JP4983019B2 - Paper manufacturing method, paper manufacturing apparatus - Google Patents

Description

The present invention enables printing using, for example, a general recording material such as ink or toner (for example, printing using an electrophotographic or inkjet image forming apparatus), and magnetic or electromagnetic means. non-fibrous pulp (e.g., magnetic) which can record and reproduce information by a method the production of paper comprising, apparatus for producing paper.

  Shortly after the Personal Information Protection Law was put in place, personal information leak cases were still occurring. In particular, while electronic information is being strengthened, there are a number of incidents of leaking paper documents on which personal information has been written out, and rapid development of security technology for paper documents is desired. In particular, documents can be easily copied with a copying machine. Recently, a method for suppressing copying of important documents and prohibiting copying has been developed. However, these technologies are effective for a copier manufactured by the same company, and even if copying cannot be performed by a specific company, copying can be easily performed by using a copier of a different company. There are many cases where several copiers are located in the same company in the workplace.

  In this situation, there was no effective means other than strict monitoring of measures to prevent the copied material from flowing out of the company.

  Therefore, it was considered to insert a detectable marker on paper, which is an important document. Conventionally, on copy paper, substances other than pulp are used except for chemical additives used to make paper. Was treated as a foreign body.

  When materials other than pulp (non-pulp fibers) are mixed in the pulp, as shown in Japanese Patent Publication (B2) No. 3-27679, is it relatively long compared to the fiber or the length of the pulp? Those of the same degree (length of 7 mm or less) could be mixed. A chemical fiber such as rayon is also conceivable as a substance to be mixed. Moreover, although it is a pulp, the pseudo fiber etc. which were aggregated and aggregated by a certain amount beforehand are also used.

  In non-pulp fibers (examples other than organic matter), Japanese Patent Application Laid-Open No. 11-323786, Japanese Patent Publication No. 2893321, and Japanese Patent Publication No. (b2) 2893309 performed a work of attaching a metal needle-like material to the surface of wet paper. There is something.

  As non-pulp fibers, magnetic materials having a large Barkhausen effect that are currently on the market have a diameter of 80 μm to 100 μm (for example, Nihon Hojo Co., Ltd.) (300 μm with a coating layer), and the surface is simply In order to insert the sheet without exposing it, a paper thickness of 600 μm or more is required, and the use of such a paper is limited, so that it cannot be used as a copy sheet having a thickness of 60 to 110 μm. Regardless of the paper thickness, there is no method for producing such a large quantity of paper, and at present, a magnetic wire is later attached to the base paper or article that has been produced. Although there is a method of putting something other than pulp inside the paper as a thread, only a production amount far from the mass production required by the present case can be obtained.

Patent Gazette (B2) No. 3-27679 JP-A-11-323786 Japanese Patent Publication No. 2893321 Patent Publication (b2) 2893309

  However, there is no paper in which a magnetic fiber having a length of 10 mm or more is sprinkled on paper while maintaining the large Barkhausen effect, and the magnetic fiber does not appear on the surface. It is also demanded to produce such paper in large quantities and at a low price. In particular, especially for electrophotographic paper, there is a problem that the image can be transferred and fixed without problems even through a copying machine. Therefore, there is a great demand for paper on which a magnetic material does not appear on the surface. is the current situation.

Accordingly , the present invention provides a paper manufacturing method and a paper manufacturing apparatus capable of producing a large amount and a low cost of paper that does not expose non-pulp fibers to the outside of the paper and is difficult to visually recognize from the outside. This is the issue.

The above-mentioned subject is achieved by the following present invention. That is ,

In addition, the method for producing the paper of the present invention,
In the middle of a supply pipe for supplying the non-pulp fiber-containing aqueous medium to the first wet pulp from a dispersion tank in which the non-pulp fiber-containing aqueous medium containing the non-pulp fiber and the first aqueous medium is stored, the non-pulp fiber Supplying a second aqueous medium to the aqueous medium, and reducing the viscosity of the non-pulp fiber-containing aqueous medium;
The non-pulp fiber-containing aqueous medium supplied with the second aqueous medium is used as the first wet pulp in a pouring section for supplying the first wet pulp to the papermaking net from the raw material tank in which the first wet pulp is stored. by supplying the, the incorporation step of incorporating the non-pulp fibers in the first wet pulp,
In the papermaking net, a first paper making process to form a first wet pulp layer from said first wet pulp non pulp fibers are mixed,
A second papermaking step of forming a second wet pulp layer from the second wet pulp on the first main surface of the first wet pulp layer;
A third papermaking step of forming a third wet pulp layer from the third wet pulp on the second main surface of the first wet pulp layer;
It is characterized by having.

  In the paper manufacturing method of the present invention, the mixing step may be a step of mixing the non-pulp fibers into the first wet pulp over the formation width of the first wet pulp layer.

In the paper manufacturing method of the present invention, the mixing step may be a step of mixing the non- pulp fibers by diversion.

In the paper manufacturing method of the present invention, the non-pulp fiber-containing aqueous medium is preferably one in which the non-pulp fiber is stirred and dispersed in the first aqueous medium by air .

Moreover, the paper manufacturing apparatus of the present invention comprises:
In the middle of a supply pipe for supplying the non-pulp fiber-containing aqueous medium to the first wet pulp from a dispersion tank in which the non-pulp fiber-containing aqueous medium containing the non-pulp fiber and the first aqueous medium is stored, the non-pulp fiber An aqueous medium supply means for supplying a second aqueous medium to the aqueous medium, and lowering the viscosity of the non-pulp fiber-containing aqueous medium;
The non-pulp fiber-containing aqueous medium supplied with the second aqueous medium is used as the first wet pulp in a pouring section for supplying the first wet pulp to the papermaking net from the raw material tank in which the first wet pulp is stored. by supplying the, the contamination means the incorporation of the non-pulp fibers in the first wet pulp,
In the papermaking net, a first paper making means for forming a first wet pulp layer from said first wet pulp non pulp fibers are mixed,
A second papermaking means for forming a second wet pulp layer from the second wet pulp on the first main surface of the first wet pulp layer;
A third papermaking means for forming a third wet pulp layer from the third wet pulp on the second main surface of the first wet pulp layer;
It is characterized by having.

  In the paper manufacturing apparatus of the present invention, the mixing means may be means for mixing the non-pulp fibers into the first wet pulp over the formation width of the first wet pulp layer.

In the paper manufacturing apparatus of the present invention, it is preferable that the mixing means is a means for diverting and mixing the non- pulp fibers.

In the paper manufacturing apparatus of the present invention, the non-pulp fiber-containing aqueous medium is preferably one in which the non-pulp fiber is stirred and dispersed in the first aqueous medium by air .

According to the present invention, there are provided a paper manufacturing method and a paper manufacturing apparatus capable of producing a large amount and a low price of paper that does not expose non-pulp fibers to the outside of the paper and is hardly visible from the outside. be able to.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is provided to the member which has the substantially same function through all the drawings, and the overlapping description may be abbreviate | omitted.

  FIG. 1 is a plan view showing paper according to an embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a schematic configuration diagram illustrating a paper manufacturing apparatus according to the embodiment. FIG. 4 is a perspective view showing a non-pulp fiber dispersing / mixing device according to the embodiment. FIG. 5 is a schematic configuration diagram showing a flow divider of a non-pulp fiber dispersing / mixing device.

  The paper 100 according to the embodiment is a multilayer paper obtained by multilayer papermaking of three or more layers (in this embodiment, a three-layer paper obtained by three-layer papermaking), as shown in FIGS. The first outer layer 102 and the second outer layer 104 are made through the intermediate layer 106. Then, non-pulp fibers 108 are encased in the paper-made intermediate layer 106. Depending on the manufacturing conditions, the non-pulp fibers 108 may be randomly drawn into the paper 100 or may be arranged in a predetermined direction. However, the non-pulp fibers 108 are preferably randomly drawn.

  Note that the interlayers of the intermediate layer 106, the first outer layer 102, and the second outer layer 104 are actually difficult to distinguish, but in the drawing, the layers are clearly separated for easy understanding. Also. In the figure, the non-pulp fibers 108 are included only in the intermediate layer 106, but the non-pulp fibers 108 are also present in the first outer layer 102 and the second outer layer 104 by, for example, a pressing step as a post-papermaking step. Sometimes it is embedded.

  As described above, since the paper 100 according to the embodiment is inserted into the intermediate layer 106 of the paper obtained by the three-layer papermaking, the non-pulp fibers 108 included in the paper 100 are the first outer layer 102 and the second layer 102. Since the non-pulp fiber 108 contained in the paper 100 is present so as to be sandwiched between the outer layers 104, the non-pulp fiber 108 contained in the paper 100 is in a general environment or use condition (for example, under normal indoor illumination light or sunlight, Even when the paper is placed on top or when the paper is seen through the light, it is difficult to be easily seen from the outside.

  The paper can be used as paper, recording paper, electrophotographic paper, or the like, and a good image can be formed by an electrophotographic system or an inkjet system.

  Further, since it can be obtained by multilayer papermaking, it can be produced in large quantities and at low cost.

  In addition, it is not limited to three-layer papermaking, and may be a multilayer papermaking of four or more layers, and the non-pulp fibers 108 may be included in at least one of the inner layers.

  Hereinafter, each component (material) will be described in detail. Note that the reference numerals are omitted.

First, non-pulp fibers will be described. Non-pulp fibers include inorganic fibers and organic fibers. Among these, materials having specific gravity as close as possible to paper pulp are particularly suitable. As the organic fibers, nylon, polyethylene, used tea leaves.

  Inorganic fibers include iron-based, cobalt-based, nickel-based, silicon-based or magnetic alloys made of these alloys. Among these, iron-cobalt-based amorphous alloys are magnetic fibers in terms of detection. Is preferred.

  As long as this magnetic fiber is made of a magnetic material having a characteristic that causes a large Barkhausen effect, its magnetic properties, composition, shape, and the like are not particularly limited. However, as magnetic properties, it is preferable that the hysteresis loop is substantially rectangular and the coercive force (Hc) is relatively small.

  The composition of the magnetic fiber includes, for example, magnetic elements (for example, Co, Fe, Ni), alloys containing transition metals and glass forming elements (for example, Si, B, C, P) (for example, Co-based, There are Fe-based, Ni-based, and mixed systems such as Co-B-Si, Co-Fe-B-Si, etc.), and the composition ratio and manufacturing method of the constituent elements should be selected. Can be used with various magnetic properties. Note that the hue of an amorphous alloy composed of the above elements is not significantly affected by the ratio of the elements.

  The magnetic fiber is in the form of a fiber, in other words, a line or a band, and this shape is suitable because a predetermined length is required for the cross-sectional area to cause the large Barkhausen effect. .

  The magnetic fiber should be such a size that the magnetic fiber is exposed on the surface of the paper or the paper is dispersed so that it is not located near the surface. Is good. On the other hand, in order for the magnetic fiber to have a large Barkhausen effect, the outer diameter (fiber diameter) is preferably 10 μm or more.

  For this reason, for example, when the magnetic fiber is encapsulated in paper having a thickness of 80 to 120 μm, for example, the magnetic fiber (magnetic wire) has a circular cross section and an outer diameter (fiber diameter) of 10 to 60 μm. More preferably, it is 15-55 micrometers, More preferably, it is 25-45 micrometers. On the other hand, the length (fiber diameter) of the magnetic fiber (magnetic wire) depends on the outer diameter, and when the outer diameter is 10 to 60 μm, it is preferably 10 to 40 mm, more preferably 5 to 40 mm. .

  The magnetic fiber can be used as it is dispersed in paper, but is preferably covered with an insulating layer (hereinafter sometimes referred to as “insulating layer”). This is because, when the magnetic fiber enters the paper, the volume resistance value of the paper is reduced, or if it is exposed to the paper surface, it causes an electrical short in the transfer process in the electrophotographic recording process. This is because there is a possibility that application to a PPC application becomes difficult, or the large Barkhausen effect may be hindered. Such a magnetic fiber becomes, for example, a composite material having a fiber shape in which an amorphous magnetic material having soft magnetism is used as a magnetic core, and the magnetic core is covered with an insulating layer.

  The material constituting the insulating layer is not particularly limited as long as it is a known insulating material, and for example, resin, glass, or the like can be used. In addition, when using resin as an insulating material, it is preferable to use polyimide resin etc. which have heat resistance.

  Such an insulating layer preferably has a thickness of 2.5 to 10 [mu] m, more preferably 2.0 to 5.0 [mu] m, in order to exhibit its covering effect.

  The method for forming the insulating layer is not particularly limited, and depending on the material for forming the insulating layer, vapor deposition methods such as sputtering, CVD (Chemical Vapor Deposition), vacuum deposition, dip coating, roller coating, spray coating, A known thin film forming method such as a liquid phase film forming method such as coating using a sol-gel method can be appropriately selected. However, in order to form a uniform and thinner insulating layer, a vapor phase film forming method can be used. Is preferred. The insulating layer can be formed almost simultaneously with the wire formation of the magnetic material. For example, immediately after the molten magnetic material is processed into a wire shape, the magnetic fiber is cooled and CVD is performed. The insulating layer can also be formed by a phase film formation method.

  When the paper is applied to the use of PPC, the magnetic fiber is assumed to pass through a high-heated part through a fixing heater or the like for toner fixing. Therefore, considering the fixing temperature, the Curie temperature of the magnetic material is preferably 200 ° C. or higher, and more preferably 300 ° C. or higher.

  Here, the Curie temperature is also referred to as the Curie point, and when the amorphous material reaches that temperature, the physical structure changes in the amorphous state even after cooling, and the characteristics such as the loss of the large Barkhausen effect in the present invention. is there.

  The magnetic fiber is obtained by melting a magnetic material, passing it through a discharge port having a shape corresponding to a desired cross-sectional shape, and then cooling it. Specifically, for example, an underwater rotary spinning method can be used.

  Also, the magnetic fiber and the insulating layer can be manufactured almost simultaneously. For example, immediately after a molten magnetic material is processed into a fiber shape (wire shape) having a desired cross-sectional shape, a method of forming an insulating layer by a vapor deposition method such as CVD, which also serves to cool magnetic fibers Can be applied.

  In addition, a magnetic fiber (magnetic wire) covered with glass (insulating layer) can be manufactured by a manufacturing method (Taylor-Ulitovsky method) described in USP 3,256,584. That is, a metal alloy is charged in the glass tube, and the tip of the glass tube is heated and melted by an induction coil to create a state where the periphery of the metal melting material is covered with melted glass, which is rapidly cooled with a cooling medium. Thereby, the magnetic fiber which coat | covered the amorphous magnetic wire with glass can be obtained.

The inclusion amount of the magnetic substance in the paper is preferably 154 / m ² , σ = 42 (A4 conversion, 10 and σ = 5), more preferably σ is 20 or less. Is preferred. . By making the inclusion amount within the above range, detection using the large Barkhausen effect is possible, and the appearance as paper can be improved.

  Next, paper components (hereinafter referred to as base paper) constituting the intermediate layer and the outer layer of paper will be described. The base paper is made mainly of at least pulp fibers.

  The base paper contains pulp fibers, but known pulp fibers can be used. Specifically, chemical pulp, specifically hardwood bleached kraft pulp, hardwood unbleached kraft pulp, softwood bleached kraft pulp , Softwood unbleached kraft pulp, hardwood bleached sulfite pulp, hardwood unbleached sulfite pulp, softwood bleached sulfite pulp, softwood unbleached sulfite pulp, etc. Used pulp can be used.

  In addition, ground wood pulp that mechanically pulped wood and chips, chemimechanical pulp mechanically pulped after soaking chemicals into wood and chips, and pulp with a refiner after digesting the chips until they become slightly soft Thermomechanical pulp that has been made into a material can also be used.

  Cotton pulp fiber, hemp pulp fiber, kenaf pulp fiber, bagasse pulp fiber, viscose rayon fiber, regenerated cellulose fiber, copper ammonia rayon fiber, cellulose acetate fiber, polyvinyl chloride fiber, polyacrylonitrile fiber, polyvinyl alcohol fiber, Polyvinylidene chloride fiber, polyolefin fiber, polyurethane fiber, polyvinyl chloride, polyvinyl alcohol copolymer, fluorocarbon fiber, glass fiber, carbon fiber, alumina fiber, metal fiber, silicon carbide fiber, etc. can also be used. .

  Moreover, if necessary, fibers obtained by impregnating or heat-sealing synthetic fibers such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyester into pulp fibers can be used.

  These may be used only in virgin pulp, and if necessary, high-quality and medium-quality waste paper pulp can be blended. The amount of waste paper pulp is determined according to the purpose of use and purpose. For example, when waste paper pulp is blended from the viewpoint of resource protection, it is 10% by weight or more, preferably 30% by weight or more in the total fiber. Can be blended.

  In particular, pulp used in virgin is bleached mainly using ozone / hydrogen peroxide without using chlorine gas and without using chlorine dioxide (Elementary Chlorine Free; ECF) or chlorine compounds. It is preferably one that has been bleached by a method (Total Chlorine Free; TCF).

  In addition, as raw materials for waste paper pulp, unprinted waste paper such as cuts, damaged paper, widened white, special white, medium white, and white loss generated in bookbinding, printing factories, cutting offices, etc .; printing and copying Used high-quality printed paper, high-quality coated paper, etc .; used paper printed with water-based ink, oil-based ink, pencil, etc .; printed high-quality paper, high-quality coated paper, medium-sized paper, medium-sized coated paper, etc. Including used newspapers; used paper such as medium quality paper, medium quality coated paper, and reprint paper;

  The waste paper pulp is preferably obtained by treating the waste paper raw material with at least one of ozone bleaching treatment and hydrogen peroxide bleaching treatment. Moreover, in order to obtain a base paper with higher whiteness, it is desirable that the blending ratio of the used paper pulp obtained by the bleaching treatment is 50% by weight or more and 100% by weight or less. Furthermore, from the viewpoint of resource reuse, it is more desirable that the ratio of waste paper pulp is 70 wt% or more and 100 wt% or less.

  Ozone treatment has the effect of decomposing fluorescent dyes and the like normally contained in fine paper, and hydrogen peroxide treatment has the effect of preventing yellowing due to alkali used during deinking treatment. In particular, it is known that the combination of the two not only facilitates deinking of waste paper, but also improves the whiteness of the pulp. Moreover, since it also has an action of decomposing and removing residual chlorine compounds in the pulp, it has a great effect in reducing the content of organic halogen compounds in the waste paper using chlorine bleached pulp.

In order to adjust the opacity, whiteness and surface properties, it is preferable to add a filler to the base paper. In particular, when it is desired to reduce the amount of halogen in the paper, it is preferable to use a filler containing no halogen.
Fillers include heavy calcium carbonate, light calcium carbonate, chalk, kaolin, calcined clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, aluminum silicate, calcium silicate, magnesium silicate, synthetic Examples include white inorganic pigments such as silica, aluminum hydroxide, alumina, sericite, white carbon, saponite, calcium montmorillonite, sodium montmorillonite, and bentonite, and organic pigments such as acrylic plastic pigments, polyethylene, and urea resins. . Further, thermoplastic resin particles (for example, polyester-based or styrene-acrylic-based) can be used as a filler. In addition, when mix | blending waste paper, it is necessary to estimate the ash content contained in a waste paper raw material previously, and to adjust addition amount.

  The blending amount of the inorganic pigment as the filler is desirably 0% by mass or more and 10% by mass or less, and more desirably 0% by mass or more and 8% by mass or less. In addition, the blending amount of the organic pigment, particularly thermoplastic resin particles as the filler can be fused between the fibers by heat in the fixing process in the case of electrophotography, and is blended in an amount of 0% by mass to 10% by mass. It is desirable that 0 to 5% by mass is blended. When blended in an amount of 10% by mass or more, the opacity of the paper is lowered as in the case of impregnation with resin, which is not preferable.

  Various chemicals such as a sizing agent can be used for the base paper by internal or external addition. Types of sizing agents can include sizing agents such as rosin sizing agents, synthetic sizing agents, petroleum resin sizing agents, and neutral sizing agents. Suitable sizing agents such as sulfate bands and cationized starch, fibers Can be used in combination with other fixing agents. In particular, in the case of electrophotographic applications, from the viewpoint of paper storage stability after copying in an electrophotographic copying machine or printer, neutral sizing agents such as alkenyl succinic anhydride sizing agents, alkyl ketene dimers, alkenyl ketene dimers are used. Neutral rosin, petroleum size, olefin resin, styrene-acrylic resin and the like are preferable. As the surface sizing agent, modified cellulose such as oxidized modified starch, enzyme modified starch, polyvinyl alcohol and carboxymethyl cellulose can be used alone or in combination.

In the case where the surface of the base paper is adjusted to be cationic, for example, a hydrophilic cationic resin or the like can be treated on the surface as the cationic substance, in order to suppress penetration of the cationic resin into the inside. In this case, the paper sizing degree before applying the cationic resin is preferably 10 seconds or more and less than 60 seconds.
For base paper, inorganic substances such as sodium chloride, potassium chloride, calcium chloride, sodium sulfate, zinc oxide, titanium dioxide, tin oxide, aluminum oxide, magnesium oxide, and alkylphosphoric acid ester acid are used to adjust the electrical resistivity of the paper. In addition, organic materials such as alkylsulfuric acid esters, sodium sulfonates, and quaternary ammonium salts can be used alone or in combination.

  A paper strength enhancer can be internally or externally added to the base paper. Examples of paper strength enhancers include starch, modified starch, vegetable gum, carboxymethyl cellulose, polyvinyl alcohol, modified polyvinyl alcohol, polyacrylamide, styrene-maleic anhydride copolymer, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer. Polymers, polyacrylate urea-formaldehyde resin, melamine-formaldehyde resin, dialdehyde starch, polyethyleneimine, epoxidized polyamide, polyamide-epichlorohydrin resin, methylolated polyamide, chitosan derivatives, etc. Alternatively, they can be mixed and used.

  For the base paper, in addition to the above-mentioned ones, various auxiliaries blended in ordinary coated paper base paper such as dyes and pH adjusters may be used as appropriate.

The basis weight (JIS P-8124) of the base paper (each layer) is not particularly defined, but is preferably 50 g / m ² or more and 105 g / m ² or less. When the basis weight is less than 50 g / m ² , in the case of electrophotographic use, paper squeezing becomes small, so that it is easy to generate wrapping in the fixing process and image defects due to peeling failure. If it exceeds 105 g / m ² , in order to make it easy to fix the toner, means such as a reduction in fixing speed is required, and productivity may be reduced, which is not desirable from this viewpoint.

  In addition to these, various auxiliaries such as dyes and pH adjusters that are blended in ordinary paper media are appropriately used.

Next, other characteristics and configuration of the paper will be described. The paper is made of polyvinyl alcohol, modified polyvinyl alcohol, styrene-maleic anhydride copolymer, vinyl chloride-vinyl acetate containing at least starch and having a saponification degree of 90 mol% or more using a size press, gate roll, etc. on the surface. It is preferable to blend a copolymer, a styrene-butadiene copolymer, and a polyacrylic ester. At that time, with respect to starch 100 parts by weight, mixing 5 parts by mass or more preferably, coated to be at least dry weight 0.8 g / ^{m 2} or more per side at 3 g / ^{m 2} or less. More preferably, it is desirable to apply 1 g / m ² or more and 3 g / m ² or less. If it exceeds 3 g / m ² , it is not preferable because it has adhesiveness particularly in a high-humidity environment and a paper feed failure occurs.

  The paper may be surface-treated with a surface sizing liquid or may be provided with a coating layer as necessary. For surface treatment, coating liquid for surface sizing or coating layer formation is usually applied using size press, shim size, gate roll, roll coater, bar coater, air knife coater, rod blade coater, blade coater, etc. Can be performed by applying to the base paper.

  Examples of the pigment used in this coat layer include pigments used in ordinary general coated paper, such as heavy calcium carbonate, light calcium carbonate, titanium dioxide, aluminum hydroxide, satin white, talc, calcium sulfate, barium sulfate, Mineral pigments such as zinc oxide, magnesium oxide, magnesium carbonate, amorphous silica, colloidal silica, white carbon, kaolin, calcined kaolin, delaminated clay, aluminosilicate, sericite, bentonite, smectite, and polystyrene resin fine particles Urea formaldehyde resin fine particles, fine hollow particles, and other organic pigments can be used alone or in combination.

As an adhesive used for the coat layer, a synthetic adhesive or a natural adhesive can be used.
Synthetic adhesives include styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, vinyl acetate / butyl acrylate, and other copolymers, polyvinyl alcohol, maleic anhydride copolymer, Examples thereof include acrylic acid / methyl methacrylate copolymer. Among these synthetic adhesives, one or more types can be used depending on the purpose. These adhesives are preferably used in the range of about 5 to 50% by weight, more preferably about 10 to 30% by weight per 100% by weight of the pigment.

  Examples of natural adhesives include generally known adhesives such as oxidized starch, esterified starch, enzyme-modified starch, cold water soluble starch obtained by flash drying them, casein, and soy protein. These adhesives are also used in the range of about 0.1 to 50% by weight, more preferably about 2 to 30% by weight per 100% by weight of the pigment.

  Moreover, various auxiliary | assistant mix | blended with the pigment for normal coated papers, such as a dispersing agent, a thickener, a water retention agent, an antifoamer, and a water-proofing agent, are used suitably as needed.

The coating composition prepared to contain the components as described above is a coating apparatus used in general coated paper production, such as a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, A die slot coater, a gravure coater, or the like can be applied on the base paper in one layer or multiple layers by on-machine or off-machine. The coating amount is generally applied so that the dry weight is about 5 to 15 g / m ^{2 on} one side. However, in the present invention, in order to make it difficult to visually recognize the magnetic material from the outside, It may be larger than the range.

  For the smoothing treatment after coating, a commonly used smoothing device, for example, a super calendar, a machine calendar, a soft nip calender or the like is used, and it is preferably finished so that the gloss of the blank paper is 30% or more.

  Since the thickness of the paper is preferably 80 to 120 μm, the thickness of each layer (intermediate layer, outer layer) is preferably 20 μm to 60 μm, more preferably 20 μm to 50 μm, and even more preferably 30 μm to 50 μm.

Further, as means for reducing the ten-point average surface roughness Rz of paper, the pressure in the wet press process in the paper making process can be increased, or the linear pressure of the calendar roll can be increased in the calendar process. A calendar process is particularly effective. The adjustment can also be made by reducing the freeness of the pulp used. Furthermore, although it is effective to increase the amount of filler, it is preferable not to add a large amount because it may promote the generation of paper dust. The means for lowering Rz is not necessarily limited to these, and any known means may be used.

Further, when finishing paper, the product moisture content immediately after opening is within an appropriate range, specifically, preferably 3 to 6.5% by mass, more preferably about 4.5 to 5.5% by mass. It is preferable to adjust the water content with a paper machine so as to be within the range. Moreover, it is desirable to wrap using moisture-proof wrapping paper such as polyethylene laminate paper or material such as polypropylene so that moisture absorption and desorption does not occur during storage.

The use of paper is not particularly limited, and examples thereof include electrophotographic paper and inkjet paper. For example, when applied to application to electrophotographic paper, for example, the surface electrical resistivity under the environmental conditions of 22 ° C. and 55% RH is in the range of 1.0 × 10 ^{9 to} 1.0 × 10 ¹¹ Ω, and 22 ° C. The volume electrical resistivity under an environmental condition of 55% RH is preferably in the range of 1.0 × 10 ^{10 to} 1.0 × 10 ¹² Ω · cm. Thus, when printing is performed by an electrophotographic recording method, toner transfer failure does not occur, and a clear image quality can be obtained.

  In addition, the paper which has the said surface electrical resistivity and volume electrical resistivity can be obtained by selecting each structural material according to Unexamined-Japanese-Patent No. 2003-76051, for example.

Hereinafter, a paper manufacturing method according to the embodiment will be described. In the paper according to the embodiment, non-pulp fibers are mixed into the first wet pulp, and a first wet pulp layer is formed from the first wet pulp mixed with non-pulp fibers (hereinafter sometimes referred to as “non-pulp”). Then, a second wet pulp layer is formed from the second wet pulp on the first main surface of the first wet pulp layer, and a third wet pulp layer is further formed from the third wet pulp to the first wet pulp layer. It is obtained by forming on the second main surface.

  An example of a manufacturing apparatus used in the recording medium manufacturing method according to the embodiment is the manufacturing apparatus shown in FIG. Note that. In the manufacturing apparatus shown in FIG. 3, only the wet part is shown, and a press part, a dryer part, a calendar part, a reel part, and the like, which are subsequent processes, can be configured with known ones, and are omitted.

  The paper manufacturing apparatus shown in FIG. 3 is a three-layer paper machine, a long-mesh type intermediate layer paper machine 10, a circular net type first outer layer paper machine 20, and a circular net type second outer layer paper machine 30. And. And the dispersion | distribution and supply apparatus 40 which disperse | distributes a non-pulp fiber to an aqueous medium and supplies this to the 1st wet pulp 11 is further provided. Reference numeral 50 denotes a felt endless body. The felt endless body 50 is for absorbing the moisture of the wet pulp layer.

  The long-mesh type intermediate layer paper machine 10 is for forming a first wet pulp layer from a first wet pulp 11 serving as an intermediate layer, and a long net 12 stretched by a pair of rolls 12A, A first raw material tank 13 for storing one wet pulp 11 and pouring the first wet pulp 11 onto the long net 12.

  The circular net-type first outer layer paper machine 20 is for forming a second wet pulp layer from the second wet pulp 21 serving as the first outer layer, in which the circular net 22 and the second wet pulp 21 are stored. The second raw material tank 23 in which the circular net 22 is half-immersed is provided.

  The circular net-type second outer layer paper machine 30 is for forming a third wet pulp layer from the third wet pulp 31 serving as the second outer layer, in which the circular net 32 and the third wet pulp 31 are stored. The third raw material tank 33 in which the circular net 32 is half-dipped is provided.

  The dispersion / supply device 40 stirs and disperses non-pulp fibers in an aqueous medium (for example, water) (hereinafter, this may be referred to as a non-pulp fiber-containing aqueous medium 41), and stores a dispersion tank 42. A stirrer blade 43 for stirring and dispersing non-pulp fibers, an air supply pipe 44 for stirring and dispersing non-pulp fibers, and a non-pulp fiber-containing aqueous medium 41 of a long-mesh intermediate layer paper machine 10 And a supply device 45 that supplies the first raw material tank 13.

  As shown in FIG. 4, one end of the air supply pipe 44 is disposed along the side wall in the dispersion tank 42. Although not shown, the other end is connected to an air pump. The supply pipe 44 is bent at the end, and the air supply port 44A is directed so that an air bubble flow is supplied along the peripheral edge of the bottom of the dispersion tank 42. The air supply port 44 </ b> A is preferably directed so that the air bubble flow is supplied in a direction opposite to the rotation direction, particularly when all the stirring blades 43 have the same rotation direction. As a result, a liquid flow is generated by rotation of the stirring blade 43, and a liquid flow is also generated by air bubbles to the bottom peripheral edge of the dispersion tank 42 where non-pulp fibers are likely to settle and accumulate. The dispersed state can be kept uniform.

  As described above, in order to maintain a non-pulp fiber in a physically dispersed state in a physically dispersed medium ((diffusion / dispersed and floating state), for example, an aqueous medium that rotates in a spiral shape can be considered. When the rotation stops, the non-pulp fiber has a specific gravity greater than that of the aqueous medium, so that the non-pulp fiber settles down over time. Non-pulp fibers can be supplied in a uniformly dispersed state (diffused, dispersed and suspended), so that non-pulp fibers can be dispersed in the intermediate layer with good dispersibility and random orientation. Can do.

  The direction of the air supply port 44A is not limited to the above, and for example, the air supply port 44A may be arranged so that an air bubble flow is supplied toward the bottom surface of the dispersion tank 42. As a result, the air bubbles flow over the bottom surface, and as a result, an air bubble flow is supplied along the bottom peripheral edge of the dispersion tank 42 and an air bubble flow is generated at the bottom peripheral edge of the dispersion tank 42. Become.

  Here, the diameter of the air supply port 44A of the air supply pipe 44 is, for example, 3 cm or less. The arrangement position of the air supply port 44A is set to a height of, for example, 1 to 2 cm from the bottom surface of the dispersion tank 42. Further, the air to be supplied is not limited to the bubble shape, but the bubble shape is most suitable in view of maintaining an efficient non-pulp fiber dispersion state.

  Meanwhile, the supply device 45 includes a supply pipe 45A, a flow divider 45B connected to one end of the supply pipe on the first raw material tank 13, a pump 45C, and an aqueous medium supply pipe 45D connected to the supply pipe 45A. It has. The connection position of the aqueous medium supply pipe 45D to the supply pipe 45A is preferably immediately after the pump 45C. This is because it is better that the non-pulp fiber-containing aqueous medium 41 and the aqueous medium supplied from the aqueous medium supply pipe 45D are mixed for a longer time. As shown in FIG. 5, the flow divider 45 </ b> B constitutes a supply port of the supply device 45, and has a supply width equivalent to the first wet pulp layer width formed from the first wet pulp 11 serving as an intermediate layer. In addition, the flow dividing plate 45B-1 is arranged in parallel so that the non-pulp fiber-containing aqueous medium 41 supplied to the inside can be divided and supplied. It is desirable that the flow distributor 45B including the fractionating plate 45B-1 has a structure in which the corners are chamfered and rounded (by forming a curved surface) so that the non-pulp fibers are not clogged.

  Thereby, when supplying the non-pulp fiber-containing aqueous medium 41, the non-pulp fiber-containing aqueous medium 41 is evenly distributed over the first wet pulp layer width, and the supply hydraulic pressure is dispersed, whereby the first wet pulp 11 is distributed. The non-pulp fiber-containing aqueous medium 41, that is, the non-pulp fibers can be supplied without breaking the formation of the (first wet pulp layer to be formed).

  The diverter 45B is disposed at the pouring portion of the first raw material tank 13 (the most downstream side of the long net 12) so that it can be supplied immediately before the first wet pulp 11 is poured onto the long net 12 from the first raw material tank 13. Yes. This also makes it possible to supply the non-pulp fiber-containing aqueous medium 41, that is, non-pulp fibers, without breaking the formation of the first wet pulp 11 (the first wet pulp layer to be formed).

  Non-pulp fibers are supplied from the supply pipe 45A, an aqueous medium (for example, water) is supplied from the aqueous medium supply pipe 45D, and an additive-free aqueous medium is mixed with the non-pulp fibers and supplied to the first wet pulp. It is good. In order to maintain the dispersion state, the non-pulp fiber is dispersed and supplied in an aqueous medium having a certain degree of viscosity in the dispersion tank 42 by an additive. By supplying to the pulp, the viscosity of the non-pulp fiber-containing aqueous medium 41 can be reduced, and the mixing (sedimentation) of the non-pulp fibers into the first wet pulp can be accelerated, and as a result, the intermediate layer is satisfactorily mixed. It will be.

  Next, in the paper manufacturing apparatus shown in FIG. 3, paper making is performed as follows. First, separately, non-pulp fibers are dispersed and mixed in an aqueous medium (for example, water). At this time, other chemicals (for example, the paper strength enhancer and the thickener) are added to the aqueous medium. A small amount of a surfactant can also be added as necessary.

  Here, the paper strength enhancer is, for example, water-based for the purpose of maintaining the paper strength when wet, preventing paper breakage during papermaking, improving the surface strength of the finished paper, and preventing paper dust generation. It is added in an amount of 0.1 to 3.0 parts by weight per 100 parts by weight of the medium.

  A thickener is an additive that increases the viscosity of an aqueous medium and functions non-pulp fibers as a uniform dispersion aid. Specifically, for example, a cellulose-modified product (for example, carboxymethylcellulose, methylcellulose, ethylcellulose, etc.), Examples thereof include polyacrylic acid type, starch type (oxidized starch, enzyme-modified starch, amphoteric starch, etc.), polyvinyl alcohol, and the like. Among these, water-soluble cellulose is preferable because it has a thickening effect with a relatively small addition amount, and has little influence on the desorption performance of moisture on paper after paper making. The amount of the water-soluble cellulose added can be 0.3 to 10 parts by weight (in terms of solid content) with respect to 100 parts by weight of the aqueous medium.

  Further, the surfactant is an additive for preventing the non-pulp fibers from being entangled with each other. Specifically, any of cationic, anionic and nonionic surfactants can be used. preferable.

  Separately, the non-pulp fibers dispersed in the aqueous medium are put into the dispersion tank 42 of the dispersion / supply device 40, and the dispersion state is maintained by the stirring blades and air bubbles.

  Next, the non-pulp fiber-containing aqueous medium 41 is pumped up by the supply device 45 (the pump 45C) of the dispersion / supply device 40, and is supplied from the first raw material tank 13 onto the long net 12 through the supply pipe 45A and the flow divider 45B. 1 wet pulp 11 is supplied immediately before pouring.

  Then, the first wet pulp 11 mixed with the non-pulp fibers is poured onto the long mesh 12 by the long-mesh type intermediate layer paper machine 10 to form the first wet pulp layer, that is, the non-pulp fibers are mixed. An intermediate layer is formed.

  At this time, the pumping of the non-pulp fiber-containing aqueous medium 41 is preferably performed, for example, by turning the pump 45C on and off at regular intervals and by a predetermined amount at regular intervals. Although it may be pumped continuously and supplied, the ratio of non-pulp fibers to the paper (intermediate layer) can be controlled to some extent by changing the interval. Further, since non-pulp fibers can be supplied over a long period of time without being released at a time, they can be poured into paper (intermediate layer) while maintaining the dispersed state.

  Further, before supplying the non-pulp fiber-containing aqueous medium 41 to the first wet pulp 11, an aqueous medium (for example, water) is supplied from the aqueous medium supply, and the non-pulp fiber-containing aqueous medium 41 is added to the non-added aqueous medium 41. Mix.

  And after forming the 1st wet pulp layer (intermediate layer) in which the non-pulp fiber was infiltrated, the 1st wet pulp layer of the 1st wet pulp layer was carried out by the 1st outer-layer-type paper machine 20 (circular mesh 22). The second wet pulp 21 is adhered to the main surface side to form a second wet pulp layer, that is, a first outer layer.

  Next, the third wet pulp 31 is adhered to the second main surface side of the first wet pulp layer by the second net type paper machine 30 (circular mesh 32) of the circular net type, that is, the third wet pulp layer is formed. A second outer layer is formed.

Here, the basis weight of the papermaking of the first wet pulp by the long net type is 40 to 50 g / m ² for the long net, for example. Further, the basis weight of the papermaking by the second and third wet pulp by the circular net type is, for example, 15 to 30 g / m ² with respect to the circular net.

  Thereafter, although not shown, as a subsequent process, pressing (pressing), dryer (drying), calendar (drying), and reel (winding) are performed by a known method.

  In this way, the first wet pulp layer (intermediate layer) in which the non-pulp fibers are encased is sandwiched between the second wet pulp layer (first outer layer) and the third wet pulp layer (second outer layer). A large amount of paper can be obtained at a low price. For this reason, the non-pulp fibers contained in the paper are exposed to the outside of the paper, are placed on a desk under normal environment or usage conditions (for example, under normal indoor lighting or sunlight, Even if it is taken in), it is difficult to visually recognize from the outside.

(Test example)
Paper was manufactured according to the paper manufacturing method described in the above embodiment (see FIGS. 3 to 5). Note that the description is omitted.

  First, the following magnetic wires were obtained as non-pulp fibers. First, as a magnetic material, an Fe—Co amorphous magnetic material wire (Hc = 19.1 A / m) having a length of 25 mm and a diameter of 27 μm was prepared. This magnetic wire is gray black, and the color coordinates L *, a *, b * of the L * a * b * color system defined by JIS Z 8729 are 16.9, 0.0, 12. 6.

  Next, the magnetic wire was obtained by coating the magnetic wire with a transparent glass insulating layer having a thickness of about 5 μm by the following procedure. The magnetic wire after the coating treatment has the same color as the magnetic wire.

  The insulating layer was formed by processing the melted magnetic material into a wire shape and passing this magnetic wire through the sealed chamber and simultaneously depositing a silica film in the chamber.

Next, as a paper strength enhancer and a thickening agent, 2.5 parts by weight of oxidized starch (trade name: Ace A, manufactured by Oji Cornstarch Co., Ltd.) is added to 100 parts by weight of water and stirred at 95 ° C. for 10 minutes. Thereafter, an aqueous solution cooled to 50 ° C. was prepared, and 10 km of the magnetic wire, that is, 400,000 magnetic wires of 25 mm, was added to this and stirred and mixed.

This magnetic wire-containing aqueous solution is put into a dispersion tank of a dispersion / supply device, and a stirring blade (maximum length: 15 cm, maximum width: 6 cm) is performed at a rotational speed of 400 to 600 rpm and an air supply pipe (diameter: 3 cm, arrangement) The height and length were substantially the same as the height of the stirring layer), and air bubbles were jetted at a flow rate of 1 m ³ / min to stir and disperse the magnetic wire.

While stirring and dispersing, the mixture was supplied to the first wet pulp of the long net paper machine by the supply device of the mixing and stirring device.

This supply is performed through a flow divider (see FIG. 5) over the first wet pulp layer width that continuously forms a fixed amount of 0.5 m ³ / min of the magnetic wire-containing aqueous solution, and the first wet pulp. Went just before the flow into the Nagaami. Moreover, the magnetic wire-containing aqueous solution was supplied in a state where the amount of water further mixed was the same as the amount of the magnetic wire-containing aqueous solution released and the viscosity thereof was lowered immediately before supply.

  Then, the first wet pulp supplied with the magnetic wire is poured into a long mesh to form a first wet pulp layer having a thickness of 30 μm, and accordingly, the magnetic wire sinks into the first wet pulp layer, Was sown into the wet pulp layer.

  Next, the second wet pulp is attached to the first main surface side of the first wet pulp layer in which the magnetic wire is wound by a circular net type first outer layer paper machine, and the first outer layer has a thickness of 35 μm. A two-wet pulp layer was formed. Subsequently, the third wet pulp is adhered to the first main surface side of the first wet pulp layer in which the magnetic wire is wound by a circular net type second outer layer paper machine, and the thickness of 35 μm which becomes the second outer layer is A three-wet pulp layer was formed.

  Here, as the first to third wet pulps, the following pulp slurries were used. Contains 80 parts by weight of hardwood bleached kraft pulp (LBKP), 10 parts by weight of softwood bleached kraft pulp (NBKP) and 10 parts by weight of organic synthetic fiber (generic name: para-aramid fiber, trade name: Technora, manufactured by Teijin Ltd.) To a pulp slurry having a freeness of 430 ml obtained by beating the pulp slurry with Niagara Beata (manufactured by Kumagai Riki Kogyo Co., Ltd.), light calcium carbonate (Tama Pearl TP-121, Okutama Industry ( 8 parts by weight, 0.5 parts by weight of aluminum sulfate, 0.5 parts by weight of cationized starch (trade name: MS4600, manufactured by Nippon Food Chemical Co., Ltd.), alkenyl succinic anhydride (Fibrane 81, Oji National) Co., Ltd.) 0.09 parts by weight and crosslinking agent (generic name: carbodiimide-based crosslinking agent, carbodilite V-04) 0 .8 parts by weight was added, and these mixtures were diluted with white water to prepare a pulp slurry having a solid concentration of 0.3% by weight.

  Thereafter, pressing (pressing), dryer (drying), calendar (drying), and reel (winding) were performed, and the paper was cut into A4 size to obtain a paper having a predetermined size.

  When the obtained paper was examined, it was difficult to visually recognize the magnetic wire from the appearance. Further, when the magnetic wire was confirmed by cutting the paper or peeling the outer layer, the orientation was randomly drawn in all directions of 360 degrees. Then, for 100 sheets of paper, when the number of magnetic wires squeezed per sheet is counted, the magnetic body follows a normal distribution as shown in FIG. 6 while maintaining a uniform dispersion state. It turns out that the wire has been drawn. Here, FIG. 6 is a diagram showing the distribution of the number of magnetic substance wires (number of non-pulp fibers) wound into the paper produced in the test example. This normal distribution indicates the number of magnetic wires (non-pulp fibers) per unit area of paper.

  Further, when the total number of magnetic wires inserted into all the obtained papers was examined, 52% of the total number of magnetic wires used (400,000) was found in the paper. Since the production loss due to cutting or the like is considered to be 30 to 40%, the loss during the production process is considered to be about 8 to 18%.

  On the other hand, with the paper produced in the same manner except that 5 km magnetic wires, that is, 200,000 25 mm magnetic wires and no air bubbles were used, the total number of magnetic wires used (200,000) ) Was 7% on paper. Since the production loss due to cutting or the like is considered to be 30 to 40%, the loss during the production process is considered to be about 53 to 63%.

  As a result, the magnetic wire was satisfactorily wound into the paper in all cases, but using the air bubbles, to the peripheral edge of the bottom of the dispersion tank (the tank that stirs and disperses the magnetic wire before supplying it to the wet pulp) It can be seen that the loss during the production process of the magnetic wire can be reduced by sending the air flow and generating the liquid flow. Further, there was an effect of reducing the clogging of the wire at the outlet of the magnetic wire mixed water due to the turbulent water flow caused by the bubbles. It was also found that the number of magnetic wires inserted per sheet increased.

  In addition, the wet pulp used in the circular net type paper machine does not contain a magnetic wire, and when the circular net is dehydrated, there is basically a problem that the magnetic wire is clogged in the net. Did not occur.

It is a top view which shows the paper which concerns on embodiment. It is AA sectional drawing of FIG. It is a schematic block diagram which shows the paper manufacturing apparatus which concerns on embodiment. It is a perspective view which shows the dispersion | distribution and mixing apparatus of the non-pulp fiber which concerns on embodiment. It is a schematic block diagram which shows the flow divider of the dispersion | distribution / mixing apparatus of a non-pulp fiber. It is a figure which shows distribution of the number of magnetic body wires (number of non-pulp fibers) entrapped in the paper produced in the test example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intermediate layer paper machine 11 1st wet pulp 12 Long mesh 12A Roll 13 1st raw material tank 20 1st outer layer paper machine 21 2nd wet pulp 22 Circular net 23 2nd raw material tank 30 2nd outer layer paper machine 31 3rd wet pulp 32 Circular net 33 Third raw material tank 40 Dispersion / feed device 41 Non-pulp fiber-containing aqueous medium 42 Dispersion tank 43 Stirring blade 44 Air supply pipe 44A Air supply port 45 Supply apparatus 45A Supply pipe 45B Shunt 45C Pump 45D Aqueous medium supply pipe 45B-1 flow dividing plate 50 felt endless body 100 paper 102 first outer layer 104 second outer layer 106 intermediate layer 108 non-pulp fiber

Claims (8)

In the middle of a supply pipe for supplying the non-pulp fiber-containing aqueous medium to the first wet pulp from a dispersion tank in which the non-pulp fiber-containing aqueous medium containing the non-pulp fiber and the first aqueous medium is stored, the non-pulp fiber Supplying a second aqueous medium to the aqueous medium, and reducing the viscosity of the non-pulp fiber-containing aqueous medium;
The non-pulp fiber-containing aqueous medium supplied with the second aqueous medium is used as the first wet pulp in a pouring section for supplying the first wet pulp to the papermaking net from the raw material tank in which the first wet pulp is stored. A mixing step of mixing the non-pulp fibers into the first wet pulp,
A first papermaking step of forming a first wet pulp layer from the first wet pulp mixed with the non-pulp fibers in the papermaking net;
A second papermaking step of forming a second wet pulp layer from the second wet pulp on the first main surface of the first wet pulp layer;
A third papermaking step of forming a third wet pulp layer from the third wet pulp on the second main surface of the first wet pulp layer;
A method for producing paper.   The paper manufacturing method according to claim 1, wherein the mixing step is a step of mixing the non-pulp fibers into the first wet pulp over the formation width of the first wet pulp layer. The paper manufacturing method according to claim 1, wherein the mixing step is a step of diverting and mixing the non- pulp fibers.   2. The paper manufacturing method according to claim 1, wherein the non-pulp fiber-containing aqueous medium is obtained by stirring and dispersing the non-pulp fibers in the first aqueous medium with air. In the middle of a supply pipe for supplying the non-pulp fiber-containing aqueous medium to the first wet pulp from a dispersion tank in which the non-pulp fiber-containing aqueous medium containing the non-pulp fiber and the first aqueous medium is stored, the non-pulp fiber An aqueous medium supply means for supplying a second aqueous medium to the aqueous medium, and lowering the viscosity of the non-pulp fiber-containing aqueous medium;
The non-pulp fiber-containing aqueous medium supplied with the second aqueous medium is used as the first wet pulp in a pouring section for supplying the first wet pulp to the papermaking net from the raw material tank in which the first wet pulp is stored. A mixing means for mixing the non-pulp fiber into the first wet pulp;
A first papermaking means for forming a first wet pulp layer from the first wet pulp mixed with the non-pulp fibers in the papermaking net;
A second papermaking means for forming a second wet pulp layer from the second wet pulp on the first main surface of the first wet pulp layer;
A third papermaking means for forming a third wet pulp layer from the third wet pulp on the second main surface of the first wet pulp layer;
A paper manufacturing apparatus.   The paper manufacturing apparatus according to claim 5, wherein the mixing unit is a unit that mixes the non-pulp fibers into the first wet pulp over the formation width of the first wet pulp layer. 6. The paper manufacturing apparatus according to claim 5, wherein the mixing means is means for diverting and mixing the non- pulp fibers.   The paper manufacturing apparatus according to claim 5, wherein the non-pulp fiber-containing aqueous medium is obtained by stirring and dispersing the non-pulp fibers in the first aqueous medium with air.

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