derives a plurality of filaments arranged in the CD direction by the spinneret 22 having a plurality of spinning nozzles. The cooling unit 14 includes a cooling chamber 26 into which a plurality of spun filaments are introduced, and a cooling air supply duct 28 is connected to the cooling chamber 26. The cooling unit 14 uses the air supplied from the cooling air supply duct 28 as cooling air, and cools the plurality of filaments introduced into the cooling chamber 26 with the cooling air.

The extending section 16 includes an extending shaft 30 that has an opening cross section that is long in the CD direction (in FIG. 1, the front and back directions in the drawing) and short in the MD direction and extends in the vertical direction. In the stretching section 16, the stretching shaft 30 is connected to the cooling chamber 26, and a plurality of filaments are introduced from the cooling chamber 26 into the stretching shaft 30. The drawing unit 16 uses cooling air introduced together with a plurality of filaments or air supplied into the drawing shaft 30 separately from the cooling air as drawing air, and draws the filament introduced from the cooling unit 14 by drawing air. To do.

The collecting unit 18 includes a moving band 32 as a collecting medium formed by mesh or punching metal, and suction means (not shown) provided below the moving band 32. In addition, the diffusing unit 20 ejects the drawing air introduced from the drawing shaft 30 or air introduced separately from the drawing wind toward the moving zone 32 of the collection unit 18. The collection unit 18 collects the plurality of ejected filaments on the collection surface 32A of the moving band 32 while sucking them by a suction unit, and generates a web that becomes a nonwoven fabric. In addition, the spinning unit 12, the cooling unit 14, the stretching unit 16, and the collecting unit 18 of the manufacturing apparatus 10 generate a plurality of filaments by spinning the molten resin, a cooling stretching process for the generated plurality of filaments, and A known configuration for collecting a plurality of filaments can be applied.

FIG. 2 shows a schematic configuration of the diffusion unit 20 according to the present embodiment. The diffusion unit 20 includes a jet nozzle 34 as a main nozzle. In the ejection nozzle 34, an opening 34A at the tip as an opening serving as an ejection outlet is formed in a slit shape that is long in the CD direction, and is directed onto the moving band 32 of the collection unit 18. Further, the ejection nozzle 34 is continued to the stretching shaft 30 of the stretching section 16 and a plurality of filaments that have been subjected to cooling and stretching processing are introduced. In addition, in the diffusing unit 20, air is introduced into the ejection nozzle 34 separately from the air by the stretched air or the air of the stretched wind.

The diffusion unit 20 ejects air and a plurality of filaments introduced into the ejection nozzle 34 toward the moving band 32 of the collection unit 18 from the opening 34A. The diffusing unit 20 sends a plurality of filaments ejected from the ejection nozzle 34 toward the collection unit 18 by the air current ejected from the ejection nozzle 34. Hereinafter, the air flow generated by the air ejected from the ejection nozzle 34 together with the plurality of filaments is referred to as a transport flow.

The diffusion unit 20 is provided with a diffusion space 36 between the ejection nozzle 34 and the collection surface 32 A of the moving band 32 of the collecting unit 18, and the carrier flow is directed toward the moving band 32 in the diffusion space 36. Flowing. The diffusion space 36 is a space that is not provided with a wall surface or the like that restricts the flow of the carrier flow by the air ejected from the ejection nozzle 34. That is, the diffusion space 36 is a space in which the carrier flow ejected from the ejection nozzle 34 is not affected by a structure such as a wall surface other than the collection unit 18. The diffusion space may be partitioned by the partition wall as long as the partition wall is provided so as not to interfere with the airflow.

Thereby, in the diffusing section 20, the carrier flow by the air ejected from the ejection nozzle 34 flows in the diffusion space 36 while gradually (naturally) expanding in the MD direction and the direction opposite to the MD direction. Further, the flow velocity of the transport flow gradually decreases as it approaches the moving zone 32. The plurality of filaments ejected from the ejection nozzle 34 are diffused in the MD direction and in the direction opposite to the MD direction by the conveyance flow expanding in the diffusion space 36. As a result, in the manufacturing apparatus 10, the filament is diffused and collected in a predetermined collection region on the collection surface 32 A of the moving band 32.

The manufacturing apparatus 10 generates the nonwoven fabric to be produced, the production speed of the nonwoven fabric, the width in the CD direction of the web produced by collecting the filaments in the collection unit 18, the opening width of the ejection nozzle 34, the opening length, The moving speed of the moving band 32 and the interval between the ejection nozzle 34 and the collecting surface 32A of the moving band 32 are determined. In the diffusing unit 20, the interval (height H) between the tip of the ejection nozzle 34 and the surface of the moving band 32 of the collecting unit 18 is set between 0.1 m and 1 m, and the interval H Is the height of the diffusion space 36.

Further, in the manufacturing apparatus 10, the flow velocity of the air ejected from the ejection nozzle 34 or the air volume per unit time of the ejected air is determined, and in the following, the air flow velocity at the opening of the ejection nozzle 34 is the flow velocity Vm of the carrier flow. Is written. In the diffusing section 20, the spread of the carrier flow in the diffusion space 36 changes according to the flow velocity Vm. When the flow velocity Vm is high, the spread of the carrier flow is smaller than when it is low.

The diffusion unit 20 is provided with the diffusion space 36 so that the carrier flow ejected from the ejection nozzle 34 reaches the moving band 32 while gradually spreading mainly along the MD direction. In the following description, the area of the conveyance flow in the diffusion space 36 is referred to as a conveyance flow area 38. In FIG. 2, the conveyance basin 38 is shown virtually.

As shown in FIGS. 1 and 2, the diffusing section 20 is provided with a sub nozzle 40 as an airflow generating means. The sub-nozzle 40 is provided with a slit-like opening 40A that is long in the CD direction as an opening. In the diffusing section 20, the sub nozzle 40 is disposed on each of the ejection nozzle 34 on the MD direction side and the opposite side to the MD direction, and the opening 40 A of the sub nozzle 40 is aligned with the opening 34 A of the ejection nozzle 34.

The air supply pipe 42 is connected to the sub nozzle 40, and the air supplied through the air supply pipe 42 is ejected from the opening 40A. The diffusing unit 20 is connected to the sub nozzle 40 via the air supply pipe 42 so that the air flow from the sub nozzle 40 becomes a flow velocity Vs determined according to the flow velocity Vm of the carrier flow ejected from the ejection nozzle 34. The air supplied to is controlled. In the diffusing unit 20, the sub nozzle 40 is provided so that the air ejection direction is substantially parallel to the air ejection direction from the ejection nozzle 34. Here, the flow velocity Vs is preferably equal to or less than the flow velocity Vm (Vs ≦ Vm), and more preferably equal to or greater than 1/10 of the flow velocity Vm (Vs ≧ (Vm / 10)). The supply of air to the sub nozzle 40 is controlled so that the flow velocity Vs becomes 1/2 of the flow velocity Vm (Vs = Vm / 2).

In this embodiment, the opening 34A of the ejection nozzle 34 and the opening 40A of the sub nozzle 40 are arranged side by side. However, the present invention is not limited to this, and one of the opening 34A of the ejection nozzle 34 and the opening 40A of the sub nozzle 40 is arranged. May be arranged with a step so as to be farther from the collection surface 32A of the moving band 32 than the other.

As a result, as shown in FIG. 2, in the diffusing section 20, an air stream that is close to the transport flow is generated around the transport flow (transport flow area 38) in the diffusion space 36 by the air ejected from the sub nozzle 40. ing. In FIG. 2, the airflow generated by the air ejected from the sub nozzle 40 is virtually shown as an airflow layer 44.

In the manufacturing apparatus 10 configured as described above, a plurality of filaments spun from a molten resin and subjected to cooling processing and stretching processing are introduced into the ejection nozzle 34 of the diffusion unit 20. The ejection nozzle 34 is introduced with air for generating a transport flow (stretching air or air supplied separately from the stretching air).

In the diffusing unit 20, a diffusion space 36 is provided between the ejection nozzle 34 and the moving band 32 of the collection unit 18, and air and a plurality of filaments introduced into the ejection nozzle 34 are opened in the ejection nozzle 34. It is ejected from 34A toward the diffusion space 36. As a result, the plurality of filaments are sprayed onto the moving surface 32 of the collection unit 18 and collected on the collection surface 32 A while being diffused by the carrier flow by the air ejected from the ejection nozzle 34.

Incidentally, the diffusing section 20 is provided with a sub nozzle 40 together with the ejection nozzle 34, and the sub nozzle 40 ejects air supplied via the air supply pipe 42 to the diffusion space 36. As a result, in the diffusion space 36, an airflow is generated around the conveyance flow and close to the conveyance flow, and the air in the diffusion space 36 is suppressed from entering the conveyance flow (in the conveyance flow area 38).

The plurality of filaments transported in the diffusion space 36 by the transport flow cause fluctuations in the flow velocity inside the transport flow, but in regions where the flow velocity fluctuation is larger than the surroundings, the larger the flow velocity fluctuation, the greater the entanglement of the filament. Become. Thereby, the nonwoven fabric obtained from the web produced by collecting the filaments has high tensile strength. However, in the collected web, when the entanglement of filaments increases, the uniformity of the nonwoven fabric decreases.

On the other hand, in the diffusing unit 20 provided with the sub nozzle 40, an air flow that is close to the transport flow is formed around the transport flow by the air ejected from the sub nozzle 40, and is generated inside the transport flow. In a region where the flow velocity fluctuation is large, the magnitude of the flow velocity fluctuation is suppressed. Thereby, in the web collected in the collection part 18, it is suppressed that the tangle of a filament increases, and the nonwoven fabric by which the improvement of the uniformity was achieved is obtained.

Here, in FIG. 3A and FIG. 3B, the simulation result of the flow velocity fluctuation (speed fluctuation) of the air flow in the diffusion space 36 is shown by the distribution of the flow velocity fluctuation. FIG. 3A corresponds to the diffusing section 20 of the present embodiment (below, Example 1) provided with the ejection nozzle 34 and the sub nozzle 40, and FIG. 3B is a sub nozzle that is proportional (below, Comparative Example 1). A diffusing portion 20A in which only the ejection nozzle 34 is provided without providing 40 is shown.

In the simulation of the flow velocity fluctuation, the diffusing

sections

20 and 20A set the flow velocity of air ejected from the ejection nozzle 34 to the same flow velocity Vm, and the diffusing section 20 sets the flow velocity Vs of air ejected from the sub nozzle 40 to the flow velocity Vm. It is set to 1/2 (Vs = Vm / 2), and the air is jetted in parallel with the jet direction of the air from the jet nozzle 34. In addition, the flow rate fluctuation is obtained by calculating the speed difference of the flow rate for each sampling time from the flow rate for each sampling time set in advance, and using the root mean square (RMS) of the obtained speed difference.

In the comparative diffusion unit 20A shown in FIG. 3B, a region in which the flow velocity fluctuation is extremely large as compared with the surroundings is generated inside the airflow ejected from the ejection nozzle 34. By producing such a region where the flow rate fluctuation is extremely large, the nonwoven fabric is improved in tensile strength, but the uniformity of the mesh formed by the filament is lowered.

On the other hand, in the diffusing unit 20 of the first embodiment shown in FIG. 3A, the magnitude of the flow velocity fluctuation is suppressed in a region where the flow velocity fluctuation inside the air flow ejected from the ejection nozzle 34 is larger than that of the diffusing section 20A. Yes. Thereby, as for the diffusion part 20, the tangle of the filament in the web collected by the collection part 18 is suppressed from the diffusion part 20A.

Therefore, the manufacturing apparatus 10 provided with the sub nozzle 40 of the diffusion unit 20 can obtain a non-woven fabric with improved uniformity as compared with the case where the sub nozzle 40 is not provided. Moreover, in the spreading | diffusion part 20 of a present Example, the fall of the tensile strength of a nonwoven fabric is suppressed because the area | region where a flow velocity fluctuation | variation is larger than the periphery remains in a conveyance flow.

In the present embodiment described above, the flow velocity Vs of the sub nozzle 40 is halved with respect to the flow velocity Vm of the ejection nozzle 34. However, the present invention is not limited to this. The flow velocity Vs of the sub-nozzle 40 only needs to be equal to or less than the flow velocity Vm of the ejection nozzle 34, thereby suppressing the flow velocity fluctuation in the conveyance flow without suppressing the spread of the conveyance flow in the diffusion space 36. it can.

Further, the flow velocity Vs of the sub nozzle 40 may be larger than the flow velocity Vm of the ejection nozzle 34 (Vs> Vm). In this case, when the direction in which the air is ejected from the sub nozzle 40 is substantially parallel to the direction in which the air is ejected from the ejection nozzle 34, the air ejected from the sub nozzle 40 spreads the transport flow in the diffusion space 36. May be regulated. From this point, when the flow velocity Vs of the sub nozzle 40 is made larger than the flow velocity Vm of the ejection nozzle 34 (Vs> Vm), the sub nozzle 40 has air that is ejected from the ejection nozzle 34 in the direction of the opening 40A or the air ejection direction. In the vicinity of the carrier flow, the direction along the carrier flow, that is, the direction of flowing in contact with the carrier flow may be used.

Further, in the present embodiment, the sub nozzle 40 is provided on the MD direction side and the direction opposite to the MD direction with respect to the ejection nozzle 34, but the sub nozzle 40 places the sub nozzle 40 on the MD side relative to the ejection nozzle 34. You may provide in the direction side opposite to a direction side or MD direction. In other words, the sub nozzle 40 only needs to be provided with the sub nozzle 40 on at least one of the MD direction side and the direction opposite to the MD direction with respect to the ejection nozzle 34.

Further, in the present embodiment, the sub nozzle 40 is provided as the air flow generation means. However, the air flow generation means is not limited to the sub nozzle 40, and generates an air flow that is close to the transport flow around the transport flow. Anything is fine.

Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.
The physical properties in the present embodiment (hereinafter referred to as Example 1) and the proportionality to the present embodiment (hereinafter referred to as Comparative Example 1) were measured by the following methods.

(1. basis weight [g / m ² ])
Five test pieces of 100 mm (MD) × 100 mm (CD) were collected from the nonwoven fabric. In addition, the sampling place (sampling position) of the test piece is arbitrarily set at five places.
Subsequently, the mass of each test piece was measured with respect to each collected test piece using an upper plate electronic balance (manufactured by Kensei Kogyo Co., Ltd.), and the average value of the mass of each test piece was determined. Calculated from the mean values obtained in the mass [g] per 1 m ^2, and a second decimal point basis weight of each specimen sample was rounded to 2 decimal places [g / m ^2].

(2. Weight variation per unit [%])
100 test pieces of 50 mm (MD) × 50 mm (CD) were collected from the nonwoven fabric. In addition, the sampling place was 10 places in the width direction (CD) of the nonwoven fabric, and 10 times in the flow direction (MD).
Next, each mass [g] was measured for each collected test piece using an upper plate electronic balance (manufactured by Kensei Kogyo Co., Ltd.), and the average value and standard deviation of the mass of each test piece were obtained. The value obtained by dividing the standard deviation by the average value was defined as the basis weight variation [%] of each nonwoven fabric sample.

(3. Fiber diameter [μm])
Five test pieces of 10 mm (MD) × 10 mm (CD) were collected from the nonwoven fabric. In addition, the collection place was one arbitrary place.
Next, the test piece was photographed at a magnification of 200 times using an optical microscope, and the photographed image was analyzed with image dimension measurement software (Innotech Co., Ltd .: Pixes2000 Version 2.0). Ten fiber diameters were measured for each test piece, the fiber diameter average value of each test piece was determined, and the second decimal place was rounded off to obtain the fiber diameter [μm] of each nonwoven fabric sample.

(4. Nonwoven yarn bundles [points])
One test piece of 250 mm (MD) × 200 mm (CD) was collected from the nonwoven fabric. In addition, the collection place was one arbitrary place.
Next, the nonwoven fabric was visually confirmed, and the number of locations (yarn bundles) where two or more fibers were entangled in a bundle was counted and evaluated according to the following criteria.
A: 0 yarn bundle B: 1 or more and less than 20 yarn bundles C: 20 or more yarn bundles

(5. MD5% strength and MD strength [N / 25mm])
Five MD test pieces of 25 mm (CD) × 200 (MD) were collected from the nonwoven fabric. In addition, sampling places were arbitrary five places.
Next, each collected specimen was stretched by using a universal tensile testing machine (IM-201, manufactured by Intesco) under the conditions of a chuck distance of 100 mm and a tension speed of 100 mm / min. At that time, the load [N] and the maximum load [N] were measured. The average value of each test piece was obtained, and the second decimal place was rounded off to obtain the MD 5% strength [N / 25 mm] and MD strength [N / 25 mm] of each nonwoven fabric sample. The MD 5% strength corresponds to the strength when stretched 5% in the machine direction, and the MD strength corresponds to the maximum strength when stretched in the machine direction.

(6. CD 5% strength and CD strength [N / 25mm])
Five pieces of 25 mm (MD) × 200 mm (CD) CD test pieces were collected from the nonwoven fabric. In addition, sampling places were arbitrary five places.
Next, each collected specimen was stretched by using a universal tensile testing machine (IM-201, manufactured by Intesco) under the conditions of a chuck distance of 100 mm and a tension speed of 100 mm / min. At that time, the load [N] and the maximum load [N] were measured. The average value of each test piece was obtained, and the second decimal place was rounded off to obtain the CD 5% strength [N / 25 mm] and CD strength [N / 25 mm] of each nonwoven fabric sample. The CD 5% strength corresponds to the strength when stretched 5% in the direction perpendicular to the machine direction, and the CD strength corresponds to the maximum strength when stretched in the direction perpendicular to the machine direction.

Example 1
As the first propylene polymer, a propylene homopolymer having a melting point of 162 ° C and MFR (measured at a temperature of 230 ° C and a load of 2.16 kg in accordance with ASTM D1238, the same applies hereinafter) 60 g / 10 min was used. As the second propylene polymer, a propylene / ethylene random copolymer having a melting point of 142 ° C., an MFR of 60 g / 10 min, and an ethylene unit component content of 4.0 mol% was used. Using the first propylene polymer and the second propylene polymer, composite melt spinning is performed by a spunbond method, the core is a propylene homopolymer, and the sheath is a propylene / ethylene random copolymer ( An eccentric core-sheath type composite continuous fiber having a core part / sheath part = 20/80 (weight ratio) was obtained as a fiber (filament).

The obtained fiber was dispersed from the main nozzle (ejection nozzle 34) shown in FIG. 1 and then volume on the collection medium (moving zone 32). At this time, the speed of the air ejected from the ejection nozzle 34 (main nozzle) is 107.3 m / sec, and the auxiliary speed provided at a position 38 mm away from the ejection outlet (opening 34A) of the ejection nozzle 34 in the horizontal direction. The air ejected from the nozzle 40 (ejection width 12 mm) was set to 1/4 (26.8 m / sec) with respect to the speed of the air ejected from the ejection nozzle 34.

Thereafter, the embossed pattern is peeled from the collection medium, the embossed pattern has an area ratio of 6.7%, the embossed area is 0.19 m ² , and is thermally bonded by heating embossing under conditions of a heating temperature of 130 ° C. and a linear pressure of 60 kg / cm, A spunbond nonwoven fabric was obtained. The basis weight of the obtained spunbonded nonwoven fabric was 20.0 g / m ² . The obtained spunbonded nonwoven fabric was evaluated by the method described above. The evaluation results are shown in FIG.

(Comparative Example 1)
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the air ejected from the sub nozzle 40 was changed to 0 (speed 0 m / sec). Basis weight of the resulting spunbonded nonwoven fabric was 20.2 g / ^{m 2.} The obtained spunbonded nonwoven fabric was evaluated by the method described above. The evaluation results are shown in FIG.

Here, the variation in basis weight was 3.5 [%] in Comparative Example 1, while 2.0 [%] in Example 1. In addition, the evaluation of the yarn bundle [point] in the non-woven fabric was Evaluation B for Comparative Example 1 while Example 1 was Evaluation B. At this time, the MD5% strength is 4.3 [N / 25 mm] in Example 1 and 5.2 [N / 25 mm] in Comparative Example 1, and the CD5% strength is 2.7 [N] in Example 1. / 25 mm] and Comparative Example 1 were 1.2 [N / 25 mm]. In addition, the MD5% strength / CD5% strength was 1.6 in Example 1 and 4.3 in Comparative Example 1. From this, it can be seen that compared to Comparative Example 1, Example 1 has reduced strength reduction and improved uniformity.

Therefore, the nonwoven fabric manufacturing apparatus and manufacturing method according to the present embodiment are suitable for manufacturing a nonwoven fabric in which strength reduction is suppressed and uniformity is improved. In addition, the nonwoven fabric manufacturing apparatus and method according to the present embodiment is stretched 5% in the machine direction (MD direction) relative to the strength (CD 5% strength) when stretched 5% in the direction perpendicular to the machine direction (CD direction). It is suitable for the manufacture of a nonwoven fabric having a ratio of strength (MD5% strength) (MD5% strength / CD5% strength) of 2.0 or less.

Furthermore, the nonwoven fabric manufacturing apparatus and manufacturing method in the present embodiment is suitable for manufacturing a nonwoven fabric having a basis weight variation of preferably 3.0 [%] or less, more preferably 2.5 [%] or less.
Further, in the nonwoven fabric manufacturing apparatus and manufacturing method in the present embodiment, the maximum strength (MD strength) when stretched in the machine direction is more preferably 37.5 [N / 25 mm] or more, and further preferably 40.0 [N / 25 mm], most preferably 42.5 [N / 25 mm].

The disclosure of Japanese Patent Application No. 2016-020144 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims

A collection unit for collecting the filament ejected toward the collection medium on the collection medium;
A main nozzle that blows air supplied together with the filament collected by the collection medium toward the collection medium, and the main nozzle and the collection medium; A diffusion portion including a diffusion space in which the filament is diffused by an airflow flowing while air ejected from the nozzle diffuses;
An airflow generating means for generating an airflow in close proximity to the airflow around the airflow of the air ejected from the main nozzle into the diffusion space;
Manufacturing apparatus for nonwoven fabrics.
The non-woven fabric manufacturing apparatus according to claim 1, wherein the airflow generation means includes a sub-nozzle that ejects air into the diffusion space.
The non-woven fabric manufacturing apparatus according to claim 1 or 2, wherein the airflow generation means includes a sub nozzle that has an opening arranged in parallel with the opening of the main nozzle and jets air into the diffusion space.
The non-woven fabric manufacturing apparatus according to claim 2 or 3, wherein the sub nozzle is provided on the machine direction side and the machine direction side of the main nozzle.
The apparatus for producing a nonwoven fabric according to any one of claims 2 to 4, wherein a flow velocity of air ejected from the sub nozzle is equal to or less than a flow velocity of air ejected from the main nozzle.
The apparatus for producing a nonwoven fabric according to claim 5, wherein a flow velocity of air ejected from the sub nozzle is 1/10 or more of a flow velocity of air ejected from the main nozzle.
The filament is flown between the main nozzle from which air is ejected together with the filament and the collection medium for collecting the filament ejected from the main nozzle while the air ejected from the main nozzle is diffused together with the filament. Providing a diffusion space where
While generating an air flow in close proximity to the air flow around the air flow of the air ejected from the main nozzle to the diffusion space by the air flow generating means,
The filament is ejected together with air from the main nozzle toward the collection medium,
Collecting and depositing the filaments diffused in the diffusion space on the collection medium;
The manufacturing method of the nonwoven fabric including this.
Air is spouted from the sub nozzle in which the opening is arranged alongside the opening of the main nozzle to the diffusion space, and close to the air flow around the air flow of air from the main nozzle to the diffusion space The manufacturing method of the nonwoven fabric of Claim 7 including producing the airflow which goes along.
The method for producing a nonwoven fabric according to claim 8, wherein the sub nozzle is provided on the machine direction side and the machine direction side of the main nozzle.
The method for producing a nonwoven fabric according to claim 8 or 9, wherein a flow velocity of air ejected from the sub nozzle is set to be equal to or lower than a flow velocity of air ejected from the main nozzle.
The method for producing a nonwoven fabric according to claim 10, wherein the flow velocity of air ejected from the sub nozzle is set to 1/10 or more of the flow velocity of air ejected from the main nozzle.
A nonwoven fabric in which the ratio of the strength at 5% elongation in the machine direction to the strength at 5% elongation in the direction perpendicular to the machine direction is 2.0 or less.
The nonwoven fabric according to claim 12, wherein the maximum strength when stretched in the machine direction is 35.0 (N / 25mm) or more.