JP2021105237A - Composite-type nonwoven fabric and method for manufacturing the same - Google Patents

Abstract

To provide a composite-type nonwoven fabric which, even though a pulp fiber web obtained by an air-laid method is used, can inhibit pulp fibers from falling off, is reduced in the contamination of foreign matter and is excellent in use feeling.SOLUTION: A composite-type nonwoven fabric is formed such that a pulp fiber web obtained by an air-laid method is stacked on and integrated with a spun-bonded nonwoven fabric. A paper-strengthening agent is added to the pulp fiber web. In the composite-type nonwoven fabric, a basis weight is 51.0 g/m2 or more and less than 85.0 g/mm2, a thickness is 0.28 mm or more and less than 0.48 mm, and the amount of the paper-strengthening agent added, as expressed in terms of a solid content, is 0.1 to 2.0% based on the solid weight of the pulp fiber web.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite non-woven fabric obtained by water-flow entanglement of a pulp fiber web and a spunbonded non-woven fabric.

The composite non-woven fabric made of pulp fiber web and spunbonded non-woven fabric has both liquid absorption property based on pulp fiber and strength based on spunbonded non-woven fabric. It is widely used in various applications such as wipers for interpersonal use.

For example, as disclosed in Patent Document 1, a pulp fiber web and a spunbonded non-woven fabric are laminated and then integrated by a water flow entanglement treatment in which a high-pressure water jet (water flow) is sprayed. Here, since the spunbonded non-woven fabric has excellent strength, it functions as a backing layer of the manufactured composite non-woven fabric. On the other hand, the pulp fiber web has an excellent liquid absorbing function. Therefore, such a composite type non-woven fabric is an excellent composite type having both advantages of a pulp fiber web having good absorbency in both water-based and oil-based liquids and a spunbonded non-woven fabric having excellent strength. It can be provided to consumers as a non-woven fabric.

By the way, it is preferable that the composite non-woven fabric is commercially designed so that the pulp fibers do not easily fall off when used. The composite non-woven fabric is used as a wiper or the like in either a dry state or a wet state. When used, if the pulp fibers are noticeably dropped off, the commercial value will decrease.
By the way, conventionally, it is known that when a non-woven fabric containing pulp fibers is manufactured by diverting the sheet manufacturing technique by a wet papermaking method, a paper strength agent is sufficiently added to the pulp fibers in advance. (For example, Patent Documents 2 and 3). In the pulp fiber web produced in this way, the state of the constituent fibers is stabilized, so that the fibers can be prevented from falling off.

Japanese Patent No. 2533260 Japanese Unexamined Patent Publication No. 2012-21142 Special Table 2018-535126

As for the pulp fiber web used for the composite non-woven fabric of the pulp fiber web and the spunbonded non-woven fabric, it is easily conceived to use the pulp fiber web to which the paper strength agent is added by the conventional wet papermaking method.
However, compared to the case where the air-laid method is adopted, when the pulp fiber web is manufactured by the wet papermaking method, the manufacturing equipment becomes large and the manufacturing cost increases, and the foreign matter circulating in the white water is completely removed in the papermaking process. Therefore, there is a problem that foreign matter is easily mixed in the produced composite non-woven fabric.

Therefore, a main object of the present invention is to provide a composite non-woven fabric that can prevent the pulp fibers from falling off even if the pulp fiber web obtained by the air-laid method is used, and that has less foreign matter mixed in and has a good usability. To do.

The above object is a composite non-woven fabric in which pulp fiber webs obtained by an air-laid method are laminated and integrated on a spunbonded non-woven fabric, and a paper strength agent is added to the pulp fiber webs, and the composite is said. The basis weight of the molded non-woven fabric is 51.0 g / m ² or more and less than 85.0 g / m ^{2 ,} the thickness is 0.28 mm or more and less than 0.48 mm, and the addition amount converted by the solid content of the pulp strength agent is the above. This can be achieved with a composite nonwoven fabric characterized by 0.1 to 2.0% of the solid weight of the pulp fiber web.

The paper strength agent is preferably unevenly distributed on the surface layer side of the pulp fiber web.

Further, it is preferable that the drip water absorption is 0.5 to 4.0 seconds, the water retention amount is 220 to 380 g / m ² , and the wet taber value is at least 5 times.

Further, the basis weight of the spunbonded nonwoven fabric is 7.0 to 20.0 g / m ² , and the spunbonded nonwoven fabric contains a plurality of fusion points connecting the resin fibers forming the spunbonded nonwoven fabric. The area of one fusion point is 0.10 to 0.50 mm ² , the area ratio of the fusion point per unit area is 7 to 20%, and the number of fusion points per unit area is 10 to 150 pieces. It is preferably / cm ^2.

Further, the material of the spunbonded non-woven fabric can be one kind selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more kinds selected.

The basis weight of the pulp fiber web is 40.0 to 70.0 g / m ² , and the weight composition ratio of the spunbonded nonwoven fabric and the pulp fiber web is 40/60 to 10/90 (wt%). Is preferable.

The pulp fiber web is preferably made of fibers of softwood bleached kraft pulp selected from the group consisting of radiata pine, slash pine, southern pine, lodge pole pine, spruce and douglas fur.

For the above purpose, a pulp fiber web supplied by an airlaid method is placed on a spunbonded non-woven fabric and then subjected to a water flow entanglement treatment, and after the water flow entanglement treatment, a paper strength agent is added to the pulp fiber web. It can also be achieved by a manufacturing method for manufacturing any of the above-mentioned composite non-woven fabrics.
The addition of the paper strength agent is preferably spray coating.

According to the present invention, it is possible to provide a composite non-woven fabric that can prevent the pulp fibers from falling off, has less foreign matter mixed in, and has a good usability, even if the pulp fiber web obtained by the airlaid method is used.

(A) is a figure showing the cross-sectional structure of the composite non-woven fabric WP according to the present invention, and (b) is a cross-sectional view of a composite non-woven fabric using a pulp fiber web manufactured by diverting a sheet manufacturing technique by a wet papermaking method. It is a figure which showed the structure. It is a figure which showed the apparatus suitable for manufacturing the composite type nonwoven fabric which concerns on this invention.

Hereinafter, the composite nonwoven fabric according to the embodiment of the present invention will be described.
FIG. 1A is a diagram schematically showing a cross-sectional structure of the composite nonwoven fabric WP according to the present invention.
The composite non-woven fabric WP has a structure in which a pulp fiber web PFW is laminated on a spunbonded non-woven fabric SW and integrated. This structure can be formed by water flow confounding treatment as described later.

The composite non-woven fabric WP has a basis weight of 51.0 g / m ² or more and less than 85.0 g / m ² and a thickness of 0.28 mm or more and less than 0.48 mm. This composite non-woven fabric WP is designed as a thin non-woven fabric having a relatively low basis weight as compared with a conventional general composite non-woven fabric. Such a low basis weight composite non-woven fabric WP is most suitable for wiping liquids having various viscosities used in homes, food factories, etc., is comfortable to wipe, and has a relatively weak force. However, it has the advantage of being able to be wiped clean.

The upper pulp fiber web PFW is obtained by the airlaid method. When the pulp fiber web PFW is supplied by the air-laid method, the manufacturing cost can be suppressed and the mixing of foreign substances can be prevented as compared with the case where the pulp fiber web PFW is diverted and manufactured by the wet papermaking method.
On the other hand, as described above, the pulp fiber web provided by the airlaid method is concerned about fiber falling off, but the present inventors have an effect of fiber falling off by adding a paper strength agent to the pulp fiber web. The present invention was reached after confirming that it can be prevented.
As the paper strength agent, it is desirable to use a so-called wet paper strength agent, and for example, polyamide epichlorohydrin type, polyamide epoxy type, polyamide polyamine type and the like can be preferably used. The amount of the paper strength agent added in terms of solid content is preferably 0.1 to 2.0%, more preferably 0.3 to 1.5%, based on the solid weight of the pulp fiber web.
By setting the addition amount within the above range, the pulp fibers can be suppressed from falling off, and the composite non-woven fabric can be used with a soft wiping feeling (if the addition amount of the paper strength agent is too large, it becomes hard and the usability is inferior). The amount of the paper strength agent added can be measured using a trace nitrogen meter.
In addition, the amount of the paper strength agent added to the pulp fibers in the composite non-woven fabric that has become a product can be confirmed, for example, by the following steps.
1) Solid content weight of pulp: Cellulase or the like is allowed to act on the product to dissolve and remove the pulp.
Check the weight of the pulp by subtracting the weight of the remaining non-woven fabric from the weight of the product.
2) Amount of paper strength agent added: The amount of paper strength agent added is confirmed by measuring the pulp part with a "trace nitrogen meter".
3) From the above 1) and 2), confirm the addition amount converted by the solid content of the paper strength agent with respect to the solid weight of the pulp fiber web.

FIG. 1 (b) shows a composite when a pulp fiber web obtained by diverting the sheet manufacturing technique by the wet papermaking method is used for comparison with the composite non-woven fabric WP according to the present invention shown in FIG. 1 (a). It is a figure which showed typically about the type non-woven fabric. In the composite non-woven fabric of FIG. 1 (b), fiber shedding is suppressed in a state where the paper strength agent SA is added to the entire pulp fiber web. However, as described above, there is a problem of foreign matter contamination.
On the other hand, the composite non-woven fabric WP according to the present invention shown in FIG. 1A shows the suppression of fiber shedding and the inclusion of foreign matter by adding the paper strength agent SA to the pulp fiber web PFW obtained by the airlaid method. Prevention can be realized at the same time.

The composite non-woven fabric WP according to the present invention shown in FIG. 1A is manufactured by applying a liquid paper strength agent SA from the pulp fiber web PFW side. As a result, more paper strength agent SA is present on the surface side of the pulp fiber web PFW, that is, as shown in FIG. 1A, the paper strength agent SA is unevenly distributed on the surface side of the pulp fiber web PFW. It is in a state of being. The state of FIG. 1 (a) suppresses fiber shedding by using a relatively small amount of paper strength agent as compared with the state of FIG. 1 (b).
Therefore, since the composite nonwoven fabric WP according to the present invention efficiently uses the paper strength agent SA, the manufacturing cost can be suppressed in this respect as well.

The composite non-woven fabric WP preferably has a drip water absorption of 0.5 to 4.0 seconds and a water retention capacity (TWA: Total Water Absorbency) of 220 to 380 g / m ² , and the wet taber value by the Taber test is It is at least 5 times, preferably 5 times or more.
A composite non-woven fabric WP within the above condition range can satisfy the water retention and durability required for products such as wipers.

Further, the basis weight of the spunbonded nonwoven fabric SW contained in the composite nonwoven fabric WP of the present invention is preferably ^{7.0 to 20.0 g / m 2.} Further, the spunbonded nonwoven fabric SW includes a plurality of fusion points connecting the resin fibers forming the spunbonded nonwoven fabric, and the area of one fusion point is 0.10 to 0.50 mm ² . It is desirable that the area ratio of the fusion point per unit area is 7 to 20% and the number of the fusion points per unit area is 10 to 150 pieces / cm ^2. The spunbonded non-woven fabric SW satisfying such conditions can stably maintain the shape of the composite non-woven fabric WP. The shape of the fusion point is not limited, but for example, a circular shape, an elliptical shape, a polygonal shape, or the like can be adopted.
A composite non-woven fabric WP produced by using a spunbonded non-woven fabric within the above condition range has moderately soft strength and excellent usability.

The material of the spunbonded non-woven fabric SW may be one selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more selected. It is preferable to use polypropylene.

The basis weight of the pulp fiber web PFW ^{is preferably 40.0 to 70.0 g / m 2} , and the weight composition ratio of the spunbonded non-woven fabric SW and the pulp fiber web PFW is 40/60 to 10/90 ( It is desirable to design so that it is wt%).
The pulp fiber web PFW is preferably composed of fibers of softwood bleached kraft pulp selected from the group from radiata pine, slash pine, southern pine, lodge pole pine, spruce and Douglas fur.
The composite non-woven fabric according to the present invention formed so as to satisfy the above conditions can prevent the pulp fibers from falling off even if the pulp fiber web obtained by the airlaid method is used, and can prevent foreign matter from being mixed in and reduce the manufacturing cost. You can expect it.

Hereinafter, a manufacturing apparatus suitable for manufacturing the composite nonwoven fabric of the present invention will be described with reference to FIG.
First, a schematic configuration of the composite nonwoven fabric manufacturing apparatus 1 will be described. The manufacturing apparatus 1 shown in FIG. 2 is provided with an air-laid apparatus 2 for supplying a pulp fiber web, a spunbonded non-woven fabric supply device 3 for supplying a spunbonded non-woven fabric, and a suction device 4 on the upstream side. The suction device 4 is arranged so as to face the lower side of the air raid device 2.
In the transport direction TD of the web, downstream of these devices 2, 3 and 4, in order from the upstream side, a water flow entanglement device 5 for injecting a water jet for performing water flow entanglement processing, and a suction device for performing dehydration processing. 6. The drying device 7 is arranged. A winding device 8 for winding the continuously manufactured composite non-woven fabric WP is provided downstream of the drying device 7.

The air-laid device 2 is provided with a defibrating machine 21 for defibrating raw pulp RP, which is a sheet of dense fibers, and a blower (not shown), and defibrated pulp fiber PF to the air-laid hopper 23. It has a duct 22 for carrying the pulp.

Further, an air-laid hopper 23 is arranged on the downstream side of the duct 22. Inside the air-laid hopper 23, the pulp fibers in the defibrated state are dispersed and lowered, and the pulp fiber web PFW is gradually formed at the stacking position 24 set on the lower surface.
As described above, the air-laid device 2 is a device and equipment capable of supplying the pulp fiber web in a dry manner, and can suppress the equipment cost as compared with the device for producing the pulp fiber web in a wet manner by applying the wet papermaking method. Further, in the air-laid device 2, a closed system space is provided from defibration to dispersion and descent of the pulp to prevent foreign matter from being mixed in. Therefore, as compared with the case where the pulp fiber web is supplied by the wet papermaking method, foreign matter is introduced. Mixing can be suppressed overwhelmingly low.

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 has a suction force (negative pressure) on the pulp fiber web PFW with respect to the stacking position 24. It has been set.
Note that FIG. 2 illustrates a case where the pulp fiber web PFW is formed by arranging the air-laid hopper 23 and the suction device main body 41 one by one in one stage. However, the present invention is not limited to this, and the air-laid hopper 23 and the suction device main body 41 may be arranged in two or more stages according to the basis weight (basis weight) and the manufacturing speed of the pulp fiber web PFW.

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 web PFW on which the pulp fiber PF is deposited can be placed at the stacking position 24 and is conveyed to the downstream side. However, the pulp fiber web PFW is not placed directly 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).

The spunbonded non-woven fabric supply device 3 is arranged below the airlaid device 2 and upstream of the suction device 4. A spunbonded non-woven fabric SW prepared in advance is set in the spunbonded non-woven fabric supply device 3 in a roll shape. That is, as described above, the designed spunbonded non-woven fabric SW is wound into a roll shape during manufacturing, and this is drawn out from the spunbonded non-woven fabric supply device 3 and rides on the above-mentioned transport wire 43. It is designed to be transported to the stacking position 24.

The pulp fiber web PFW described above is placed on the spunbonded non-woven fabric SW located at the lamination position 24. At that time, at the lamination 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 spunbonded non-woven fabric SW and the pulp fiber web PFW on the conveying wire 43. Therefore, the preliminary laminated body PWeb (laminated web) in which the spunbonded non-woven fabric SW and the pulp fiber web PFW are laminated is conveyed to the downstream side.
By controlling the supply amount of the pulp fiber web PFW on the spunbonded nonwoven fabric SW when the preliminary laminate PWeb is formed as described above, the pulp fibers contained in the composite nonwoven fabric produced by this apparatus The basis weight of the web PFW is, for example, 40.0 to 70.0 g / m ^2, and it is desirable to design the web PFW so that the ratio of the pulp fiber web is higher than that of the conventional general composite non-woven fabric. The basis weight of the spunbonded non-woven fabric SW is, for example, 7.0 to 20.0 g / m ² , and the produced composite non-woven fabric (spunbonded non-woven fabric SW + pulp fiber web PFW) is 51.0 g / m ² or more 85. It shall be less than 0 g / m ^2. By appropriately adjusting the transport speed of the pulp fiber web and the supply amount of the pulp fiber web PFW per hour, and confirming the basis weight of the pulp fiber web PFW of the manufactured composite non-woven fabric, the basis weight can be within the desired range. It may be set so as to be. The transport speed of the pulp fiber web is preferably 150 to 300 m / min, for example.

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 fibers of the upper pulp fiber web PFW are in a dense state. However, if the preliminary laminated body PWeb is conveyed and thrown into the water flow confounding device 5 on the downstream side as it is, a part of the pulp fiber PF may be blown up by the water jet (high pressure water flow).
Therefore, in the present manufacturing apparatus 1, the sandwiching roller 28 for stabilizing the placement state of the pulp fiber web PFW on the spunbonded nonwoven fabric SW by sandwiching the preliminary laminated body PWeb from above and below, and the upstream of the water flow confounding apparatus 5. A pre-wet device 30 for applying moisture to prevent fiber scattering is provided on the side. 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 pulp fiber web PFW). It is configured to include a suction device 32.

Note that FIG. 2 illustrates a case where the pre-wet device 30 is provided as a new device in front of the water flow confounding device 5 as described above, but the present invention is not limited to this. Regarding a plurality of sets including the water jet head 51 and the suction device 52, which will be described later, included in the water flow confounding device 5, the design may be changed so that the set located at the head is diverted as the pre-wet device 30. In this case, it is sufficient to adjust so that the low-pressure water mist is sprayed from the head water jet head 51.
In the case of the water flow entanglement device 5 in which a sufficient number of sets of the water jet head 51 and the suction device 52 are secured to perform the water flow entanglement process, the head water jet head 51 and the suction device 52 are pre-pressed as described above. Utilizing it as a wet device is effective in controlling the cost of equipment.

Then, in the water flow entanglement device 5, the entanglement of the pulp fibers is promoted by spraying a high-pressure water jet on the pretreated laminated body PWeb of the sandwiching roller 28 and the pre-wet device 30 which are the pretreatment portions. As a result, the integration of the pulp fiber web PFW layer located on the upper side and the spunbonded non-woven fabric SW layer located on the lower side is promoted (water flow entanglement treatment).
In the water flow confounding device 5 exemplified in FIG. 2, water jet heads 51 are arranged in multiple stages (four stages are illustrated in FIG. 2) along the transport direction TD.
Although FIG. 2 does not show the state of the nozzles provided in the water jet head 51 extending in the direction perpendicular to the transport direction TD (CD in the width direction of the web), a plurality of nozzles are provided in the width direction. Water jet nozzles are located at appropriate positions. The hole diameter φ of this water jet nozzle is preferably 0.06 to 0.15 mm. The distance between the water jet nozzles is preferably 0.4 to 1.0 mm.

It is desirable that the water pressure at the time of performing the water flow entanglement treatment is set in consideration of the basis weight of the pulp fiber web PFW and the spunbonded non-woven fabric SW. 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 jet head 51. While spraying the high-pressure water jet emitted from the water jet head 51 onto the pulp fiber web PFW located on the upper side, the suction force of the suction device 52 is applied to the lower side of the spunbonded non-woven fabric SW located on the lower side. Due to the cooperative action of the water jet head 51 and the suction device 52, the pulp fibers on the pulp fiber web PFW side have entered the lower spunbonded non-woven fabric SW, or penetrated the spunbonded non-woven fabric SW to the opposite side. It is presumed that a non-woven fabric is formed. The action promotes the integration of the two layers.

The transport wire 55 is also arranged in the water flow entanglement 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 confounding device 5. The transfer wire 55 is arranged so as to pass between the water jet head 51 of the water flow confounding device 5 and the suction device 52 from the upstream side to the downstream side.
Therefore, the preliminary laminate 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 leaves the water flow entanglement device 5, the pulp fiber on the upper side is subjected to. Sufficient entanglement treatment between the web PFW layer and the lower spunbonded non-woven fabric SW layer is realized.
The composite non-woven fabric immediately after leaving the water flow entanglement device 5 is in a wet state, and the bonds between the pulp fibers and the like are not sufficiently established.

Therefore, as shown in FIG. 2, the downstream side of the water flow entanglement device 5 is subjected to a dehydration treatment for sucking and removing the water remaining on the pulp fiber web, and then a drying treatment to complete the production of the composite non-woven fabric WP. The suction device 6 and the drying device 7 of the above are deployed. In this way, if the dehydration treatment and the drying treatment are performed by the suction device 6 and the drying device 7 in the subsequent stage of the production of the composite non-woven fabric WP, the composite non-woven fabric can be efficiently manufactured, and the composite non-woven fabric after water flow entanglement is produced. A dry composite non-woven fabric can be produced without applying a large external pressure to the fabric.
Here, the composite non-woven fabric WP of the present invention is designed so as to suppress pulp fibers leaving the pulp fiber web PFW. Therefore, the paper power agent adding device 9 for adding the paper power agent is arranged in the present manufacturing apparatus 1.

The suction device 6 is, for example, a vacuum type and dehydrates the composite non-woven fabric after water flow confounding from the lower side. A paper strength agent adding device 9 is arranged above the suction device 6 with the conveyed composite non-woven fabric WP in between.
The paper strength agent adding device 9 spray-applies the paper strength agent from the upper side of the composite non-woven fabric WP after being composited by the water flow confounding device 5, that is, from the pulp fiber web PWF side. Since the paper strength agent is applied from the surface side of the pulp fiber web of the composite non-woven fabric that has been composited, the paper strength agent is unevenly distributed on the surface layer side of the pulp fiber web PWF. Therefore, a relatively small amount of paper strength agent acts efficiently as compared with the case where the whole is coated or impregnated, and functions to connect the pulp fibers to each other. Since the drying process is performed downstream from the paper strength agent adding device 9, there is no waste such as the spray-coated paper strength agent being washed away and flowing out.
Since there is a suction device on the lower side, it is advantageous for the sprayed and liquefied paper strength agent to penetrate into the pulp fiber web, which can more reliably prevent the pulp fiber from falling off. .. With respect to the paper strength agent adding device 9, it is also possible to easily control the amount of the paper strength agent by checking the state of the manufactured composite non-woven fabric WP.

The water content of the pulp fiber web PWF portion (% of the water content at the inlet immediately before entering the paper power agent adding device 9) when the paper power agent is spray-applied by the paper power agent adding device 9 is, for example, 120 to 400%. It is preferable to adjust so as to be. When the traveling pulp fiber web has an appropriate moisture in the above range, the scattering of the paper strength agent during spray application is suppressed, the yield of the paper strength agent is increased, and the paper strength agent is easily adapted to the pulp fiber web. Therefore, the effect of suppressing fiber dropout can be more exerted.
Further, it is preferable to dehydrate the paper within 10 seconds after applying the paper strength agent by spraying. That is, as described with reference to FIG. 2, the paper strength agent may be dehydrated directly under the spray coating, or may be dehydrated at a position slightly distant from the spray coating (a position within a transport time of 10 seconds). In short, the optimum time (however, within 10 seconds after spray application) may be appropriately determined by confirming the permeation and diffusion state of the chemical solution into the pulp fiber web PWF when the paper strength agent is spray-applied. By going through the dehydration process at the same time as the spray application of the paper strength agent or within 10 seconds after the spray application, the components of the paper strength agent can easily penetrate into the pulp fiber web, and the effect of suppressing fiber dropout is greater. Can be demonstrated.
In the above, the case of spray coating as a form of adding the paper strength agent to the pulp fiber web PWF has been described, but the case of adding the paper strength agent is not limited to this, and the forms of addition include size press, roll coating, gravure coating, rod bar coating, air knife coating and the like. May be adopted.

The amount of the paper strength agent added in the pulp fiber web PWF in terms of solid content is preferably 0.1 to 2.0% with respect to the solid weight of the pulp fiber web PWF, and more preferably. , Pulp fiber web PWF is added so as to be 0.3 to 1.5% based on the solid weight. If the amount of the paper strength agent added is too small, the effect of suppressing the fiber dropout is reduced, and conversely, if the amount added is too large, the fiber dropout can be suppressed, but the usability (softness) deteriorates.
The paper strength agent preferably has a concentration of 0.5 to 2.0%, more preferably 0.7 to 1.5%, and a discharge pressure of 0.1 to 1.0 Mpa, more preferably 0. . Spray-apply to pulp fiber web PWF as 3-0.8 Mpa. When the pressure is low, the wind generated by the pulp fiber web being transported causes the paper force agent to scatter, resulting in a decrease in yield. On the other hand, if the pressure is too high, the paper surface of the pulp fiber web being conveyed will bounce off, and the yield will also deteriorate in this case as well.
Then, as the paper strength agent, at least one can be selected and used, for example, from polyamide epichlorohydrin type, polyamide epoxy type, polyamide polyamine type and the like. It is preferable to use a polyamide epichlorohydrin type, and for example, WS4030, WS4038, WS4027 and the like, which are wet paper strength agents manufactured by Seiko PMC Corporation, can be used. By using a polyamide epichlorohydrin-based paper strength agent, the effect of suppressing fiber shedding can be preferably obtained, and the feeling of use of the composite non-woven fabric is improved.

A drying device 7 is further installed downstream of the suction device 6 and the paper strength agent adding device 9, and the composite non-woven fabric WP provided with the pulp fiber web PWF to which the paper strength agent is spray-coated is dried. NS. As the drying device 7 here, it is preferable to use a non-compression type dryer, preferably an air-through dryer. In FIG. 2, 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) flows from the outer periphery to the center of the dryer body. It is better to have a configuration that sucks toward the side.
The composite non-woven fabric WP continuously produced in this way is wound on the roll 81 of the winding device 8 after drying.

According to the composite non-woven fabric manufacturing apparatus 1 described above, it is possible to manufacture a composite non-woven fabric with less fiber loss even when the pulp fiber web by the airlaid method is used. In addition, the yield of the paper strength agent used can be increased as compared with the conventional case, and the paper strength agent can be efficiently used to suppress the manufacturing cost. In addition, it is possible to suppress the mixing of foreign substances into the composite non-woven fabric WP.

(Example)
Hereinafter, the composite non-woven fabric of the example manufactured by the above manufacturing apparatus will be described.
For composite non-woven fabric, specify the basis weight, thickness, drip water absorption, water retention (TWA), wet taber value (number of times), and amount of paper strength agent added, and for spunbonded non-woven fabric SW, the basis weight and fusion point. The area, area ratio, number and material were specified, the basis weight of the pulp fiber web PFW was specified, and the weight composition of the spunbonded non-woven fabric SW and the pulp fiber web PFW was specified.
The drip water absorption is determined by the Japan Technical Association of the Pulp and Paper J. TAPPI No. Measurement was performed according to 32-2: 2000 (paper-water absorption test method-Part 2: dropping method). The wet tabor value is the value when a wet non-woven fabric is tested using a friction wheel H-18 with a tabor testing machine conforming to the tabor method described in the fabric test method for woven fabrics and knitted fabrics specified in JIS L 1096. The value (number of times) was used.
As shown in Table 1 below, the composite non-woven fabrics of Examples 1 to 3 and Comparative Examples 1 to 3 were manufactured, and the composite non-woven fabric had a small amount of shedding fibers (deterrence of shedding fibers), foreign matter contamination, and the like. The sensory evaluation at the time of use was performed for the feeling of use (softness). As the paper strength agent, WS4030 (polyamide epichlorohydrin type) manufactured by Seiko PMC Corporation was used in both the airlaid method and the wet papermaking method. Southern pine is used for the pulp fiber web in all of the composite non-woven fabrics.
1) Low amount of shed fibers: Almost no shed fibers when using composite non-woven fabric (excellent ◎)
Although some fallen fibers are seen, it can be used without problems (good ○)
Difficult to use due to many fallen fibers (impossible ×)
2) Foreign matter mixed: Foreign matter on the surface of the composite non-woven fabric No foreign matter can be seen in the range of 1m x 1m (good ○)
At least one foreign matter of color other than white ^{of 1 mm 2} or more is recognized in the range of 1 m x 1 m (impossible x)
3) Usability (softness): Usability and softness when the composite non-woven fabric is used for wipes Soft and good usability (excellent ◎)
It feels a little hard, but it can be used without problems (good ○)
Hard and inferior in usability (impossible ×)

As shown in Table 1 above, Examples 1 to 3 can be provided as a product, but in Comparative Examples 1 to 3, it is not possible to suppress fiber falling off, mix foreign substances, or evaluate the sensory feeling of use. there were.
In Examples 1 to 3 above, the basis weight is 51.0 g / m ² or more and less than 85.0 g / m ² , the thickness is 0.28 mm or more and less than 0.48 mm, and the solid content of the paper strength agent is used. The converted addition amount is in the range of 0.1 to 2.0% with respect to the solid weight of the pulp fiber web.

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 Spunbonded non-woven fabric supply equipment 4 Suction equipment 5 Water flow entanglement equipment 6 Suction equipment 7 Drying equipment 8 Winding equipment 9 Paper force agent addition equipment 21 Defibering machine 22 Duct 23 Air-laid hopper 24 Lamination position 28 Holding roller 30 Pre-wet device 31 Spray nozzle 32 Suction device 41 Suction device body 42 Suction section 43 Transport wire 51 Water jet head 52 Suction device 55 Transport wire SW Spanbonded non-woven fabric PF Pulp fiber PFW Pulp fiber Web PWeb Preliminary laminate ( Laminated web)
WP composite non-woven fabric TD transport direction CD width direction SA paper force agent

Claims (9)

A composite non-woven fabric in which pulp fiber webs obtained by the air-laid method are laminated and integrated on a spunbonded non-woven fabric.
A paper strength agent is added to the pulp fiber web,
The basis weight of the composite non-woven fabric is 51.0 g / m ² or more and less than 85.0 g / m ² , the thickness is 0.28 mm or more and less than 0.48 mm, and the addition amount converted by the solid content of the paper strength agent is A composite non-woven fabric characterized by being 0.1 to 2.0% with respect to the solid weight of the pulp fiber web. The composite nonwoven fabric according to claim 1, wherein the paper strength agents are unevenly distributed so as to increase on the surface layer side of the pulp fiber web. The composite type according to claim 1 or 2, wherein the drip water absorption is 0.5 to 4.0 seconds, the water retention amount is 220 to 380 g / m ^{2, and the wet taber value is at least 5 times.} Non-woven fabric. The basis weight of the spunbonded non-woven fabric is 7.0 to 20.0 g / m ² .
The spunbonded nonwoven fabric contains a plurality of fusion points connecting the resin fibers forming the spunbonded nonwoven fabric, and the area of one fusion point is 0.10 to 0.50 mm ^2. The composite according to any one of claims 1 to 3, wherein the area ratio of the fusion point per unit area is 7 to 20%, and the number of fusion points per unit area is 10 to 150 pieces / cm ^2. Molded non-woven fabric. The material of the spunbonded non-woven fabric is one selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more selected. The composite nonwoven fabric according to any one of 1 to 4. The basis weight of the pulp fiber web is 40.0 to 70.0 g / m ² .
The composite nonwoven fabric according to any one of claims 1 to 5, wherein the weight composition ratio of the spunbonded nonwoven fabric and the pulp fiber web is 40/60 to 10/90 (wt%). 13. The composite type non-woven fabric according to any one. A pulp fiber web supplied by an airlaid method is placed on the spunbonded non-woven fabric and then subjected to a water flow entanglement treatment, and after the water flow entanglement treatment, a paper strength agent is added to the pulp fiber web to carry out claims 1 to 7. A method for producing a composite nonwoven fabric, which comprises producing the composite nonwoven fabric according to any one of the above. The method for producing a composite nonwoven fabric according to claim 8, wherein the addition of the paper strength agent is spray coating.

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