JP2022138533A - Conjugate type nonwoven fabric and manufacturing method thereof - Google Patents

Abstract

To provide a conjugate type nonwoven fabric suppressed in generation of paper powder even when used in any of a dry state or a wet state.SOLUTION: A conjugate type nonwoven fabric is composed of pulp fiber webs laminated onto and integrated with a spun-bonded nonwoven fabric. The conjugate type nonwoven fabric has basis weight of 52.0 to 95.0 g/m2, thickness of 0.20 to 0.42 mm, density of 0.19 to 0.25 g/m3, and a TS7 value of 15.0 dBV2 rms or less on the pulp fiber web side measured by a tissue softness measuring device TSA.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite nonwoven fabric obtained by hydroentangling a pulp fiber web and a spunbond nonwoven fabric.

A composite nonwoven fabric composed of a pulp fiber web and a spunbonded nonwoven fabric has both liquid absorbency based on pulp fibers and strength based on a spunbonded nonwoven fabric. It is widely used in various applications such as personal wipers such as.

For example, as disclosed in Patent Document 1, a pulp fiber web and a spunbond nonwoven fabric are laminated and then integrated by a hydroentangling treatment in which a high-pressure water jet is applied. Since the spunbond nonwoven fabric is excellent in strength, it functions as a backing layer for the manufactured composite nonwoven fabric. On the other hand, pulp fiber webs have an excellent liquid absorption function. Therefore, such a composite nonwoven fabric is an excellent composite type that has both the advantages of a pulp fiber web that has good absorbency for both aqueous and oily liquids and the spunbond nonwoven fabric that has excellent strength. It can be provided to the consumer as a nonwoven fabric.

Japanese Patent No. 2533260

As described above, when a pulp fiber web is supplied on a spunbonded nonwoven fabric in a dry or wet manner and then hydroentangled, the pulp fibers on the spunbonded nonwoven fabric are oriented in various directions (three-dimensionally) under the influence of water flow. randomly). Then, it is dried to obtain a composite nonwoven fabric as a product. Some of the pulp fibers arranged in the thickness direction of such a composite nonwoven fabric are found to be protruded. The fibers arranged in the thickness direction are directly molded into a bulky shape through the drying process. The bulky nonwoven fabric is used in either a dry state or a wet state, and at that time, the protruding fibers are partially abraded to become fine paper dust (fine pulp fibers). The phenomenon of falling down has been confirmed. Such a nonwoven fabric is inferior in value as a product.
However, conventionally, there is no established technology capable of effectively suppressing the above paper dust.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a composite nonwoven fabric that can suppress the generation of paper dust when used in either a dry state or a wet state.

The above object is a composite nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbond nonwoven fabric, and has a basis weight of 52.0 to 95.0 g/m ² and a thickness of 0.20 to 0.20 g/m 2 . 42 mm and a density of 0.19 to 0.25 g/m ³ , and a TS7 value measured by a tissue softness measuring device TSA on the pulp fiber web side of 15.0 dBV ² rms or less. This can be achieved with a type nonwoven.

It is preferable that the drip water absorbency is 0.5 to 3.0 seconds and the water absorption amount (T.W.A.) is 250 to 450 g/m ² .
Further, it is preferable that the Wet Taber value is 5 times or more.

Further, the basis weight of the pulp fiber web is 40.0 to 83.0 g/m ² , and the weight composition ratio of the spunbond nonwoven fabric and the pulp fiber web is 40/60 to 10/90 (wt%). It is preferable to have

In addition, the spunbond nonwoven fabric has a basis weight of 7.0 to 20.0 g/m ² and is formed to include a plurality of fusion points that join spun resin fibers, It is preferable that the area of one fusion point is 0.10 to 0.50 mm ² , the area ratio of the fusion points per unit area is 7 to 20%, and the number of fusion points is 10 to 150/cm ² .

The spunbond nonwoven fabric can be formed of one selected from the group consisting of nylon, vinylon, polyester, acryl, polyethylene, polypropylene and polystyrene, or a mixture of two or more.
is preferred.

The pulp fiber web is preferably fibers of bleached softwood kraft pulp selected from the group consisting of radiata pine, slash pine, southern pine, lodgepole pine, spruce and Douglas fir.

The above object is a method for producing a composite nonwoven fabric in which a pulp fiber web is laminated on a spunbond nonwoven fabric and integrated, and the laminate is formed by promoting the integration of the pulp fiber web and the spunbond nonwoven fabric. and a drying step of drying the laminate after the hydroentanglement step, wherein after the hydroentanglement step, the laminate in the wet state before the drying step is pressed with a press roll. It can also be achieved by a method for producing a composite nonwoven fabric characterized by further including a pressing step.

In the wet pressing step, the roll equivalent calculated by the formula (roll equivalent diameter)=(upper press roll diameter)×(lower press roll diameter)/{(upper press roll diameter)+(lower press roll diameter)} Using an upper press roll and a lower press roll with a diameter of 75 to 300 mm, the conveying speed is set to 100 to 280 m/min, the gap between rolls is set to 0 to 0.3 mm, and the roll nip pressure is set to 1.0 to 8.0 MPa. preferably.

The composite nonwoven fabric according to the present invention, in which the basis weight, thickness, density, and the TS7 value measured by the tissue softness measuring device TSA on the pulp fiber web side are set within a predetermined range, the generation of paper dust is suppressed. It can be provided as a non-woven product. Moreover, according to the production method of the present invention, the composite nonwoven fabric can be produced efficiently.

1 shows an apparatus implementing a method for manufacturing a composite nonwoven fabric; FIG.

A composite nonwoven fabric according to one embodiment of the present invention will be described below.
The inventors of the present application conducted intensive studies on composite nonwoven fabrics, and measured basis weight (g/m ² ), thickness (mm) and density (g/m ³ ), and tissue softness on the pulp fiber web side. The inventors have confirmed that a composite nonwoven fabric having a TS7 value (dBV ² rms) determined by the apparatus TSA within a predetermined range can suppress the generation of paper dust, leading to the present invention. Such a composite nonwoven fabric can be produced by subjecting the laminate in a wet state after the hydroentanglement step to a wet press treatment using press rolls.

The composite nonwoven fabric according to the present invention has a basis weight of 52.0 to 95.0 g/m ² , preferably 60.0 to 85.0 g/m ² , and a thickness of 0.20 to 0.42 mm, preferably It is set at 0.28-0.40 mm, and the density is set at 0.19-0.25 g/m ³ , preferably 0.21-0.25 g/m ³ . The TS7 value measured by a tissue softness measuring device TSA on the pulp fiber web side is set to 15.0 dBV ² rms or less, preferably 12.0 dBV ² rms or less.

The TS7 value was measured using a tissue softness measuring device TSA (Tissue Softness Analyzer). In the tissue softness measuring device TSA, when a composite nonwoven fabric (sample) placed on a sample table with the pulp side facing up is pressed against a rotor with blades and rotated, the vibration data detected by various sensors is measured. By analyzing and parameterizing (TS value), the softness (softness) of nonwoven fabrics is usually quantitatively evaluated. It is the product name.
In the measurement by the tissue softness measuring apparatus TSA, for example, the vibration of the sample table is measured by a vibration sensor installed inside the sample table, and the vibration frequency is analyzed and parameterized (TS value). The frequency of vibration depends on the structural dimensions, such as creep and embossing, and the number of rotations of the blade. Induction of horizontal vibration of the blade itself (resonance frequency: eg 6500 Hz) occurs due to momentary interception by the ridges of the sample and vibration of the blade as it traverses the surface of the sample. Resonance frequency: Let the intensity of the maximum peak of the spectrum including 6500 Hz (before and after 6500 Hz) be the TS7 value (dBV ² rms).

In addition, emtec measurement system can be used as software for vibration analysis and parameterization (TS value). This software is equipped with various algorithms (e.g., Base Tissue, Facial, TP, etc.), and the TS7 value is automatically acquired on the software, and various algorithms are calculated from this TS7 value or basis weight, thickness, number of plies, etc. The HF (hand feel) value is calculated according to the type of In the present invention, the TS7 value is defined instead of the HF value, and any algorithm may be used as long as the measurement conditions are satisfied, and the TS7 value does not change depending on the type of algorithm. In the present invention, the TS7 value, which has been an index of softness in the past, is used to evaluate the state of fibers protruding from the surface of the pulp fiber web. The intention will be described later.

As described above, the basis weight (g/m ² ), thickness (mm), density (g/m ³ ), and the TS7 value (dBV ² rms) on the pulp fiber web side are within the predetermined preferred ranges. The designed composite nonwoven fabric of the present invention can be a composite nonwoven fabric that generates less paper dust and has good water absorbency. The thickness of the composite nonwoven fabric can be measured, for example, with a Peacock paper thickness meter under a load of 37.85 g/cm ² .
Furthermore, drip water absorption, which is an index of water absorption performance, is set to 0.5 to 3.0 seconds, and water absorption (TWA: Total Water Absorbency) is set to 250 to 450 g / m ² . Some are preferred. The drip water absorption is based on the water absorption speed test specified in JIS L 1907, and the time (seconds) from when a 0.1 ml water droplet reaches the surface of the test piece until the specular reflection of the test piece disappears. It can be obtained by measurement. Also, the above TWA can be determined as follows. First, the nonwoven fabric is cut into a square of 75×75 mm to prepare a sample piece, and the dry weight is measured. Next, after immersing this sample piece in distilled water for 2 minutes, in a vessel saturated with water vapor, one corner of the sample piece was placed on the top of the upper side, and this top and the two adjacent corners and hang it in a stretched state (100% RH), leave it for 30 minutes, and measure the weight after draining. A paper towel cut into 3×38 mm is used for draining. Then, the measured value can be obtained by converting it into a water retention amount (g/m ² ) per 1 m ² of the sample piece.
Further, it is preferable that the wet taber value, which is an index of durability, is designed to be 5 times or more. Using a Taber tester specified by JIS, a sample wetted with water is attached to a rotating horizontal disc, and a pair of friction wheels made of bonded abrasives are applied under a specified load to wet the sample. It preferably has an abrasion resistance with a Taber value of at least 5 times.

The basis weight of the pulp fiber web is 40.0 to 83.0 g/m ² , and the weight composition ratio of the spunbond nonwoven fabric and the pulp fiber web is 40/60 to 10/90 (wt%). is preferred. Those within this range are excellent in water absorption performance and excellent in shape stability of the composite nonwoven fabric.
Further, the basis weight of the spunbond nonwoven fabric is preferably 7.0 to 20.0 g/m ² . In addition, the spunbond nonwoven fabric is formed including a plurality of fusion points that join spun resin fibers, and the area of one fusion point is 0.10 to 0.50 mm ² , and the unit of the fusion point is It is preferable that the area ratio per area is 7 to 20% and the number of particles is 10 to 150/cm ² . Such a spunbonded nonwoven fabric has an appropriate rigidity and is suitable as a spunbonded nonwoven fabric to be used in combination with a pulp fiber web for a composite nonwoven fabric. The shape of the fusion point is not particularly limited, and may be circular, elliptical, polygonal, or the like.

Preferably, the spunbond nonwoven fabric is made of one selected from the group consisting of nylon, vinylon, polyester, acryl, polyethylene, polypropylene and polystyrene, or a mixture of two or more. Among these, it is preferable to use polypropylene.
As for the pulp fiber web, it is preferable to employ one formed of softwood bleached kraft pulp fibers selected from the group consisting of radiata pine, slash pine, southern pine, lodgepole pine, spruce and Douglas fir. .

Below, the process of manufacturing the above-described composite nonwoven fabric of the present invention will be described. The composite nonwoven fabric of the present invention is efficiently manufactured by subjecting the laminate in a wet state after the hydroentanglement step to a predetermined wet press treatment using press rolls to efficiently produce a composite nonwoven fabric that suppresses the generation of paper dust. be able to. Here, first, the main configuration of the manufacturing apparatus for manufacturing the composite nonwoven fabric WP will be described, and then the wet press process according to the present invention will be described.

An apparatus 1 for manufacturing a composite nonwoven fabric shown in FIG. 1 includes an airlaid device 2, a spunbond supply device 3 for supplying a spunbond nonwoven fabric, and a suction device 4 on the upstream side. The suction device 4 is arranged to face the lower side of the air raid device 2 .
Downstream of these devices 2, 3, and 4 in the web transport direction TD are, in order from the upstream side, a hydroentangling device 5 that injects water jets for hydroentangling treatment, a suction device 6, and a drying device 7. are placed. Downstream of the drying device 7, a winding device 8 is further provided for winding the continuously manufactured composite nonwoven fabric WP.

The air-laid device 2 includes a defibrator 21 that defibrates the sheet-like raw material pulp RP in which the fibers are densely packed into pulp fibers, and an air blower (not shown) that feeds the defibrated pulp fibers PF to an air-laid hopper 23 . and a duct 22 for conveying.

An air raid hopper 23 is arranged downstream of the duct 22 . The air-laid hopper 23 is designed so that the disentangled pulp fibers descend while being dispersed, and are gradually piled up at a stacking position 24 set on the lower surface to form a pulp fiber web PFW.
A suction device 4 is arranged below the stacking position 24 so as to face it. More specifically, the suction device 4 has a suction portion 42 on the upper surface of the device main body 41, and the suction portion 42 moves toward the stacking position 24 so as to apply a suction force (negative pressure) to the pulp fiber web PFW. have been set.
Note that FIG. 1 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 arrangement is not limited to this, and the arrangement may be changed so that the air laid hopper 23 and the suction device main body 41 are arranged in two or more stages according to the basis weight (basis weight) and production speed of the pulp fiber web PFW.

A carrier wire 43 for carrying the web is arranged around the suction device 4 . The conveying wire 43 is arranged such that the pulp fiber web PFW on which the pulp fibers PF are piled up at the stacking position 24 can be placed thereon and is conveyed downstream. However, the pulp fiber web PFW is not placed directly on the conveying wire 43 . This will become clear in the description below.
The conveying wire 43 is formed with an open mesh (mesh) so that the suction force of the suction portion 42 extends to the opposite side (upper side).

Below the airlaid device 2 and upstream of the suction device 4, a spunbond supply device 3 is arranged. A spunbonded nonwoven fabric SW prepared in advance is set in the spunbond supply device 3 in the form of a roll. The spunbond nonwoven fabric SW is pulled out from the spunbond supply device 3 and transported to the stacking position 24 on the transport wire 43 described above. As the spunbond nonwoven fabric SW, it is preferable to use a synthetic resin continuous filament web formed by a spunbond method.

The aforementioned pulp fiber web PFW is placed on the spunbond nonwoven fabric SW positioned at the stacking position 24 . At the stacking position 24, the suction force of the suction portion 42 of the suction device 4 passes through the conveying wire 43 and acts on the spunbond nonwoven fabric SW and the pulp fiber web PFW thereon. Therefore, the preliminary laminate PWeb in which the spunbond nonwoven fabric SW and the pulp fiber web PFW are laminated is conveyed downstream.

The above-described preliminary laminate PWeb is suction-compressed by the suction force of the suction device 4, so that the laminated state is maintained. At this time, the fibers of the upper pulp fiber web PFW are in a densified state. However, if the preliminary laminate PWeb is transported into the hydroentangling device 5 on the downstream side as it is, there is a risk that some of the pulp fibers PF will be blown up by water jets (high-pressure water streams).
Therefore, in the present manufacturing apparatus 1, nipping rollers 28 for sandwiching the preliminary laminate PWeb from above and below to stabilize the state of placement of the pulp fiber web PFW on the spunbond nonwoven fabric SW, and upstream of the hydroentangling device 5 A pre-wet device 30 is provided on the side to apply water to prevent scattering of fibers. The pre-wetting device 30 preferably applies a suction force from a spray nozzle 31 that sprays water mist from above the preliminary laminated body PWeb and from the lower side of the preliminary laminated body PWeb (that is, the lower surface of the pulp fiber web PFW). and a suction device 32 .
Although FIG. 1 illustrates the case where the prewetting device 30 is provided as a new device in front of the hydroentangling device 5 as described above, the present invention is not limited to this. Among a plurality of sets each including a water jet head 51 and a suction device 52 (to be described later) included in the hydroentangling device 5 , the design may be changed such that the head set is used as the prewetting device 30 . In this case, adjustment should be made so that low-pressure water mist is sprayed from the leading water jet head 51 .
In the case of the hydroentangling device 5 in which the number of sets of the water jet head 51 and the suction device 52 sufficient to perform the hydroentanglement treatment is ensured, the top water jet head 51 and the suction device 52 are preliminarily set as described above. Utilizing it as a wet device is effective in suppressing the equipment cost.

Then, in the hydroentangling device 5, a high-pressure water jet is blown onto the preliminarily laminated body PWeb that has been treated by the nipping roller 28 and the prewetting device 30 serving as a pretreatment unit, thereby promoting the entangling of the pulp fibers. This promotes integration of the upper pulp fiber web PFW layer and the lower spunbond nonwoven fabric SW layer.
The hydroentangling device 5 exemplarily shown in FIG. 1 has water jet heads 51 arranged in multiple stages (four stages are illustrated in FIG. 1) along the transport direction TD.
Although FIG. 1 does not show the nozzles provided in the water jet head 51 extending in the direction perpendicular to the transport direction TD (the width direction of the web), a plurality of water jets are arranged in the width direction. A jet nozzle is placed at an appropriate position. The hole diameter φ of this water jet nozzle is preferably 0.06 to 0.15 mm. Also, the interval between the water jet nozzles is preferably 0.4 to 1.0 mm.

It is desirable to set the water pressure for the hydroentangling treatment in consideration of the basis weights of the pulp fiber web PFW and the spunbond web SW. For example, it is preferable to select in the range of 1 to 30 MPa.

A suction device 52 is arranged so as to face the water jet head 51 . While blowing a high-pressure water jet from a water jet head 51 onto the pulp fiber web PFW positioned above, the suction force of a suction device 52 is applied to the lower side of the spunbond nonwoven fabric SW positioned below. 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 enter the lower spunbond nonwoven fabric SW or penetrate the spunbond nonwoven fabric SW to reach the opposite side. It is presumed that such a state is formed. Its action promotes the integration of the two layers.

A carrier wire 55 is also arranged in the hydroentangling device 5 . A transport wire 55 receives the preliminary laminate PWeb downstream of the pretreatment stations 28 , 30 and transports it into the hydroentangling device 5 . The carrier wire 55 is arranged to pass between the water jet head 51 of the hydroentangling device 5 and the suction device 52 from the upstream side to the downstream side.
Therefore, the preliminary laminate PWeb conveyed on the conveying wire 55 is subjected to more hydroentangling treatment as it goes downstream in the conveying direction TD, and when it leaves the hydroentangling device 5, the upper pulp fibers Sufficient entangling treatment is realized between the web PFW layer and the lower spunbond nonwoven fabric SW layer.
The nonwoven fabric immediately after leaving the hydroentangling device 5 is in a wet state, and the bonds between the pulp fibers are not sufficiently established.

Therefore, as shown in FIG. 1, on the downstream side of the hydroentangling device 5, there is a suction device 6 and a suction device 6 for removing residual moisture from the web by suction, drying the web, and completing the production of the composite nonwoven fabric WP. A drying device 7 is provided. By performing dehydration and drying by the suction device 6 and the drying device 7 in the latter stage of the production of the composite nonwoven fabric WP, the nonwoven fabric can be efficiently produced, and a large external pressure can be applied to the produced nonwoven fabric after hydroentanglement. It is possible to produce a nonwoven fabric that is dried without drying.
The suction device 6 dewaters the hydroentangled nonwoven fabric by, for example, a vacuum system. The drying device 7 preferably employs a non-compression type dryer, preferably an air-through dryer. In FIG. 1, a rotatable dryer body 71 of the air-through dryer is a cylindrical body, and has a large number of through-holes on its peripheral surface. It is preferable to adopt a configuration in which the air is sucked in toward the side.
The composite type composite nonwoven fabric WP continuously produced in this way is taken up by the roller 81 of the take-up device 8 to complete a series of steps.

Although a general composite nonwoven fabric can be produced by the above steps, the composite nonwoven fabric according to the present invention is a nonwoven fabric in which the generation of paper dust is suppressed. For this reason, a step is provided for applying a wet press treatment with rolls to the laminate in a wet state after the hydroentanglement step by the hydroentanglement device.

A wet press device 9 for performing a wet press process is arranged immediately after the hydroentangling device 5 and before the suction device 6, and includes an upper upper press roll 9a and a lower lower press roll 9a that contact the pulp fiber web PFW side. and a press roll 9b. The pulp fiber web PFW is in contact with the upper press roll 9a, and the spunbond nonwoven fabric SW layer is in contact with the lower press roll 9b.
The above upper press roll and lower press roll are calculated by the formula (roll equivalent diameter)=(upper press roll diameter)×(lower press roll diameter)/{(upper press roll diameter)+(lower press roll diameter)}. It is desirable to design the roll equivalent diameter to be 75 to 300 mm, more preferably 100 to 250 mm. The equivalent roll diameter here is based on the literature presented by AV Lyons et al. (1990 TAPPI Finishing and Converting, P5).
The roll-equivalent diameter can be used as an index of the smoothing effect of fibers protruding from the pulp fiber web PFW (hereinafter simply referred to as pulp fiber web) in the composite nonwoven fabric WP. For example, when the equivalent roll diameter is less than 75 mm, the force applied to the surface is too small, and the effect of leveling the protruding pulp fibers is small, so the effect of suppressing paper dust is reduced. It should be noted here that the pulp fibers protruding to the pulp fiber web side surface of the composite nonwoven fabric can be evaluated using the TS7 value of the TSA measurement described above (measured on the pulp surface side). As mentioned above, the TS7 value is originally an index of the softness of tissue paper, but when there are many protruding fibers, the number of fibers that come into contact with the blade (measurement feather) in the TSA measurement increases, and the TS7 value increases. Such a composite nonwoven fabric having a large TS7 value has a large number of protruding fibers, and therefore generates a large amount of paper dust when used as a wiper. In the present invention, the TS7 value is used to confirm a composite nonwoven fabric in which the generation of paper dust is suppressed. As mentioned above, the TS7 value is preferably between 8.0 and 15.0 dBV2rms.
If the equivalent roll diameter is larger than 300 mm, the pulp fiber web side surface of the composite nonwoven fabric will be hardened.

Furthermore, it is preferable that the roll nip pressure between the upper press roll 9a and the lower press roll 9b is set to 1.0 to 8.0 MPa. The gap between rolls is preferably set to 0 to 0.3 mm. Further, the conveying speed of the roll is preferably set to 100 to 280 m/min, more preferably 150 to 250 m/min.
By setting the operating conditions of the wet press device 9 within the above range, the fibers protruding from the pulp surface of the composite nonwoven fabric are evened out, and paper dust generated during use of the composite nonwoven fabric can be reliably suppressed.
If the transport speed is too fast, the gap between rolls is too wide, or the roll nip pressure is too low, the effect of suppressing fiber popping out of the pulp fiber web of the composite nonwoven fabric will be weakened, and as a result, paper dust will be suppressed. less effective (more paper dust is produced during use).
Conversely, if the transport speed is too slow or the roll nip pressure is too high, too much force will act on the composite nonwoven fabric, and the pulp fiber web surface of the composite nonwoven fabric will harden, reducing the thickness and reducing the density. becomes higher. Such a composite nonwoven fabric has a slow water absorption rate, a low T.W.A. value, and a paper-like hard feel. This composite type nonwoven fabric has a poor feel when used as a wiper.
The materials of the upper press roll 9a and the lower press roll 9b are not particularly limited, but metal rolls are preferably used for both.

In the composite type nonwoven fabric manufacturing apparatus shown in FIG. can be In this case, the suction device 6 may be designed to suck the remaining moisture around the laminate WP to such an extent that the pulp fiber web PFW is maintained in a wet state.
The composite type nonwoven fabric WP according to the present invention is subjected to a wet press treatment after hydroentanglement, so that the fibers protruding from the surface are flattened. As described above, in the pulp fiber web PFW in the wet state, the bonds (hydrogen bonds) between the pulp fibers are not firmly established and the bonds are loose. By leveling and then quickly drying, the leveled state is maintained, and a smooth and high-density pulp fiber web PFW can be formed. This makes it possible to obtain a composite nonwoven fabric that suppresses the generation of paper dust. Then, the state of the surface of the pulp fiber web PFW side where the protruding fibers have been leveled can be confirmed by the TS7 value.
As a method for increasing the bonding between pulp fibers, it has been considered to perform a press roll treatment after the drying process. However, in this case, although the density of the surface is increased, hydrogen bonding is not promoted due to the dry state, and paper dust generated during use was not improved.

(Example)
Composite type nonwoven fabrics of examples manufactured by the above-described manufacturing apparatus will be described below.
The composite nonwoven fabrics of Examples 1 to 5 and Comparative Examples 1 to 6 thereof, which were manufactured so that the basis weight, thickness, density and TS7 values were as shown in Table 1, were composited according to the criteria shown below. A sensory evaluation was made of the amount of fibers that fell off and the easiness of wiping off when the type nonwoven fabric was used (in dry and wet conditions). Since it is particularly important to evaluate the easiness of wiping off the nonwoven fabric used as a wiper, we decided to evaluate it together with the falling off of paper dust. A composite nonwoven fabric with less sloughing fibers but inferior in ease of wiping is regarded as an unfavorable composite type nonwoven fabric and used as a comparative example.
1) The easiness of wiping off an object such as dirt with the composite nonwoven fabric was evaluated.
Evaluation of ease of wiping: Both flexibility and stiffness are moderately soft and easy to wipe (excellent ◎), wiping is easy without problems (good ◯), too soft and has no stiffness and is difficult to wipe (improper × ¹ ), too hard It was evaluated as having no flexibility and being difficult to wipe (improper x ² ).
2) A smooth black plastic plate was rubbed with the pulp surface of the composite nonwoven fabric, and the amount of paper dust that fell off was visually evaluated. Load: 3.5 kg, number of wipes: 250 mm x 20 times.
o Dry state: The composite nonwoven fabric was rubbed against a plate in a dry state without attaching liquid or the like.
○ Wet state: The composite nonwoven fabric was impregnated with liquid (water) (impregnation rate: about 200%) and rubbed against a plate in a wet state. Moisture content=moisture content (g)/nonwoven fabric (g).
Evaluation of dropped paper powder: Almost no dropped paper powder (excellent ◎), some dropped paper powder but at a level that can be used without problems (good 〇), too much dropped paper powder makes it difficult to use (poor ×) , and.

As shown in Table 1 above, Examples 1 to 5 can be provided as products. rice field.

Examples 1-5 above have a basis weight of 52.0-95.0 g/m ² , a thickness of 0.20-0.42 mm, a density of 0.19-0.25 g/m ³ , and a TS7 value of It is within the preferred range of 15.0 dBV ² rms or less.

On the other hand, in Comparative Example 1, the thickness is too thin, the density is too high, and although the TS7 value is small and the paper dust that falls off is suppressed, it is too hard and has no flexibility, and is evaluated as being difficult to wipe off. . It can be confirmed that the water absorption is also low.
In Comparative Example 2, the thickness was too thick, the density was too low, and the TS7 value was too large.
Comparative Example 3 is too thick and has too large a TS7 value, and is evaluated to be excellent in terms of ease of wiping off, but to have a large amount of paper dust.
In Comparative Example 4, the density was too high, and although the TS7 value was within a suitable range and paper dust falling off was suppressed, it was evaluated as too hard, lacking flexibility, and difficult to wipe off.
In Comparative Example 5, the basis weight was too low, the thickness was too thin, and the TS7 value was small. there is
In Comparative Example 6, the grammage was too large and the thickness was too thick, and although the TS7 value was in a suitable range and the paper dust that fell off was suppressed, it was too hard and had no flexibility, and was difficult to wipe off. It has become.

Although the description of the embodiments is finished above, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

1 Composite type nonwoven fabric manufacturing device 2 Airlaid device 3 Spunbond nonwoven fabric supply device 4 Suction device 5 Hydroentangling device 6 Suction (dewatering) device 7 Drying device 8 Winding device 9 Wet press device 9a Upper press roll 9b Lower press roll 21 Solution Textile Machine 22 Duct 23 Air Laid Hopper 24 Stacking Position 28 Clamping Roller 30 Prewet Device 31 Spray Nozzle 32 Suction Device 41 Suction Device Body 42 Suction Part 43 Conveying Wire 51 Water Jet Head 52 Suction Device 55 Conveying Wire SW Spunbond Nonwoven Fabric PF Pulp Fiber PFW Pulp fiber web PWeb Preliminary laminate (laminated web)
WP Composite type nonwoven fabric TD Conveying direction

Claims (9)

A composite nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbond nonwoven fabric,
The tissue soft on the pulp fiber web side has a basis weight of 52.0 to 95.0 g/m ² , a thickness of 0.20 to 0.42 mm and a density of 0.19 to 0.25 g/m ³ . A composite nonwoven fabric characterized by having a TS7 value of 15.0 dBV ² rms or less measured by a TSA ness measuring device. 2. The composite nonwoven fabric according to claim 1, which has a drip absorption of 0.5 to 3.0 seconds and a water absorption (T.W.A.) of 250 to 450 g/m ² . 3. The composite nonwoven fabric according to claim 1 or 2, which has a Wet Taber value of 5 times or more. The basis weight of the pulp fiber web is 40.0 to 83.0 g/m ² , and the weight composition ratio of the spunbond nonwoven fabric and the pulp fiber web is 40/60 to 10/90 (wt%). The composite nonwoven fabric according to any one of claims 1 to 3, characterized in that: The spunbond nonwoven fabric has a basis weight of 7.0 to 20.0 g/m ² and is formed to include a plurality of fusion points for joining spun resin fibers, The area of one bonding point is 0.10 to 0.50 mm ² , the area ratio per unit area of the fusion bonding points is 7 to 20%, and the number is 10 to 150/cm ² . The composite nonwoven fabric according to any one of claims 1 to 4. 2. The spunbond nonwoven fabric is formed of one selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more. 6. The composite nonwoven fabric according to any one of 5. 7. The pulp fiber web of claims 1-6, wherein said pulp fiber web comprises fibers of bleached softwood kraft pulp selected from the group consisting of radiata pine, slash pine, southern pine, lodgepole pine, spruce and Douglas fir. The composite nonwoven fabric according to any one of the above. A method for manufacturing a composite nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbond nonwoven fabric,
At least comprising a hydroentanglement step of promoting integration of the pulp fiber web and the spunbond nonwoven fabric to obtain a laminate, and a drying step of drying the laminate after the hydroentanglement step,
A method for producing a composite nonwoven fabric, further comprising a wet press step of applying pressure to the wet laminate before the drying step with press rolls after the hydroentanglement step. In the wet pressing process, the roll equivalent diameter calculated by the formula (roll equivalent diameter) = (upper press roll diameter) x (lower press roll diameter) / {(upper press roll diameter) + (lower press roll diameter)} Using an upper press roll and a lower press roll of 75 to 300 mm, the conveying speed is set to 100 to 280 m/min, the gap between rolls is set to 0 to 0.3 mm, and the roll nip pressure is set to 1.0 to 8.0 MPa. The method for producing a composite nonwoven fabric according to claim 8, characterized in that:

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