JP3628467B2 - Bulky paper manufacturing apparatus and bulky paper manufacturing method using the same - Google Patents

Description

【００５８】
【表２】

【００５９】
表１及び表２に示す結果から明らかなように、特定の開孔パターンネットを用いて得られた嵩高紙（実施例１〜６）は、比較例の紙に比べて厚みが大きく、吸収性が高く、かつ適度な強度を有していることが分かる。
また、実施例１と実施例６との対比から明らかなように、水に対する接触角が特定の値以上である開孔パターンネットを用いることにより、特に高速抄紙時における繊維シートの剥がれ性が一層良好になることが分かる。
【００６０】
【発明の効果】
以上、詳述した通り、本発明の嵩高紙製造装置及びそれを用いた嵩高紙の製造方法によれば、厚みが大きく、吸収性が高く、柔らかさに優れ、かつ適度な強度を有する嵩高紙が得られる。
また、本発明の嵩高紙製造装置によれば、上記開孔パターンネットが上記吸引ドラムに固定されており、可動部分がないので、劣化しにくく、その耐用年数が長くなる。
また、本発明の嵩高紙製造装置によれば、上記開孔パターンネットを取り替えるだけの簡単な操作で、パターン形状の変更が容易にできる。さらに、上記吸引ドラムを下方に移動させて繊維シートの走行パスから外すだけで、通常抄紙の生産も容易にでき、通常抄紙の生産との切り替えが簡単である。
【図面の簡単な説明】
【図１】本発明の嵩高紙製造装置の一実施形態を示す模式図である。
【図２】図１に示す装置に備えられた開孔パターンネットの一実施形態の要部を拡大して示す平面図である。
【図３】吸引ドラムにおける繊維シートの吸引の様子を示す要部拡大図である。
【図４】図１に示す嵩高紙製造装置を用いて得られた嵩高紙の断面の構造を示す模式図である。
【図５】図５（ａ）及び（ｂ）は、それぞれ開孔パターンネットの他の例を示す模式図（図２相当図）である。
【符号の説明】
１ 嵩高紙製造装置
２ 繊維シート
３ 嵩高紙
４ 低繊維密度領域
５ 高繊維密度領域
１０ 原料供給部
２０ 紙層形成部
３０ パターン付与部
３１ 開孔パターンネット
３２ 吸引ドラム
３３ 開孔部
３５ 支持用ネット
３６ ネット材
３７ 吸引ボックス
４０ 乾燥部
４１ ドラム状スルー・エアー・ドライヤー
５０ 巻取部[0001]
BACKGROUND OF THE INVENTION
The present invention manufactures bulky paperapparatusAbout. Themanufacturing deviceThe bulky paper produced using is preferably used for absorbent substrates such as paper towels, tissues, cleaning paper products and sanitary materials. The present invention also provides themanufacturing deviceTheUsingBulky paperofManufacturingMethodAbout.
[0002]
[Prior art]
In the conventional papermaking process, a smooth paper layer forming belt or a conveyor belt having fine openings of 50 to 100 mesh / inch is used for forming a fiber sheet, and further, on such a belt. The formed fiber sheet is uniformly subjected to press dehydration.
[0003]
Such a papermaking process is advantageous in terms of paper smoothness and strength, but disadvantageous in terms of paper thickness, water absorption capacity and softness. In addition, there is a manufacturing method using a through air dryer that allows the fiber sheet to pass through hot air and dry without performing the press dehydration process described above, but at a level that significantly increases the thickness of the paper, water absorption capacity, etc. Not reached.
[0004]
Further, in order to increase the paper thickness, water absorption capacity, and softness using such a conventional papermaking process, as a method for obtaining a larger inter-fiber gap, 1) a high concentration alkaline agent (for example, hydroxylation) A method of using mercerized fibers in which cellulose fibers are swollen with sodium) to increase the fiber cross-sectional area, and 2) a twisted shape prepared by crosslinking cellulose fibers with a crosslinked resin containing N-methylol groups, etc. For example, there is a method using a cross-linked fiber having. According to these methods, the gap between fibers can be increased to some extent and the thickness and absorption capacity can be increased, but the cost is higher than that of untreated cellulose fibers and the liquid is absorbed. When a little pressure is applied, the interfiber gap is easily broken.
[0005]
Thus, attempts have been made to produce bulky paper with improved thickness, water absorption capacity and softness from the viewpoint of the production process using untreated cellulose fibers.
[0006]
For example, in Japanese Patent Laid-Open No. 52-21405, the area of one aperture is 0.0072 mm.²~ 2.1mm²6.45cm²Using a perforated pattern transport belt having 100 to 3600 perforations per hole, the wet fiber sheet before drying is held on the perforated pattern transport belt and patterned by suction, and then not compressed Discloses a method for producing bulky paper, which is subjected to intermediate drying by passing through hot air and final drying with a Yankee dryer.
[0007]
Further, in Japanese Patent Laid-Open No. 5-506277 and Japanese Patent Laid-Open No. 5-506893, a hole pattern resin having a predetermined hole-shaped portion using a photosensitive resin and a conventional reinforcing pattern resin have been used. Using a perforated pattern conveyor belt combined with a paper transport belt, the wet fiber sheet before drying is patterned by suction, then passed through hot air without compression and intermediate dried, Yankee A method for producing a bulky paper that is finally dried by a dryer is disclosed. In particular, in these publications, in long-time continuous papermaking, chemicals such as antioxidants are showered on the belt during papermaking operation for the purpose of suppressing or delaying deterioration caused by oxidation of the resin of the aperture pattern conveying belt. Is added directly.
[0008]
Similarly, in Japanese Laid-Open Patent Publication No. 5-508449, Japanese Laid-Open Patent Publication No. 5-508450, and Japanese Laid-Open Patent Publication No. 5-508442, an aperture pattern resin using a photosensitive resin and a conventionally used papermaking are also used. An aperture pattern conveying belt in which the conveying belt is combined is disclosed. In particular, in these publications, in order to prevent the pulp from falling off from the pulp fiber sheet before drying by a strong suction process, the surface side of the hole pattern transport belt that contacts the suction box side is finished to a rough surface. It is disclosed.
[0009]
[Problems to be solved by the invention]
However, the prior art described in the above publication has the following drawbacks.
[0010]
That is, in Japanese Patent Laid-Open No. 52-21405, it is described that a versatile papermaking belt woven from 10 mesh to 60 mesh / inch is used as the aperture pattern conveying belt. Since the area of the belt is too small, the belt can be deflected to the hole if it is a short fiber up to an average fiber length of about 1.5 mm, but softwood pulp made of relatively long fibers is opened. It was impossible to deflect inward to form low density protrusions.
[0011]
Also disclosed in JP-T-5-506277, JP-T-5-506893, JP-T-5-508499, JP-T-5-508450, and JP-T-5-508852. In the case of using a perforated pattern belt in which a photosensitive resin-paper-making transport belt having a uniform perforated hole shape is combined, a continuous high-density network region and a low-density island region are formed. It will be formed by suction. In these publications, it is described that the diagonal of the rhombus is 1.6882 mm × 1.2379 mm as the most preferable dimension of the rhomboid opening. This is 1.046 mm as the area of one hole.²It corresponds to. However, the area of the opening is 3mm²If it is less than this, since the volume of the low density protrusion formed by suction is small, sufficient thickness, water absorption capacity and softness cannot be expressed. In addition, in the method of patterning the pulp sheet before drying by suction and transporting it to the drying process, the aperture pattern transport belt becomes considerably long, and an aperture pattern transport belt of a certain pattern is manufactured. But it will be quite expensive. When long-term continuous operation is carried out with such an aperture pattern conveyor belt, the resin part of the aperture pattern conveyor belt, which is responsible for transporting paper, is rubbed against the surface of many reversing rolls and Yankee dryers under strong pressure. Therefore, there is a problem in terms of the life of the belt. Furthermore, since such a long perforated pattern conveying belt requires a great deal of time for removal and replacement, in a single paper machine, normal paper having a uniform structure and a mesh-like high-density region It has been impossible to alternately produce bulky paper having island-like low density regions, or to easily change the pattern shape of the bulky paper.
[0012]
Therefore, the object of the present invention is suitable for the production of a bulky paper having a large thickness, high absorbency, excellent softness, and moderate strength.Manufacturing apparatus and manufacturing method using the sameIs to provide. In addition, the object of the present invention is a bulky paper manufacturing apparatus that can cope with long-term continuous operation and can easily switch to normal paper production and change the pattern shape.And manufacturing method using the sameIs to provide.
[0013]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the above object can be achieved by an aperture pattern net having a specific aperture pattern and a bulky paper manufacturing apparatus in which the aperture pattern net is installed at a specific position. I found out.
[0014]
The present invention has been made based on the above findings,One hole area is 3-25mm ² And an aperture pattern net having a large number of apertures where the aperture area ratio is 19 to 91% and the minimum width of the net material forming the apertures is 0.2 to 2 mm. Bulky paper manufacturing apparatus installed between or in a layer forming step and a drying stepBy providing the above, the above object is achieved.
[0015]
The present invention also provides the aboveA bulky paper manufacturing method using a bulky paper manufacturing apparatus, in which a fiber sheet having a moisture content of 50 to 99% by weight is held on an aperture pattern net, and the fiber sheet is patterned by suction. Paper manufacturing methodIs to provide.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present inventionBulk ofA preferred embodiment of a high paper manufacturing apparatus will be described in detail with reference to the drawings. Here, FIG. 1 is a schematic view showing an embodiment of a bulky paper manufacturing apparatus of the present invention, and FIG. 2 shows a main part of an embodiment of an aperture pattern net provided in the apparatus shown in FIG. 3 is an enlarged plan view, and FIG. 3 is an enlarged view of a main part showing a state of suction of the fiber sheet in the suction drum.
[0017]
The apparatus (paper machine) 1 shown in FIG. 1 and FIG. 2 has a suction drum in which a perforated pattern net having a large number of perforations is arranged on the peripheral surface, and is installed between the paper layer forming step and the drying step. This is a bulky paper manufacturing apparatus, and the apparatus 1 includes a raw material supply unit 10, a paper layer forming unit 20, a pattern applying unit 30, a drying unit 40, and a winding unit 50. The outline of each part of the apparatus 1 will be described as follows.
[0018]
The raw material supply unit 10 includes a papermaking raw material supply head 11, and a fiber suspension adjusted to a predetermined concentration is supplied from the papermaking raw material supply head 11 to the paper layer forming unit 20. .
The paper layer forming unit 20 includes a paper layer forming belt 21 and a suction box 22 for dehydration provided adjacent to the paper layer forming belt 21. The paper layer forming belt 21 is composed of a wire mesh belt used in an ordinary paper machine. On the other hand, the suction box 22 allows the fiber sheet 2 formed on the paper layer forming belt 21 to be dehydrated, and the moisture of the fiber sheet 2 conveyed to the pattern applying unit 30 as a downstream process. The rate is adjusted. Further, the conveyance pickup belt 23 travels from the paper layer forming unit 20 to the pattern applying unit 30 and the drying unit 40 described below, and the fiber sheet 2 can be stably conveyed. The suction box 24 is responsible for transferring the fiber sheet 2 from the paper layer forming belt 21 to the transport pickup belt 23.
The pattern applying unit 30 includes a suction drum 32. On the peripheral surface of the suction drum 32, as shown in FIG. 3, a fine support net 35 (about 40 to 120 mesh) made of wire mesh and a large number of apertures located on the outer periphery thereof. An aperture pattern net 31 having The suction box 37 provided in the suction drum 32 can suck air from the outside to the inside through the hole pattern net 31 and the support net 35. Further, the pattern applying unit 30 is provided with an air nozzle 38 and a weak suction box 39, whereby the fiber sheet 2 attached to the aperture pattern net 31 is transferred to the transport pickup belt 23. Making it easy.
The drying unit 40 includes a drum-shaped through air dryer (TAD) 41. In the drum-like through-air dryer 41, hot air passes from the outside to the inside of the drum peripheral surface. On the peripheral surface of the drum-like through-air dryer 41, a mesh net 42 is disposed. As the mesh net 42, a net having an opening degree that does not hinder the passage of hot air is used. Further, a suction box 43 is disposed in the vicinity of the lower end portion inside the drum-shaped through-air dryer 41, and the fiber sheet 2 transferred from the pattern applying unit 30 by the suction box is formed in the mesh shape. It is easy to transfer to the network 42.
In addition, the winding unit 50 includes a winder 51 for winding the manufactured bulky paper 3.
[0019]
The device 1 will be described in more detail. The aperture pattern net 31 disposed on the suction drum 32 in the pattern applying unit 30 is manufactured by punching a metal plate having a predetermined thickness as shown in FIG. A continuous mesh pattern is formed over the entire surface. More specifically, the opening pattern net 31 has a large number of equilateral triangular opening portions 33 formed over the entire surface thereof. The equilateral triangular apertures 33 are arranged so as to form one regular hexagonal pattern 34 via the net material (that is, the portion remaining after punching) 36, and the regular hexagonal pattern 34. Are arranged regularly to form a tortoiseshell pattern.
[0020]
In order to pattern the wet fiber sheet 2 by suction, it is important to use the aperture pattern net 31. The aperture pattern net 31 may be installed at any position as long as it is between the paper layer forming process and the drying process (including the drying process) in the apparatus 1. The installation form may be any, for example, it may be installed on a conveyor belt. Preferably, as described above, the opening pattern net 31 is disposed in the suction drum 32, and the suction drum is arranged. 32 is installed at a specific position in the apparatus 1.
[0021]
One area of the opening 33 in the opening pattern net 31 is 3 to 25 mm.²It is. The area is 3mm²If it does not satisfy this condition, the fibers are not sufficiently deflected into the aperture 33, and good low density protrusions (corresponding to a low fiber density region described later) cannot be formed in the resulting bulky paper. 25mm²If it exceeds, the fibers will fall off due to suction, and the resulting bulky paper will be easily perforated, and the area of the network-like high density region (corresponding to the high fiber density region described later) formed in the bulky paper Becomes small and bulky paper having sufficient strength cannot be obtained. The area of the opening 33 is 4 to 10 mm.²Is preferably 5 to 8 mm.²More preferably.
[0022]
Further, the area of the aperture 33 is related to the aperture area ratio in the aperture pattern net 31. That is, even if the individual areas of the apertures 33 are within the above-described range, a sufficiently bulky paper cannot be produced unless a certain aperture area is obtained as the entire aperture pattern net 31. Therefore, in the aperture pattern net 31, the individual areas of the apertures 33 are within the above range, and the aperture area ratio of the apertures 33 is 19 to 91%. Here, if the aperture area ratio is less than 19%, the area of the entire region (corresponding to a low fiber density region described later) in which low density protrusions are formed in the resulting bulky paper is reduced, and the absorption capacity And a bulky paper having a high texture cannot be obtained. On the other hand, if it exceeds 91%, the entire area (corresponding to a high fiber density region described later) forming a mesh-like high density region in the resulting bulky paper becomes small, and the bulky paper having sufficient strength is obtained. It can no longer be obtained. The opening area ratio is preferably 40 to 82%, and more preferably 50 to 75%. The aperture area ratio referred to in this specification refers to a value measured with respect to a region where the aperture 33 is formed in the aperture pattern net 31. The left and right side portions of the hole pattern net 31 that are not formed are excluded from the measurement target area of the hole area ratio.
[0023]
The area of the opening 33 is also related to the width of the net member 36 that forms (encloses) the opening 33 in the opening pattern net 31. That is, even if the individual areas of the apertures 33 are within the above-mentioned range, it is impossible to produce a paper that is sufficiently bulky and has good strength depending on the width of the net member 36. Therefore, in the hole pattern net 31, the individual areas of the hole portions 33 are in the above-described range, and the minimum width of the net material 36 is 0.2 to 2 mm. Here, if the width is less than 0.2 mm, the line width of the network-like high density region (corresponding to the high fiber density region described later) formed in the resulting bulky paper is too thin, Bulky paper having a sufficient strength cannot be obtained. If it exceeds 2 mm, the line width of the network-like high density region (corresponding to the high fiber density region described later) formed in the resulting bulky paper becomes too thick, resulting in a hard texture paper. The minimum width of the net member 36 is preferably 0.3 to 1 mm, and more preferably 0.3 to 0.8 mm. The minimum width of the net material referred to in the present invention is the narrowest width of the net material when the width of the net material is not constant (for example, when the aperture pattern net has a circular aperture). This refers to the width of the part, and when the width of the net material is constant, this width.
[0024]
Considering the above-described hole area, hole area ratio, and width of the net material 36 in the hole pattern net 31, when considering a square with a side of 1 cm, the holes in the hole pattern net 31 In any region where the portion 33 is formed, it is preferable that 4 to 17 hole portions 33 exist on average in the square, and more preferably 7 to 14 holes exist.
[0025]
Further, the thickness of the aperture pattern net 31, in other words, the depth of the aperture 33 is preferably 0.3 to 10 mm, more preferably 0.3 to 5 mm, and more preferably 0.5 to More preferably, it is 3 mm. If the thickness is less than 0.3 mm, the strength of the aperture pattern net 31 is not sufficient, and damage may easily occur during high-speed operation. If the thickness exceeds 10 mm, the stiffness of the aperture pattern net 31 increases and deformation occurs. Therefore, it may be difficult to install on the peripheral surface of the suction drum 32. Therefore, it is preferable that the suction drum 32 is within the above range.
[0026]
Further, the aperture pattern net 31 is preferably water-repellent from the viewpoint of papermaking stability (easy peeling of the fiber sheet 2 in close contact with the aperture pattern net 31). More preferably, the aperture pattern net 31 has a water repellency with a water repellent coating treatment and a water contact angle of 70 ° or more. Examples of the water-repellent coating treatment include surface treatment with a Teflon resin or the like. By using such an aperture pattern net, separation from the aperture pattern net is even better when the fiber sheet once attached to the aperture pattern net by patterning by suction is transferred to another conveying belt. This makes it more suitable for high-speed papermaking. Moreover, the peelability of the fiber sheet can also be improved by spraying a release agent onto the aperture pattern net. In this case, examples of the release agent used include polyolefin release agents, higher fatty acid release agents, and mineral oil release agents.
The contact angle was measured using a CONACT ANGLEMETER CA-D manufactured by Kyowa Interface Science Co., Ltd. at a temperature of 25 ° C., after 10 microliters of water was dropped on a small sample plate (76 mm × 26 mm) of an aperture pattern net with a syringe. It was obtained by measurement.
[0027]
Next, a method for producing bulky paper using the apparatus 1 shown in FIG. 1 will be described. First, a fiber suspension is supplied from the papermaking material supply head 11 onto the paper layer forming belt 21 to form the paper layer. Fibers are deposited on the belt 21 to form a wet fiber sheet (paper layer) 2. In addition, there is no restriction | limiting in particular in the density | concentration of the said fiber suspension, It can select suitably from the range which can perform a paper layer formation process stably.
[0028]
Next, the moisture contained in the fiber sheet 2 is dehydrated by the suction box 22 as a suction device, and the moisture content of the fiber sheet 2 before being transferred to the suction drum 32 as a downstream process is determined. Set to a predetermined value. The moisture content is sufficient to allow the fiber sheet 2 to be sufficiently patterned in the suction drum 32.Of 50 to 99% by weight, preferably 70 to 95% by weight, and more preferably 80 to 90% by weight. That is, if the moisture content is less than 50% by weight, the degree of freedom of each fiber in the wet fiber sheet 2 is low, so that it is difficult to reconstruct the fiber structure by suction. Further, the structure of the fiber sheet 2 cannot be maintained, and it is difficult to convey the fiber sheet 2.
[0029]
The fiber sheet 2 adjusted to a predetermined moisture content is separated from the paper layer forming belt 21 and transferred onto the surface of the aperture pattern net 31 of the suction drum 32. In the suction drum 32, air is sucked by the suction box 37 from the outside to the inside through the hole pattern net 31. Therefore, in the fiber sheet 2, a region (this region is referred to as “region A”) located on the opening portion 33 in the opening pattern net 31, as shown in FIG. Then, it has a convex shape that bites into the opening 33 and increases in thickness toward the inside of the suction drum 32. Further, the region A is a low fiber density region in which the fiber density of the constituent fibers is lower than before suction. In this case, since the supporting net 35 (about 40 to 120 mesh) finer than the aperture pattern net 31 is disposed below the aperture pattern net 31, the thickness in the region A is reduced. An abrupt increase (abrupt decrease in density) is regulated by the support net 35, and a large hole is not opened in the region A, or the fiber sheet 2 is not broken.
[0030]
On the other hand, the portion of the fiber sheet 2 located on the net material 36 in the aperture pattern net 31 and the vicinity thereof (this region is referred to as “region B”) are pressed against the net material by the suction. Therefore, the thickness is slightly reduced and the fiber density is slightly increased as compared with that before suction. That is, the region B is a high fiber density region relative to the region A. Such a high fiber density region has an action of suppressing a tendency of a decrease in tensile strength due to the low fiber density region in the obtained bulky paper. In particular, as described above, since the aperture pattern net 31 is formed from a continuous mesh pattern, the high fiber density region also becomes a continuous mesh pattern, and the tensile strength of the resulting bulky paper is further improved.
[0031]
Thus, patterning corresponding to the mesh pattern of the aperture pattern net 31 is performed on the fiber sheet 2 while the suction drum 32 makes a half turn.
[0032]
The suction force of the suction box 37 in the suction drum 32 depends on the basis weight, moisture content, and the like of the fiber sheet 2, but as a general range, it is preferably 50 to 500 mmHg, and 100 to 350 mmHg. More preferably it is.
[0033]
The fiber sheet 2 having a predetermined pattern in the suction drum 32 is then introduced into the drum-type through-air dryer 41 as a drying process and dried by passing through hot air. At this time, the consolidation step generally performed in a normal papermaking process is not performed. The reason for this is to prevent the bulkiness of the resulting bulky paper from being impaired.
[0034]
The fiber sheet is dried while the drum-type through-air dryer is rotated almost once to obtain a bulky paper 3 as a final product. The bulky paper 3 obtained is wound up by the winder 51 in the winding unit 50.
[0035]
Bulky paper is manufactured by the above steps. In the apparatus 1, by arranging the aperture pattern net 31 on the suction drum 32, the following cannot be obtained by the conventional bulky paper manufacturing method. There are advantages as described.
That is, the aperture pattern net 31 is fixed to the suction drum 32, and since the aperture pattern net 31 has no movable part, it is not easily deteriorated even if used continuously for a long time, and its service life is prolonged. . Further, the pattern shape can be easily changed by a simple operation of simply replacing the aperture pattern net 31. Further, by moving the suction drum 32 downward and removing it from the traveling path of the fiber sheet 2, normal papermaking can be easily performed, and switching to normal papermaking is easy.
[0036]
FIG. 4 schematically shows the cross-sectional structure of the bulky paper obtained using the bulky paper manufacturing apparatus provided with the aperture pattern net.
As shown in FIG. 4, the low fiber density region 4 and the high fiber density region 5 exist in the bulky paper 3 obtained by the above-described method. The low fiber density region 4 is formed corresponding to the opening portion 33 in the opening pattern net 31 and has a relatively large thickness. On the other hand, the high fiber density region 5 is formed corresponding to the net 36 material surrounding the hole portion 33 in the hole pattern net 31 and has a relatively small thickness. As a result, the bulky paper 3 has a concavo-convex shape and is extremely bulky and thick. Therefore, it has high absorbency and excellent softness. Moreover, since the high fiber density region 5 having high strength has a continuous mesh pattern, the bulky paper 3 also has appropriate strength. Further, when a wet paper strength enhancer such as a polyamidoamine or epichlorohydrin resin that expresses wet strength is used, the fibers can be bonded to each other in a state of having an uneven structure defined by the aperture pattern net 31. Since adhesion occurs, it has an excellent feature that its uneven shape is maintained even when wet.
[0037]
The fiber constituting the bulky paper 3 will be described. As the fiber, a short fiber having a fiber length of 10 mm or less, particularly 0.5 to 5 mm is preferably used. Such short fibers include, for example, wood pulp such as softwood and hardwood chemical pulp, semi-chemical pulp and mechanical pulp, mercerized pulp and crosslinked pulp obtained by chemically treating these wood pulp, non-wood fibers such as hemp and cotton, and Cellulosic fibers such as regenerated fibers such as rayon fibers; and synthetic fibers such as polyethylene fibers, polypropylene fibers, polyester fibers, and polyamide fibers. Among these fibers, it is preferable to use cellulosic fibers such as wood pulp, non-wood harp, and rayon fibers from the viewpoint of product cost, strength, papermaking suitability, and the like. In particular, wood pulp is more preferable from the viewpoint of product cost. These short fibers are preferably used in an amount of 50 to 100% by weight, more preferably 70 to 100% by weight, based on the whole fibers constituting the bulky paper 3.
[0038]
When the bulky paper 3 is used as a cleaning sheet impregnated with an absorbent base material such as a paper towel or tissue, or a cleaning agent, the cellulose fiber is contained in an amount of 50 to 100% by weight based on the whole fiber. Is preferred. In addition to this, it is also preferable to add a wet paper strength enhancer such as a polyamidoamine / epichlorohydrin resin in order to develop wet strength. In general, the wet paper strength enhancer is preferably added in an amount of 0.2 to 2.0% by weight based on the whole bulky paper. In order to develop higher wet strength, it is also preferable to use a wet paper strength enhancer in which an appropriate amount of an anionic polymer such as carboxymethyl cellulose or an amphoteric polymer such as amphoteric polyacrylamide is mixed with the above-mentioned polyamidoamine / epichlorohydrin resin.
[0039]
In order to increase the strength when using the bulky paper 3 as an absorbent base material such as a paper towel or tissue, or to maintain the thickness of the two-ply embossed bulky paper 3, It is preferable to contain 70 to 97% by weight of the cellulose fiber and 3 to 30% by weight of thermoplastic fiber. As such a thermoplastic fiber, a fiber containing a thermal adhesive component having an average melting point of 160 ° C. or lower, that is, a fiber in which a part of the fiber surface is melted by heat treatment at a high temperature (eg, 100 ° C. or higher) is preferably used. Examples of such fibers include a core having a low melting point type fiber such as a low melting point polyester copolymer fiber, a polyethylene fiber, an ethylene vinyl alcohol fiber or a polyvinyl alcohol fiber as a sheath component and a high melting point type fiber as a core component. Examples of the sheath-type fiber and those in which one of the side-by-side fibers is the low-melting-point type fiber can be given.
[0040]
As described above, the present inventionBulk ofHigh paper manufacturing equipmentAnd method for producing bulky paper using the sameHowever, the scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, as the above-mentioned opening pattern net, in addition to the one shown in FIG. 2, one having a square opening as shown in FIG. 5A or a regular hexagonal opening as shown in FIG. Or those having a circular aperture, or those arbitrarily combining these shapes can also be used.
Further, as the hole pattern net, in addition to those produced by punching a metal plate, those produced by etching a metal plate, those produced by weaving metal or synthetic resin wires (threads), etc. are used. be able to.
In the apparatus shown in FIG. 1, the pattern applying unit 30 may be installed in the drying unit 40 so that the pattern applying unit 30 and the drying unit 40 are integrated. That is, the opening pattern net is disposed on the peripheral surface of the drum-shaped through-air dryer 41 in the drying unit 40, and the fiber sheet 2 is dried while being sucked and patterned. May be.
Moreover, in the apparatus shown in FIG. 1, while installing a Yankee dryer between the said drying part 40 and the winding-up part 50, a creping doctor is installed in parallel at the exit of this Yankee dryer, The texture may be further improved. In this case, it is preferable that the degree of drying of the fiber sheet in the drum-shaped through-air dryer 41 is lowered.
Further, in the above embodiment, the case of patterning a wet fiber sheet formed in a line of a paper machine (in-line patterning) has been described as an example, but instead of this, normal paper making is once performed. The paper obtained by the normal paper making may be re-wetted to form a fiber sheet having the above moisture content, and then the fiber sheet may be patterned (off-line patterning) by the aperture pattern net.
In addition, as for the points that are not particularly described with respect to the above-described bulky paper manufacturing apparatus, the description relating to a conventionally known paper machine is applied as appropriate.
[0041]
【Example】
The following examples illustrate the effectiveness of the present invention. However, the scope of the present invention is not limited to such examples.
[0042]
[Example 1]
Sponge bleached kraft pulp (NBKP, weight average fiber length 2.35 mm) beaten to 680 ml of Canadian Standard Freeness (CSF) in a pulp slurry dispersed at a concentration of 1% by weight, Kaimen WS- as a wet paper strength enhancer 570 (manufactured by DIC Hercules) 0.625% (% by weight of pulp), 0.25% of carboxymethylcellulose (WS-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a dry paper strength enhancer and a sponge yield improver % (Vs. pulp weight%) was added to obtain a papermaking raw material.
Using the prepared papermaking raw material, a bulky paper was produced using a test papermaking apparatus as shown in FIG. As the paper layer forming belt 21 in FIG. 1, a polyester 1,4-satin woven belt having a length of 90 mesh / inch × width of 85 mesh / inch was used.
The above papermaking raw material was supplied onto the paper layer forming belt 21 from the papermaking raw material supply head 11 of the apparatus shown in FIG. 1 and sucked and dehydrated by the suction box 22 to form a fiber sheet 2 having a moisture content of 85% by weight.
Next, the fiber sheet 2 is transferred to a suction drum 32 provided with a perforated pattern net 31 on the peripheral surface, and is sucked at 150 mmHg by a suction box 37 provided on the suction drum 32, and the fiber sheet 2 is paper layer. The pattern was imparted by moving from the forming belt 21 onto the surface of the aperture pattern net 31. Here, as the aperture pattern net 31, an aperture area having a regular triangular aperture shape shown in FIG. 2 is 5.3 mm.²A metal pattern plate having a net material width of 0.5 mm, an aperture area ratio of 64.2%, and a thickness of 0.5 mm was used. The metal pattern plate has a Teflon coating treatment with a surface contact angle of 95 ° with respect to water, so that the fiber sheet 2 can be peeled off from the suction drum 32.
The patterned fiber sheet 2 is transferred to the transport pickup belt 23 by the weak suction of the air nozzle 38 and the weak suction box 39 and is introduced into the drum-shaped through air dryer 41. The fiber sheet 2 is dried with hot air at 150 ° C. in the dryer 41, and the basis weight is 25 g / m.²Of bulky paper 3 was obtained. The paper making speed when producing bulky paper was 10 m / min.
The peelability of the patterned fiber sheet 2 from the perforated pattern net 31 disposed on the suction drum 32 when producing bulky paper was evaluated. The results are shown in Table 1 together with the production conditions. In Table 1, “◯” indicates that the peelability is very good, and “Δ” indicates that the peelability is such that it does not interfere with production. The peelability was also evaluated at a paper making speed of 50 m / min.
In order to investigate the thickness, strength and absorbency of the bulky paper thus obtained, the average dry thickness (3 g / cm²23 g / cm under load²Under load), average wet thickness (3 g / cm²23 g / cm under load²Under load), dry tensile strength (MD, CD), wet tensile strength (MD, CD), and saturated water absorption per unit area were measured by the following methods. The results are shown in Table 2.
[0043]
<Average dry thickness>
Using a thickness meter (R5-C) manufactured by Ozaki Mfg. Co., Ltd., a 75 g acrylic plate having a 5 × 5 cm bottom is placed on a piece of bulky paper and 3 g / cm.²The average dry thickness under load was measured. In addition, a further 500 g of weight is placed on the acrylic plate and 23 g / cm.²The average dry thickness under load was measured.
[0044]
<Average wet thickness>
The bulky paper was cut into 7 cm × 7 cm, soaked in a large amount of water for 5 seconds, then drained for 10 seconds, and the average wet thickness was measured in the same manner as in the case of the average dry thickness.
[0045]
<Dry tensile strength>
After the bulky paper is cut into a strip shape having a width of 25 mm and a length of 100 mm, it is promptly used with a universal compression tensile tester (Orientic Co., RTM-25) with a tensile speed of 300 mm / min and a test piece gripping interval of 50 mm. The strength at break was measured under the conditions. In Table 1, MD indicates the strength in the flow direction of the paper machine, and CD indicates the strength in the direction orthogonal thereto.
[0046]
<Wet tensile strength>
The bulky paper was cut into strips having a width of 25 mm and a length of 100 mm, immersed in a large amount of water for 5 seconds, drained for 10 seconds, and then the strength at break was measured by the same method as the dry tensile strength.
[0047]
<Saturated water absorption>
Cut bulky paper into 7cm x 7cm, soak in a large amount of water for 20 seconds, drain water for 30 seconds, and then the weight of water absorbed by bulky paper (g / 49cm²) Was measured with a balance.
[0048]
[Example 2]
As shown in FIG. 5A, the hole pattern area 31 in the device used in Example 1 (the device shown in FIG. 1) has a square hole shape of 5.3 mm.²The same as in Example 1 except that a metal pattern plate (contact angle with respect to water: 95 °) treated with a Teflon coating with a net material width of 0.5 mm, an aperture area ratio of 67.5%, and a thickness of 0.5 mm was used. Basis weight 25g / m²Of bulky paper. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained bulky paper. The results are shown in Table 2.
[0049]
Example 3
An opening area of 5.3 mm having a regular hexagonal opening shape as shown in FIG. 5B as the opening pattern net 31 in the apparatus used in Example 1 (apparatus shown in FIG. 1).²The same as in Example 1 except that a metal pattern plate (contact angle with respect to water: 87 °) treated with a Teflon coating having a net material width of 0.5 mm, an aperture area ratio of 69.2%, and a thickness of 0.5 mm was used. Basis weight 25g / m²Of bulky paper. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained bulky paper. The results are shown in Table 2.
[0050]
Example 4
An aperture area of 20 mm having a square aperture shape as shown in FIG. 5 (a) as the aperture pattern net 31 in the apparatus used in Example 1 (apparatus shown in FIG. 1).²The same operation as in Example 1 except that a Teflon-coated metal pattern plate (contact angle with respect to water: 98 °) having a net material width of 2 mm, an aperture area ratio of 47.7%, and a thickness of 1.5 mm was used. With a basis weight of 25 g / m²Of bulky paper. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained bulky paper. The results are shown in Table 2.
[0051]
Example 5
An aperture area of 9 mm having a square aperture shape as shown in FIG. 5A as an aperture pattern net 31 in the apparatus used in Example 1 (apparatus shown in FIG. 1).², Except for using a woven net (contact angle with respect to water: 77 °) of a flat glass fiber woven fabric treated with a Teflon coating having a width of 1 mm, an aperture area ratio of 56.3%, and a thickness of 0.61 mm. The basis weight is 25 g / m in the same operation as in Example 1.²Of bulky paper. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained bulky paper. The results are shown in Table 2.
[0052]
Example 6
A basis weight of 25 g / m was obtained in the same manner as in Example 1 except that the metal pattern plate used in Example 1 was not treated with Teflon coating.²Paper was manufactured. In addition, the contact angle with respect to the water of this metal pattern plate was 42 degrees. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained paper. The results are shown in Table 2.
[0053]
[Comparative Example 1]
In Example 1, a basis weight of 25 g / m was obtained in the same manner as in Example 1 except that suction by the suction box 37 was not performed.²Paper was manufactured. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained paper. The results are shown in Table 2.
[0054]
[Comparative Example 2]
As shown in FIG. 5 (a), the hole pattern area 31 in the apparatus used in Example 1 (the apparatus shown in FIG. 1) has a square hole part shape of 2 mm.²The same as in Example 1 except that a metal pattern plate (contact angle with respect to water: 95 °) treated with a Teflon coating having a width of net material of 0.5 mm, an aperture area ratio of 54.6%, and a thickness of 0.5 mm was used. Basis weight 25g / m²Paper was manufactured. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained paper. The results are shown in Table 2.
[0055]
[Comparative Example 3]
As shown in FIG. 5A, the hole pattern area 31 in the apparatus used in Example 1 (apparatus shown in FIG. 1) has a square hole part shape of 30 mm.²The same as in Example 1 except that a metal pattern plate (contact angle with respect to water: 87 °) treated with a Teflon coating with a net material width of 0.5 mm, an aperture area ratio of 84.0%, and a thickness of 0.5 mm was used. Basis weight 25g / m²Paper was manufactured. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained paper. The results are shown in Table 2.
[0056]
[Comparative Example 4]
In Example 1, the papermaking raw material was supplied onto the paper layer forming belt 21 from the papermaking raw material supply head 11 of the apparatus shown in FIG. 1 and sucked and dehydrated by the suction box 22 to form a fiber sheet 2 having a moisture content of 45% by weight. . Thereafter, the basis weight was 25 g / m by the same operation as in Example 1.²Paper was manufactured. The production conditions are shown in Table 1 together with the evaluation of the peelability of the fiber sheet.
Moreover, the same measurement as Example 1 was performed about the obtained paper. The results are shown in Table 2.
[0057]
[Table 1]

[0058]
[Table 2]

[0059]
As is clear from the results shown in Tables 1 and 2, the bulky paper (Examples 1 to 6) obtained using the specific aperture pattern net has a larger thickness and absorbability than the paper of the comparative example. It can be seen that it is high and has an appropriate strength.
In addition, as is clear from the comparison between Example 1 and Example 6, the use of the aperture pattern net having a contact angle with water of a specific value or more further improves the peelability of the fiber sheet particularly during high speed papermaking. It turns out that it becomes favorable.
[0060]
【The invention's effect】
As detailed above, the present inventionBulk ofHigh paper manufacturing equipmentAnd method for producing bulky paper using the sameAccording to this, a bulky paper having a large thickness, high absorbency, excellent softness, and moderate strength can be obtained.
Further, according to the bulky paper manufacturing apparatus of the present invention, since the aperture pattern net is fixed to the suction drum and there are no movable parts, it is difficult to deteriorate and its service life is prolonged.
Moreover, according to the bulky paper manufacturing apparatus of the present invention, the pattern shape can be easily changed by a simple operation of simply replacing the aperture pattern net. Furthermore, by simply moving the suction drum downward and removing it from the fiber sheet traveling path, normal paper production can be facilitated, and switching to normal paper production is easy.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a bulky paper manufacturing apparatus according to the present invention.
2 is an enlarged plan view showing a main part of one embodiment of an aperture pattern net provided in the apparatus shown in FIG. 1; FIG.
FIG. 3 is an enlarged view of a main part showing a state of suction of the fiber sheet in the suction drum.
4 is a schematic diagram showing a cross-sectional structure of a bulky paper obtained using the bulky paper manufacturing apparatus shown in FIG. 1. FIG.
FIGS. 5A and 5B are schematic views (corresponding to FIG. 2) showing another example of the aperture pattern net, respectively.
[Explanation of symbols]
1 Bulky paper manufacturing equipment
2 Fiber sheet
3 Bulky paper
4 Low fiber density region
5 High fiber density region
10 Raw material supply department
20 Paper layer forming section
30 pattern giving section
31 Opening pattern net
32 Suction drum
33 Openings
35 Supporting net
36 Net material
37 Suction box
40 Drying section
41 Drum-shaped through air dryer
50 Winding part

Claims (5)

One hole area is 3-25mm ² And an aperture pattern net having a large number of apertures where the aperture area ratio is 19 to 91% and the minimum width of the net material forming the apertures is 0.2 to 2 mm. A bulky paper manufacturing apparatus installed between or within a layer forming step and a drying step. The bulky paper manufacturing apparatus according to claim 1, wherein the perforated pattern net has water repellency with a water contact angle of 70 ° or more. The area of one aperture in the aperture pattern net is 4 to 7 mm ² and the area ratio of the aperture is 40 to 82%, and the minimum width of the net material forming the aperture is 0.3 to 1 mm. The bulky paper manufacturing apparatus according to claim 1, wherein the aperture pattern net has a thickness of 0.3 to 10 mm. The bulky paper manufacturing apparatus in any one of Claims 1-3 whose shape of the said opening part is a triangle. A method for producing a bulky paper using the bulky paper production apparatus according to any one of claims 1 to 4, wherein the fiber sheet having a moisture content of 50 to 99% by weight is held on the aperture pattern net. A method for producing bulky paper, wherein the fiber sheet is patterned by suction.

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