JP2022029744A - Nonwoven fabric, and method and device for manufacturing the same - Google Patents

Abstract

To provide a technique capable of suppressing the occurrence of width shrinkage in a nonwoven fabric.SOLUTION: A nonwoven fabric is composed of a plurality of fiber layers containing a first fiber layer which is made of a crimpable fiber having a crimp number of 15 pcs./25 mm or more, and a second fiber layer which is made of a fiber having a fiber diameter of 2 to 100 denier and is in a state where the fibers are oriented in an MD direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a non-woven fabric, a non-woven fabric manufacturing method, and a non-woven fabric manufacturing apparatus.

Conventionally, composite fibers for forming a non-woven fabric are known (for example, Patent Document 1). The composite fiber described in Patent Document 1 has crimpability in order to provide a bulky nonwoven fabric.

Japanese Unexamined Patent Publication No. 2017-22927

The non-woven fabric having crimpability has high elasticity because the fibers are loop-shaped. When a highly elastic non-woven fabric is used as a material for an absorbent article or a mask, the non-woven fabric stretches in the MD direction when pulled in the MD direction inside the processing machine during the manufacturing process, resulting in width reduction. Occur. Since the width of the non-woven fabric is set according to the dimensions of the finished product, it is not preferable that the width of the non-woven fabric shrinks. Further, in order to ensure stable operation, it is conceivable to adjust the width of the nonwoven fabric in a state where it is fully extended in the MD direction to the dimensions of the finished product in consideration of the occurrence of width shrinkage in the nonwoven fabric. The stretched non-woven fabric loses its bulkiness.

An object of the present invention is to provide a technique capable of suppressing the occurrence of width shrinkage in a nonwoven fabric.

In order to solve the above problems, in the present invention, it is decided to provide a first fiber layer composed of crimpable fibers and a second fiber layer in which the fibers are oriented in the MD direction.

Specifically, the present invention is a nonwoven fabric composed of a plurality of fiber layers, the first fiber layer composed of crimpable fibers having a crimp number of 15 pieces / 25 mm or more, and a fiber diameter of 15 pieces / 25 mm or more. It is 2 to 100 denier and includes a second fiber layer in which the fibers are oriented in the MD direction.

In the above-mentioned nonwoven fabric, the first fiber layer may have a breaking elongation in the MD direction of 50% or more.

In the above-mentioned nonwoven fabric, the first fiber layer, the second fiber layer, and the first fiber layer may be laminated in this order.

In addition, the present invention can be grasped from the aspect of the method for producing a nonwoven fabric. For example, the present invention is a method for producing a nonwoven fabric composed of a plurality of fiber layers, wherein the first fiber layer composed of crimpable fibers having a crimping number of 15 pieces / 25 mm or more is used. It may include a step of forming and a step of forming a second fiber layer having a fiber diameter of 2 to 100 denier and in which the fibers are oriented in the MD direction.

Further, the present invention can be grasped from the side surface of the nonwoven fabric manufacturing apparatus. For example, the present invention is a fiber spraying device that ejects fibers and a sheet transporting device that collects a bundle of the fibers sprayed from the fiber spraying device on a transport surface to form a sheet-like non-woven fabric and transports the fibers in the transfer direction. A non-woven fiber manufacturing apparatus for producing a non-woven fiber composed of a plurality of fiber layers, wherein the fiber spraying device is composed of crimpable fibers having a crimping number of 15 pieces / 25 mm or more. In order to form a first fiber spraying device that ejects filaments in a bundle to form a first fiber layer, and a second fiber layer having a fiber diameter of 2 to 100 denier and having fibers oriented in the MD direction. It may have a second fiber spraying device that bundles and ejects filaments.

According to the present invention, the occurrence of width shrinkage in the non-woven fabric can be suppressed.

FIG. 1 is a plan view of the nonwoven fabric according to the embodiment. FIG. 2 is a cross-sectional view of the nonwoven fabric according to the embodiment in the CD direction. FIG. 3 is a diagram showing a nonwoven fabric manufacturing apparatus for manufacturing the nonwoven fabric according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

<Embodiment>
FIG. 1 is a plan view of the nonwoven fabric C according to the present embodiment when viewed from above. FIG. 2 is a cross-sectional view in the CD direction when the nonwoven fabric C is cut along the line AA shown in FIG. The nonwoven fabric C is a sheet whose MD direction is the longitudinal direction, and is composed of a plurality of layers.

As shown in FIG. 2, the nonwoven fabric C has a crimped fiber layer C1 (an example of the “first fiber layer” in the present application) and a spunbond fiber layer C2 (an example of the “second fiber layer” in the present application) from the bottom. It has a layer structure in which fiber layers are laminated in the order of the crimped fiber layer C1. The crimped fiber layer C1 is a fiber layer composed of crimpable fibers, and is formed bulky because the fibers are loop-shaped. The spunbond fiber layer C2 has fibers oriented in the MD direction (flow direction) and is formed thinner than the crimp fiber layer C1. Since the nonwoven fabric C according to the present embodiment has bulky crimp fiber layers C1 arranged on both the upper and lower sides, it improves the feel when used for an absorbent article, a mask, or the like.

The degree of crimpability of the fiber in the crimped fiber layer C1 can be indicated by, for example, the number of crimped fibers measured in accordance with Japanese Industrial Standards JIS L1015. The number of crimps of the crimp fiber layer C1 in the present embodiment is 15 pieces / 25 mm. Further, the crimped fiber layer C1 has a breaking elongation of 50% or more in the MD direction.

In the spunbond fiber layer C2, the fiber diameter is 2 to 100 denier (2 denier or more, 100 denier or less). The fiber diameter is a numerical value when the line speed is 23 to 1125 m / min in the spunbond manufacturing method described later. Further, in the spunbond fiber layer C2, the number density in the CD direction is 2 to 8 fibers / mm.

In the nonwoven fabric C, each fiber layer is squeezed together by embossing. The area ratio of embossing is 5 to 25%. The basis weight of each fiber layer is 10 to 30 g / m ² . Such non-woven fabric C is suitable as a material for absorbent articles and masks.

The nonwoven fabric C according to the present embodiment is provided with the spunbond fiber layer C2, so that elongation in the MD direction is suppressed. As a result, the nonwoven fabric C is prevented from stretching in the MD direction even when it is pulled in the MD direction inside the processing machine. Therefore, the nonwoven fabric C according to the present embodiment can suppress the occurrence of width shrinkage. Such a non-woven fabric C can realize stable operation when used as a material while maintaining bulkiness.

Next, a manufacturing method and a manufacturing apparatus for the nonwoven fabric C according to the present embodiment will be described with reference to FIG. FIG. 3 is a diagram showing a nonwoven fabric manufacturing apparatus M for manufacturing the nonwoven fabric C according to the present embodiment. In FIG. 3, the nonwoven fabric manufacturing apparatus M includes three sets of ejection devices (fiber ejection devices) 10, and each of the ejection devices 10 (10A, 10B, 10C) includes a spinning device 20, a cold air device 30, and an injector. It is built with 40. The ejection devices 10A and 10C are examples of the "first fiber ejection device" for forming the crimped fiber layer C1, and the ejection device 10B is a "second fiber ejection device" for forming the spunbond fiber layer C2. This is an example of "attached device".

In the non-woven fabric manufacturing apparatus M, a collecting conveyor (sheet transporting apparatus) 50, an embossing processing apparatus 60, and a winder 70 are arranged in series with the ejection device 10 so that various processes can be executed. The ejection devices 10A, 10B, and 10C are arranged in series in the transport direction with respect to the transport surface on the upper part of the collection conveyor 50. The nonwoven fabric manufacturing apparatus M is constructed so as to continuously manufacture the nonwoven fabric C in which the direction toward the paper surface in FIG. 3 is the CD direction (width direction), and the fibers (filaments) to be spun are collected in the form of a sheet. The non-woven fabric C is manufactured by a so-called spunbond manufacturing method in which fibers are appropriately bonded by being embossed while being embossed.

The spinning device 20 includes an extruder 21 and a spinneret 23. The extruder 21 melts the raw material resin R (R1, R2, R3) supplied to the hopper 22 and sends the melt of a predetermined flow rate to the spinneret 23 by the rotation of the spiral rotor 21r. The spinneret 23 has a plurality of composite spinning nozzles (not shown) configured to discharge while forming a desired fibrous structure, and a plurality of filaments (fibers) f of the melt from the extruder 21. Bundles (hereinafter referred to as "filament aggregates") F are spun (discharged) in the direction of gravity.

Here, the raw material resin R may be formed into a multilayer by stacking sheet-like filaments of the same material R1, R2, R3 without changing the type for each of the ejection devices 10A, 10B, and 10C, and the ejection devices 10A, 10B, The type may be changed for each 10C, and sheet-like filaments of different materials R1, R2, and R3 may be stacked to form a multilayer. For example, the raw material resin R contains a thermoplastic resin as a main component, and the same or different kinds of polyolefin resins such as polypropylene (PP) and polyethylene (PE) can be used, as appropriate, for example. , Various stabilizers such as known heat-resistant stabilizers and weather-resistant stabilizers, antistatic agents, slip agents, antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes and other additives. It may be contained.

The cold air device 30 includes a pair of open type blowers 31 and 32 arranged at opposite positions. The cold air device 30 cools the filament aggregate F discharged from the spinning device 20 and passing from above to the bottom by blowing cooling air Ac from each of the blowers 31 and 32. Here, as the cold air device 30, a large type is selected and installed so that one blower 31 can be used as a main, and a small type is selected and installed so that the other blower 32 facing the other can be used as a sub. ..

The injector 40 blows downward high-pressure air as a driving fluid onto the filament aggregate F that descends so as to pass through the body 41 from the upper side to the lower side in the spinning direction, so that the injector 40 has a low pressure on the inlet side of the body 41. It has a structure that generates an area. The injector 40 pulls the descending filament aggregate F so as to be drawn into the low pressure region on the entrance side of the body 41, and at the same time, pulls the falling filament aggregate F downward by high pressure air even in the body 41, thereby passing through the cold air device 30. The filament aggregate F descending from the upper side to the lower side in the spinning direction is stretched.

The collection conveyor 50 is constructed with a main conveyor 51, sub-conveyors 52 and 53, and a suction box (suction means) 54. The main conveyor 51 is installed so that a net-like collection belt 151, which is formed wider than the width of the filament aggregate F and can be ventilated on the front and back surfaces, is wound around the rollers 151r group and is driven around. The sub-conveyors 52 and 53 are also formed to be wider than the width of the filament aggregate F, and the net-like collection belts 152 and 153 that can be ventilated on the front and back are wound around the rollers 152r group and the roller group 153r in opposite directions. It is installed so as to drive around.

The collection belt 151 is wound around a group of rollers 151r having a length at which the upper surface 151a is reliably located at the injection points below the ejection devices 10A, 10B, and 10C, and is towed down by the injector 40. By receiving and transferring the coming filament aggregate Fa, it is collected in a cloth shape (sheet shape). That is, the collection belt 151 is driven orbiting from the upstream end (head) to the downstream end (tail) of the upper surface 151a in the orbital movement direction (transfer direction), thereby forming a sheet-like filament aggregate. It has a sufficient area for collecting Fa and functions as a collecting surface and a transport surface. The filament aggregate Fa is the crimped fiber layer C1 on the lower layer side of the nonwoven fabric C.

The collection belt 152 has the upper surface 152a located at the lower injection point of the ejection device 10B located in the middle of the circumferential movement direction of the upper surface 151a of the collection belt 151 and is wound around the rollers 152r group, and is wound around the injector 40. By transporting the filament aggregate Fb towed down while receiving it, the filament aggregate Fb is collected in the form of a sheet. Further, in the collection belt 153, the upper surface 153a is located at the lower spraying point of the ejection device 10C located at the downstream end (rearmost end) of the upper surface 151a of the collection belt 151 in the circumferential movement direction, and the roller 153r group. The filament aggregate Fc, which is towed and lowered by the injector 40, is received and transferred to be collected in a sheet shape. The filament aggregate Fb becomes the spunbond fiber layer C2 in the nonwoven fabric C.

These collection belts 152 and 153 are installed at positions deviated from the lower side to the downstream side of the ejection device 10A located at the upstream end (top) of the upper surface 151a of the collection belt 151 in the circumferential movement direction. By being located between the upper surface 151a and the ejection devices 10B and 10C and being driven orbiting in the reverse direction, the upper surfaces 152a and 153a respectively have a collecting surface and a transport surface for collecting the sheet-shaped filament aggregates Fb and Fc. Functions as. Then, these collection belts 152 and 153 circulate so as to sandwich the sheet-shaped filament aggregates Fb and Fc between the collection belt 151 and the lower surface facing the upper surface (upper part) 151a without peeling off and turning over. It functions to drive and assist transportation to the downstream side.

The suction box 54 is housed in a collection belt 151 of the main conveyor 51 and is divided into suction chambers 154a, 154a-2, 154b, 154b-2, 154c, and 154c-2, which function as decompression chambers, respectively. The suction chambers 154a to 154c-2 are arranged with suction ports (not shown) so as to suck the upper side, and suction fans 155a to 155c-2 that can be individually driven are connected to each other so as to be suctionable.

The suction chambers 154a, 154b, and 154c are installed so as to be located below the injectors 40 of the ejection devices 10A, 10B, and 10C, respectively, and the suction chambers 154a-2, 154b-2, and 154c-2 are these suction chambers 154a. It is installed so as to be located on the downstream side of 154b and 154c.

The suction chamber 154a is installed so as to be located directly below the collection belt 151 of the main conveyor 51 below the injector 40 of the ejection device 10A, and the collection belt 151 is decompressed by driving the suction fan 155a. Suction from directly below to above.

The suction chamber 154a-2 is located adjacent to the downstream side of the suction chamber 154a and directly below the collection belt 151 of the main conveyor 51 between the suction chamber 154b and the suction chamber 154b located below the ejection device 10B, as will be described later. The suction fan 155a-2 is driven to reduce the pressure to suck the suction from directly below the collection belt 151.

As a result, the filament aggregate Fa spun by the ejection device 10A is sucked so as to be collected on the upper surface 151a by the suction chamber 154a under the collection belt 151 of the main conveyor 51. Therefore, the filament aggregate Fa is held and transferred while being collected in a sheet shape on the upper surface 151a as the collection belt 151 orbits in the length direction. After this, the filament aggregate Fa is transferred from the suction chamber 154a to the adjacent suction chamber 154a-2 as the collection belt 151 orbits in the length direction, and is sucked so as to maintain a sheet shape. Retained and transferred.

The suction chamber 154b is installed so as to be located directly below the collection belt 151 of the main conveyor 51 below the injector 40 of the ejection device 10B, and the collection belt 151 is decompressed by driving the suction fan 155b. The upper part of the collection belt 152 of the sub-conveyor 52 is sucked from directly below.

The suction chamber 154b-2 is located adjacent to the downstream side of the suction chamber 154b and directly below the collection belt 151 of the main conveyor 51 between the suction chamber 154c and the suction chamber 154c located below the ejection device 10C, as will be described later. The suction fan 155b-2 is driven to reduce the pressure to suck the suction from directly below the collection belt 151.

As a result, the filament aggregate Fa spun by the ejection device 10A is placed on the upper surface 151a by the suction chambers 154b and 154b-2 under the collection belt 151 of the main conveyor 51, following the suction chambers 154a and 154a-2 described above. It is sucked and held in the form of a sheet and transferred.

Further, the filament aggregate Fb spun by the ejection device 10B is collected on the upper surface 152a of the collection belt 152 of the sub-conveyor 52 on the upper surface 151a by the suction chamber 154b under the collection belt 151 of the main conveyor 51. Is sucked into. Therefore, the filament aggregate Fb is held and transferred while being collected in a sheet shape on the upper surface 152a as the collection belt 152 orbits in the length direction.

By the way, since the collection belt 152 of the sub-conveyor 52 orbits in the opposite direction to the collection belt 151 of the main conveyor 51, the upper surface 152a of the collection belt 152 moves upside down after moving in the opposite direction. Then, they move in the same direction facing the upper surface 151a of the collection belt 151 of the main conveyor 51. Therefore, the filament aggregate Fb spun by the ejection device 10B is collected and held in a sheet shape on the upper surface 152a of the collection belt 152 of the sub-conveyor 52, and then transferred to the collection belt 151 of the main conveyor 51. It is fitted so as to overlap the sheet-shaped filament aggregate Fa on the upper surface 151a, and is sucked and held in the form of a sheet by the suction chamber 154b under the collection belt 151 of the main conveyor 51 and transferred.

From this, the filament aggregate Fab (Fa, Fb) collected and held in a sheet shape under the ejection device 10B and stacked is the suction chamber 154b as the collection belt 151 orbits in the length direction. It is delivered to the adjacent suction chamber 154b-2 and is sucked and held and transferred so as to maintain the sheet shape.

The suction chamber 154c is installed so as to be located directly below the collection belt 151 of the main conveyor 51 below the injector 40 of the ejection device 10C, and the collection belt 151 is decompressed by driving the suction fan 155c. The upper part of the collection belt 153 of the sub-conveyor 53 is sucked from directly below.

The suction chamber 154c-2 is installed adjacent to the downstream side of the suction chamber 154c so as to be located directly below the end of the collection belt 151 of the main conveyor 51, as will be described later, and is a suction fan. By driving the 155c-2 and reducing the pressure, suction is performed from directly below the collection belt 151 to above.

As a result, the filament aggregate Fab to be spun by the ejection devices 10A and 10B has an upper surface 151a by the suction chambers 154c and 154c-2 under the collection belt 151 of the main conveyor 51, following the suction chambers 154a to 154b-2 described above. It is sucked and held and transferred in the form of a sheet that overlaps on top.

Further, the filament aggregate Fc spun by the ejection device 10C is collected on the upper surface 153a of the collection belt 153 of the sub-conveyor 53 on the upper surface 151a by the suction chamber 154c under the collection belt 151 of the main conveyor 51. Is sucked into. Therefore, the filament aggregate Fc is held and transferred while being collected in a sheet shape on the upper surface 153a as the collection belt 153 orbits in the length direction. The filament aggregate Fc is the crimped fiber layer C1 on the upper layer side of the nonwoven fabric C.

By the way, since the collection belt 153 of the sub-conveyor 53 also orbits in the opposite direction to the collection belt 151 of the main conveyor 51, the upper surface 153a of the collection belt 153 moves upside down after moving in the opposite direction. Then, they move in the same direction facing the upper surface 151a of the collection belt 151 of the main conveyor 51. Therefore, the filament aggregate Fc spun by the ejection device 10C is collected and held in a sheet shape on the upper surface 153a of the collection belt 153 of the sub-conveyor 53, and then transferred to the collection belt 151 of the main conveyor 51. It is further overlapped with the sheet-shaped filament aggregate Fab on the upper surface 151a, and is sucked and held in the form of a sheet by the suction chamber 154c under the collection belt 151 of the main conveyor 51 and transferred.

From this, the filament aggregate Fabc (Fa, Fb, Fc) collected, held and stacked in a sheet shape under the ejection device 10C is sucked as the collection belt 151 orbits in the length direction. It is transferred from the chamber 154c to the adjacent suction chamber 154c-2, sucked and held so as to maintain the sheet shape, and transferred.

In short, the collection conveyor 50 has a sheet shape of filament aggregates Fa, Fb, and Fc spun by the ejection devices 10A, 10B, and 10C on the upper surfaces 151a to 153a of the collection belts 151 to 153 by a suction box 54. The filament aggregate Fabc (nonwoven fabric C) before embossing is made into a filament aggregate Fabc (nonwoven fabric C) by being held while being sucked and collected, and then conveyed downstream and delivered to the embossing apparatus 60.

The embossing apparatus 60 includes a pair of embossing rolls 61 and 62, and the cylindrical outer peripheral surfaces 61a and 62a are pressed against each other to rotate relative to each other. The embossing apparatus 60 desires embossing projections (not shown) arranged regularly or irregularly on the smooth cylindrical outer peripheral surface 61a of the lower embossing roll 61 and on the cylindrical outer peripheral surface 62a of the upper embossing roll 62. Press with pressure contact force.

As a result, the embossing apparatus 60 sends out the filament aggregate Fabc sandwiched between the embossing rolls 61 and 62 in the relative rotation direction, and entangles the filaments f with each other at a plurality of embossing points corresponding to the formation positions of the embossed protrusions. It is embossed while being pressed and joined, and processed into a non-woven fabric C that maintains its sheet-like morphology. The embossed protrusions formed on the cylindrical outer peripheral surface 62a of the embossed roll 62 may be formed on the cylindrical outer peripheral surface 61a side of the embossed roll 61, or may be formed on both of these cylindrical outer peripheral surfaces 61a and 62a. Further, the shape is not limited to the convex shape, but may be formed into a concave shape, and for example, a continuous rib shape may be pressed against the mating cylindrical surface to be squeezed and joined.

The winder 70 receives the nonwoven fabric C in which the filaments f of the filament aggregate Fabc are entangled and bonded by the embossing apparatus 60 while adjusting the tension so as not to loosen, and continuously winds the nonwoven fabric C as desired without wrinkles. Wind up in a roll with hardness.

Thereby, the winder 70 can prepare the non-woven fabric C having a desired length in which the filament aggregate Fabc is formed into a sheet and wound into a roll so that it can be supplied to the next processing step or the like.

In the collection conveyor 50 of the present embodiment, as described above, the suction chambers 154a to 154c-2 of the suction box 54 installed under the collection belt 151 of the main conveyor 51 are the injectors of the ejection devices 10A to 10C. The suction fans 155a to 155c-2, which are partitioned and installed so as to correspond to each 40, are also connected to the suction chambers 154a to 154c-2 in the section range (region) and the required suction pressure. It is set to suck at the corresponding wind speed (air volume). Here, the suction section range and the suction pressure of the suction chambers 154a to 154c-2 may be appropriately set.

Specifically, the suction chamber 154a captures the filament aggregate Fa that is towed down from the outlet of the injector 40 of the ejection device 10A directly above the collection belt 151 of the main conveyor 51 without the intervention of a sub-conveyor. The collecting belt 151 is sucked from below to collect and hold it in the form of a sheet.

The suction chamber 154a is partitioned so that a suction pressure Pa capable of stably holding the falling filament aggregate Fa is generated under the transport surface of the collection belt 151 in a narrow range as small as the spray region in the transfer direction. The inside of the section is sucked by the suction fan 155a to generate a negative pressure.

The suction chambers 154b and 154c subconveyor the filament aggregates Fb and Fc that are towed down from the outlets of the injectors 40 of the ejection devices 10B and 10C directly above the collection belts 152 and 153 of the subconveyors 52 and 53, respectively. It is sucked from under the collection belt 151 via 52 and 53 to collect and hold it in the form of a sheet. These sub-conveyors 52 and 53 have a sheet-shaped filament aggregate Fb and Fc collected and held on the collection belts 152 and 153, respectively, so as to be sandwiched between the lower collection belt 151 and the filament aggregate Fab. , Fabc is sent downstream.

In these suction chambers 154b and 154c, suction fans 155b and 155c generate suction pressures Pb and Pc capable of stably holding the falling filament aggregates Fb and Fc under the transport surface of the collection belts 152 and 153. It is driven to a negative pressure. Similar to the suction chamber 154a, these suction chambers 154b and 154c also generate desired suction pressures Pb and Pc in a narrow section range such as a spraying region in the transfer direction of the falling filament aggregates Fb and Fc. , It is sucked by the suction fans 155b and 155c to make it a negative pressure. At the same time, these suction chambers 154b and 154c suck on the collection belts 152 and 153 of the subconveyors 52 and 53 with the filament aggregates Fab and Fabc on the collection belt 151 interposed therebetween. Therefore, these suction chambers 154b and 154c adjust the suction range in the transfer direction under the collection belt 151 so that the optimum suction pressures Pb and Pc are generated on the collection belts 152 and 153 to increase the suction volume. The number may be increased or decreased, and the suction belts 152 and 153 may also be similarly partitioned or the like so that the suction range can be adjusted.

As a result, the suction chambers 154b and 154c are continuously sucked and held by the filament aggregates Fab and Fabc increased from the sheet-shaped filament aggregate Fa via the collection belt 151 of the main conveyor 51, similarly to the suction chamber 154a. can do.

The suction chambers 154a-2, 154b-2, and 154c-2 continuously connect the sheet-like filament aggregates Fa, Fab, and Fabc on the collection belt 151 of the main conveyor 51 on the downstream side of the suction chambers 154a, 154b, and 154c, respectively. Suction and hold.

These suction chambers 154a-2, 154b-2, and 154c-2 have suction pressures Pa-2 and Pb-2 that continuously and hold the sheet-shaped filament aggregates Fa, Fab, and Fabc on the collection belt 151, respectively. , Pc-2 is driven and the suction fan 155a-2 is driven to generate negative pressure. Since the suction chambers 154a-2 and 154b-2 are continuous so as to be interposed between the suction chambers 154a, 154b and 154c so as to suck without a gap, the collection positions of the ejection devices 10 are separated from each other. It is installed so as to suck a wide area so as to connect. Further, since the suction chamber 154c-2 only transfers the sheet-shaped filament aggregate Fabc received from the suction chamber 154c to the embossing apparatus 60 adjacent to the downstream side, the suction chamber 154c-2 is installed so as to suck a short section range. ing.

As a result, the suction chambers 154a-2, 154b-2, and 154c-2 suck the sheet-like filament aggregates Fa, Fab, and Fabc located on the upper surface 151a via the collection belt 151 of the main conveyor 51, respectively. It can be sucked and held in succession to the chambers 154a, 154b, 154c. At this time, the sheet-shaped filament aggregates Fa and Fab on the collection belt 151 of the main conveyor 51 are suction-held by the suction chambers 154a-2 and 154b-2, respectively, so that the sub-conveyor 52 does not float. It is sandwiched between the collection belts 152 and 153 of 53. Further, the sheet-shaped filament aggregates Fa and Fab are collected and held by the collection belts 152 and 153 and turned upside down. The sheet-shaped filament aggregates Fb and Fc are overlapped with each other to form a sheet-like filament aggregate Fab. It is transferred to the downstream while being sucked and held by being made into a Fabc.

As described above, the collection conveyor 50 applies a suction pressure P sufficient for collecting and holding the sheet-shaped filament aggregate F on the collection belt 151 of the main conveyor 51 in the suction chamber 154a of the suction box 54. The individual suction fans 155a to 155c-2 are set to suck at the required wind speed so as to generate every ~ 154c-2. The relative relationship (strength) of the suction pressure P on the collection surface (conveyance surface) of the filament aggregate F for each suction chamber 154a to 154c-2 described below is from the connection point of the suction fans 155a to 155c-2. This will be explained by calculating and substituting the wind speed value according to the separation space to the collection surface.

For example, in the suction box 54, the suction pressures Pa, Pb, and Pc of the suction chambers 154a, 154b, and 154c located at the injection points of the filament aggregates F by the ejection devices 10A, 10B, and 10C in the collection conveyor 50 are downstream of each other. It is adjusted to be larger than the suction pressures Pa-2, Pb-2, and Pc-2 of the suction chambers 154a-2, 154b-2, and 154c-2 located on the side. Further, the suction pressure Ps (Pa, Pa-2) of the suction chambers 154a and 154a-2 on the leading side in the transfer direction of the filament aggregate F and the suction pressure Pm (suction pressure Pm) of the intermediate suction chambers 154b and 154b-2 (of these). Pb, Pb-2) and the suction pressure Pe (Pc, Pc-2) of the suction chamber 154c and 154c-2 on the rearmost side are intermediate because both the upstream side and the downstream side are suction-held. The suction pressure Pm at the position can be adjusted so as to be smaller than each of the front suction pressure Ps and the rearmost suction pressure Pe (Ps> Pm and Pe> Pm). Further, the suction pressures Pa, Pb, and Pc are the filament aggregates on the transport surface so as not to excessively reduce the pressure in the suction chambers 154a, 154b, and 154c and hinder the smooth relative movement of the collection belt 151. It is adjusted according to the amount of F.

Specifically, the suction chamber 154a is wound in a roll shape by, for example, a winder 70 as a suction pressure Pa in the collection belt 151 of the main conveyor 51 that collects and holds the filament aggregate Fa spun by the ejection device 10A in a sheet shape. The wind speed Pa = 7.5 is set when the non-woven fabric C having a semi-finished product with a grain size of 10 to 30 g / m ² is manufactured. Since the suction pressure (wind speed) Pa is a position where the filament aggregate Fa is sucked and the collection and holding in the form of a sheet is started, the suction pressure (wind speed) Pa is attracted to the upper surface 151a of the collection belt 151 regardless of the amount of the attachment. It is set to a strong value to make it.

In the suction chamber 154a-2, similarly, following the suction chamber 154a, the suction pressure Pa-2 is used, for example, when a non-woven fabric C having a texture of 10 to 30 g / m ² is produced, the wind speed Pa-2 = 3.8. Is set to. Here, as the suction pressure (wind velocity) Pa-2, it is sufficient to maintain the shape of being sucked and held in the form of a sheet regardless of the amount (weighing) of the filament aggregate Fa, as in the case of the suction pressure Pa. Since it is directly sandwiched between the collection belts 151 and 152 of the main conveyor 51 and the sub-conveyor 52, the suction pressure is suppressed to about half of the suction pressure Pa.

The suction chamber 154b is set to a suction pressure Pb of, for example, a wind speed Pb = 6.0 when producing a nonwoven fabric C having a texture of 10 to 30 g / m ² . As for the suction pressure (wind velocity) Pb, since the filament aggregate Fb is collected and formed in a sheet shape on the collection belt 152 of the sub-conveyor 52 as in the suction pressure Pa, it is strengthened regardless of the amount of the attachment. However, since the filament aggregate Fab on the collection belt 151 of the main conveyor 51 is interposed and sucked, the movement of the collection belt 151 is suppressed to a low level so as not to be restricted.

The suction chamber 154b-2 is set to a suction pressure Pb-2 following the suction chamber 154b, for example, when a non-woven fabric C having a texture of 10 to 30 g / m ² is manufactured, the wind speed Pa = 3.2. Here, the suction pressure (wind velocity) Pb-2 maintains a shape in which the filament aggregates Fb and Fab are suction-held in a sheet shape regardless of the amount (weighing) of the filament aggregates Fb and Fab, as in the case of the suction pressure Pb. Since it is sandwiched between the collection belts 151 and 153 of the main conveyor 51 and the sub-conveyor 53 as it is, it can be suppressed to an extremely low value, and it is surely sucked and held between the collection belts 151 and 153. The filament aggregate F, which has a small amount of grain, is set to suck more strongly so as to enter the surface. The sheet-shaped filament aggregate Fc collected and held by the collection belt 153 is sandwiched on the collection belt 151 of the main conveyor 51 under the sub-conveyor 53 in a state of being overlapped with the sheet-like filament aggregate Fab. It is sucked and held and transferred downstream.

The suction chamber 154c is set to Pa = 7.4 as the suction pressure Pc, for example, when producing a nonwoven fabric C having a basis weight of 10 to 30 g / m ² . As the suction pressure (wind velocity) Pc, the filament aggregate Fc is collected and formed on the collection belt 153 of the sub-conveyor 53, similarly to the suction pressures Pa and Pb. Although it is set to a value, since it is sucked while interposing the filament aggregate Fabc on the collection belt 151 of the main conveyor 51, it is suppressed to a low level so as not to limit the movement of the collection belt 151.

The suction chamber 154c-2 is set to Pa = 3.2 to 3.8 as the suction pressure Pb-2 following the suction chamber 154c, for example, when manufacturing a nonwoven fabric C having a basis weight of 10 to 30 g / m ² . Will be done. As the suction pressure (wind speed) Pc-2, the filament aggregate Fabc carried out from under the sub-conveyor 53 is surely sucked and held by the collection belt 151 of the main conveyor 51 and delivered to the embossing apparatus 60. The suction pressure is set lower than the suction pressure Pa according to the amount of the grain.

Further, in the nonwoven fabric manufacturing apparatus M, the line speeds of the collection belts 151, 152, and 153 are 100 to 1200 m / min. The fiber discharge amount of the ejection devices 10A and 10C is 0.2 to 1.0 g / hole / min, and the fiber discharge amount of the ejection device 10B is 0.2 to 1.0 g / hole / min. be. Further, the filament aggregates Fa and Fc (crimped fiber layer C1) are produced at a spinning speed of 1200 to 6500 m / s, and the filament aggregate Fb (spunbond fiber layer C2) has a spinning speed of 100 to 1200 m / s. Created with. Further, in the nonwoven fabric C produced under this condition, the fiber diameter in the crimped fiber layer C1 is 8 to 30 μm, and the fiber diameter in the spunbonded fiber layer C2 is 30 to 100 μm.

By the way, in the spunbond fiber layer C2, it is necessary to adjust so that the fibers are oriented almost straight in the MD direction. For this adjustment, for example, by installing an adjustment roller 162 that pulls the spunbond fibers at a line speed on the upper surface 152a of the collection belt 152 of the nonwoven fabric manufacturing apparatus M, the fibers can be oriented straight in the MD direction. The adjusting roller 162 may have a cooling function for cooling the fibers.

Further, even when the roller 162 is not installed, the fibers can be oriented straight in the MD direction by matching the spinning speed in the ejection device 10B with the line speed of the collection belt 152. The spinning speed in the ejection device 10B can be adjusted by the injection pressure of the ejection device 10B.

Further, the spinning speed in the ejection devices 10A and 10C is set to be faster than the line speeds of the collection belts 151 and 153. As a result, the fibers can be deposited in a loop shape (spiral shape) on the collection belts 151 and 153, so that the crimped fiber layer C1 can be created. The crimped fiber layer C1 has a width shrinkage (width 230 mm, reduction rate of the original fabric width after a load of 2 kg is applied for 30 seconds) within 15%, and is bulky (reciprocal of density). Is 20 or more.

The nonwoven fabric C according to the present embodiment is manufactured by the manufacturing method described above. According to the non-woven fabric C according to the present embodiment, it is possible to realize stable operation when used as a material while maintaining bulkiness.

<Other embodiments>
Although the embodiments of the present invention have been described above, the various embodiments described above can be combined as much as possible. Further, the nonwoven fabric C according to the above embodiment has a three-layer structure in which two crimp fiber layers C1 are arranged and a spunbond fiber layer C2 is arranged between them, but the present invention is not limited to this. .. For example, the nonwoven fabric C may have a two-layer structure in which the crimp fiber layer C1 and the spunbond fiber layer C2 are laminated. Further, when the nonwoven fabric C has a three-layer structure, the spunbond fiber layer C2 may not be arranged between the two crimp fiber layers C1, for example, the spunbond fiber layer C2 and the crimp fiber layer. C1 and the crimped fiber layer C1 may be laminated in this order. Further, the nonwoven fabric C may be composed of four or more layers as long as it has at least one spunbond fiber layer C2. Further, the nonwoven fabric manufacturing apparatus M can be appropriately changed according to the nonwoven fabric C to be manufactured.

Further, in the nonwoven fabric manufacturing apparatus M, if the fiber ejection speed of the ejection device 10B and the line speed of the repair belt 151 can be matched, the sub-conveyor 52 may not be provided.

C ... Nonwoven fabric C1 ... Curly fiber layer C2 ... Spunbond fiber layer M ... Nonwoven fabric manufacturing device 10, 10A, 10B, 10C ... Injection device 20 ... Spinning device 30 ... Cold air device 40 ... Injector 50・ ・ Collection conveyor 51 ・ ・ Main conveyor 52, 53 ・ ・ Sub-conveyor 54 ・ ・ Suction box 60 ・ ・ Embossing device 70 ・ ・ Winder 141, 142 ・ ・ Guide plate 151, 152, 153 ・ ・ Collection belt 154a , 154b, 154c ... Suction chamber 162 ... Adjustment roller f ... Filament fr ... Rotation diameter F, Fa, Fab, Fabc, Fb, Fc ... Filament aggregate Lc ... Crossing interval Ld ... Opening interval Lr ...・ Retraction interval P, Pa, Pb, Pc, Pe, Pm, Ps ・ ・ Suction pressure (wind speed)

Claims (5)

A non-woven fabric composed of multiple fiber layers.
A first fiber layer composed of crimpable fibers having a number of crimps of 15/25 mm or more, and
A second fiber layer having a fiber diameter of 2 to 100 denier and the fibers oriented in the MD direction,
A non-woven fabric. The first fiber layer has a breaking elongation in the MD direction of 50% or more.
The non-woven fabric according to claim 1. The first fiber layer, the second fiber layer, and the first fiber layer are laminated in this order.
The non-woven fabric according to claim 1 or 2. A non-woven fabric manufacturing method for manufacturing a non-woven fabric composed of a plurality of fiber layers.
A step of forming a first fiber layer composed of crimpable fibers having a crimp number of 15 pieces / 25 mm or more, and a step of forming the first fiber layer.
A step of forming a second fiber layer having a fiber diameter of 2 to 100 denier and in which the fibers are oriented in the MD direction,
Non-woven fabric manufacturing method including A plurality of fiber spraying devices for ejecting fibers and a sheet transporting device for collecting bundles of the fibers sprayed from the fiber spraying device on a transport surface to form a sheet-like non-woven fabric and transporting the fibers in the transfer direction. A non-woven fabric manufacturing device that manufactures non-woven fabrics composed of the above fiber layers.
The fiber spraying device is
A first fiber spraying device that bundles and ejects filaments in order to form a first fiber layer composed of crimpable fibers having a number of crimps of 15/25 mm or more.
A second fiber spraying device having a fiber diameter of 2 to 100 denier and ejecting filaments in a bundle to form a second fiber layer in which the fibers are oriented in the MD direction.
Non-woven fabric manufacturing equipment.

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