JP2022003173A - Composite nonwoven fabric and production method thereof - Google Patents

Abstract

To provide a composite nonwoven fabric having required voluminousness and smoothness, and moderate bounce with exfoliation of fiber suppressed.SOLUTION: A composite nonwoven fabric including a spun-bonded nonwoven fabric on which a pulp fiber web is laminated and integrated has a basis weight of 40.0 to 110.0 g/m2, a bulk density of 4.3 to 7.5 cm3/g, and a TSA (D value) as index of bounce (strength) of 1.0 to 2.5 mm/N.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 nonwoven fabric has excellent strength, it functions as a backing layer of the manufactured composite nonwoven 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.

Japanese Patent No. 2533260

The composite non-woven fabric as described above has an appropriate volume feeling (volume feeling) that can be felt by the user through the bulk and thickness, and the surface is smooth, so that the fibers do not fall off. The few are highly evaluated as products.
For example, by applying a calendar treatment to a composite non-woven fabric, it is possible to adjust the thickness to an arbitrary value and impart surface uniformity and smoothness. However, on the other hand, since the composite non-woven fabric is pressurized and smoothed, so-called stiffness (a type of strength, resistance when a bending force is applied to the nonwoven fabric, hereinafter simply referred to as "koshi". There is) will decrease. On the other hand, as a method of imparting elasticity to the composite nonwoven fabric, a method of heat embossing with an embossed roll having a high temperature is known. In this treatment, heat is applied to the spunbonded non-woven fabric (synthetic resin fiber) side of the composite non-woven fabric while pressing the emboss on the surface of the composite non-woven fabric using a roll in which a plurality of protrusions corresponding to so-called columns are arranged, which is called embossing. In addition, by curing it after that, it is possible to give an appropriate elasticity. However, on the other hand, it is difficult to finely adjust the thickness by the heat embossing treatment, which may cause a problem in the smoothness of the appearance.
As described above, the calendar treatment and the heat embossing treatment on the composite non-woven fabric have a contradictory relationship, and have the required volume feeling (volume feeling) and smoothness, and also have an appropriate elasticity, and the fiber. It was difficult to obtain a composite non-woven fabric in which the dropout of the non-woven fabric was suppressed.

The pulp fiber web of the composite non-woven fabric can be obtained by diverting the conventional wet papermaking method or by using the dry airlaid method. When the pulp fiber web by the dry airlaid method is used, the above problem, that is, when the heat embossing treatment is performed, it is difficult to adjust the delicate thickness, and the problem of the smoothness of the appearance tends to increase. Admitted. However, from the viewpoint of manufacturing equipment and cost, it is preferable to adopt the dry airlaid method rather than the wet papermaking method.

An object of the present invention is to provide a composite nonwoven fabric having the required volume and smoothness, having an appropriate elasticity, and further suppressing the falling off of fibers.

The above object is a composite type non-woven fabric in which a pulp fiber web is laminated and integrated on a spunbonded non-woven fabric, the basis weight is 40.0 to 110.0 g / m ² , and the bulk is 4.3. It can be achieved by a composite nonwoven fabric characterized by having a TSA (D value) of about 7.5 ^{cm 3 / g and an index indicating stiffness (strength) of 1.0 to 2.5 mm / N.}

The TSA (TS7 value) indicating softness is 12.0 to 20.0 dBV ² rms, and the TSA (TS750 value) indicating smoothness is 33.0 to 100.0 dBV ² rms. Is preferable.
Further, the thickness is preferably 0.30 to 0.50 mm.

Further, the basis weight of the pulp fiber web is 30.0 to 80.0 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%). It is preferable to have.

Further, the spunbonded nonwoven fabric has a basis weight of 10.0 to 30.0 g / m ² , and the spunbonded nonwoven fabric is formed to include a plurality of fusion points for joining 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 spunbonded nonwoven fabric is preferably formed of one type selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more types.

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

The above-mentioned object is a method for manufacturing a composite type nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbonded nonwoven fabric, and a laminated body is formed by promoting integration of the pulp fiber web and the spunbonded nonwoven fabric. A calendar step of obtaining at least a water flow entanglement step and a drying step of drying the laminate after the water flow entanglement step, and after the drying step, a calendar step of passing the laminate while pressurizing between the calendar rolls, and the calendar. It can also be achieved by a method for producing a composite nonwoven fabric, which further comprises a heat embossing step of applying a heat embossing treatment to the pulp fiber web side after the step.

Then, in the calendar step and / or the thermal embossing step, it is calculated by the formula (roll equivalent diameter) = (main roll diameter) × (receiving roll diameter) / {(main roll diameter) + (receiving roll diameter)}. Using the main roll diameter with a roll equivalent diameter of 75 to 300 mm and the receiving roll, the transport speed is 100 to 300 m / min, the gap between rolls is 0 to 0.5 mm, and the roll nip pressure is 0.5 to 6.5 MPa. It is desirable to set it to.
Further, in the heat embossing step, it is desirable that the temperature of the main roll is set to 40 to 200 ° C.

According to the present invention, it is possible to provide a composite nonwoven fabric having the required volume and smoothness, having an appropriate elasticity, and further suppressing the falling off of fibers. Further, according to the production method of the present invention, the composite nonwoven fabric can be efficiently produced.

It is a figure which shows the manufacturing apparatus of a composite type non-woven fabric. It is a figure which shows the schematic structure of the embossing apparatus, and the state of the embossed composite type non-woven fabric schematically. It is a figure shown for demonstrating the form of the emboss roll, FIG. 3 (a) or FIG. 3 (b) is an enlarged sectional view which showed a part of the surface of the emboss roll, and FIG. It is a top view which showed the part of the surface of a roll enlarged.

Hereinafter, the composite nonwoven fabric according to the embodiment of the present invention will be described.
The inventors of the present application have diligently studied the composite non-woven fabric, and the TSA (D value), which is an index indicating ^{the basis weight (g / m 2} ), bulk (cm ^{3 / g), and stiffness (strength), is used.} It is confirmed that the composite non-woven fabric designed to be within a predetermined range has the required volume and smoothness, has an appropriate elasticity, and further suppresses the falling off of fibers. This is what led to the present invention. Such a composite nonwoven fabric can be manufactured by subjecting a calender treatment and a heat embossing treatment in order after the drying step.
Furthermore, the composite nonwoven fabric according to the present invention is an index indicating softness TSA (TS7 value ^(dBV 2 rms)) and is an index indicating the smoothness TSA (TS750 value ^(dBV 2 rms)) also predetermined range It is preferable that the material is designed to be inside, and the thickness (mm) is also preferably designed to be within a predetermined range.
Hereinafter, the above-mentioned factors relating to the composite nonwoven fabric and their preferred ranges will be described.

The composite non-woven fabric according to the present invention has a basis weight of 40.0 to 110.0 g / m ² , preferably 62.0 to 77.0 g / m ² , and a bulk of 4.3 to 7.5 g / m ² . It is preferably set to 5.0 to 6.4 g / m ² , and the TSA (D value) is set to 1.0 to 2.5 mm / N.
The composite non-woven fabric formed so that the basis weight, bulk, and TSA (D value) are within the above ranges has the required volume and smoothness, has an appropriate elasticity, and further loses fibers. Can also be suppressed.
Here, further, the index TSA (TS7 value) is 12.0~20.0dBV ² rms, TSA (TS750 value) is set to 33.0~100.0dBV ² rms, also zero thickness. It is set to 30 to 0.50 mm, preferably 0.35 to 0.45 mm.

To indicate that each of the above D value, TS7 value, and TS750 value was measured using the tissue softness measuring device TSA (Tissue Software Analyzer), TSA (D value), TSA (TS7 value), and TSA (TS7 value). It is shown as TSA (TS750 value). In the tissue softness measuring device TSA, a rotor with a blade is pressed from the top of a composite non-woven fabric (sample) placed on a sample table with the pulp surface side facing up, for example, with a pushing pressure of 100 mN, and rotated at 2.0 / sec. The softness (feel) of non-woven fabrics, etc. is quantitatively evaluated by analyzing the vibration data detected by various sensors and parameterizing (TS value). The Japanese distributor is a product name manufactured by Nihon Rufuto Co., Ltd.).
In the measurement by the tissue softness measuring device TSA, for example, the vibration of the sample table is measured by a vibration sensor installed inside the sample table, the vibration frequency is analyzed, and the parameterization (TS value) is performed. The vibration frequency depends on the structural dimensions such as creeping and embossing and the rotation speed of the blade. The induction of horizontal vibration of the blade itself (resonance frequency: eg 6500 Hz) occurs due to the momentary interruption by the protrusions of the sample and the vibration of the blade as it travels on the surface of the sample. The intensity of the maximum peak of the first spectrum from the low frequency side is the TS750 value (dBV ² rms), and the intensity of the maximum peak of the spectrum including the resonance frequency: 6500 Hz (around 6500 Hz) is the TS7 value (dBV ² rms). do.
Further, without rotating the rotor with a blade, the amount of deformation (mm / N) in the vertical direction when the sample is deformed at, for example, pushing pressures of 100 mN and 600 mN is measured as a D value.

The software for vibration analysis and parameterization (TS value) can use the emtec measurement system. This software is provided with various algorithms (for example, Base Tissue, Financial, TP, etc.), and the TS7 value, TS750 value, and D value are automatically acquired on the software, and these TS7 value, TS750 value, and D value are automatically acquired. Alternatively, the HF (hand feel) value is calculated according to the type of various algorithms from the basis weight, thickness, number of plies, and the like. In the present invention, the TS7 value, the TS750 value and the D value are defined instead of the HF value, and any algorithm may be used as long as the measurement conditions are satisfied, and the TS7 value, the TS750 value and the D value are the algorithms. It does not change depending on the type of.

The basis weight of the pulp fiber web is, for example, 30.0 to 80.0 g / m ² , and the weight composition ratio of the spunbonded nonwoven fabric and the pulp fiber web is, for example, 40/60 to 10/90 (wt%). It is preferable to have. Those in this range are excellent in water absorption performance and hand-held feeling, and are also excellent in shape stability of the composite non-woven fabric.
The basis weight of the spunbonded nonwoven fabric is preferably ^{10.0 to 30.0 g / m 2, for example.} Further, the spunbonded nonwoven fabric is formed to include a plurality of fusion points for joining the spun resin fibers, and the area of one fusion point is 0.10 to 0.50 mm ² , a unit of fusion points. It is preferable that the area ratio per area is 7 to 20% and the number is 10 to 150 pieces / cm ^2. Such a spunbonded nonwoven fabric has appropriate rigidity and is suitable as a spunbonded nonwoven fabric to be used for a composite type nonwoven fabric in combination with a pulp fiber web. The shape of the fusion point is not particularly limited and may be circular, elliptical, polygonal or the like.

It is desirable that the spunbonded nonwoven fabric is formed by one kind selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more kinds. Among these, it is preferable to use polypropylene.
As for the pulp fiber web, it is preferable to use one formed of fibers of coniferous bleached kraft pulp selected from the group consisting of radiata pine, slush pine, southern pine, lodge pole pine, spruce and Douglas fur. ..

Hereinafter, the process of manufacturing the composite nonwoven fabric of the present invention described above will be described. The composite nonwoven fabric of the present invention can be efficiently manufactured by subjecting a calender treatment and then a heat embossing treatment in order after the drying step. Here, the calender device and the embossing device will be described after explaining the main configuration of the manufacturing device for manufacturing the composite nonwoven fabric WP which is the premise.

The composite nonwoven fabric manufacturing apparatus 1 shown in FIG. 1 is provided with an airlaid apparatus 2, a spanbond supply apparatus 3 for supplying a spunbonded nonwoven 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.
Water flow entanglement device 5, suction device 6, drying device 7 that injects a water jet for performing water flow entanglement processing in order from the upstream side downstream of these devices 2, 3 and 4 in the transport direction TD of the web. Is placed. Downstream of the drying device 7, a winding device 8 for winding a continuously manufactured composite nonwoven fabric WP is further provided.

The air-laid device 2 is provided with a defibrating machine 21 for defibrating raw pulp RP in which fibers are densely packed into a sheet, 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, the 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 descend while being dispersed, and the pulp fiber web PFW is gradually formed 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 has an attractive force (negative pressure) on the pulp fiber web PFW with respect to the stacking position 24. It has 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 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 transport wire 43 is capable of mounting the pulp fiber web PFW on which the pulp fiber PF is deposited at the stacking position 24, and is arranged so as to transport the pulp fiber web PF 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 explanation 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 span bond supply device 3 is arranged on the lower side of the air-laid device 2 and on the upstream side of the suction device 4. A spunbonded nonwoven fabric SW prepared in advance is set in the spunbond supply device 3 in a roll shape. The span-bonded nonwoven fabric SW is drawn out from the spun-bond supply device 3 and is conveyed to the above-mentioned stacking position 24 on the above-mentioned transfer wire 43. As the spunbonded nonwoven fabric SW, it is preferable to use a web of continuous filaments of synthetic resin formed by the spunbonding method.

The pulp fiber web PFW described above is placed on the spunbonded nonwoven fabric SW located at the laminating position 24. 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 spunbonded nonwoven fabric SW and the pulp fiber web PFW on the transfer wire 43. Therefore, the preliminary laminated body PWeb in which the spunbonded nonwoven fabric SW and the pulp fiber web PFW are laminated is transported to the downstream side.

The above-mentioned preliminary laminated body PWeb 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 holding 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 entanglement device 5. A pre-wet device 30 for imparting 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. 1 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. With respect to 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, the water jet head 51 at the head may be adjusted so that the low pressure water mist is sprayed.
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 reducing 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 preliminary laminated body PWeb treated by the sandwiching roller 28 and the pre-wet device 30 which are the pretreatment portions. This promotes the integration of the pulp fiber web PFW layer located on the upper side and the spunbonded nonwoven fabric SW layer located on the lower side.
In the water flow confounding device 5 exemplifiedly shown in FIG. 1, water jet heads 51 are arranged in multiple stages (four stages are exemplified in FIG. 1) along the transport direction TD.
Although FIG. 1 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 (the width direction of the web), a plurality of waters in the width direction are not shown. The 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 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 web PFW and the spunbond web 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 nonwoven 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 fiber on the pulp fiber web PFW side has entered the lower spunbonded non-woven fabric SW, or penetrated the spunbonded nonwoven fabric SW to the opposite side. It is presumed that a non-woven fabric is formed. The action promotes the unification of the two layers.

The transport wire 55 is also arranged in the water flow entanglement device 5. The transport wire 55 receives the preliminary laminated body PWeb downstream of the pretreatment sections 28 and 30 and transports them 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 laminated body PWeb transported on the transport wire 55 is subjected to more water flow entanglement processing as it goes downstream in the transport direction TD, and the pulp fiber on the upper side when leaving the water flow entanglement device 5. Sufficient entanglement processing between the web PFW layer and the lower spunbonded non-woven fabric SW layer is realized.
The 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. 1, the suction device 6 and the suction device 6 for completing the production of the composite nonwoven fabric WP by sucking and removing the water remaining on the web on the downstream side of the water flow confounding device 5 and then drying the web. A drying device 7 is deployed. In this way, if dehydration and drying are performed by the suction device 6 and the drying device 7 in the subsequent stage of the production of the composite nonwoven fabric WP, the nonwoven fabric can be efficiently manufactured, and a large external pressure is applied to the nonwoven fabric after water flow entanglement. Since it is possible to produce a non-woven fabric that is completely dry, it is possible to finish the product with a bulky feeling.
The suction device 6 is, for example, a vacuum type and dehydrates the non-woven fabric after confounding with water flow. It is preferable to use a non-compression type dryer, preferably an air-through dryer, for the drying device 7. 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 from the outer periphery to the center of the dryer body. It is better to use a configuration that sucks toward the side.
The composite composite nonwoven fabric WP continuously manufactured in this way is wound by the roller 81 of the winding device 8 to complete a series of steps.

In the manufacturing apparatus shown in FIG. 1, since the pulp fiber web is supplied by the dry air-laid method adopting the above-mentioned air-laid device 2, the equipment and manufacturing cost are suppressed as compared with the case of forming the pulp fiber web by wet method. can. On the other hand, as described above, in the case of a composite nonwoven fabric containing a pulp fiber web by the airlaid method, it is difficult to adjust the thickness thereof, and there is a concern about the smoothness of the appearance. The composite nonwoven fabric of the present invention eliminates this concern. This point will be clarified by the following explanation.

Although a general composite nonwoven fabric can be produced by the above steps, the composite nonwoven fabric according to the present invention has the required volume and smoothness even when a pulp fiber web produced by the airlaid method is used. It has an appropriate elasticity, and the shedding of fibers is also suppressed. Therefore, after the drying step by the drying device 7, as shown in FIG. 1, the calendering process is performed by the calendering device CA, and further downstream thereof, the pulp fiber web PFW side is heat-embossed by the embossing device EA under predetermined conditions. The composite non-woven fabric according to the present invention is manufactured by subjecting the treatment.

As the calendar device CA, a device having the same configuration as the well-known calendar device that has been conventionally used in the subsequent stage of the paper manufacturing device can be adopted. Although detailed illustration is omitted here, the calendar device CA includes a pair of metal rolls having a smooth surface. By passing a composite non-woven fabric between the metal rolls and applying pressure, smoothness to the surface is imparted while adjusting the thickness.

The pair of metal rolls are arranged so as to overlap each other in a horizontal posture, and the composite non-woven fabric after drying passes between them. The upper side is the main roll and the lower side is the receiving roll.
The main roll and the receiving roll have a roll equivalent diameter of 75 calculated by the formula (roll equivalent diameter) = (main roll diameter) × (receiving roll diameter) / {(main roll diameter) + (receiving roll diameter)}. It is desirable to design the diameter to be ~ 300 mm, more preferably 100 to 250 mm. The roll equivalent diameter here is based on the literature (1990 TAPPI Finishing and Converting, P5) presented by AV Lyons et al., And is an index of the strength of the calendar processing applied to the composite non-woven fabric. For example, if the roll equivalent diameter is less than 75 mm, the calendar processing applied to the composite nonwoven fabric tends to be insufficient, while if the roll equivalent diameter is larger than 300 mm, the calendar processing becomes too strong.
The roll nip pressure of the main roll and the receiving roll is set to 0.5 to 6.5 MPa, more preferably 2.0 to 5.0 MPa. The gap between the rolls is set to 0 to 0.5 mm. Further, it is desirable that the roll transport speed is set to be 100 to 300 m / min, more preferably 150 to 250 m / min.

An embossing device EA is further arranged on the downstream side of the calendar device CA. The embossing device EA is illustrated in FIG. FIG. 2 shows the schematic configuration of the embossing device EA on the left side, and schematically shows the state of the embossed composite nonwoven fabric WP on the right side.
The embossing device EA of FIG. 2 includes an embossing roll a1 which is an upper main roll in contact with the pulp fiber web PFW side and a plain receiving roll a2 on the lower side. An uneven portion pattern formed on the pulp fiber web PFW is engraved on the outer peripheral surface of the embossed roll a1. On the other hand, the outer peripheral surface of the receiving roll a2 is formed flat.
The roll equivalent diameter described above is also calculated and set for the relationship between the embossed roll a1 and the receiving roll a2. That is, the roll equivalent diameter calculated by the formula (roll equivalent diameter) = (embossed roll diameter) × (receiving roll diameter) / {(embossed roll diameter) + (receiving roll diameter)} is 75 to 300 mm, more preferably 100. It is desirable to design it to be ~ 250 mm. The roll equivalent diameter here is an index of the strength of embossing applied to the composite nonwoven fabric. For example, if the roll equivalent diameter is less than 75 mm, it becomes difficult for the embossing applied to the composite nonwoven fabric to enter, while if the roll equivalent diameter is larger than 300 mm, the embossing becomes too strong. In addition, there are problems such as an increase in running cost due to equipment and an increase in installation space.

The roll nip pressure of the embossed roll a1 and the receiving roll a2 is set to 0.5 to 6.5 MPa, more preferably 2.0 to 5.0 MPa. The gap between the rolls is set to 0 to 0.5 mm, and a heating means (for example, a heater) is provided on at least one of the embossed roll a1 and the plain roll a2 so that the temperature of the embossed roll a1 is 40 to 200 ° C. More preferably, it is set to 100 to 150 ° C. Further, it is desirable that the roll transport speed is set to be 100 to 300 m / min, more preferably 150 to 250 m / min.
By setting the embossing operating conditions within the above range, the pulp surface of the composite non-woven fabric after the calendar processing is appropriately embossed to give elasticity, and paper dust generated when the composite non-woven fabric is used is suppressed. You can also do it.
The force applied to the surface of the composite non-woven fabric, such as the roll equivalent diameter used for heat embossing is too small, the transport speed is too fast, the gap between rolls (Gap) is too large, the roll nip pressure is too small, and the temperature is too low. If it is small, the unevenness of the surface and the hardening due to heat are small, and the stiffness (strength) is inferior. On the other hand, if the equivalent roll diameter is too large, the transport speed is too slow, the roll nip pressure is too large, the temperature is too high, etc., the force applied to the surface of the composite nonwoven fabric becomes too large, and the composite nonwoven fabric itself becomes It deteriorates and has holes on the surface, and its strength decreases.
The materials of the embossed roll a1 and the receiving roll a2 are not particularly limited, but it is preferable to use a metal roll for both of them.
With the embossing device EA set so as to satisfy the above conditions, a suitable uneven portion pattern can be formed on the pulp fiber web PFW by heat embossing treatment of heat crimping. The surface of the spunbonded nonwoven fabric SW (the backside of the composite nonwoven fabric WP) located on the lower side is in contact with the receiving roll a2 and thus becomes flat.

Further, FIG. 3 is a diagram shown for explaining the form of the embossing roll which is preferable to be adopted in the embossing device EA. FIG. 3A or FIG. 3B is an enlarged cross-sectional view showing a part of the surface fa of the emboss roll a1, and a plurality of embossed convex portions EP for forming embossing are formed on the surface fa. Existing. As shown in FIG. 3A, the area of the root portion and the area of the tip portion are the same, and as shown in FIG. 3B, the area of the root portion and the area of the tip portion are different. can. The height EH of the embossed convex portion from the surface fa to the tip portion is preferably set to 0.2 to 1.0 mm, preferably 0.4 to 0.8 mm.
FIG. 3C is an enlarged plan view showing a part of the surface fa of the embossed roll a1. In FIG. 3C, the area of the embossed portion, which is the ratio of the area where the convex portion EP exists (the total area of the root portions) to the total area of the surface fa (indicated by the rectangular area here). The rate is preferably set to 2.0 to 40.0%, more preferably 10.0 to 30.0%.
By setting the height and area ratio of the embossing within the above ranges, appropriate embossing is applied to the pulp surface of the composite nonwoven fabric, and paper dust generated when the composite nonwoven fabric is used is suppressed.
The shape (cross-sectional shape) of the embossed convex portion EP and the arrangement method are not particularly limited, but the shape may be a round shape as shown in FIG. 3 (c), or may be a polygon or a star. Shapes can be adopted. Regarding the arrangement, the alignment type as shown in FIG. 3C may be used, or the staggered type may be used.

In the composite nonwoven fabric manufacturing apparatus shown in FIG. 1, a calendar apparatus CA designed according to the above conditions is arranged on the downstream side of the drying apparatus 7, and an embossing apparatus EA is arranged further downstream thereof. It is possible to efficiently manufacture a composite non-woven fabric having a structure.
That is, the composite non-woven fabric WP according to the present invention is a composite non-woven fabric using a pulp fiber web by a dry airlaid method by performing calendar treatment and heat embossing treatment in this order according to the above conditions. However, it has the required volume and smoothness, has an appropriate elasticity, and further suppresses fiber shedding.
It is also conceivable to perform the heat embossing treatment and the calendering treatment on the composite non-woven fabric WP in the reverse order. However, in this case, the unevenness formed by the heat embossing treatment is smoothed by the subsequent calendar processing, and the stiffness deteriorates. Furthermore, demerits such as a decrease in water absorption capacity were confirmed. It is also conceivable to apply a thermal calender treatment to the composite nonwoven fabric WP. However, it was confirmed that the thermal calender treatment has disadvantages such as a remarkable decrease in the thickness of the non-woven fabric because the heat is transferred while pressurizing on a flat surface, a weak stiffness, and a decrease in water absorption capacity.
Therefore, as described above, the composite non-woven fabric WP after drying has the required volume and smoothness by the calendar treatment without heating and the subsequent heat embossing treatment, and has an appropriate elasticity. Furthermore, it is possible to form a composite non-woven fabric in which fibers are suppressed from falling off.

Note that FIG. 1 exemplifies the case where the calendar device CA and the embossing device EA are added online, and it is preferable to provide the calendar device CA and the embossing device EA integrally with the nonwoven fabric wiper manufacturing device in this way. However, it is also possible to once wind the non-woven fabric wiper WP around the roller 81 and perform calendar processing and embossing processing offline by the separately provided calendar device CA and embossing device EA.

(Example)
Hereinafter, the composite nonwoven fabric of the example manufactured by supplying the pulp fiber web by the dry air-laid method by the above-mentioned manufacturing apparatus and performing the calendar treatment and the heat embossing treatment will be described.
Composite nonwoven fabrics of Examples 1 to 11 and Comparative Examples 1 to 6 manufactured so that the basis weight, bulk, D value, TS7 value, TS750 value, and thickness described above are as shown in Table 1. With respect to (Table 2), the smoothness, stiffness (strength) of the appearance of the composite nonwoven fabric, and the sensory evaluation of the shed fibers were evaluated according to the criteria shown below. It was possible to visually confirm the pressed and heat-bonded parts of the calender-treated and heat-embossed non-woven fabric.

1) Smoothness of appearance: The smoothness (touch, feel) of the surface of the non-woven fabric was evaluated.
Especially excellent (excellent ◎), no problem (good 〇), rough and bad touch (impossible ×)
2) Koshi (strength): The firmness when touched was evaluated.
Strong and firm (excellent ◎), no problem strength (good 〇), no stiffness and soft (impossible ×)
3) Fallen fibers: The amount of fallen fibers at the time of wiping was visually evaluated.
There is little fiber shedding (good 〇), and there is a lot of fiber shedding (impossible ×).

The thickness (mm) and bulk (cm ³ / g) of the composite nonwoven fabric were measured as follows.
Thickness (mm): Measured with a Peacock paper thickness gauge under a weight of ^{37.85 g / cm 2.}
Bulk (cm ³ / g): Calculated from thickness (cm) ÷ basis weight (g / cm ^2).

As shown in Table 1 above, Examples 1 to 11 can be provided as products, but as shown in Table 2 above, in Comparative Examples 1 to 6, the smoothness of appearance, stiffness (strength) and fiber loss are observed. It was not possible with either.

In Examples 1 to 11 above, the basis weight is 40.0 ^{to 110.0 g / m 2} , the bulk is 4.3 to 7.5 cm ³ / g, and the TSA (D value) is 1.0 to 2.5 mm / N. and TSA (TS7 value) 12.0~20.0dBV ² rms, is an index indicating the smoothness TSA (TS750 value) 33.0~100.0dBV ² rms, thickness 0.30 to 0. Within a suitable range of 50 mm, it has a voluminous feel and smooth appearance required for a composite non-woven fabric, has an appropriate elasticity (strength), and further suppresses shedding fibers.

On the other hand, in Comparative Example 1, after drying, neither calendering nor heat embossing was applied, and the bulk and thickness were excessively high and there was only a voluminous feeling, but other items, smoothness of appearance, and stiffness (strength). ) And the evaluation of shed fibers are all impossible.
Further, in Comparative Example 2, only the calendar treatment was applied after drying, and the volume feeling was moderate in view of the bulk and thickness, and the smoothness of the appearance and the evaluation of the fallen fibers were good, but the required elasticity (strength) was obtained. ) Is missing.
Further, in Comparative Example 3, after drying, only the heat embossing treatment was applied, and there was an excessive voluminous feeling in view of the bulk and thickness, and the stiffness (strength) and the shed fibers were evaluated well, but the appearance was smooth. being insufficient.
Further, in Comparative Example 4, the thermal calendar treatment was applied, and the volume feeling was appropriate in view of the bulk and thickness, and the smoothness of the appearance and the evaluation of the shed fibers were good, but the required elasticity (strength) was insufficient. ing.
Further, in Comparative Example 5, the basis weight was 30.0 g / m ^2, which was too small, and all of the thickness, bulk, D value, TS7 value and TS750 value were out of the preferable range, and the stiffness (strength) and the fallen fiber were lost. Evaluation is insufficient.
Further, in Comparative Example 6, the basis weight is 120.0 g / m ² , which is too large, the thickness is out of the preferable range, and the smoothness of the appearance is insufficient.

The composite nonwoven fabric of the above-described embodiment is a case where the pulp fiber web is supplied by the dry airlaid method, and it can be confirmed that the present invention is effective for the composite nonwoven fabric using the pulp fiber web by the dry airlaid method. However, the present invention is not limited to this, and the present invention can be similarly applied to a composite nonwoven fabric using a pulp fiber web obtained by a wet papermaking method. However, as described above, the dry air-laid method can reduce the manufacturing equipment and cost as compared with the wet papermaking method.

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 21 Defibering machine 22 Duct 23 Air-laid hopper 24 Laminating position 28 Holding roller 30 Pre-wet Equipment 31 Spray nozzle 32 Suction equipment 41 Suction equipment main body 42 Suction part 43 Conveyance wire 51 Water jet head 52 Suction equipment 55 Conveyance wire SW Spunbond non-woven fabric PF Pulp fiber PFW Pulp fiber web PWeb Preliminary laminate (laminated web)
WP Composite non-woven fabric TD Transport direction CA Calendar device EA Embossing device a1 Embossing roll (main roll)
a2 receiving roll

Claims (10)

It is a composite type non-woven fabric in which a pulp fiber web is laminated and integrated on a spunbonded non-woven fabric.
The basis weight is 40.0 to 110.0 g / m ² , the bulk is 4.3 to 7.5 cm ³ / g, and the TSA (D value), which is an index indicating the stiffness (strength), is 1. A composite non-woven fabric characterized by having a volume of 0 to 2.5 mm / N. TSA (TS7 value), which is an index showing softness, is 12.0 to 20.0 dBV ² rms, and TSA (TS750 value), which is an index showing smoothness, is 33.0 to 100.0 dBV ² rms. The composite nonwoven fabric according to claim 1. The composite nonwoven fabric according to claim 1 or 2, wherein the thickness is 0.30 to 0.50 mm. The basis weight of the pulp fiber web is 30.0 to 80.0 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%). The composite nonwoven fabric according to any one of claims 1 to 3, wherein the composite type nonwoven fabric is characterized in that. The spunbonded nonwoven fabric has a basis weight of 10.0 to 30.0 g / m ² , and the spunbonded nonwoven fabric is formed to include a plurality of fusion points for joining spun resin fibers. It is characterized in that the area of one landing 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 is 10 to 150 pieces / cm ^2. The composite nonwoven fabric according to any one of claims 1 to 4. From claim 1, the spunbonded nonwoven fabric is formed of one kind selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene and polystyrene, or a mixture of two or more kinds. 5. The composite nonwoven fabric according to any one of 5. The pulp fiber web is made of fibers of coniferous bleached kraft pulp selected from the group consisting of radiata pine, slush pine, southern pine, lodge pole pine, spruce and douglas fur, according to claims 1 to 6. The composite type non-woven fabric described in any of them. It is a method for manufacturing a composite non-woven fabric in which a pulp fiber web is laminated on a spunbonded non-woven fabric and integrated.
It includes at least a water flow entanglement step of promoting the integration of the pulp fiber web and the spunbonded nonwoven fabric to obtain a laminate, and a drying step of drying the laminate after the water flow entanglement step.
After the drying step, a calendar step of passing the laminate while pressurizing between the calendar rolls,
After the calendar step, a heat embossing step of applying a heat embossing treatment to the pulp fiber web side is further included.
A method for manufacturing a composite non-woven fabric. In the calendar step and / or the thermal embossing step, the roll equivalent calculated by the formula (roll equivalent diameter) = (main roll diameter) × (receiving roll diameter) / {(main roll diameter) + (receiving roll diameter)} Using the main roll diameter with a diameter of 75 to 300 mm and the receiving roll, the transfer speed is set to 100 to 300 m / min, the gap between the rolls is set to 0 to 0.5 mm, and the roll nip pressure is set to 0.5 to 6.5 MPa. The method for producing a composite nonwoven fabric according to claim 8, wherein the composite nonwoven fabric is made. The method for producing a composite nonwoven fabric according to claim 9, wherein in the heat embossing step, the temperature of the main roll is set to 40 to 200 ° C.

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