WO2017188248A1

WO2017188248A1 - Method for manufacturing laminated pulp sheet and device for manufacturing laminated pulp sheet

Info

Publication number: WO2017188248A1
Application number: PCT/JP2017/016374
Authority: WO
Inventors: 山田菊夫
Original assignee: 山田菊夫
Priority date: 2016-04-28
Filing date: 2017-04-25
Publication date: 2017-11-02
Also published as: JP6837058B2; JPWO2017188248A1

Abstract

To improve efficiency in the production of a laminated pulp sheet having a desired strength, the present invention provides a method for manufacturing a laminated pulp sheet, the method comprising: an application step for applying a binder several times to the same surface of a laminated pulp sheet containing a pulverized pulp or a fiber the main ingredient of which is the pulverized pulp; and a drying step for drying the laminated pulp sheet every time the binder is applied.

Description

Pulp product sheet manufacturing method and pulp product sheet production apparatus

The present invention relates to a method for producing a pulp fiber sheet that can be used as a cleaning sheet and a pulp fiber sheet manufacturing apparatus.

As a wet tissue that is a pulp-stacked sheet obtained by stacking pulp into a sheet, there is one composed of a first layer composed of a tissue web containing cellulose fibers and a second layer composed of an airlaid nonwoven web (patent) Document 1, claim, and claim 11).

The wet tissue described in Patent Document 1 requires a first layer obtained by papermaking, a second layer obtained by an airlaid method different from the first layer, and a binder that integrates both. Here, as a method of giving strength to the wet tissue, it is conceivable to increase the coating amount of the binder.

US Pat. No. 8,257,553

However, if the coating amount of the binder is increased, there is a problem that a desired amount cannot be applied, and the pulp pile fiber sheet cannot be given strength, or it takes a long time for drying. is there.

An object of the present invention is to provide a pulp product sheet manufacturing method and a pulp product sheet manufacturing apparatus that improve the production efficiency of a pulp product sheet having a desired strength.

The pulp fiber sheet manufacturing method according to the first aspect of the present invention includes a coating step in which a binder is applied a plurality of times to the same surface of a pulp fiber sheet containing pulverized pulp or fibers mainly composed of the pulverized pulp; And a drying step of drying the pulp pile fiber sheet each time a binder is applied.

The pulp pile sheet manufacturing apparatus according to the second aspect of the present invention is a first binder coating apparatus that coats a binder on at least one surface of a pulp pile sheet containing pulverized pulp or fibers mainly composed of the pulverized pulp. And a first drying device that dries the pulp pile fiber sheet on which the binder has been applied by the first binder coating device, and the binder is applied to the surface that has been dried and the first binder coating device has applied the binder. The structure which comprises a 2nd binder coating apparatus and the 2nd drying apparatus which dries the said pulp fiber sheet | seat with which the binder was apply | coated by the said 2nd binder coating apparatus is taken.

According to the present invention, it is possible to improve the production efficiency of a pulp fiber sheet having a desired strength.

The schematic diagram which shows the structure of the pulp pile fiber sheet manufacturing apparatus which concerns on one Embodiment of this invention. The figure for demonstrating a liquid supply apparatus and a pulp detection apparatus Schematic diagram showing how pulverized pulp is piled

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(One embodiment)
A pulp pile fiber sheet according to an embodiment of the present invention is composed of a pulp layer, and is typically a hydrolyzable product such as a non-hydrolyzable cleaning sheet for cleaning, a water-degradable cleaning sheet for body cleaning, and a toilet cleaner. It is suitable for use as a cleaning sheet. Moreover, the manufacturing method concerning this embodiment can manufacture a pulp fiber sheet reasonably and appropriately.

In the present embodiment, water disintegration is the minimum strength necessary for functions such as sheet forming and wiping when the adhesive strength between fibers constituting the sheet is not significantly immersed in water. However, in a state of being soaked in water as in the case of being dumped in water, the adhesive force is extremely reduced, and it is easily decomposed or dispersed when given some external force. Non-hydrolysis means that the adhesive strength between the fibers constituting the sheet is easily decomposed or dispersed even if it is not soaked in water, in a state of being soaked in water, or by applying some external force. It means not to.

FIG. 1 is a schematic diagram showing a configuration of a pulp fiber sheet manufacturing apparatus 100 according to an embodiment of the present invention. Hereinafter, the pulp fiber sheet manufacturing apparatus 100 will be described with reference to FIG. In FIG. 1, in order to avoid complication of the drawing, the pulp fiber sheet 101 is given a reference numeral only to a part of the pulp fiber sheet manufacturing apparatus 100, and the illustration is omitted otherwise. In FIG. 1, the right side direction (MD: Machine Direction) is defined as the X direction, the back side direction (CD: Cross Direction) is defined as the Y direction, and the upper side (corresponding to the upper side in the vertical direction) is defined as the Z direction. .

The pulp original fabric 103 is formed of natural fibers such as pulp and pulverized pulp, regenerated fibers such as rayon, or a mixture of natural fibers and regenerated fibers. As natural fibers other than pulp, for example, kenaf, bamboo fiber, cocoon, cotton, silk thread, sugar cane and the like can be used.

Here, the pulverized pulp refers to a pulp material that is finely pulverized with a pulverizer or the like into a cotton form. Examples of the raw material pulp include wood pulp, synthetic pulp, and waste paper pulp. Toilet paper materials can also be used. As wood pulp, a blend of softwood bleached kraft pulp and hardwood bleached kraft pulp can be used, but it is preferable from the viewpoint of production to use raw material pulp made of softwood bleached kraft pulp. Softwood bleached kraft pulp has a longer fiber length than hardwood bleached kraft pulp. Therefore, when the pulp stacking fiber sheet 101 described later is configured using pulverized pulp obtained from softwood bleached kraft pulp, the degree of entanglement between the fibers increases. As a result, the strength is improved. In addition, when using softwood bleached kraft pulp, the inter-fiber space volume due to entanglement between fibers becomes larger than when using hardwood bleached kraft pulp with a short fiber length, and the degree of freedom of movement of each fiber increases. Flexibility is also improved.

When the raw material fiber is a material mainly composed of pulverized pulp, the blending ratio of the pulverized pulp is preferably 30% or more, and more preferably 50% or more. Furthermore, the blending ratio of the pulverized pulp is preferably 80% or more, and more preferably 100% is formed of the pulverized pulp. Since the pulverized pulp is formed by pulverizing a pulp material and forming a cotton-like shape, innumerable spaces are formed between the fibers compared to the paper-made paper in which the fibers are compressed. When innumerable spaces are formed between the fibers, it is possible to increase the degree of freedom of movement of each fiber constituting the pulp stacking sheet 101. For this reason, the bulkiness of the pulp stacking sheet 101 can be increased even with a smaller basis weight by adjusting the blending ratio of the pulverized pulp as described above. As a result, the flexibility as a whole can be improved, and the production efficiency at the time of manufacturing can be improved.

Incidentally, the basis weight of the pulp fiber stacking sheet 101 is preferably 80 g / ^{m 2} or less, more preferably 60 g / ^{m 2} or less. By making the basis weight of the pulp pile fiber sheet 101 within the above range, the pulp pile fiber sheet 101 can be easily manufactured and packaged, so that it is easy for the user to use and is easy to pack. Can be configured. In addition, by setting the basis weight within the above range, the fiber density does not become too high, and the amount of the binder for joining the fibers can be reduced. For this reason, the fall of the liquid permeability of the pulp pile fiber sheet 101 by a large amount of binder adhering to the surface of the pulp pile fiber sheet 101 can be prevented, and the overall water absorption of the pulp pile fiber sheet 101 can be prevented. Can be secured.

The pulp fiber sheet manufacturing apparatus 100 is roughly divided into a pre-grinding treatment device, a grinding device 106, a fiber accumulation device 107, a pressing device, a binder coating device, and a drying device.

The pulverization pretreatment device includes a liquid supply device 104 and a pulp detection device 105. The liquid supply device 104 supplies liquid to the pulp original fabric 103. Further, the pulp detection device 105 detects whether the pulp original fabric 103 is supplied to the pulp pile sheet manufacturing device 100.

FIG. 2 is a diagram for explaining the liquid supply device 104 and the pulp detection device 105. As shown in FIG. 2, the liquid supply device 104 supplies liquid to the central region 104 a of the pulp original fabric 103 that has been conveyed. As will be described later, since the pulp original fabric 103 is piled on a mesh and conveyed, there is a possibility that static electricity is charged. For this reason, as the liquid supplied by the liquid supply device 104, a solution such as ethanol, methanol, 2-propanol (IPA), or water may be used for preventing static electricity.

Moreover, the pulp fiber sheet 101 manufactured by the pulp fiber sheet manufacturing apparatus 100 may be used as an absorber that absorbs excreta. For this reason, the liquid supplied by the liquid supply device 104 includes activated carbon, zeolite, silica, ceramic, Oya stone, charcoal polymer, carbon nanotube, carbon nanohorn, citric acid, succinic acid, etc. Organic acid; alum (potassium alum) etc. can be used.

In FIG. 1, the liquid supply device 104 is shown as a single unit, but a plurality of liquid supply devices 104 may be provided depending on the application, such as for static electricity prevention or deodorization. In the present embodiment, as shown in FIG. 2, not the entire pulp original fabric 103 in the Y direction but a partial region such as the central region 104 a is used as the liquid supply region. This is because the pulp original fabric 103 is pulverized in a cotton shape by a pulverizing apparatus 106 described later, and thus the above-described liquid is mixed with almost the entire pulverized pulp even if the liquid supply region is a partial region. Thereby, the excessive liquid supply by the liquid supply apparatus 104 can be prevented, and the manufacturing cost of the pulp stacking sheet 101 can be suppressed. As an example, the length of the central region 104 a in the Y direction is about 10% to 50% of the width of the pulp original fabric 103. The liquid supply area may be an area shifted from the center shown in FIG. 2 in the Y direction instead of the center area 104a.

Further, the liquid supply device 104 may adjust the supply amount of the liquid for preventing static electricity according to the humidity of the pulp fiber sheet manufacturing apparatus 100. Specifically, when the room in which the pulp fiber sheet manufacturing device 100 is installed is dry (for example, when the humidity is 50% or less), the liquid supply device 104 is a pulp fiber sheet manufacturing device 100. The amount of antistatic liquid supplied may be increased as compared to the case where the room where the is installed is not dry (for example, when the humidity is 65% or more). That is, the liquid supply device 104 may increase the supply amount of the antistatic liquid as the humidity decreases, and decrease the supply amount of the antistatic liquid as the humidity increases.

Similarly, the liquid supply device 104 may change the supply amount of the deodorizing liquid depending on the use of the pulp fiber sheet 101. Specifically, the liquid supply device 104 increases the supply amount of the deodorizing liquid when the pulp pile fiber sheet 101 is used for the above-described absorbent body, and when the pulp pile fiber sheet 101 is used for the cleaning sheet, The supply amount of the odor liquid may be reduced.

The pulp detection device 105 detects whether or not the pulp original fabric 103 is being conveyed. Specifically, when the pulp detection apparatus 105 irradiates the pulp original fabric 103 with the detection light 105a (see FIG. 2) and detects the reflected light from the pulp original fabric 103 by a detection unit (not shown), 103 is determined to be supplied. On the other hand, if the above-described reflected light cannot be detected by a detection unit (not shown), the pulp detection device 105 determines that the pulp original fabric 103 is not supplied, and notifies using, for example, sound or light.

In the pulp fiber sheet manufacturing apparatus 100, the pulverizing apparatus 106 pulverizes the raw pulp 103 following the pre-pulverization processing apparatus. The pulverizer 106 has a primary pulverization unit and a secondary pulverization unit, the primary pulverization unit pulverizes the pulp original fabric 103 into chips, and the secondary pulverization unit pulsates the pulp original fabric 103 crushed into chips. Grind into cotton. The pulverizer 106 stores the primary pulverization unit and the secondary pulverization unit in a case or the like in order to avoid scattering of the pulverized raw pulp 103 (pulverized pulp). In the present embodiment, the pulverized pulp is preferably 100%. However, when the pulp pile fiber sheet 101 is not hydrolyzed, a heat-fusible conjugate fiber (ES fiber) is mixed with the pulverized pulp. It doesn't matter.

The fiber pile device 107 piles the pulverized pulp obtained by the pulverizer 106. Specifically, it is as follows. The pulverized pulp passes through the pipe 108 by high-pressure air or the like and is stored in the three

tanks

107a, 107b, and 107c. However, the number of tanks is not limited to three. In addition, in order to prevent scattering (diffusion) of the pulverized pulp, the fiber stacking device 107 is also provided with a scattering prevention cover. Thereby, it can reduce that the operator of the pulp pile sheet manufacturing apparatus 100 sucks pulverized pulp. In this embodiment, the average fiber length of the pulverized pulp is about 1 mm to 3 mm as an example.

The pulverized pulp stored in the three

tanks

107a, 107b, and 107c is piled on the lower conveyance mesh 109. The lower transfer mesh 109 has a mesh shape, and 30th to 50th meshes having 30 to 50 meshes per 1 inch × 1 inch can be used. In this embodiment, 40th (for example, 0.5 mm × 0.5 mm) mesh. The lower transport mesh 109 can be made of a polymer compound as a material, and synthetic fibers such as synthetic resin (thermoplastic resin) such as polytetrafluoroethylene, nylon, and PET (Polyethylene terephthalate). Can do.

The lower conveying mesh 109 conveys the pulverized pulp (hereinafter referred to as “stacked pulp”) in the X direction in the drawing by a driving force from a driving source (not shown). An air flow forming device 111 is disposed inside the annular lower transfer mesh 109. The air flow forming device 111 forms an air flow, and adsorbs the piled pulp on the mesh-shaped lower transfer mesh 109 located on the upper surface of the device.

FIG. 3 is a schematic diagram showing how the pulverized pulp is piled up. As shown in FIG. 3 (a), the pulverized pulp piled up from the tank 107a to the lower transport mesh 109 has a small pile length (-low volume) on the -X side where the pile time is short, and as it goes in the + X direction, Since the fiber accumulation time becomes longer, it increases (bulk increases).

However, the air flow by the air flow forming device 111 becomes weaker as the amount of fiber piled up (Vac small in the figure). In other words, the air flow generated by the air flow forming device 111 is less likely to be weak at a portion where the amount of accumulated fibers is small (Vac in the figure).

For this reason, as shown in FIG. 3B, the difference in the amount of pulverized pulp piled up from the tank 107 b to the lower transfer mesh 109 does not depend on the position of the lower transfer mesh 109. Less. As shown in FIG. 3 (c), the amount of pulverized pulp stacked from the tank 107 c to the lower transport mesh 109 becomes substantially equal regardless of the position of the lower transport mesh 109. In this way, by utilizing the change in the air flow by the air flow forming device 111 that changes in accordance with the amount of pulverized pulp, the amount of pulverized pulp that is laid on the lower conveyance mesh 109 is substantially reduced. It can be made uniform. In addition, when the amount of fiber piles of a pulverized pulp varies depending on the location, it may be adjusted by shifting the position of an air flow forming port (not shown) or changing the number of air flow forming ports.

Also, since the upper surface of the lower transfer mesh 109 is close to the air flow forming device 111, a strong adsorption force acts and the pulverized pulp is densely stacked. On the other hand, as the distance from the lower transfer mesh 109 increases in the + Z direction, the air flow by the air flow forming device 111 becomes weaker and the density of the pulverized pulp becomes sparse. When the pulp pile fiber sheet 101 produced by the pulp pile fiber sheet manufacturing apparatus 100 is made into a product, if it is a cleaning product such as a flooring sheet and a toilet cleaner, the ground surface of the pulverized pulp is mainly used. By this, dirt can be removed firmly. On the other hand, if it is a product used for skin, such as a body sheet and a face sheet, a skin product having a good touch can be provided by mainly using a sparsely-pulverized surface.

In the pulp stacking sheet manufacturing apparatus 100, a plurality of pressing devices press the pulverized pulp that has been stacked. The flat roll 112 has a pair of roll members, presses the piled pulp, adjusts its bulk, and forms the pulp piled sheet 101. In this embodiment, the flat roll 112 is subjected to a pressure of 4 Kgf / cm ² between the rolls. Thereby, the mesh shape unevenness | corrugation of the lower conveyance mesh 109 is formed in the lower surface (surface which touches the lower conveyance mesh 109) of the pulp fiber sheet 101. FIG. Note that the pressure of the flat roll 112 may be set to, for example, ² kgf / cm ² to 8 kgf / cm ² .

The flat roll 112 is not limited to being pressed including the lower conveyance mesh 109, and may be pressed including a belt that is not a mesh. However, in this case, it goes without saying that the mesh-shaped irregularities are not formed on the pulp stacking sheet 101.

Moreover, as long as the pressure resistance of the lower conveyance mesh 109 is excellent, a mesh shape may be formed on the pulp pile fiber sheet 101 by applying a pressure of 8 kgf / cm ² or more. Note that a liquid supply device 104 may be provided before and after the flat roll 112 to supply at least one liquid for preventing static electricity and deodorizing.

The lower conveyance mesh 109 conveys the pulp pile fiber sheet 101 to the boundary with the upper conveyance mesh 113. The pulp fiber sheet 101 is conveyed from the boundary between the lower conveyance mesh 109 and the upper conveyance mesh 113 to the flat roll 116 using the upper conveyance mesh 113 and the air flow forming device 115. Specifically, the air flow forming device 115 provided inside the annular upper transfer mesh 113 causes the air flow to flow in the direction of adsorbing the upper surface of the pulp fiber sheet 101 that contacts the lower surface of the upper transfer mesh 113. Form. In this state, the pulp fiber sheet 101 is conveyed in the X direction in the figure by a driving force from a driving source (not shown).

The flat roll 116 has a pair of roll members, presses the pulp pile fiber sheet 101 that has passed through the flat roll 112, adjusts its bulk, or changes the mesh shape of the upper conveyance mesh 113 to the pulp pile sheet 101. Or an upper surface (a surface in contact with the upper conveyance mesh 113). The upper transfer mesh 113 is also the 40th mesh as the lower transfer mesh 109. The pressure of the flat roll 116 is also set between ² kgf / cm ² and 8 kgf / cm ² .

The embossing device 117 has a corrugated shape on the circumferential surface of the roll, and embosses the pulp pile fiber sheet 101 that has passed through the flat roll 116 in cooperation with a transfer mesh (not shown). Here, the embossed shape is formed only on one side of the pulp piled fiber sheet 101, but the embossed shape may be formed on both front and back sides of the pulp piled fiber sheet 101. When embossing is performed on both the front and back surfaces of the pulp stacking sheet 101, an embossing roll composed of a pair of upper and lower metal rolls formed by projecting a large number of protrusions for embossing on the peripheral surface of the roll is used. Here, the wave shape is an embossed shape, but the embossed shape may be any shape. Further, a plurality of embossing devices 117 may be provided and embossing may be performed a plurality of times. In this case, the embossing of the same shape may be sufficient and the embossing of a different shape may be sufficient. Further, in this embodiment, the pressure of the embossing device 117 is set higher than the pressure set by the

flat rolls

112 and 116, and is set, for example, between 4 kgf / cm ² to 10 kgf / cm ^2. The

In addition, the number of times embossing may be performed may be set according to the use of the product using the pulp pile fiber sheet 101, or a water-decomposable product or a non-hydrolyzed product, or embossing may not be performed. . When embossing is not performed in the embossing device 117 having a pair of embossing rolls, the distance between the pair of embossing rolls may be made larger than the thickness of the pulp stacking sheet 101 in the Z direction. As is clear from FIG. 1, the pulp fiber sheet 101 does not interpose a transport mesh during embossing. This is to avoid damage to the transport mesh due to embossing.

At this time, the pulp pile fiber sheet 101 is in a non-wetting state, and the embossing is applied to the pulp pile fiber sheet 101 in a non-wet state. Here, the non-wet state means that it does not include an aspect in which water is supplied by spraying water on the pulp fiber sheet 101. Normally, the pulp pile sheet 101 contains moisture (moisture) corresponding to the temperature and humidity conditions, but since this moisture is not moisture actively supplied from the outside, even if such moisture is contained. Corresponds to the non-wetting state. Therefore, although the content rate of the water | moisture content contained in a pile layer also changes with temperature and humidity conditions, it can be said that it corresponds to a non-wet state whatever the content rate is.

Thus, in this embodiment, the pulp pile fiber sheet 101 is embossed in a normal dry state in the atmosphere without supplying moisture to the pulp pile fiber sheet 101 from the outside. Therefore, since the embossing is not performed in a state where the binder is impregnated, there is no possibility that the pulp stacking sheet 101 adheres to the embossing roll. Therefore, it is not necessary to apply a release agent to the embossing device 117 or the pulp stacking sheet 101. During embossing, the embossing device 117 may not be heated, but the embossing device 117 may be heated to a predetermined temperature to perform embossing. In the latter case, the heating temperature of the embossing device 117 is preferably 60 ° C. to 150 ° C.

In the present embodiment, liquid is supplied to the pulp pile fiber sheet 101 by the liquid supply device 104, but the pulp pile fiber sheet 101 may be non-wet by the flat roll 112. For example, it is sufficient that the moisture content of the pulp pile sheet 101 is less than about 15% when the flat roll 112 is pressed, and it is sufficient that the moisture content is not affected by static electricity when transported by the mesh.

In addition, by heating the

flat rolls

112 and 116 and the embossing device 117 in the range of about 60 ° C. to 150 ° C., and setting the temperature of the pulp stacking sheet 101 to about 40 ° C. to about 70 ° C., The binder easily penetrates into the pulp pile sheet 101, the amount of binder applied can be reduced, and the manufacturing cost can be reduced. The flat rolls 112 and 116 and the embossing device 117 may be heated so that the temperature of the pulp stacking sheet 101 becomes the same as the melting temperature of the binder (for example, 40 ° C. to 60 ° C.).

In the pulp stacking sheet manufacturing apparatus 100, the binder coating apparatus applies a binder to the pulp stacking sheet 101. In the present embodiment, the binder coating apparatus includes a first binder coating apparatus 121 and a second binder coating apparatus 130, and a first described later is provided between the first binder coating apparatus 121 and the second binder coating apparatus 130. A drying device 124 is arranged. Here, the 1st binder coating device 121 is demonstrated.

The first binder applicator 121 has a plurality of nozzles facing the pulp product sheet 101 above the pulp product sheet 101 (+ Z direction), and applies the binder to the upper surface of the pulp product sheet 101. The supply of the binder is typically performed by spraying the binder from the nozzle of the spray device. As the nozzle used for spraying, a conventionally known nozzle may be arbitrarily selected and used. In addition, supply of a binder is not limited to spraying, You may use other well-known methods, such as using a gravure printing machine.

Further, in the first binder coating device 121, the pulp pile sheet 101 is placed on the mesh-shaped lower conveyance mesh 118, and the air flow is provided inside the annular lower conveyance mesh 118. It is conveyed in the X direction while being adsorbed in the −Z direction by the device 120. The mesh of the lower transfer mesh 118 may be a coarser mesh than the lower transfer mesh 109 and the upper transfer mesh 113, and 10th to 30th may be used. In this embodiment, the 16th (for example, 1) .0 mm × 1.0 mm) mesh.

As described above, the first binder coating device 121 applies the binder from the upper side (+ Z direction) to the lower side (−Z direction) with respect to the upper surface of the pulp fiber sheet 101, and the air flow forming device. By 120, the pulp pile fiber sheet 101 is adsorbed from the lower surface side to the lower side (−Z direction).

Various binders can be used as the binder applied (sprayed) on the upper surface of the pulp stacking sheet 101. Examples of the binder that can be used in the present embodiment include polysaccharide derivatives, natural polysaccharides, and synthetic polymers. Examples of the polysaccharide derivative include carboxymethyl cellulose (CMC), carboxyethyl cellulose, carboxymethylated starch or a salt thereof, starch, methyl cellulose, ethyl cellulose and the like. Examples of natural polysaccharides include guar gum, tant gum, xanthan gum, sodium alginate, carrageenan, gum arabic, gelatin, and casein. Examples of the synthetic polymer include polyvinyl alcohol (PVA), ethylene-vinyl acetate copolymer resin (EVA), polyvinyl alcohol derivatives, polymers or copolymers of unsaturated carboxylic acids, salts thereof, and the like. Examples of the carboxylic acid include acrylic acid, methacrylic acid, maleic anhydride, maleic acid, and fumaric acid. Of the above, CMC, EVA, and PVA are particularly preferable.

In this embodiment, when the pulp pile fiber sheet 101 is used for a water-degradable product, CMC is applied as a binder, and when the pulp pile fiber sheet 101 is used for a non-hydrolysis product, EVA is applied as a binder. It shall be. As described above, since the pulverized pulp is sparser on the upper surface side of the pulp product fiber sheet 101 than on the lower surface side of the pulp product fiber sheet 101, the binder easily penetrates. For this reason, the possibility that the binder applied (sprayed) on the upper surface of the pulp product sheet 101 may remain on the upper surface of the pulp product sheet 101 can be reduced.

The first drying device 124 performs electromagnetic wave drying on the pulp pile fiber sheet 101 placed on the mesh-shaped lower conveyance mesh 122. The first drying device 124 may perform hot air drying and / or infrared drying instead of electromagnetic wave drying.

Electromagnetic wave drying is performed by using electromagnetic waves, and as an electromagnetic wave dryer used therefor, an apparatus having the same mechanism and structure as a microwave oven can be used. Electromagnetic wave drying is performed by microwave heating. When microwave irradiation is performed, the vibrator that connects polar water molecules absorbs the microwave and vibrates and rotates, and the temperature rises. This is based on the principle of evaporating and drying.

Electromagnetic wave drying has the advantage that it can be dried in a short time, and has a high electromagnetic wave transmission capability. It can be heated uniformly by being transmitted to the inside of the pulp pile sheet 101 and heated uniformly. It can be carried out. Also, in electromagnetic wave drying, electromagnetic energy is directly loaded and there is no secondary consumption of energy, so energy can be saved at least 30% compared to infrared heating, energy consumption can be reduced, and manufacturing costs can be reduced. Can contribute. As the electromagnetic wave dryer in the present embodiment, for example, one having an ability to dry 1 kg of water in 1 hour per 1 kW of electric power is preferable. Moreover, as an electromagnetic wave dryer installed in a continuous production facility, it is preferable to use a tunnel type electromagnetic wave dryer that can continuously pass the pulp pile fiber sheet 101 inside the dryer because it is suitable for continuous production.

The electromagnetic wave drying is unlike hot air drying, and the uneven form formed on the pulp pile sheet 101 by embossing is not crushed by the pressure of the wind, and unlike hot roll drying, the uneven form may be crushed by mechanical pressure. There is no.

Furthermore, electromagnetic wave drying is superior to hot air drying, infrared drying, and hot roll drying, and is superior in drying efficiency and can be dried in a short time. There is an advantage that there is no fear of the embossing return. Prevention of this emboss return has an important meaning in the present embodiment. That is, in this embodiment, since the binder is supplied and impregnated into the pulp fiber sheet 101 after embossing, there is a problem of so-called embossing return that the distortion due to embossing is removed by impregnation of the binder and the uneven shape is lost. In order to solve this problem, selection of a drying means is important. If electromagnetic wave drying is adopted as the drying means, the drying time can be greatly shortened compared to other drying means, so that moisture that causes embossing return can be removed quickly, and as a result, the deformation of the concavo-convex shape due to strain release is eliminated. It has the effect that it can suppress, can maintain the shape of an uneven | corrugated form, and can suppress emboss return. In the electromagnetic wave drying, as described above, since the electromagnetic wave penetrates and heats up to the inside of the pulp pile fiber sheet 101, the pulp pile fiber sheet 101 is uniformly heated not only to the surface but also to the inside in a short time. . This greatly affects the above-described emboss return suppression effect.

Infrared drying can also be suitably used as a means for drying the pulp pile fiber sheet 101 impregnated with the binder. Infrared rays are electromagnetic waves having a wavelength band of 0.75 μm to 1000 μm and a wavelength shorter than that of microwaves. Infrared rays are classified into near infrared rays (wavelengths 0.7 μm to 2.5 μm) and far infrared rays (wavelengths 4 μm to 1000 μm) depending on the wavelength. In this embodiment, near infrared rays are hardly absorbed by objects and have low heating efficiency. It is preferable to use far infrared rays that are easily absorbed by an object and have high heating efficiency. In the present embodiment, it is preferable to use a far infrared ray having a wavelength of 4 μm to 50 μm out of a far infrared wavelength band of 4 μm to 1000 μm.

The far infrared ray having a wavelength of 4 μm to 50 μm has high absorbance to water, and in the case of an object containing a lot of water, most of the far infrared ray is absorbed at a portion where the depth from the surface to the inside is relatively shallow. Therefore, when far-infrared drying is applied, there is an effect that the embossed shape formed on the pulp stacking sheet 101 can be prevented from being lost by embossing. That is, when far-infrared rays are radiated to the pulp pile fiber sheet 101 impregnated with the binder, far infrared rays are absorbed in a relatively shallow inner region from the surface of the pulp pile fiber sheet 101, so that the vicinity of the surface is quickly heated. And dry. Thereby, the drying of the surface of the pulp stacking sheet 101 proceeds in a short time, and as a result, it is possible to prevent the embossed shape from being lost due to the water content. In addition, by preventing the embossed shape from being lost, it is possible to prevent the embossing from returning, which reduces the height difference of the uneven shape. Thus, according to the far-infrared drying, the surface of the pulp pile sheet 101 can be quickly dried, so that the emboss return can be surely prevented and the time required for the drying process can be shortened.

Far-infrared drying is not a method of drying the object to be dried by heating the air, but a method of transferring heat to the object to be dried directly by heat rays from far infrared rays, and is drying by so-called radiant heat. Accordingly, the object to be dried can be efficiently heated, and the drying time can be shortened. Moreover, it is also possible to heat-dry by reflecting a heat ray in a specific direction with a reflecting plate or the like and concentrating it at a predetermined position. If such a drying method is adopted, the energy efficiency for drying can be improved, and the drying process cost can be reduced.

The far-infrared dryer may have any structure as long as it has a heating element that generates far-infrared rays, and in this case, one that can maintain the temperature of the heating element at 200 ° C. or higher is preferable. By maintaining the temperature of the heating element at 200 ° C. or higher, far infrared rays can be generated efficiently. Moreover, if it supplies with electricity intermittently with a thermostat etc., a power saving driving | operation will be attained.

In far-infrared drying, there is no load due to wind pressure as in air-drying (hot air drying), and there is no load due to mechanical pressure as in hot roll drying. There is no risk of distortion of 101 or the like.

Also, the lower conveyance mesh 122 conveys the pulp fiber sheet 101 while adsorbed by the air flow forming device 125 arranged inside the annular lower conveyance mesh 122. The lower transfer mesh 122 may be 10th to 30th, and in this embodiment, the 22nd (for example, 0.7 mm × 0.7 mm) mesh is used.

The embossed shape formed on the pulp piled sheet 101 can be easily maintained by performing the processing by the first binder coating device 121 and the first drying device 124 following the embossing by the embossing device 117.

The embossing device 126 has a pair of roll members, and, like the embossing device 117, a wave-shaped emboss shape is formed on the peripheral surface of the roll. The embossed shape is not limited to this, and may be any shape. The embossing device 126 embosses the pulp stacking sheet 101 that has passed through the first drying device 124. In the embossing, an embossed shape is formed on only one side or both sides of the pulp stacking sheet 101. Further, a plurality of embossing devices 126 may be provided and embossing may be performed a plurality of times. In this case, the embossing of the same shape may be sufficient and the embossing of a different shape may be sufficient. Further, the pressure of the embossing device 126 can be set similarly to the embossing device 117. As is clear from FIG. 1, also in the embossing device 126, the pulp pile fiber sheet 101 does not interpose a transport mesh and a transport belt during embossing. The embossing device 126 may not be provided in the pulp stacking sheet manufacturing apparatus 100, and the distance between the pair of roll members may be larger than the thickness of the pulp stacking sheet 101 in the Z direction.

The pair of roll members of the embossing device 126 is preferably heated. In addition, since the embossing by the embossing device 126 is performed prior to the processing of the second binder coating device 130 and the second drying device 133 which will be described later, the embossed shape formed on the pulp stacking sheet 101 is easily maintained.

The second binder coating device 130 has a plurality of nozzles facing the pulp stacking sheet 101 below the pulp stacking sheet 101 (−Z direction), and applies the binder to the lower surface of the pulp stacking sheet 101. The method for supplying the binder is the same as that for the first binder coating apparatus 121. The pulp pile fiber sheet 101 is conveyed in the X direction while being adsorbed in the + Z direction by the air flow forming device 129 through the mesh-shaped upper conveying mesh 127. The count of the upper transfer mesh 127 may be the same as that of the lower transfer mesh 118.

Thus, the second binder coating device 130 applies the binder from the lower side (−Z direction) to the upper side (+ Z direction) on the lower surface of the pulp pile sheet 101, and the air flow forming device. 129 adsorbs the pulp pile fiber sheet 101 from the upper surface side to the upper side (+ Z direction).

The binder applied by the second binder application device 130 is the same as the binder applied by the first binder application device 121. In the second binder coating device 130, the binder is applied to the lower surface of the pulp stacking sheet 101 from a plurality of nozzles located below the pulp stacking sheet 101 (in the −Z direction). The binder that has not permeated falls without remaining on the pulp pile fiber sheet 101, and there is no occurrence of uneven coating of the binder. For this reason, it is possible to reduce unevenness in strength and unevenness in drying of the pulp-stacked fiber sheet 101 after passing through the second drying device 133 described later.

Also, the first binder coating device 121 and the second binder coating device 130 apply the binder to the upper and lower surfaces of the pulp pile sheet 101 without inverting the pulp pile sheet 101. For this reason, complication of the pulp pile sheet manufacturing apparatus 100 can be avoided, and the speed of conveying the pulp pile sheet 101 can be increased.

A cover may be attached to the first binder applicator 121 and the second binder applicator 130 to prevent the binder from scattering, and the binder that has not been applied to the pulp pile sheet 101 may be recovered by a pump or the like. By supplying the recovered binder to the first binder coating device 121 and the second binder coating device 130 again, the amount of binder used can be reduced, and the manufacturing cost of the pulp stacking sheet 101 can be reduced. Note that the second binder coating device 130 is not necessarily provided.

The second drying device 133 performs electromagnetic wave drying on the pulp fiber sheet 101 adsorbed by the mesh-shaped upper transfer mesh 131. Note that the second drying device 133 may perform hot air drying and / or infrared drying instead of electromagnetic wave drying.

The upper transport mesh 131 is transported in the X direction by adsorbing the pulp pile fiber sheet 101 located on the lower surface in the + Z direction by the air flow forming device 132 disposed inside the annular upper transport mesh 131. The count of the upper transfer mesh 131 may be the same as the count of the lower transfer mesh 122.

The embossing device 135 has a pair of roll members, and, like the embossing device 126, a corrugated embossed shape is formed on the circumferential surface of the roll. The embossed shape is not limited to this, and may be any shape. The embossing device 135 embosses the pulp pile fiber sheet 101 that has passed through the second drying device 133. In the embossing, an embossed shape is formed on only one side or both sides of the sheet-like pulp stacking fiber sheet 101. Further, a plurality of embossing devices 135 may be provided and embossing may be performed a plurality of times. In this case, the embossing of the same shape may be sufficient and the embossing of a different shape may be sufficient. Further, the pressure of the embossing device 135 can be set similarly to the embossing device 126. Note that the embossing device 135 may not be provided in the pulp stacking sheet manufacturing apparatus 100, and the interval between the pair of roll members may be larger than the thickness of the pulp stacking sheet 101 in the Z direction.

The pair of embossing rolls of the embossing device 135 is preferably heated. In addition, since the embossing by the embossing device 135 is also performed prior to the processing of the third binder coating device 136 and the third drying device 137, which will be described later, the embossed shape formed on the pulp stacking sheet 101 is easily maintained.

The third binder coating device 136 has a plurality of nozzles facing the pulp pile fiber sheet 101 above the pulp pile sheet 101 (+ Z direction), and the binder on the surface of the pulp pile sheet 101 on which the binder has already been applied. Apply. The binder applied by the third binder application device 136 is the same as the binder applied by the first binder application device 121. The third binder application device 136 applies an amount excluding the amount of binder applied in the first binder application device 121 and the second binder application device 130 out of the final total amount of the binder applied to the pulp fiber sheet 101. . However, when the second binder coating device 130 is not provided, the third binder coating device 136 is coated in the first binder coating device 121 out of the final total amount of the binder to be applied to the pulp pile fiber sheet 101. Apply the amount excluding the binder amount. The third binder coating device 136 has a plurality of nozzles facing the pulp pile sheet 101 in the lower part (−Z direction) in addition to or instead of the upper part (+ Z direction) of the pulp pile sheet 101. May be.

3rd drying apparatus 137 performs electromagnetic wave drying with respect to the pulp fiber sheet 101 mounted on the mesh 138 for lower conveyance of mesh shape. Note that the third drying device 137 may perform hot air drying and / or infrared drying instead of electromagnetic wave drying.

The crosslinking agent solution coating apparatus 140 applies a crosslinking agent to the pulp fiber sheet 101 dried by the third drying apparatus 137 and impregnates it. Thereby, the physical strength of the pulp pile sheet 101 can be improved. The pulp pile fiber sheet 101 impregnated with the cross-linking agent is weakly dried by a drying device (not shown).

The cross-linking agent causes a cross-linking reaction with the binder to make the binder a cross-linked structure, thereby improving the physical strength. In addition to being supplied immediately after the third drying device 137, the cross-linking agent may be supplied simultaneously with the binder, or may be supplied at other locations in the pulp fiber sheet manufacturing apparatus 100.

As the crosslinking agent, when a binder having a carboxyl group such as CMC is used, a polyvalent metal ion is preferably used. Examples of the polyvalent metal ion include alkaline earth metals such as zinc, calcium and barium, magnesium. And metal ions such as aluminum, manganese, iron, cobalt, nickel and copper. Among these, ions of zinc, calcium, barium, magnesium, aluminum, iron, cobalt, nickel, copper, and the like are preferably used. These are preferable in terms of imparting sufficient wet strength. The polyvalent metal ions as the crosslinking agent are used in the form of water-soluble metal salts such as sulfates, chlorides, hydroxides, carbonates and nitrates. Moreover, when using PVA as a binder, a titanium compound, a boron compound, a zirconium compound, a compound containing silicon, or the like can be used as a crosslinking agent, and one or more of these compounds are mixed as a crosslinking agent. It can also be used. Examples of the titanium compound include titanium lactate and titanium triethanolamate, and examples of the boron compound include borax and boric acid. In addition, examples of the zirconium compound include ammonium zirconium carbonate, and examples of the compound containing silicon include sodium silicate.

The folding machine 141 cuts and folds the pulp pile fiber sheet 101 impregnated with the crosslinking agent into predetermined dimensions. Here, when the pulp pile fiber sheet 101 is folded in a completely dry state, there is a possibility that cracks may be formed in the folds, but here, since the sheet is not completely dried, there is a possibility that cracks may be formed in the folds. Absent.

The aqueous drug solution application device 142 applies and impregnates the folded pulp stacking sheet 101 with the aqueous drug solution. As an aqueous | water-based chemical | medical solution, what mix | blends water, a water-soluble organic solvent, surfactant, disinfectant, antiseptic | preservative, deodorant, a fragrance | flavor, etc. is mentioned. It is possible to supply the aqueous chemical solution so that it is impregnated in an amount of 50% to 200% by weight, preferably 130% to 150% by weight, based on the weight of the folded pulp pile fiber sheet 101. This is preferable.

Thus, the pulp fiber sheet 101 impregnated with the aqueous chemical solution can be used as a body wipe for an infant, a toilet cleaner, or other cleaning articles by the aqueous chemical solution. A plurality of bundles of the cleaning articles thus obtained are packed in a sealed bag and packed as a product 143.

Next, as described above, the reason why the binder is applied to the pulp fiber sheet 101 in a plurality of times will be described. Here, in order to simplify the description, the second binder coating device 130 is omitted, and the first binder coating device 121 and the third binder coating device 136 each apply a binder to the same surface of the pulp stacking sheet 101. explain.

There is a case where a large amount of binder is applied to the pulp product sheet 101 to improve the strength of the pulp product sheet 101. In such a case, if a large amount of binder is applied to the pulp stacking fiber sheet 101 at a time, the amount of water increases and drying takes a long time. For this reason, production efficiency will fall.

Therefore, the binder is applied in a plurality of times (here, twice). The amount of the binder to be finally applied to the pulp stacking sheet 101 is assigned to the first binder application device 121 and the third binder application device 136 in a distributed manner. For example, when 8% by weight of binder is finally applied to the pulp pile fiber sheet 101, the first binder applying device 121 applies 6% by weight, and the third binder applying device 136 applies 2% by weight. Alternatively, the first binder coating device 121 may apply 4% by weight, and the third binder coating device 136 may apply 4% by weight. Furthermore, the first binder coating device 121 may apply 2% by weight, and the third binder coating device 136 may apply 6% by weight. These are merely examples, and the final total amount of the binder to be applied to the pulp pile fiber sheet 101 may be appropriately distributed and assigned to the first binder coating device 121 and the third binder coating device 136.

Note that the amount applied by the first binder coating device 121 is preferably smaller than the amount coated by the third binder coating device 136. This is due to the following reason. When a large amount of binder is applied, the pulp pile fiber sheet 101 containing a large amount of moisture has a reduced tensile strength and may be damaged during transportation. Therefore, first, a small amount of binder is applied to suppress a decrease in the tensile strength of the pulp stacking sheet 101 and prevent breakage during conveyance. The pulp pile fiber sheet 101 coated with a small amount of binder is dried to give strength, and then a large amount of binder is applied to suppress a decrease in the tensile strength of the pulp pile fiber sheet 101. it can.

Moreover, since the surface of the pulp pile sheet 101 can be hardened by the first binder application and drying, the emboss shape formed on the pulp pile sheet 101 by the embossing device 126 can be made clear.

Furthermore, when an amount of a binder that cannot be applied at one time (for example, 20% by weight or more) is applied, even if the amount of the binder cannot be applied at one time, it is applied in multiple steps. Application becomes possible.

In this way, by applying the binder in two steps, drying time can be reduced by drying a small amount of water twice compared to drying a large amount of water at a time. Can be improved. Moreover, the intensity | strength of the pulp pile fiber sheet 101 can be improved by binder application | coating twice. However, when the pulp pile fiber sheet 101 is a water-decomposable product, even the pulp pile fiber sheet 101 with increased strength is hydrolyzed.

In addition, when the 1st drying apparatus 124 and the 3rd drying apparatus 137 perform hot air drying or infrared drying, the 1st drying apparatus 124 is a 3rd drying apparatus according to the coating amount of the binder in the 1st binder coating apparatus 121. 137 adjusts the drying temperature in accordance with the amount of binder applied in the third binder coating device 136. For example, the drying temperature is set higher as the coating amount of the binder is larger, and the drying temperature is set lower as the coating amount of the binder is smaller. Thus, the pulp pile fiber sheet 101 coated with the binder is appropriately dried without changing the length of each drying device while keeping the conveyance speed of the pulp pile fiber sheet 101 in the pulp pile fiber sheet manufacturing apparatus 100 constant. Can be made.

In addition, although the case where the binder is applied in two steps has been described here, the present invention is not limited to this and may be applied in two or more steps. However, the larger the number of times of application, the better. The appropriate number of times, for example, about 2 to 3, is preferable. Moreover, although the case where a binder was apply | coated to the single side | surface of the pulp pile fiber sheet 101 was demonstrated here, you may perform similarly when not only this but apply | coating to both surfaces.

Thus, the pulp fiber sheet manufacturing apparatus 100 of this embodiment apply | coats a binder in multiple times with respect to the same surface of the pulp fiber sheet 101, and makes it dry of the pulp fiber sheet 101 each time it is dried. The strength can be improved, the time required for drying can be reduced, and the production efficiency can be improved.

In addition, in this embodiment, although the pulp pile fiber sheet manufacturing apparatus 100 was demonstrated as one apparatus (one line), this invention is not restricted to this, You may divide | segment a pulp pile fiber sheet manufacturing apparatus into plurality. . For example, the device from the pulverization pretreatment device to the second drying device 133 may be one device, and the device from the embossing device 135 to the aqueous drug solution coating device 142 may be one device.

DESCRIPTION OF SYMBOLS 106 Crusher 107 Fiber stacker 112

Flat roll

117, 126, 135 Embossing device 121 1st binder coating device 124 1st drying device 130 2nd binder coating device 133 2nd drying device 136 3rd binder coating device 137 3rd drying device

Claims

An application step of applying a binder a plurality of times to the same surface of a pulverized pulp or a pulp fiber sheet containing fibers mainly composed of the pulverized pulp;
A drying step of drying the pulp pile sheet each time a binder is applied;
A pulp fiber sheet manufacturing method comprising:
The coating process includes
A first binder coating step of coating a binder on at least one surface of the pulp pile fiber sheet;
A second binder coating step for drying and applying a binder to the surface on which the binder is coated in the first binder coating step;
The pulp fiber sheet manufacturing method according to claim 1, comprising:
The drying step
A first drying step of drying the pulp pile sheet to which the binder is applied in the first binder application step;
A second drying step of drying the pulp pile fiber sheet to which the binder has been applied in the second binder application step;
The pulp fiber sheet manufacturing method according to claim 2, comprising:
In the application step, the amount of binder that cannot be applied at one time is applied to one side of the pulp pile fiber sheet in a plurality of times.
The pulp fiber sheet manufacturing method according to claim 1.
In the drying step, when performing hot air drying or infrared drying, the drying temperature is adjusted according to the coating amount of the binder in the coating step.
The pulp fiber sheet manufacturing method according to claim 1.
In the first drying step, when hot air drying or infrared drying is performed, if the amount of the binder applied in the first binder coating step is large, the drying temperature is increased, and the amount of the binder coated in the first binder coating step is small. And lowering the drying temperature,
In the second drying step, when hot air drying or infrared drying is performed, if the amount of binder applied in the second binder coating step is large, the drying temperature is increased, and the amount of binder applied in the second binder coating step is increased. If less, the drying temperature is lowered,
The pulp fiber sheet manufacturing method according to claim 3.
Comprising an embossing step for imparting an embossed shape to the pulp pile fiber sheet dried in the first drying step;
The pulp fiber sheet manufacturing method according to claim 3.
A first binder coating device that coats a binder on at least one surface of a pulverized pulp or a pulp fiber sheet containing fibers mainly composed of the pulverized pulp;
A first drying device that dries the pulp fiber sheet to which the binder is applied by the first binder coating device;
A second binder coating device that is dried and the binder is applied to the surface on which the first binder coating device has applied the binder;
A second drying device that dries the pulp fiber sheet to which the binder is applied by the second binder coating device;
A pulp fiber sheet manufacturing apparatus comprising: