JP6902341B2 - Manufacturing method of composite non-woven fabric and its manufacturing equipment - Google Patents

Description

The present invention relates to a composite type nonwoven fabric composed of pulp fibers and synthetic fibers, and more particularly to a method for producing a nonwoven fabric to which an uneven pattern is imparted, and an apparatus therefor.

The non-woven fabric has a cloth-like texture, has liquid absorption and wiping properties, and can be mass-produced. Therefore, non-woven fabrics are widely used in various fields.
Generally, a non-woven fabric is produced through a web forming step of forming a web (sometimes called a fleece) as a base material and a fiber bonding step of binding the fibers constituting the web to each other. Many proposals have been made conventionally for each of the web forming step and the fiber bonding step.

For example, after stacking a pulp fiber layer (web) and a synthetic fiber layer (web) to form a laminated web, a high-pressure water jet (water flow) is sprayed to perform water flow entanglement treatment to bond the fibers to a composite type. Non-woven fabric can be obtained. As described above, the composite non-woven fabric formed by the pulp fiber layer and the synthetic fiber layer has advantages of the pulp fiber having good absorption to both water-based and oil-based liquids and the synthetic fiber having excellent strength. An excellent non-woven fabric product that also has the above can be provided to consumers as a wiper.

It is desired that the non-woven fabric used as a wiper be manufactured with sufficient bulkiness. The bulkiness here is also called bulky (or bulk) property, and it is said that the non-woven fabric as a product has a sufficient texture and can give a good impression to consumers in terms of texture and feel. This is one of the finishing conditions. In addition, since a bulky non-woven fabric generally has a large surface area, it is also excellent in liquid absorption.
Conventionally, a web that has been entangled with water flow and is in a wet state is generally heat-dried using a cylinder dryer. However, when the non-woven fabric is dried by the cylinder dryer, the surface pressure becomes high, so that the thickness of the non-woven fabric after production is reduced and the bulkiness is also reduced.
In order to deal with the decrease in bulkiness after drying as described above, the bulkiness may be improved by imparting an uneven pattern to the raw web fabric after production with an embossing device. However, the embossing treatment performed here is to give a concavo-convex pattern by heating while pressurizing a predetermined region, and in the case of a non-woven fabric containing a synthetic fiber layer, a part of the fiber is melted and solidified to be concavo-convex. The pattern is fixed. Such embossing requires a long time, and there is a problem that the melted and solidified portion becomes hard and the texture and strength are lowered. Further, there is a problem that the uneven pattern disappears when the heating in the embossing device is insufficient.
Further, since the embossing device as described above is an independent facility separately from the non-woven fabric manufacturing device, there is a problem that the manufacturing cost increases.

Therefore, an object of the present invention is to provide a manufacturing method capable of easily and effectively imparting an uneven pattern to a composite non-woven fabric composed of pulp fibers and synthetic fibers. Another object of the present invention is to provide a manufacturing apparatus for carrying out the method.

The above object is a method for producing a composite non-woven fabric in which a pulp fiber layer and a synthetic fiber layer are laminated and integrated, and also has an uneven pattern.
After the pulp fiber layer forming step of obtaining the pulp fiber layer by a dry air-laid method, the water flow entanglement step of promoting the integration of the pulp fiber layer and the synthetic fiber layer to obtain a laminate, and the water flow entanglement step. Including at least a drying step of drying the laminate,
Between the water flow entanglement step and the drying step, an embossing treatment step of imparting the unevenness pattern to the laminated body which is in a wet state immediately after the water flow entanglement treatment by the water flow entanglement step is further set.
In the drying step, the laminate is dried in an uncompressed state.
In the embossing treatment step, the process of imparting the unevenness pattern to the laminated body is executed in a non-heated state, and at that time, the laminated body is sandwiched, water is squeezed, and the unevenness pattern is imparted.
This can be achieved by a method for producing a composite nonwoven fabric, which is characterized by the above.

The above object is a manufacturing apparatus for manufacturing a composite non-woven fabric in which a pulp fiber layer and a synthetic fiber layer are laminated and integrated, and also has an uneven pattern.
A pulp fiber layer forming portion that obtains the pulp fiber layer by a dry air-laid method, a water flow confounding portion that promotes integration of the pulp fiber layer and the synthetic fiber layer to obtain a laminate, and a downstream of the water flow confounding portion. It is provided with at least a drying portion for drying the laminate.
An embossed portion that imparts the unevenness pattern to the laminated body that is in a wet state immediately after the water flow entanglement treatment by the water flow entanglement portion is further arranged between the water flow entanglement portion and the dry portion.
The drying portion includes a non-compressed dryer that dries the laminate .
The embossed unit is a processing unit that imparts an unevenness pattern to the laminated body in a non-heated state, and has a plate having an unevenness corresponding to the unevenness pattern on the surface. It includes a rotating body of 1 and a second rotating body having an elastic body on its surface and being press-contacted with the first rotating body to be rotatable.
The first rotating body is a metal roll engraved with an uneven pattern or an endless wire having an uneven pattern set in advance, and the second rotating body is a rubber roll or a rubber belt. Achieved by the manufacturing equipment of.

According to the manufacturing method of the present invention, a concavo-convex pattern can be imparted to a composite non-woven fabric composed of pulp fibers and synthetic fibers with a simple structure, whereby it is bulky and has a uniform texture and feel as a whole. It is possible to provide a wiper having excellent liquid absorption.
Further, according to the manufacturing method or manufacturing apparatus of the present invention, it is possible to manufacture a composite non-woven fabric having a concavo-convex pattern while suppressing the manufacturing cost in terms of both manufacturing efficiency and equipment.

It is a figure which showed the manufacturing apparatus as an example suitable for carrying out the manufacturing method of the composite nonwoven fabric which concerns on this invention. It is a figure which showed the combination example of the 1st rotating body and the 2nd rotating body in the embossing apparatus of the manufacturing apparatus of FIG.

Hereinafter, an embodiment of the present invention will be described. In the following, a manufacturing apparatus suitable for carrying out a method for manufacturing a composite nonwoven fabric to which a concavo-convex pattern is imparted will be described with reference to the drawings.

The composite non-woven fabric manufacturing apparatus 1 shown in FIG. 1 has an airlaid apparatus 2 as a pulp airlaid portion, a synthetic fiber web supply apparatus 3 as a synthetic fiber layer supply portion, and a suction device 4 as a laminate forming portion on the upstream side. It is installed. The suction device 4 is arranged so as to face the lower side of the air raid device 2.
In the transport direction TD, a water flow injection (water jet) device 5 as a water flow confounding part and a drying device 7 as a dehydration / drying part are arranged in order from the upstream side downstream of these devices 2, 3 and 4. .. Downstream of the drying device 7, a winding device 8 for winding a continuously manufactured composite non-woven fabric CWeb is further provided.

The air-laid device 2 is provided with a defibrator 21 for defibrating (also referred to as opening) the raw pulp RP, which is a sheet of raw pulp RP in which fibers are densely packed, into pulp fibers, and a blower (not shown). It has a duct 22 and the like for transporting the pulp fiber FP to the air-laid hopper 23. The air-laid hopper 23 is designed so that the defibrated pulp fiber FP descends while being dispersed inside the air-laid hopper 23 and gradually stacks at the stacking position 24 set on the lower surface.
A suction device 4 is arranged opposite to the lower side of the stacking position 24. More specifically, the suction device 4 has a suction portion 42 on the upper surface of the apparatus main body 41, and the suction portion 42 is set with respect to the stacking position 24 so as to apply a suction force (negative pressure) to the pulp fiber FP. It is done.

Further, a transport wire 43 for web transport is arranged around the suction device 4. The transfer wire 43 is arranged so that the pulp fiber FP can be placed at the stacking position 24 and the pulp fiber FP is conveyed to the downstream side. However, the pulp fiber FP is not directly placed on the transport wire 43. This will become clear in the description below.
The transport wire 43 is formed in an opening form (mesh) so that the suction force of the suction portion 42 extends to the opposite side (upper side).

Conventionally known pulp can be used as the raw material pulp RP. For example, when wood pulp is used, NBKP such as radiata pine, slash pine, southern pine, spruce, and Douglas fir is preferable as the grade, and it may be appropriately selected in consideration of defibration, yield and the like.
Further, since the raw material pulp RP is often supplied in the form of roll pulp as illustrated, it is preferable to adopt a hammer mill, a disc mill type or the like as the defibrating device 21. The defibration treatment here may be performed in one stage or a plurality of stages, if necessary.
Further, a natural fiber such as cotton or a synthetic fiber such as polyester, polypropylene or polyethylene may be additionally blended together with the raw material pulp RP. When adopting such a composition, a separate airlaid head may be added to superimpose the web layer, or an air blowing line for mixing another fiber may be added to the duct for airing the opened pulp.

The synthetic fiber web supply device 3 is arranged on the lower side of the air raid device 2 and on the upstream side of the suction device 4. In the synthetic fiber web supply device 3, a synthetic fiber web SW prepared in advance is set in a roll shape. The synthetic fiber web SW is pulled out from the synthetic fiber web supply device 3 and is conveyed to the laminated position 24 on the conveying wire 43 described above.
As the synthetic fiber web SW, it is preferable to use a web of continuous filaments formed by the spunbond method. The synthetic fiber here is preferably selected from nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polystyrene and the like.

The pulp fiber FP described above is placed (stacked) on the synthetic fiber web SW located at the stacking position 24, and the synthetic fiber web SW is transported downstream on the transport wire 43.
At that time, at the laminated position 24, the suction force by the suction portion 42 of the suction device 4 passes through the transport wire 43 and acts on the synthetic fiber web SW and the pulp fiber FP on the transfer wire 43. Therefore, in the laminated web that has moved to the downstream side through the lamination position 24, the lower synthetic fiber layer (synthetic fiber web SW) and the pulp fiber layer (pulp web) placed on the lower synthetic fiber layer are laminated. It becomes a preliminary laminated body PWeb in a state of being in a state of being.

The preliminary laminated body PWeb described above is maintained in a laminated state by being suction-compressed by the suction force of the suction device 4. At this time, the pulp fiber layer on the upper side is in a state where the pulp fiber FP is densely packed. However, if the preliminary laminated body PWeb is conveyed and thrown into the water flow injection device 5 on the downstream side as it is, a part of the pulp fiber FP may fly up due to the water flow (water jet).
Therefore, in the present manufacturing apparatus 1, the holding roller 28 for stabilizing the placement state of the pulp fiber FP on the synthetic fiber web SW by sandwiching the preliminary laminated body PWeb from above and below, and the upstream side of the water flow injection device 5. A pre-wet device 30 for imparting water to the pulp fiber FP to prevent scattering is provided. The pre-wet device 30 preferably applies a suction force from the spray nozzle 31 that sprays water mist from above the preliminary laminate PWeb and the lower side of the preliminary laminate PWeb (that is, the lower surface of the synthetic fiber web SW). It is configured to include a suction device 32.

The sandwiching roller 28 and the pre-wet device 30 can be understood as a pretreatment unit for smooth execution of the water flow entanglement processing in the water flow injection device 5. The pretreatment section shown in FIG. 1 is a suitable configuration example, and the sandwiching roller 28 may be omitted.

The water flow injection device 5 promotes entanglement of pulp fibers by spraying a high-pressure water jet on the preliminary laminated body PWeb treated by the pretreatment units 28 and 30. This promotes the integration of the pulp fiber layer located on the upper side and the synthetic fiber layer located on the lower side.
In the water flow injection device 5 exemplified in FIG. 1, water flow injection nozzles 51 are arranged in multiple stages (four stages are illustrated in FIG. 1) along the transport direction TD. By spraying the water flow injection nozzle of the first stage at a low pressure, the pre-wet device 30 described above may be substituted.
In FIG. 1, the state of the nozzles in the direction perpendicular to the transport direction TD (the width direction of the device 1) is not shown, but a plurality of water flow injection nozzles are also arranged in the width direction.

It is desirable to set the water pressure at the time of performing the water flow entanglement treatment in consideration of the basis weight of the pulp fiber layer (web) and the synthetic fiber layer (web). For example, it is preferable to select in the range of 1 to 30 MPa.

The suction device 52 is arranged so as to face the water flow injection nozzle 51. While spraying the high-pressure water jet emitted from the water flow injection nozzle 51 onto the pulp web located on the upper side, the suction force of the suction device 52 is applied to the lower side of the synthetic fiber layer located on the lower side. By the cooperative action of the water flow injection nozzle 51 and the suction device 52, the pulp fibers of the pulp web have entered the fibers of the synthetic fiber web on the lower side, or have penetrated the synthetic fiber web to reach the opposite side. Is presumed to be formed. The action promotes the integration of the two layers.

The transport wire 55 is also arranged in the water flow injection device 5. The transfer wire 55 receives the preliminary laminated body PWeb downstream of the pretreatment units 28 and 30, and transfers the transfer wire 55 into the water flow injection device 5. The transfer wire 55 is arranged so as to pass between the water flow injection nozzle 51 of the water flow injection device 5 and the suction device 52 from the upstream side to the downstream side.
Therefore, the preliminary laminated body PWeb transported on the transport wire 55 is subjected to more water flow entanglement treatment as it goes downstream in the transport direction TD, and when it exits the water flow injection device 5, the pulp fiber on the upper side is subjected to. Sufficient entanglement between the layer and the underlying synthetic web is achieved.
Immediately after leaving the water flow injection device 5, the web is in a wet state, and the bond between the pulp fibers is not sufficiently established before drying.

In the composite non-woven fabric manufacturing apparatus 1 shown in FIG. 1, an embossing apparatus 6 is further provided between the water flow injection apparatus 5 and the drying apparatus 7 located on the downstream side.
Immediately after the water flow entanglement treatment is performed by the water flow injection device 5, the embossing device 6 becomes an embossing treatment unit for imparting an uneven pattern to the laminated body TWeb in a wet state (wet).
The embossing device 6 does not have a heating device, and therefore, in a non-heated state, the process of imparting the unevenness pattern to the laminated body TWeb is executed. The embossing device 6 is set to carry the laminated body TWeb toward the drying device 7 on the downstream side while sandwiching the laminated body TWeb, and at that time, water is squeezed based on the holding pressure and an uneven pattern is formed on the laminated body TWeb. Grant.

Specifically, in the embossing device 6, the first rotating body 61 and the second rotating body 62 are arranged above and below the laminated body TWeb so as to sandwich the laminated body TWeb. Here, the first rotating body 61 has a plate having unevenness corresponding to the unevenness pattern imparted to the laminated body TWeb on the surface. The second rotating body 62 has an elastic body on its surface, and is set to be rotatable by being pressure-contacted with the first rotating body.
In the composite non-woven fabric used as a wiper, the pulp fiber layer is the main wiping surface. Therefore, it is preferable to impart an uneven pattern to the pulp fiber layer located on the upper side. Therefore, the first rotating body 61 having the plate of the uneven pattern is arranged on the upper side.
The first rotating body 61 and the second rotating body 62 are not particularly limited, but for example, the first rotating body 61 is a metal roll engraved with an uneven pattern or an endless shape in which an uneven pattern is set in advance. Wires can be adopted. Further, the second rotating body 62 may be a rubber roll or a rubber belt.
In FIG. 1, the case where the first rotating body 61 is an endless wire having a concavo-convex pattern set and the second rotating body 62 is a rubber belt is illustrated.

As the first rotating body 61 and the second rotating body 62 described above, it is possible to select from an endless wire having a concavo-convex pattern set, a pattern roll having a concavo-convex pattern set, a rubber roll, and a rubber belt. .. Then, by appropriately combining these, it is possible to design various embossing devices 6.

FIG. 2 is a diagram specifically showing other combinations of the first rotating body 61 and the second rotating body 62 arranged in the embossing device 6.
In the example shown in FIG. 2A, the upper first rotating body 61 is configured as a composite structure of the endless wire 611 in which the uneven pattern is set and the vacuum roll 612 arranged inside the endless wire 611. ing. A rubber roll 621 is adopted as the lower second rotating body 62.
The vacuum roll 612 includes a ring-shaped member 612a and a suction portion 612b formed of a porous material that rotates in contact with the back surface side (inside) of the endless wire 611. The suction portion 612b is arranged so as to face the rubber roll 621 and exerts a predetermined suction force.
The rubber roll 621 is pressed against the endless wire 611 with a predetermined pressure so as to sandwich the laminated body TWeb (not shown here). In the configuration example shown in FIG. 2A, a vacuum roll 612 is additionally deployed as a water squeezing means for actively squeezing water from the laminated body TWeb. Therefore, according to such a configuration, the uneven pattern can be more reliably imparted to the pulp fiber layer.

FIG. 2B shows a structural example when the pattern roll 613 is adopted as the upper first rotating body 61. As the pattern roll 613, a metal roll engraved with an uneven pattern can be adopted. A second rotating body 62 is composed of an endless porous rubber belt 621 in which a large number of through holes are formed and a vacuum roll 622 arranged therein. The vacuum roll 622 includes a ring-shaped member 622a and a suction portion 622b formed of a porous material that rotates in contact with the back surface side of the porous rubber belt 621. Even with such a configuration, the uneven pattern can be more reliably imparted to the pulp fiber layer.

FIG. 2C is a modification of FIG. 2B, in which a porous rubber roll 625a formed as a ring-shaped member that rotates in contact with the upper pattern roll 613 and a suction portion 625b arranged inside the porous rubber roll 625a. A structural example is shown in the case where the vacuum roll 625 is configured and the vacuum roll 625 is used as the second rotating body 62. According to this example, the structure on the side of the second rotating body 62 can be simplified. Even with such a configuration, the uneven pattern can be reliably imparted to the pulp fiber layer.
In the examples shown in FIGS. 2 (b) and 2 (c), the porous rubber belt 621 or the porous rubber roll 625 is used, but these may be used as a felt belt or felt roll formed of a felt material.

With the first rotating body 61 and the second rotating body 62 described in detail above, the uneven pattern can be transferred onto the laminated body TWeb in a non-heated state. However, as it is, the uneven pattern imparted to the laminated body TWeb is in an unstable state.
Therefore, as shown in FIG. 1, a drying device 7 is provided on the downstream side of the embossing device 6 to complete the production of the composite non-woven fabric while drying the laminated body TWeb to fix the uneven pattern. is there. The drying device 7 adopted here is an uncompressed dryer. The non-compression type dryer suppresses the uneven pattern and the thickness of the web imparted to the laminated body TWeb by the embossing device 6 from being reduced during drying. As the non-compression type dryer, an air-through dryer can be preferably adopted.
In FIG. 1, the rotatable dryer body 71 of the air-through dryer is a tubular body, and a large number of through holes are provided on the peripheral surface thereof, and hot air heated by a heat source (not shown) is centered from the outer periphery of the dryer body 71. It is configured to suck toward the part side.
Therefore, since no pressure is applied to the surface of the laminated body TWeb during drying, it is possible to prevent the unevenness pattern and the like from being reduced. When the laminated body TWeb comes out of the drying device 7, the product is sufficiently dried, the fibers are completely bonded to each other, has an uneven pattern, has a uniform texture and feel as a whole, and has excellent liquid absorption. A composite non-woven fabric CWeb is obtained. The composite non-woven fabric CWeb continuously produced in this way is wound by the roller 81 of the winding device 8 to complete a series of steps.

The composite non-woven fabric manufacturing apparatus 1 described with reference to FIG. 1 imparts an uneven pattern to the nonwoven fabric with a new idea of inserting a non-heating embossing device 6 between the water flow injection device 5 and the drying device 7. .. Conventionally, a web raw fabric is manufactured by a non-woven fabric manufacturing apparatus and once wound on a roll. After that, the non-woven fabric was given an uneven pattern by a process of pulling out the raw fabric from the roll and hanging it on the embossing device. In particular, in the past, since there was no idea of embossing during the manufacturing process of the non-woven fabric, an embossing device was prepared separately. Therefore, it took a lot of time and cost to manufacture the final product of the non-woven fabric having the uneven pattern.
On the other hand, in the manufacturing apparatus 1 shown in FIG. 1, since the embossing apparatus 6 is a so-called on-machine type in which the embossing apparatus 6 is arranged in the manufacturing apparatus 1, the equipment is simplified and the equipment is simplified as compared with the conventional case. Since the manufacturing speed can be increased, the manufacturing cost can be significantly reduced.

Although the description of the embodiment is completed above, it is needless to say that the present invention is not limited to the above embodiment and can be variously modified and implemented without departing from the gist thereof.

1 Composite non-woven fabric manufacturing equipment 2 Air-laid equipment 3 Synthetic fiber web supply equipment 4 Suction equipment 5 Water flow injection equipment 6 Embossing equipment 7 Drying equipment 8 Winding equipment 21 Decomposing machine 22 Duct 23 Air-laid hopper 24 Laminating position 28 Holding roller 30 Pre-wet Device 31 Spray nozzle 32 Suction device 41 Suction device body 42 Suction section 43 Conveying wire 51 Water flow injection nozzle 52 Suction device FP Pulp fiber (pulp fiber layer)
PWeb preliminary laminate TWeb laminate (wet laminate)
CWeb laminate (completed composite non-woven fabric)
SW Synthetic Fiber Web (Synthetic Fiber Layer)

Claims (2)

It is a method for producing a composite non-woven fabric in which a pulp fiber layer and a synthetic fiber layer are laminated and integrated, and has an uneven pattern.
After the pulp fiber layer forming step of obtaining the pulp fiber layer by a dry air-laid method, the water flow entanglement step of promoting the integration of the pulp fiber layer and the synthetic fiber layer to obtain a laminate, and the water flow entanglement step. Including at least a drying step of drying the laminate,
Between the water flow entanglement step and the drying step, an embossing treatment step of imparting the unevenness pattern to the laminated body which is in a wet state immediately after the water flow entanglement treatment by the water flow entanglement step is further set.
In the drying step, the laminate is dried in an uncompressed state.
In the embossing treatment step, the process of imparting the unevenness pattern to the laminated body is executed in a non-heated state, and at that time, the laminated body is sandwiched, water is squeezed, and the unevenness pattern is imparted.
A method for producing a composite non-woven fabric. It is a manufacturing apparatus for manufacturing a composite non-woven fabric in which a pulp fiber layer and a synthetic fiber layer are laminated and integrated, and has an uneven pattern.
A pulp fiber layer forming portion that obtains the pulp fiber layer by a dry air-laid method, a water flow confounding portion that promotes integration of the pulp fiber layer and the synthetic fiber layer to obtain a laminate, and a downstream of the water flow confounding portion. It is provided with at least a drying portion for drying the laminate.
An embossed portion that imparts the unevenness pattern to the laminated body that is in a wet state immediately after the water flow entanglement treatment by the water flow entanglement portion is further arranged between the water flow entanglement portion and the dry portion.
The drying portion includes a non-compressed dryer that dries the laminate .
The embossed unit is a processing unit that imparts an unevenness pattern to the laminated body in a non-heated state, and has a plate having an unevenness corresponding to the unevenness pattern on the surface. It includes a rotating body of 1 and a second rotating body having an elastic body on its surface and being press-contacted with the first rotating body to be rotatable.
The first rotating body is a metal roll engraved with an uneven pattern or an endless wire having an uneven pattern set in advance, and the second rotating body is a rubber roll or a rubber belt. Manufacturing equipment.

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