JPH11323800A - Manufacturing method of molded body - Google Patents

Abstract

(57) [Problem] To efficiently produce a molded article by forcibly passing hot air through a wet pulp molded article deposited on a molding die. SOLUTION: Canadian standard freeness (CSF) is 55.
Using a slurry composed of 0 ml or more of the composition, water, which is a medium of the slurry, is removed from the small holes of the mold having a large number of small holes, and thereby the small holes non-passing fine components in the slurry are removed to the mold 10. The molded article is formed by depositing the molded article 15 and then drying the molded article 15 in a wet state in or out of the mold to produce a molded article. The drying is performed by heating air at a flow rate of 2 liter / cm ² · min or more. It is performed under conditions that flow in the layer. When the temperature of the heating air used for drying is 100 ° C. or higher and the thickness of the wet molded product has a portion of 20 mm or more, a hole for promoting drying is opened and the heating air is injected under pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an efficient wet molding method which can be applied to environmentally friendly materials such as pulp and can produce molded articles with a compact apparatus. The present invention relates to a method for producing a molded product in which hot air is forcibly passed through a wet molded product deposited on a mold having holes and dried.

[0002]

2. Description of the Related Art Styrofoam conventionally used as a cushioning material has excellent characteristics such as excellent shock absorption, easy processing into an arbitrary shape, low cost, light weight, and good appearance. have. However, in recent years, as interest in environmental issues has increased, like other so-called plastic products, there has been an increasing demand for treating the processability after use. In other words, it has been pointed out that in the case of incineration after use, damage to the furnace and generation of toxic gas due to generation of high temperature. Further, when the landfill treatment is performed, it is considered to be one of the causes of shortage of the treatment plant because it is not decomposable and is bulky.

As a solution to the problem of the processing of the styrofoam, recently, pulp in a slurry is deposited on a mold having a large number of small holes while sucking and dewatering the pulp.
Attention has been paid to pulp molds obtained by drying thereafter, and they are increasingly used as substitutes for cushioning materials made of styrene foam.

[0004]

However, since the pulp molding method is a wet type, it requires a drying step of removing a slurry medium such as water from a wet molded product, and a large drying apparatus is required for efficient production. I need. In particular, when the molded product is a thick material with poor internal drying, a particularly large device is required. In addition, as a drying method, there is an in-mold drying in which a wet molded product is dried while being placed in a mold, or an out-of-mold drying in which a wet molded product is removed from a mold and dried. Has the advantage that the dimensional accuracy of the molded product is superior to drying outside the mold, but the productivity is increased unless a large number of special and expensive molds are prepared because the time spent in the mold is long. It is not possible to manufacture inexpensive products in industries where model changes are fast or in small lots with many kinds. In particular, it has a problem that it becomes particularly noticeable in the case of thick materials that require time for the suction / dehydration step and the drying step. The object of the present invention is also applicable to environmentally friendly materials such as pulp. It is another object of the present invention to provide a wet molding method capable of efficiently producing a molded body with a compact apparatus and capable of coping with the production of a small number of lots and various kinds.

[0005]

In view of the above situation, the present inventors have intensively studied a wet molding method which can be efficiently produced by a compact apparatus, and have found that a slurry having a specific Canadian Standard Freeness (CSF) as a raw material is obtained. The present inventors have found that this can be achieved by using the composition and further combining it with specific drying conditions, and have completed the present invention. That is, the present invention uses a slurry comprising a composition having a Canadian Standard Freeness (CSF) of 550 ml or more to remove water, which is a medium of the slurry, from the pores of a mold having a large number of pores. A method for producing a molded product obtained by depositing a fine component that does not pass through pores in a slurry into a molding die to form a molded product and then drying the wet molded product in or out of the mold. A method for producing a molded article, characterized in that the method is performed under a condition that heated air flows in a deposition layer at a flow rate of liter / cm ² · min or more. In the present invention, the temperature of the heating air used for drying is preferably 100 ° C. or higher. In the present invention, it is preferable that the molded article in a wet state has holes for promoting drying. In the present invention, it is preferable to inject heated air under pressure into the holes for promoting drying formed in the wet molded product. In the present invention, the thickness of the deposited layer of the molded product is 20 mm
It is preferable that it is above. In the present invention, the main component of the slurry composition is preferably a cellulosic fiber.
Above all, it is preferable that the cellulosic fiber is a cellulosic fiber that has been subjected to at least one of water repellency, water resistance, and curing. In the present invention, it is preferable that the cellulosic fibers are curl-treated cellulosic fibers. Above all, it is preferable that the cellulosic fiber is a cellulose fiber that has been subjected to at least one of water repellency, water resistance, and curing, and further subjected to curl treatment. Further, it is preferable that the cellulosic fiber is a used paper fiber which has been subjected to at least one of water repellency, water resistance, and curing, or a used paper fiber which has been further curled. In the present invention, it is preferable that the main component of the slurry composition is a cellulosic coarse powder.
Above all, it is preferable that the cellulosic coarse powder is obtained by mechanically pulverizing wood.

The cause of the success of the present invention is the Canadian Standard Free
Use a slurry composition with a nest (CSF) of 550 ml or more
Of the wet molded product (hereinafter simply referred to as molded product)
In this case, see that through-air drying is the most efficient drying method.
Out, especially 2 liters / cm ²・ Heating at a flow rate of
Air drying was performed under conditions where the air flowed through the sedimentary layer
Found that the drying speed was significantly increased in that case.
Therefore, without using the conventional large drying equipment,
In case of internal drying, prepare many expensive molds
Instead, it has made it possible to increase productivity.

[0007]

DETAILED DESCRIPTION OF THE INVENTION
Using a slurry having a Canadian Standard Freeness (CSF) of 0 ml or more, water, which is a medium of the slurry, is removed to deposit fine components that do not pass through the pores in the slurry into a mold to form a molded product. The drying of the molded product is performed at a flow rate of 2 liters / cm ² · min or more under the condition that heated air flows in the deposition layer. Known methods such as hot air drying, infrared drying, and microwave drying can be used for drying the wet molded product, but heated air is flowed into the deposition layer at a flow rate of 2 liter / cm ² · min or more. As the means, for example, the following means can be adopted. Heating air is injected into the deposition layer under pressure, while heating air is supplied at normal pressure or pressure from the opposite side of the molded product, the air in the deposition layer is sucked, and infrared or microwave is applied to the molded product Suction of the air in the deposition layer. Injection of room temperature air or heating air into the deposition layer under pressure while applying infrared rays or microwaves to the molded product (in some cases, simultaneously suck air in the deposition layer). And the like. Among them, a method involving pressurized air supply is preferred in terms of drying efficiency. The pressurizing condition at that time is 1 kg / c
m ² or more, particularly preferably 2 kg / cm ² or more, especially 4 kg / cm ² or more. As a method of pressurization, if the pressure is increased at once, the density of the molded body increases, so it is preferable to increase the pressure gradually. As drying conditions,
Although an air flow rate of 2 liters / cm ² · min or more is sufficiently effective, a flow rate of 5 liters / cm ² · min or more is particularly preferable. In particular, the flow rate is preferably 10 liters / cm ² · min or more.

[0008] In the through-air drying of the present invention, the thickness of the deposited layer is 20
This is particularly effective in the case of a molded article having a portion of not less than mm. Another effective means for increasing the drying efficiency is to form a hole in the molded product to improve the air flow. It is particularly effective when the thickness of the deposited layer has a portion of 30 mm or more. The size or shape of the hole is not particularly limited, but a preferred one has a cross-sectional area of 0.0
It is a cylinder having a diameter of about 1 to ¹ cm ² , and may have any cross-sectional shape such as a circle, a square, and a hexagon. One or more holes are formed in the molded product, but if there are a plurality of holes, they need not be the same hole. The size, shape, and number of the holes are determined in consideration of the drying efficiency, the strength of the molded body, and the like. The direction in which the holes are formed is not particularly limited, but considering the ease of formation and the like, the direction in which the fine components that do not pass through the small holes are more preferably deposited. The holes may be either through holes or non-through holes, but non-through holes are preferred for drying using hot air pressure injection.
The depth of the non-through hole is not particularly limited, but is preferably 20 to 90% of the thickness. The drying efficiency is particularly good when air is directly injected into this hole and a short cylindrical projection is inserted into the hole and injected, or a small hole, slit or crack is formed in the wall of the long cylindrical projection. It is effective to use a method of injecting and inserting into the through hole or the non-through hole. The cylindrical projection is preferably tapered so that it can be easily inserted into the hole.

As the heating air, air having a temperature of 50 ° C. or higher is usually used, but air having a temperature of 100 ° C. or higher is preferable in terms of drying efficiency. Among them, those having a temperature of 130 ° C. or higher are particularly preferable. For drying, heated nitrogen gas, heated steam, or the like can be used other than heated air, but heated air is most preferable in terms of drying efficiency and cost. Means for forming a penetrating or non-penetrating hole in the molded product include (a) a press-type pressing machine,
Cutting machine, water jet, air jet, needle,
A method in which a hole is drilled in a wet molded product inside or outside the mold using a drill, a drill, or the like. (B) The shape is simultaneously formed with a molding container having a convex portion for forming a hole. And (c) a method in which an object having a hole shape is immersed in a molding container and molded, and then the object is removed. In addition, it is desirable that the convex-shaped portion of (b) and the hole-shaped object of (c) have a tapered structure so that they can easily come off after molding. Drying of the molded article includes in-mold drying in which the molded article is dried, and out-of-mold drying in which the molded article is taken out of the mold and dried. In-mold drying is preferred in that a molded article having high dimensional accuracy is obtained. As a means for increasing the drying efficiency, it is also effective to apply hot water to the wet molded product under suction dehydration immediately before drying with heated air to raise the temperature of the molded product in advance.

[0010] The slurry composition of the present invention is not limited to pulp, but in the description related to the drawings, the pulp will be described below. For molding, (A) As shown in FIG. 1, a molding container 10 which is an open-top double-walled container is immersed in a pulp slurry tank and sucked, and the same thickness is applied to the entire surface of the mold as in a normal pulp mold. (B) As shown in FIG. 2, an upper guide 1 is provided in an open-type deep-bottom container (for example, a cylindrical container such as a cylinder or a square tube).
7, a type in which pulp slurry 18 is supplied and deposited in such a manner as to be packed in the container. (C) As shown in FIG. 3, pulp slurry is injected from a slurry injection pipe 22 and formed into dividable containers 19 and 20. It is possible to use a type in which pulp is filled in the voids and a molded product can be taken out by dividing the molded container before or after drying (hereinafter, the mold is referred to as a molded container in the present invention). Above all, if you need a thick molded product with excellent cushioning,
(B) and (C) type molded containers are preferred. FIG.
In 3 to 3, 11 is a large number of small holes for dewatering provided on the inner wall of the mold 12, 13 is a suction chamber, 14 is a suction port provided in the suction chamber 13, 15 is a wet pulp deposit, and 16 is a dewatering pulp. Water droplets 21 oozing from the small holes 11 to the suction chamber side are clips for holding the left and right divided containers 19 and 20 together in a sealed state.

[0011] Small holes for dehydration of a molded container (hereinafter referred to as small holes)
11 may have any shape such as a circle, an ellipse, a square, a rectangle, and the like. The size of the small holes may be such that the dispersed components other than water as a medium of the slurry hardly leak, and a circular one having a diameter of 30 μm to 3 mm is usually used. Is not particularly limited. Usually, when the impervious component is large, a larger one is used, and when it is small, a smaller one is used.
Like a mold used in a pulp mold, a mold in which a fine mesh is attached to a molding container wall having a relatively large hole can also be used. Further, the size of the small hole can be changed in the portion of the molding container. Further, the small holes need not necessarily be present on the entire surface of the wall of the molding container, and may be present only at the bottom in the case of a cylindrical container. It is preferable that the pores are present in at least 40% of the wall of the container, more preferably at least 75%. The number of parts to in pores small pores there is preferably made present one or more per cm ^2, and more preferably four or more per cm ^2.

Injecting the slurry into the molding container is as follows: (a) In the case of a cylindrical container, the slurry is injected by a pump into the molding container whose opening is upward from the opening, and (b) the slurry is opened like a normal pulp mold. Dip into the slurry tank with the opening facing downward, and suck the slurry into the molding container from the downward opening by sucking through the small holes. (C) Suction while sinking the molding container into the slurry tank with the opening facing upward Then, a method of sucking the slurry into the molding container from the opening can be employed. In the case of a split mold container, a method such as press-fitting into a molded container using a slurry injection tube can be employed. Methods for removing the medium of the slurry from the small holes include a suction dehydration method, a gas pressure dehydration method,
There are mechanical pressure dehydration method, electroosmotic dehydration method and the like, and these can be combined.

Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. FIG.
7 are sectional views showing embodiments of the present invention. As shown in FIG. 4, the molded container 10 is a double-walled container having an open top cylindrical shape, and has a large number of small holes 11 for dehydration on the inner wall.
In addition to having a convex lower mold 12 having a step on the bottom inner periphery of the inner wall, a suction chamber 13 is formed by inner and outer double walls, and a suction port 14 is attached to the outer wall bottom. I have. Although the shape of the lower mold 12 is schematically illustrated as a simple one with a stepped portion, the shape of the unevenness may be more complicated according to the shape of the product protected by the cushioning material. FIG.
While the pulp slurry 18 was being injected from the upper guide 17, the pulp was deposited on the open surface of the container by suction dehydration by suction dehydration from the lower suction port 14, and the pulp filling into the container 10 was completed. The state is shown. Numeral 16 indicates water droplets oozing out by suction, and numeral 15 indicates pulp sediment in a wet state.

FIG. 5 shows the wet pulp deposit 1 of FIG.
5 shows a state in which the raised unnecessary portion 5 is cut off by the water jet 23. Cutting is performed while moving the water jet nozzle. FIG. 6 shows a press upper mold 24 having a flat bottom surface and a large number of small holes 25 in the bottom surface.
After lightly compressing the surface to make the surface smooth, a hot air of 150 ° C. is sent from the hot air port 26 of the upper mold 24 while pressurizing, and the flow rate is 10 liter / cm.
^It shows a state of being dried under the condition of ² minutes. FIG.
Indicates a final molded product 27 obtained by taking out from the molding container 10 after drying. By the way, if the bottom of the press upper die 24 of FIG. 6 is made to have a special shape, a molded product having a more complicated surface shape can be obtained.

FIGS. 8 to 12 show a second embodiment of the present invention. FIG. 8 shows a state in which a large number of cylindrical drying promoting holes 28 are formed from the upper surface of the sediment 15 cut with a water jet in the same manner as in FIG. FIG. 9 is a plan view of FIG. Drilling is
It is possible to perform each one by using one nozzle, but using a multi-nozzle 30 as shown in FIG. A hole 28 as shown in FIG. 8 can be opened at a time by touching the surface. FIG. 11 shows that the upper lid 34 having a tapered tube projection 35 is covered from above the wet molded product (sediment) 15 having the hole 28 formed therein, and the hollow projection 35 is inserted into each hole 28. While sucking from the hollow projection 35
This shows a state in which hot air having a flow rate of 10 to 150 ° C. flows through the deposition layer at a flow rate of 10 liter / cm ² · min. This method has better drying efficiency than the first embodiment. FIG. 12 shows the final molded product 36 thus obtained.

The most preferred raw material for the slurry used in the present invention is an environmentally friendly natural material such as pulp. If the slurry composition has Canadian Standard Freeness (CSF) of 550 ml or more, the effect of the present invention can be expected, and natural, synthetic, semi-synthetic organic polymers, ceramics, and metals can be used. And the like, or a fine substance having a shape such as granular, needle-like, scaly, or fibrous made of an inorganic substance or a composite thereof. The size of the raw material is not particularly limited, and the dispersibility when making a slurry,
In consideration of the raw material yield during molding, a material having a range of usually 0.1 to 50 mm is used. These raw materials may be used in combination of two or more. Naturally, raw materials recovered for recycling can also be used. The following are more specific examples of the raw material.

Examples of natural organic polymer fibers include cellulose fibers such as pulp, protein fibers such as wool, silk and collagen fibers, and complex sugar chains such as chitin / chitosan fibers and alginic acid fibers. System fibers and the like. Examples of the synthetic organic polymer fiber include polyethylene fiber, polypropylene fiber, polyethylene-polypropylene sheath core fiber, polyacrylonitrile fiber, acrylic fiber, polyester fiber, aliphatic polyester fiber, polyamide fiber and the like. In addition, examples of the semi-synthetic organic polymer fiber include acetyl cellulose fiber. Examples of the natural organic polymer coarse powder and fine particles include, for example, cellulose, coarse powder obtained by coarsely pulverizing cellulosic materials such as wood, bacas, and rice straw, as well as rice husk, bran, beer lees, and soybean lees. No. Examples of the synthetic organic polymer coarse powder and fine particles include beads of synthetic resin such as polyethylene and polystyrene, coarsely crushed foamed resin such as expanded polystyrene, foamed microcapsules, and crushed old tires. The semi-synthetic organic polymer coarse powder / fine particles include, for example, coarsely pulverized acetyl cellulose. Examples of the inorganic fibers include glass fibers, carbon fibers, alumina fibers, silicon carbide fibers, silica / alumina silicate fibers, rock wool fibers, and stainless fibers. Examples of the inorganic coarse powder / fine particles include shirasu balloons, glass beads, granular activated carbon, and the like. Among the above-mentioned slurry raw materials, cellulosic fiber or cellulosic coarse powder is preferable because it has excellent low-density and buffer properties, has biodegradability, is environmentally friendly, and can be easily procured. Above all, cellulose fibers that have been subjected to at least one of water repellency, water resistance, and curing treatments, and cellulose-based coarse powder obtained by mechanically pulverizing wood have low density and buffering properties. It is particularly excellent in terms of surface and is preferable. Further, the curled fibers and the coarse powder are particularly preferable. Among them, waste paper fibers that have been subjected to at least one of water repellency, water resistance, and curing or waste paper fibers that have been further curled have excellent low-density and cushioning properties and are environmentally friendly. It is meaningful from the aspect of correspondence,
Particularly preferred.

A slurry is prepared using the above-mentioned materials as raw materials. However, depending on the materials, there are cases where the bonding strength between them is weak and the interlayer strength alone is insufficient, and in such a case, if necessary, A material having an effect of increasing the interlayer strength, for example, an adhesive, a fine fiber, or the like is added to the slurry. Above all, fine fibers are preferably used in that the wastewater treatment during the production of a molded article is easy. Examples of the adhesive include starch,
Processed starch, vegetable gum, gelatin, casein, PVA, C
MC, hydroxyethyl cellulose, urea formaldehyde resin, melamine formaldehyde resin, polyamide urea formaldehyde resin, ketone resin, polyamide epichlorohydrin resin, vinyl acetate resin emulsion, acrylate resin emulsion, ethylene-vinyl acetate copolymer emulsion, styrene-butadiene copolymer Polymerized emulsions and the like can be mentioned. As the fine fibers, for example, a natural polymer fiber, a synthetic polymer fiber, or a semi-synthetic polymer fiber is subjected to wet mechanical treatment with a medium stirring mill, a vibration mill, a high-pressure homogenizer, a colloid mill, a beating machine, or the like. And the like.

Examples of the above natural polymer fibers include:
Unbleached or bleached chemical pulp obtained by kraft pulping, sulfite pulping, alkali pulping of coniferous or hardwood, or mechanical pulp such as GP, TMP (thermo-mechanical pulp), cotton pulp, linter pulp Wastepaper pulp, cellulose fibers such as bacterial cellulose, protein fibers such as wool, silk and collagen fibers, and complex sugar chain fibers such as chitin / chitosan fibers and alginic acid fibers. . As synthetic polymer fibers,
For example, polyethylene fiber, polypropylene fiber, polyethylene-polypropylene sheath core fiber, polyacrylonitrile fiber, acrylic fiber, rayon fiber, polyester fiber, polyamide fiber and the like can be mentioned. Examples of the semi-synthetic polymer fibers include fibers obtained by chemically modifying natural products, such as acetyl cellulose fibers.

The slurry composition may further contain a water-proofing agent, a water-repellent,
Sizing agents, dyes, pigments, retention agents, fillers, pH regulators, slime control agents, thickeners, preservatives, fungicides, antibacterial agents, flame retardants, rodenticides, insect repellants, moisturizers, freshness preservatives , An oxygen scavenger, a microcapsule, an effervescent microcapsule, a foaming agent, a surfactant, an electromagnetic shielding material, an antistatic agent, a rust inhibitor, a fragrance, a deodorant and the like can be selected and blended. These may be used in combination of two or more.

The slurry is usually prepared batchwise or continuously using an apparatus having a stirrer. Water is usually used as a medium used for forming the slurry, but other organic solvents such as alcohol, acetone, ethyl acetate, and glycerin, or a mixture of water and an alcohol (methanol or ethanol) can be used. . When a mixture of water and alcohol is used, there are merits such as good drying properties and an increase in productivity, and a high-precision molded article with little dimensional change during drying. Heating the medium has the effect of increasing the drying rate. The concentration of the slurry is usually adjusted so that the dry solid content is in the range of 0.05 to 10% by weight, but preferably in the range of 0.05 to 4% by weight in terms of the dispersed state.

The cellulosic fiber or cellulosic coarse powder-containing system which is most suitable for carrying out the present invention will be described in more detail mainly below, but the present invention is not particularly limited thereto. As cellulosic fibers, for example, conifers,
Unbleached or bleached chemical pulp obtained by hardwood kraft pulping, sulfite pulping, alkali pulping, etc.
Alternatively, mechanical pulp such as GP and TMP (thermomechanical pulp), or cotton pulp, linter pulp, waste paper pulp, liquid ammonia-treated pulp, mercerized pulp, curled fiber, and the like may be used. Canadian Standard Freeness (CSF) is 55% when used in combination with other materials having a Canadian Standard Freeness (CSF) of 550 ml or more.
0 ml or less can be used.
Those having 0 ml or more are preferred. Above all, those having a Canadian standard freeness (CSF) in the range of 550 to 850 ml are more preferable because they have good drainage, are easy to produce and are inexpensive. Canadian Standard Freeness (CSF) 550m
Among the l or more cellulosic fibers, a curled fiber having a curled shape by performing a curling treatment is preferable since a molded article excellent in low density and cushioning property can be obtained. Especially, the wet curl factor is 0.4 ~
The curled fiber in the range of 1.0 has a property that the curl shape is well maintained even in a state of being dispersed in water for a long time. It is particularly preferable because it is suitable for stable production over time. When the wet curl factor is less than 0.4, the low-density property is slightly inferior. On the other hand, when the wet curl factor is more than 1.0, the pulp fiber is damaged due to the strengthening of the mechanical treatment when deforming the pulp fiber. The decrease in fiber strength and the generation of paper dust become remarkable, and this is practically possible, but not very preferable.

Incidentally, the wet curl factor is an index indicating the degree of deformation of the fiber in a wet state, and the actual length (LA) of the fiber after immersing the curled fiber in pure water at room temperature for 24 hours. And the maximum projected length of the fiber (the length of the longest side of the rectangle surrounding the fiber, LB) is measured using a microscope,
This is a value calculated by [(LA / LB) -1], which is a numerical value indicating how much the fiber is curved from the original length of the linear fiber.

The curled fiber is usually obtained by adding a crosslinking agent to a cellulosic fiber, subjecting the fiber to mechanical stirring for deforming the fiber, followed by fluffing and heat treatment to fix the deformation. Known ones include:
For example, a crosslinked fiber having an average water retention of 28% to 50% obtained by crosslinking the inside of a cellulosic fiber using a C2 to C8 dialdehyde and a C2 to C8 monoaldehyde having an acid functional group (Japanese Patent Publication No. 5-71702) Publication), C2 to C9
Cross-linked fibers having a water retention of 25% to 60% obtained by internally cross-linking cellulosic fibers using polycarboxylic acid of
06174, JP-A-3-206175 and JP-A-3-206176). Examples of the cellulosic fiber used as a raw material of the carded fiber include unbleached or bleached chemical pulp obtained by kraft pulping, sulfite pulping, alkali pulping, etc. of softwood or hardwood, or GP, TMP.
(Thermomechanical pulp) and the like, or cotton pulp, linter pulp, waste paper pulp and the like.

As the carded fiber, a fiber having a water retention of 25 to 65%, which is excellent in terms of good drainage and easy drying speed and excellent in production efficiency of a low density body, is preferable. The invention is not particularly limited to this. By the way, the water retention was set to 3000 minutes for 15 minutes.
The amount of water held by the fiber after dehydration by the centrifugal force of G is defined as a value (%) expressed as an amount per 1 g of absolute dry weight, and the measuring method is JAPAN TAPPI.
No. 26-78.

The curled fiber is usually blended in a range of 30 to 98% by dry weight based on the composition. Note that two or more kinds of curled fibers may be used in combination. Curled fibers are weak in entanglement between fibers due to their shape, and are less likely to form hydrogen bonds due to hydroxyl groups due to a reduction in hydroxyl groups (-OH) of cellulose molecules due to cross-linking treatment. The obtained one has low interlayer strength. Therefore, it is necessary to use other fibers in combination in order to obtain one having interlayer strength. Examples of the fibers include natural polymer fibers, synthetic polymer fibers, semi-synthetic polymer fibers, and those obtained by treating them, as described above. Any material can be used. Among them, fine fibers having a bond reinforcing factor of 0.15 or more are
The effect on increasing the interlayer strength is particularly remarkable and preferable. As fine fibers, usually the number average fiber length is 0.01 to 0.8
Those having a range of 0 mm are used. Among them, those having a range of 0.05 to 0.60 mm are preferable in terms of yield and dispersibility.

Among them, those having biodegradability such as cellulosic fibers, aliphatic polyester fibers, and acetylcellulose fibers are preferably used. Further, from the viewpoints of stability of raw material supply and cost, a cellulosic fiber or one obtained by treating the same is more preferable. Among them, fine fibers obtained by subjecting the above fibers to wet mechanical treatment with a medium stirring mill, a vibration mill, a high-pressure homogenizer, a colloid mill treatment, a beating machine treatment or the like have a large effect of increasing the interlayer strength, and thus are preferable.

The binding enhancement factor (BF) referred to in the present invention
Is calculated by (E2−E1) / E1. However, E1
Is a mixture of bleached hardwood kraft pulp 50% by weight and softwood bleached kraft pulp 50% by weight to form an aqueous slurry,
After beaten to 500 ml of Canadian Standard Freeness (CSF), dewatered and air-dried with a hand making machine according to JIS-P-8209 to produce a sheet having a basis weight of 60 g / m ² ,
The figure shows the ultrasonic elastic modulus measured after heat treatment at 30 ° C. for 2 minutes and humidity control at 20 ° C. and 65% RH. E2 indicates the ultrasonic elastic modulus when an aqueous slurry was prepared by replacing 50% of the pulp fibers with fine fibers, and a sheet was prepared and measured in the same manner as in the measurement of E1.

The above fibers may be used in combination of two or more. The mixing ratio of the carded fiber and the other fibers as described above can be appropriately selected according to the purpose because the balance between the density and the interlayer strength can be controlled by changing the ratio. That is, if the interlaminar strength is more important than the density, the blending of other fibers is increased. Conversely, if the density is more important than the interlaminar strength, the blending with more curled fibers may be selected. Above all, when other fibers are mixed and used in a ratio of 3 to 65% by weight based on the total fiber absolute dry weight, and curled fibers are used in a ratio of 35 to 97% by weight based on the total fiber absolute dry weight, the balance between the density and the interlayer strength is reduced. Particularly excellent and preferred.

The slurry composition may further contain an adhesive, a water-proofing agent, and the like, if necessary, for improving performance and imparting functions.
Water repellent, sizing agent, dye, pigment, retention aid, filler, P
H regulator, slime control agent, thickener, preservative,
Antifungal agent, antibacterial agent, flame retardant, rodenticide, insect repellent, humectant, freshness preserving agent, deoxidizer, microcapsule, foamable microcapsule, foaming agent, surfactant, electromagnetic shielding material, antistatic agent, antistatic Rust agents, fragrances, deodorants and the like can be selected and blended. These may be used in combination of two or more.

As the cellulosic coarse powder, for example, those obtained by mechanically coarsely pulverizing a cellulosic material such as wood chips, bacas, rice straw, rice husk, or the like, or rice husk itself, needle-like or sawdust-like, or fiber-like And those having a shape such as a granular shape. Preferable ones have a Canadian Standard Freeness (CSF) value of 550 ml or more, or a freeness value of 550 ml or more when an 80 mesh pass portion is removed, or a fine area processed by a mesh pass process. Those having been removed to increase the freeness value to 550 ml or more, those having an 80 mesh passage of 25% by weight or less, and the like can be mentioned. These have a freeness value of 5
In the case of 50 ml or more, the composition can be used alone, but those having a freeness value of less than 550 ml can be used in combination with another material having a freeness value of 550 ml or more. Among them, needle-like and fibrous materials are preferable because they have excellent low-density and cushioning properties, and easily exhibit interlayer strength. Above all, needle-like ones are particularly excellent in buffering property and are preferable. Needle-like, among those having a fibrous shape, coarse powder used as a raw material for fiberboard obtained by coarsely pulverizing wood chips has excellent low-density properties, and it is easy to procure raw materials, especially preferable.

As the pulverizing method, for example, an asplund method known in the fiberboard industry can be mentioned. Among them, those pulverized at a high temperature of 110 ° C. or more, particularly at 130 ° C. or more, are those treated at a lower temperature. This is preferable because it tends to have higher rigidity, and therefore tends to have excellent low-density and cushioning properties. As the pulverizing treatment, for example, a weak treatment that does not usually become a raw material for paper, such as a single-stage treatment in a refiner, is preferable because it tends to have high rigidity. In addition, as a means for increasing the rigidity, a method of performing a crosslinking reaction treatment, a hydrophobic treatment, and a surface resin treatment before and after the pulverization treatment of the wood chips is also effective. In the case of the above-mentioned pulverized product or the processed product further subjected to curling treatment with a kneader or the like, the improvement of the buffering characteristics becomes more remarkable. Among the coarse powders, those having a freeness value of 550 ml or more by removing a fine region by passing through 30 to 200 mesh are easy in drainage treatment in the production of a molded product, and furthermore, the raw material yield in the production of a molded product. Is preferred.

In the present invention, a molded product can be obtained by using a cellulose-based coarse powder alone. However, when used alone, the interlayer strength and low density tend to be slightly inferior. Preferably, fibers are added therein. Examples of the fiber include those obtained by treating natural polymer fibers, synthetic polymer fibers, semi-synthetic polymer fibers, or the like as described above,
Among them, a fine fiber having a bond reinforcing factor of 0.15 or more is preferable because the effect of improving the interlayer strength is large. In addition, curled fibers such as curled fibers are preferable because the effect of improving the low density property is large. In particular, curled fibers having a wet curl factor in the range of 0.4 to 1.0 are preferred.

The blending amount of the composition is not limited to this range, but the cellulose-based coarse powder is usually blended in a range of 30 to 100% by dry weight based on the composition. The fibers are blended in the range of 10 to 70%.

The slurry composition may further contain an adhesive, a waterproofing agent, a water repellent, a sizing agent, a dye, a pigment, a retention aid, a filler, a pH adjuster, a slime control agent, if necessary. Thickeners, preservatives, fungicides, antibacterial agents, flame retardants, rodenticides, insect repellents, moisturizers, freshness-retaining agents, oxygen absorbers, microcapsules, foamable microcapsules, foaming agents, surfactants, electromagnetic shields Materials, antistatic agents, rust inhibitors, fragrances,
Deodorants and the like can be selected and blended. These may be used in combination of two or more.

The molded product obtained by using the slurry prepared as described above may be used, if necessary, with a waterproofing agent, a water repellent, a dye, a pigment, a preservative, a fungicide, an antibacterial agent, Include flame retardants, rodenticides, insect repellents, freshness preserving agents, oxygen scavengers, electromagnetic shielding materials, antistatic agents, rust inhibitors, fragrances, deodorants, etc. by means of spraying, impregnation, coating, etc. Can be done. Further, the obtained molded bodies can be bonded together. Further, it can be bonded to other materials such as synthetic resin film, synthetic paper, synthetic resin plate, water-resistant paper, water-repellent paper, metal foil such as aluminum, metal plate, glass plate and the like. Also,
Processing such as cutting and printing can also be performed. The molded body obtained by the method of the present invention, in addition to a cushioning material for packaging and the like,
It can be widely applied to fields where foamed resin moldings are currently used, such as building materials and tatami core materials.

[0037]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but it should be understood that the present invention is not limited to these examples.
In Examples and Comparative Examples, “parts” and “%” refer to “parts by weight of solid content” and “% by weight” unless otherwise specified.
Is shown.

<Example 1> A non-formalin-based cross-linking agent (trade name: Sumitex NF-500K, manufactured by Sumitomo Chemical Co., Ltd.) and a cross-linking assistant (100 g) of 100% non-beaten softwood bleached kraft pulp were dried. Product Name: Sumitex AC
CELERATER MX, manufactured by Sumitomo Chemical Co., Ltd.) was added to 100 g of an aqueous solution containing 5 g and 2 g in terms of active ingredients, respectively, and mixed well. The crosslinker-impregnated treated pulp is kept in a wet state in a 1-liter double-arm kneader (model: S1-1,
(Moriyama Seisakusho), at room temperature with double arms 60r each
Rotation was performed at rpm and 100 rpm, and a kneading treatment was performed for 40 minutes. Next, the kneaded pulp was placed in a Warburg blender in a wet state and fibrillated. Further, the fiber was taken out of the bag, placed in a stainless steel vat, and heated in a blow dryer at 150 ° C. for 30 minutes to complete the crosslinking reaction, thereby obtaining a curled fiber. When the wet curl factor of the curled fiber was measured, it was 0.63. The Canadian standard freeness (hereinafter abbreviated as freeness) of this fiber was measured and found to be 753 ml. A water slurry of bleached kraft pulp having a solid content of 1% was mixed with glass beads having an average particle size of 2 mmφ for 80 hours.
% Dyno-Mill (Model: KD
(L-PILOT type, manufactured by Shinmaru Enterprises) at 350 ml / min and passed therethrough to obtain a number average fiber length of 0.28 mm and a bond reinforcing factor of 0.
53 fine fibers were obtained. The water retention of the fine fibers was measured and found to be 285%. 90 parts of the curled fiber obtained as described above, 10 parts of the fine fiber, and water were added to adjust the raw material slurry to a solid concentration of 2%. The freeness of these two types of mixed fibers is 7
It was 21 ml. Take 800 g of the above slurry (16 g in absolute dry conversion), and use two types of threaded copper alloy pipe fittings (50 mm inner diameter, 100 mm long nipple, 5 inner diameter)
52mmφ between 0mm × 25mm socket of different diameter)
Into a metal container with a circular punched plate made of aluminum and a stainless steel wire of 52 mmφ with a mesh of 80 mesh, suctioned from the side of the reduced-diameter socket with a water ring vacuum pump, and wet in the long nipple. A molded article was formed. Thereafter, with the vacuum pump removed from the lower part and the air flow meter attached, the hot air generator (trade name: Hot Gale, model: HT2-10,
4kg / c with a compressor at Miyamoto Manufacturing Co., Ltd.)
The molded body was dried by sending hot air at 150 ° C. while applying a pressure of m ² . The time required for complete drying was 1.9 minutes. The flow rate of hot air immediately before drying was 19.8 liter / cm ² · min. When physical properties of the obtained molded body were measured, the thickness was 78 mm, and the density was 0.106 g / cm ³ . Hereinafter, a method for measuring the wet curl factor of the curled fiber and a method for evaluating the fine fiber will be described.

[Measurement method] [Measurement method of wet curl factor] 24 hours at room temperature in distilled water.
After 100 hours of immersion, the curled fibers are placed on a microscope slide glass, and the actual (linear) length LA (μ) of each fiber is measured using an image analyzer.
m) and the maximum projected length (equal to the length of the longest side of the rectangle surrounding the fiber) LB (μm) were measured, the wet curl factor was determined from the following equation, and the average value was used. Wet curl factor = (LA / LB) -1

[Measurement Method of Bond Reinforcement Factor of Fine Fibers] 50 parts of bleached hardwood kraft pulp and 50 parts of softwood bleached kraft pulp were mixed and adjusted to a concentration of 2%, and the mixture was mixed with a laboratory Niagara beater (capacity: 23 L). Beated to 500 ml Canadian Standard Freeness (CSF). Take 3.7 g of this paper stock dry and add 15 g without adding chemicals.
Using a 0-mesh wire, square (25 cm × 25
cm) A sheet is formed by a hand-sheet making machine, and after a coating process, the sheet is formed at a pressure of 3.5 kg / cm ² according to a conventional method.
After performing wet press for 1 minute (first press) and 2 minutes (second press), drying was performed at room temperature by a blast dryer between frames. Thereafter, the sheet was heat-treated at 130 ° C. for 2 minutes to prepare a sheet 1 having a basis weight of 60 g / m ² ,
H was conditioned. On the other hand, 3.7 g of absolutely dry material was taken from a raw material in which 50 parts of the above-mentioned NL-mixed beaten pulp and 50 parts of fine fibers were well mixed, and a sheet 2 was prepared in the same manner.
The humidity was adjusted at 5% RH. After measuring the densities of the sheets 1 and 2, a dynamic Young's modulus measuring device (manufactured by Nomura Shoji Co., Ltd., model:
The elastic modulus (GPa) of the sheets 1 and 2 was measured by measuring the ultrasonic wave propagation velocity using SST-210A). The elastic modulus (E) was calculated by the following equation. E (GPa) = ρ (g / cm ³ ) × {S (km / s)}
² where ρ indicates the density of the sheet after humidity control (g / cm ³ ), and S indicates the ultrasonic wave propagation velocity (km / s). The elastic modulus of the sheet 1 is E1 (GPa), and the elastic modulus of the sheet 2 is E2 (GPa).
, The bond strengthening factor is ｛(E2 / E1) −
It is represented by 1｝.

[Measurement Method of Number Average Fiber Length of Fine Fibers] The number was measured using a Kayani fiber length measuring instrument (model: FS-200).

[Measurement Method of Water Retention] The water retention of the fine fiber is as follows.
As shown below, JAPAN TAPPI No. 26-7
8 was measured. A fine fiber slurry having a solid content of 1% was concentrated to a concentration of 6 to 9% using a Buchner funnel, and a sample was collected to an absolute dry weight of 0.7 g.
The mixture was placed in a centrifuge tube having a glass filter of No. 3 and subjected to centrifugal dehydration at a centrifugal force of 3000 G for 15 minutes using a centrifuge (model: H-103N, manufactured by Domestic Centrifuge). The sample subjected to the centrifugal dehydration treatment was taken out from the centrifuge tube, and the weight in a wet state was measured. Thereafter, the sample was dried to a constant weight with a dryer at 105 ° C., the dry weight was measured, and the water retention was calculated by the following equation. Water retention (%) = {(WD) / D} × 100 where W is the wet weight (g) of the sample after centrifugal dehydration, and D is the dry weight (g) of the sample.

<Example 2> When a wet molded product obtained in the same manner as in Example 1 was dried, the flow rate of hot air immediately before drying was adjusted to 8.0 liter / cm ² · min. Example 1 except that the pressure was lowered and hot air of 150 ° C. was sent.
And dried in exactly the same manner as described above. The time required for complete drying was 5.3 minutes. When the physical properties of the obtained molded body were measured, the thickness was 80 mm, and the density was 0.101 g /
cm ³ .

<Example 3> When the wet compact obtained in the same manner as in Example 1 was dried, the flow rate of hot air immediately before drying was adjusted to 3.0 liter / cm ² · min. Example 1 except that the pressure was lowered and hot air of 150 ° C. was sent.
And dried in exactly the same manner as described above. The time required for complete drying was 14.6 minutes. When the physical properties of the obtained molded body were measured, the thickness was 82 mm, and the density was 0.098 g.
/ Cm ³ .

<Comparative Example 1> When the wet molded product obtained in the same manner as in Example 1 was dried, the flow rate of hot air immediately before drying was adjusted to 1.0 liter / cm ² · min. Example 1 except that the pressure was lowered and hot air of 150 ° C. was sent.
And dried in exactly the same manner as described above. The time required for complete drying was 43.2 minutes. When physical properties of the obtained molded body were measured, the thickness was 82 mm, and the density was 0.097 g.
/ Cm ³ .

<Comparative Example 2> A molded article in a wet state was produced in exactly the same manner as in Example 1. The wet molded product was taken out from the cylindrical tube and dried in a constant temperature dryer at 105 ° C (model: LC-112, manufactured by Tabai). The time required for complete drying was 125 minutes. Further, an attempt was made to measure the air volume on the surface of the molded body during drying, but the measurement was not possible. When the physical properties of the obtained molded body were measured, the thickness was 8
2 mm and a density of 0.098 g / cm ³ .

Example 4 A molded article in a wet state was produced in the same manner as in Example 1. This molded body is placed in a container, and while continuing suction, the inner diameter is 5 mmφ, the outer diameter is 6 mmφ, and the length is 10 mm.
By inserting water into the center of the compact while discharging water from a water gun equipped with a 0 mm metal tube,
Holes having a diameter of mmφ and a depth of 40 mm were formed in three places. Except for drying in this state, the same conditions as in Example 2 (the hot air flow rate immediately before drying was 8.0 liter / cm ² · min, the hot air temperature was 1
(50 ° C.). The time required for complete drying was 4.2 minutes. When physical properties of the obtained molded body were measured, the thickness was 81 mm, and the density was 0.101 g / cm ^3.
Met.

Example 5 Example 3 was repeated except that 200 g of the slurry (4 g of absolute dry) was used instead of 800 g of the slurry (16 g of absolute dry) prepared in the same manner as in Example 1. Drying was performed under the same conditions as described above (the flow rate of hot air immediately before drying was 3.0 L / cm ² · min, and the temperature of hot air was 150 ° C) to obtain a molded body. The time required for complete drying was 1.8 minutes. When the physical properties of the obtained molded body were measured, the thickness was 22.1 mm, and the density was 0.097 g / cm.
It was ³ .

Example 6 Softwood bleached kraft pulp was adjusted to 2% concentration with water and beaten with a laboratory Niagara beater (23 L capacity) until the freeness reached 595 ml. Except that 200 g of this slurry (4 g in terms of absolute dryness) was used as a raw material, the same conditions as in Example 3 (the flow rate of hot air immediately before drying was 3.0 L / cm ² · min,
Drying was performed at a hot air temperature of 150 ° C.) to obtain a molded body. The time required for complete drying was 15.3 minutes. When the physical properties of the obtained molded body were measured, the thickness was 8.2 mm,
The density was 0.251 g / cm ³ .

Comparative Example 3 Softwood bleached kraft pulp was adjusted to a concentration of 2% with water and beaten with a laboratory Niagara beater (capacity: 23 L) until the freeness reached 402 ml. A wet molded body was prepared in the same manner as in Example 6 except that 200 g of this slurry (4 g in terms of absolute dryness) was used as a raw material, and dried using hot pressurized air at 150 ° C. and 3 kg / cm ^2. did. The time required for complete drying was 62.5 minutes. Incidentally, the hot air flow rate at this time was 0.8 liter / cm ² · min. In addition, 15
Drying was attempted using hot pressurized air at 0 ° C. and 6 kg / cm ² , but the drying time could hardly be reduced. When the physical properties of the obtained molded body were measured, the thickness was 5.4 mm, and the density was 0.3.
It was 75 g / cm ³ .

Example 7 100 g of used newspaper (absolute dry weight) was previously cut into small pieces of about 3 cm square, and then a non-formalin type crosslinking agent (trade name: Sumitex NF-500K, manufactured by Sumitomo Chemical Co., Ltd.) and its An aqueous solution 10 containing 5 g and 2 g of a cross-linking aid (trade name: Sumitex ACCELATOR MX, manufactured by Sumitomo Chemical Co., Ltd.)
0 g was added and mixed well. The used newspaper impregnated with the cross-linking agent is placed in a 1-liter double-arm kneader (model: S1-
1, Moriyama Seisakusho), 6 arms each at room temperature
The rotation was performed at 0 rpm and 100 rpm, and a kneading treatment was performed for 40 minutes. Next, the used newspaper that had been kneaded was placed in a Warburg blender in a wet state and fibrillated. Further, the fiber was taken out of the bag, put in a stainless steel vat, and heated in a blow dryer at 150 ° C. for 30 minutes to complete the crosslinking reaction.
A cross-linked curled used newspaper was obtained. When the freeness of this waste paper fiber was measured, it was 720 ml. Crosslinked curled newspaper used paper 9 obtained as described above
Five parts, 5 parts of the fine fibers used in Example 1, and water were added to adjust the raw material slurry to a solid concentration of 2%. The freeness of these two types of mixed fibers is 685 m.
l. 800 g of the above slurry (16 g on a dry basis)
Min) as a raw material, a wet molded body was prepared in the same manner as in Example 1, and the same conditions as in Example 2 (hot air flow immediately before drying was 8.0 liter / cm ² · min, hot air (Temperature of 150 ° C.). The time required for complete drying was 6.2 minutes. When the physical properties of the obtained molded body were measured, the thickness was 76 mm and the density was 0.125 g /
cm ³ .

<Example 8> After immersing 500 g of domestically produced coniferous wood chips in terms of absolute dryness in water for 24 hours, the temperature was measured with a 12-inch pressurized refiner (model: BRP45-300SS, manufactured by Kumagaya Riki Kogyo Co., Ltd.). Wood coarse powder was obtained by processing at 140 ° C. and a clearance of 0.45 mm. The freeness of the wood coarse powder was measured by the same operation method as the Canadian standard freeness measurement method.
It was 0 ml. Wood coarse powder 9 obtained as described above
Five parts, 5 parts of the fine fibers used in Example 1, and water were added to adjust the raw material slurry to a solid concentration of 2%. The freeness of these two types of mixed fibers is 718 m.
l. 800 g of the above slurry (16 g on a dry basis)
Min) as a raw material, a wet molded body was prepared in the same manner as in Example 1, and the same conditions as in Example 2 (hot air flow immediately before drying was 8.0 liter / cm ² · min, hot air (Temperature of 150 ° C.). The time required for complete drying was 5.7 minutes. When the physical properties of the obtained molded body were measured, the thickness was 80 mm, and the density was 0.105 g /
cm ³ .

As shown in Examples 1 to 8, by selecting a raw material having an appropriate freeness and flowing hot air into the deposition layer at a flow rate of 2 liters / cm ² · min or more, it is possible to efficiently select any material. Can be manufactured. On the other hand, when the flow rate is low as shown in Comparative Examples 1 and 2, it takes a long time to dry. Also, as shown in Comparative Example 3, when a raw material having a freeness of less than 550 ml is used, a long drying time is required because hot air is difficult to pass through.

[0054]

As described above, according to the present invention, a slurry having good drainage is poured into a mold having a large number of small holes for dewatering, and the small components that do not pass through the small holes in the slurry are deposited to form a molded product. Then, when producing a molded article obtained by drying the molded article in a wet state in or out of the mold, the flow rate is 2 liter / cm ^2.
-Since the drying is performed under the condition that the heated air flows in the deposition layer for more than a minute, it can be efficiently produced with a compact device and is suitable for small lot multi-product production.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an apparatus for practicing the present invention, in which pulp is deposited to a uniform thickness on a molding die.

FIG. 2 shows another example of the present invention, and is a cross-sectional view showing a state where pulp is fully deposited in a cylindrical molding container.

FIG. 3 shows still another example of the present invention, and is a cross-sectional view of a state in which pulp is deposited in a divided molding container that can be divided into two right and left parts. is there.

FIG. 4 shows another example of the present invention, and is a cross-sectional view of a state where pulp is deposited in a molding container.

FIG. 5 is a cross-sectional view showing a state where an unnecessary portion of the pulp deposit on the open surface of the molding container of FIG. 4 is cut off.

FIG. 6 is a cross-sectional view showing a state in which the wet pulp filler after unnecessary portions have been cut off according to FIG. 5 is dried.

FIG. 7 is a sectional view of the final product obtained according to FIG. 6;

8 is a view showing still another example of the present invention, in which pulp is deposited in a molding container in the same manner as in FIG. 4, and unnecessary portions are cut off in the same manner as in FIG. 5; FIG. 3 is a cross-sectional view of a state where a hole for promoting drying is opened.

FIG. 9 is a plan view of FIG.

FIG. 10 is a sectional view of a multi-nozzle.

11 is a cross-sectional view showing a state where the upper portion of the deposit shown in FIG. 8 is covered with an upper lid having a projection of a tapered tube, and heated air is flowed through the deposited layer to dry the deposit.

FIG. 12 is a cross-sectional view of the final product obtained according to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Molding device (molding container) 11 Small hole for dehydration 12 Molding mold 13 Suction chamber 14 Suction port 15 Wet pulp deposit 16 Water drop 17 Slurry injection tube 18 Pulp slurry 19, 20 Split mold 21 Clip 22 Slurry injection tube 23 Water Jet 24 Press upper die 25 Small hole 26 Hot air injection port 27, 36 Final molded product 28 Drying promotion hole 30 Multi nozzle 31 Water supply port 32 Nozzle 34 Top lid 35 Hollow projection

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shunsuke Shioi 4-7-5 Ginza, Chuo-ku, Tokyo Inside Oji Paper Co., Ltd. (72) Inventor Koji Iwasaki 3- 6-4 Sotokanda, Chiyoda-ku, Tokyo Oji Bag Co., Ltd.

Claims (4)

[Claims] The Canadian Standard Freeness (CSF) is 55
Using a slurry composed of 0 ml or more of the composition, water, which is a medium of the slurry, is removed from the pores of the mold having a large number of pores, thereby allowing the pores of the slurry to pass through the pores of the slurry. A method for producing a molded article obtained by depositing a molded article and then drying the molded article in a wet state in or out of a mold, wherein the drying is performed by heating air at a flow rate of 2 liter / cm ² · min or more. A method for producing a molded article, characterized in that the method is performed under conditions that flow in a deposition layer. 2. The method for producing a molded article according to claim 1, wherein the molded article in a wet state has holes for promoting drying. 3. The method according to claim 2, wherein heated air is injected under pressure into a drying-promoting hole formed in the wet molded product. 4. The method for producing a molded article according to claim 1, wherein the molded article has a portion where the thickness of the deposited layer is 20 mm or more.