JP2002020999A - Method for producing molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wet method for extremely efficiently producing a thick molding. SOLUTION: A slurry is introduced into a mesh having a projected part satisfying the four conditions of (1) having an air-permeable hollow in the inside, (2) having a wall on the bottom, (3) having a hole which is connected to the hollow and admits hot air and (4) having a hole which is connected to the hollow and discharges hot air at the lower part of a side wall, dehydrated, a deposit layer of a small hole impermeable fine component in the slurry is formed on the mesh. Then, hot air is supplied from the upper part, and passed through the deposit layer to dry the deposit layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a very efficient wet manufacturing method for a thick molded product.

[0002]

2. Description of the Related Art Styrofoam conventionally used as a cushioning material for packaging has excellent shock absorbing properties, can be easily processed into an arbitrary shape, is inexpensive, lightweight, and has a good appearance. It has the following characteristics. However, in recent years,
With increasing interest in environmental issues, as with other so-called plastic products, there has been an increasing demand for disposal after use. In other words, if incinerated after use,
It has been pointed out that damage to the furnace and generation of toxic gas due to the generation of high temperatures. In addition, landfill disposal has no decomposability and is bulky, which is considered to be one of the causes of shortage of disposal sites.

As a solution to the problem in the processing of styrofoam, the inventors of the present invention have stated, "Before filing the present application, the inventors removed water, which is a medium of slurry, from small holes of a mold having a large number of small holes. And depositing the fine pore-impermeable fine components in the slurry into a mold by using the slurry having a Canadian Standard Freeness (CSF) of 550 ml or more of the slurry composition to form a wet molded product. Various methods have been proposed for a method for producing a molded article obtained by drying the molded article in or out of the mold, and a pulp-based low-density molded article having a large thickness and excellent buffering properties obtained by the method. It also discloses that hot air can be efficiently dried by passing the hot air through the deposited layer.

[0004]

However, the molded article obtained by the wet method is much faster in drying and superior in productivity in comparison with the conventional molding method. Has a problem that the drying efficiency is lowered because it is difficult to pass through the deposited layer, and in the case of a molded article having a thickness of the deposited layer exceeding 20 mm or more, the cost becomes high unless the drying efficiency is improved. Was. An object of the present invention is to provide a manufacturing method capable of efficiently producing even a thick molded body.

[0005]

The present inventors have found that when a molded article having a thick deposited layer is produced by the above-mentioned wet method, the drying efficiency is reduced because the hot air becomes difficult to pass through the deposited layer as the thickness increases. However, as a result of intensive studies in view of the fact that the cost is high unless the drying efficiency is improved in the case of a molded body having a thickness of the deposited layer exceeding 20 mm or more, the use of a mesh having a special structure has resulted in And found that the present invention was completed. That is, the present invention introduces the slurry onto a mesh having a convex portion satisfying the following four conditions, dehydrates the slurry, forms a deposited layer of small pore non-passing fine components in the slurry on the mesh, and then, from the top, A method for producing a molded body, characterized in that hot air is supplied to pass through a deposition layer and dried. (1) It has a void that can be ventilated inside. (2) It has a wall at the bottom. (3) It has a hole at the top for taking in hot air connected to the gap. In addition, the present invention has a large number of small holes on the inner wall surface, a suction chamber is formed by an inner and outer double wall, and a suction mold is attached to the outer wall, and one surface is provided in a concave-shaped lower mold having an open state. Supply the slurry,
By removing water, which is a medium of the slurry, from the small holes, the small components that do not pass through the small holes in the slurry are deposited in the lower mold to form a wet molded product, and then the upper mold is covered with the upper mold. A method for producing a molded body that is dried by supplying hot air from an upper mold, wherein the convex body is provided with a convex portion satisfying the following four conditions on the bottom surface of the concave molded lower mold. (1) It has a void that can be ventilated inside. (2) It has a wall at the bottom. (3) It has a hole at the top for taking in hot air connected to the gap. Among them, it is preferable to perform a slicing or polishing process on the surface of the formed deposited layer that is not in contact with the mesh. In particular, it is preferable that, when a wet molded product is formed, it is deposited so as to exceed the open surface of the lower mold, and unnecessary portions deposited over the open surface of the lower mold before the drying step are cut off. In particular, it is preferable to provide holes and / or grooves in a penetrating or non-penetrating state in the wet deposited layer formed on the projections, and to dry the layers. Further, the Canadian Standard Freeness (CSF) of the slurry composition is preferably 550 ml or more.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. In addition, although it demonstrates using a pulp slurry here,
The raw material of the present invention is not limited to this. FIG. 1 is a perspective view of a mold used in the present invention, and FIG. 2 is a sectional view taken along line AA. 3 to 8 are cross-sectional views showing an embodiment of the present invention (hereinafter, referred to as embodiment I) performed using the mold. On the other hand, FIG. 9 is a perspective view of a mold used in a comparative example of the present invention, and FIG. 10 is a cross-sectional view taken along line BB. FIGS. 11 to 16 are cross-sectional views showing an embodiment performed using the mold. As shown in FIG. 2 and FIG. 10, the molding die 10 used is of a concave shape having an open top with double walls, and has a large number of small holes 11 for dehydration on the inner wall. Suction chamber 2 with double wall
0 is formed, and a suction port 21 is attached to the bottom of the outer wall. The difference is whether the bottom has a convex portion or not. The mold of FIG. 2 of the embodiment of the present invention has the convex portion 13 on the bottom surface 12. The protruding portion 13 has an air permeable space 14 therein,
The bottom has a wall 15, the upper part 16 has a hole 17 for taking in the hot air connected to the space 14, and the lower part 18 of the side wall has a hole 19 for discharging the hot air connected to the space 14.

The molding process is exactly the same for both Embodiment I (FIGS. 3 to 8) and Comparative Example (FIGS. 11 to 16).
In the process shown in FIG. 11, a hopper 22, which is an enclosure for storing a slurry, is mounted on the molding die 10, and in this state, a pulp slurry 24 having good drainage is supplied from an upper guide 23, and the hopper 22 is supplied. Up to the top. Next, as shown in FIG. 4 and FIG. 12, pulp deposits 25 are formed in the mold 10 by performing suction dehydration through the suction port 21 provided in the lower part of the mold 10. At that time, the deposition is performed in a state of rising on the open surface of the mold 10.

Next, as shown in FIGS. 5 and 13, the hopper 22 is removed, and as shown in FIGS. 6 and 14, unnecessary portions of the wet pulp deposit 25 protruding from the mold opening surface are removed. Is cut off with a tip saw 27. Subsequently, the drying device 28 is set on the upper side as shown in FIGS.
Drying is performed by sending hot air from the hot air port 30 while sucking from the suction port 21. At that time, small hole 2
The hot air coming out of 9 passes through the sedimentary layer of the pulp deposit 25 in a wet state and deprives it of moisture. However, as the thickness of the sedimentary layer increases, the resistance increases and it becomes difficult to reach the lower part of the sediment 25. Convex part 1
In the present invention provided with 3, it is possible to take in the hot air from the hot air intake hole 17 in the upper portion 16 of the projection and supply the hot air directly to the lower portion of the pulp deposit 25 from the hot air discharge hole 19 in the lower side wall 18. As a result, the drying speed is much faster than that of the comparative example having no projection. The hole of the convex portion may be provided at a portion other than the upper portion and the lower portion of the side wall as described above, or may be provided on the entire surface other than the bottom. Providing a hole at the bottom of the convex portion means that the hot air taken in from the hot air intake hole 17 escapes without contributing to the drying of the sediment. Holes may be provided as long as they do not significantly impede. FIG.
FIG. 16 shows the dry molded product 31 thus obtained.

[0009] In the above-mentioned molding, when forming a molded product in a wet state, the deposition is performed so as to exceed the open surface of the lower molding die.
Prior to the drying step, a method is used in which unnecessary portions that have accumulated beyond the open surface of the lower mold are cut off, but the molded product obtained by this method is preferable because it has excellent uniformity in density. In particular,
As in Embodiment I, a convex portion 1 for promoting drying is formed on the bottom surface of the mold.
In the case of using a molding die having a thickness of 3, the thickness of the deposited layer on the projection 13 is always constant by the process, so that the amount of hot air taken in from the hole 17 for taking in hot air is constant, and the drying time is reduced. The advantage is that there is little variation.

FIGS. 17 to 22 are sectional views showing another embodiment of the present invention (hereinafter, referred to as embodiment II). The difference from the embodiment I is that, compared to the embodiment I in which the tip of the projection 13 is located at substantially the same level as the opening surface of the mold, that of the embodiment II is at a considerably lower position. The point is that the sinking mold 32 is installed on the upper side. By using the sinking type, a pulp deposited layer is not formed on the upper surface of the convex portion, so that the amount of hot air taken in from the upper portion of the convex portion is increased and the drying efficiency is improved.

FIG. 23 shows a state in which a submerged mold 32 of a type different from that of Embodiment II is used. In addition to the upper surface of the convex portion 13, the pulp of the upper side wall surface of the convex portion 13 is also used. Since the deposited layer is not formed, the amount of hot air taken in from the upper portion of the convex portion is increased and the drying efficiency is improved as compared with the embodiment II. FIG. 24 shows that the pulp deposit on the protrusion 13 is removed using the cutting machine 33.
This method can also increase the amount of hot air taken in from above. The hole or groove formed on the convex portion by using a sinking die or a cutting machine as described above may be in a penetrating state or a non-penetrating state.
3 is preferably a penetrating state that does not leave a pulp layer on it.

A mold is usually used for producing the molded article of the present invention. As the mold, a concave mold with one side having a large number of small holes on the wall surface is usually used as an open state,
The present invention is not limited to this. In the present invention, a mold having a depth of 20 mm or more is usually used as the mold, but the effect of the present invention can be expected even when the mold is 20 mm or less. Also, as a mold, 1 to 1 so that the molded body can be easily taken out.
Those having a draft angle (taper) of 5 ° are usually used. As the mold, a mold made of a metal such as iron or aluminum is usually used, but a mold made of another material known in the pulp mold industry can also be used. As the mold, a mold having a 15 to 200 mesh wire mesh attached to the surface of a mold having small holes is usually used. It should be noted that the bonding of the metal mesh is not necessarily performed on the entire surface of the mold, but may be performed on a part of the surface of the mold. As the small hole of the mold, a circular hole having a diameter of 1 to 10 mm is usually used,
Small holes of the same size may be provided on the entire surface of the mold, but the size of the small holes is generally changed depending on the location of the mold. As a normal mold, it is preferable to increase the opening ratio as it goes deeper, but it is preferable to provide a large number of small holes in the place where the opening ratio is to be increased, and to provide a small hole in a portion where the opening ratio is to be lowered. It is common to provide small holes.

In the present invention, in order to increase the drying speed, the following four conditions must be satisfied, that is, the inside has an air-permeable space. Have a wall at the bottom. The upper part has a hole for taking in hot air that is connected to the gap. At the bottom of the side wall, there is a hole for discharging hot air to the gap. Is used, but the size and shape of the projections are
It is appropriately determined in consideration of the amount of hot air taken in from the upper part, the strength and appearance of the molded body. In addition, a convex part of a molding die for providing a concave part required for holding and fixing an object to be buffered (packaged product) as the convex part in the molded body can be used as the convex part. The protrusion is usually made of a metal such as iron or aluminum, but may be made of another material known in the pulp mold industry as well as the mold. In addition, a wire netting of 15 to 200 mesh on a part or the whole surface is usually used. As the convex portion, one having a taper of 1 to 5 ° like the other portions of the molding die is usually used. From the viewpoint of the effects of the present invention, it is preferable that the air-permeable gap provided inside the projection has a structure that allows air to pass through as much as possible. Further, in the present invention, a hole provided with a hot air intake hole connected to the gap at the upper portion of the convex portion and a hot air discharge hole connected to the gap at the lower portion of the side wall of the convex portion is used. May be provided with small holes. In addition, the bottom wall of the projection usually has no small hole. However, a small hole may be provided as long as only a small amount of hot air can pass therethrough. Alternatively, a valve that can be opened and closed may be attached to the wall, and the valve may be opened and suctioned during dehydration, and the valve may be closed during drying to allow hot air to flow. FIG.
Is mounted outside the suction chamber 20 and can be operated outside the mold. In the case of the method in which the on-off valve is attached, dehydration can be performed from the hole provided in the convex portion during suction dehydration, so that the deposition state near the convex portion tends to be better. In addition, the mounting position of the convex portion of the present invention can be provided at the end as shown in FIG.

Injecting the slurry into the concave mold is performed by injecting the slurry into the mold with the opening facing upward by a pump from the opening, and immersing the slurry in a slurry tank with the opening facing downward as in a normal pulp mold. Sucking the slurry into the mold from the downward opening by sucking from the hole, sucking the mold with the opening facing upward while sinking the mold into the slurry tank, and sucking the slurry into the mold from the opening. And the like. Examples of the method for removing the medium of the slurry from the small holes include a suction dehydration method, a gas pressure dehydration method, a mechanical pressure dehydration method, an electroosmotic dehydration method, and the like, and these can be combined. The type of slurry used for injection is usually one type, but the injection of slurry is divided into two or more stages, and by changing the composition of the slurry used at that time, a state in which deposited layers of different compositions are sequentially laminated. Molded articles can also be obtained.

Subsequently, a drying process is performed on the deposited layer formed on the mesh, and the surface of the deposited layer on the non-contact side with the mesh is usually very uneven, and is a plate-like shape having a flat and smooth surface as it is. If the material is compressed and dried, the surface of the non-contact side with the mesh of the deposited layer should be sliced or polished in advance to make the surface uniform. Is desirable. When a concave mold is used for molding, as described in Japanese Patent Application No. 10-49985, while slurry is poured into the concave mold, water as a medium of the slurry is removed from the small holes. The small pore impervious fine components in the slurry are deposited in the mold to have an unnecessary portion deposited beyond the opening surface of the mold, and subsequently, the unnecessary portion of the dry or wet molded article is formed. A method of removing the part is taken.

Unnecessary portions can be cut off using a high-pressure or low-pressure water jet, a water flow using a high-blow nozzle (manufactured by Taketsuna Seisakusho), a thread saw, a belt saw (endless belt-shaped blade), a tip saw (disk-shaped). Blade) or the like can be used. However, the excision method is not limited to the above.

Drying of the wet molded product after dehydration is performed by supplying hot air from above the deposition layer and passing the same through the deposition layer. Since the drying speed increases in proportion to the amount of air passing through the deposition layer, hot air is usually supplied while sucking from the bottom of the deposition layer.Hot air is injected under pressure from the top of the deposition layer without suction from the bottom Then, a pressure difference is generated between the upper and lower portions of the deposited layer, and drying is performed by, for example, injecting hot air from the upper portion of the deposited layer while suctioning from the lower portion. As the pressure difference between the upper part and the lower part of the deposition layer is larger, the amount of air passing through the deposition layer increases and the drying speed increases. Usually 100 to 25 as hot air
Air in the range of 0 ° C. is used. Known methods such as infrared drying and microwave drying can be used in combination for drying. For drying halfway, heated steam is also effective. In order to increase the drying speed, it is also effective to provide a hole and / or groove which penetrates or does not penetrate the wet molded product to improve the air flow. As a method of forming holes and grooves, as described above, a method of post-processing a molded article in a wet state using a pressing machine, a cutting machine, a water jet, or the like, as described in Japanese Patent Application No. 11-325871. And a method of imparting the shape to a molded article at the same time as molding using a sink mold.

As the slurry composition, a Canadian standard freeness of 550 ml capable of efficiently forming a molded article having a thick sedimentary layer is used.
Those having good filterability are preferred. When a molded article is used as a buffer, a natural organic polymer fiber is usually preferably used as a main raw material. However, in the present invention, it is not limited thereto, and fibers, coarse powder, and fine particles composed of synthetic organic polymers, fibers, coarse powder, and fine particles composed of semi-synthetic organic polymers, and natural organic polymers Coarse powder and fine particles, fibers, coarse powder and fine particles made of inorganic substances,
In addition, fibers, coarse powder, fine particles, and the like made of an organic-inorganic composite material can be used, and can be appropriately selected according to the application. These may be used alone or in combination.

Incidentally, Canadian standard freeness is based on JIS.
-P-8121 is usually a value indicating the drainage of pulp, but in the present invention, drainage of the slurry composition was determined by the same measurement method.

Hereinafter, the natural organic polymer fiber-containing system most suitable as a raw material of the buffer material will be described in more detail mainly, but the present invention is not particularly limited thereto. Examples of natural organic polymer fibers include (1) unbleached or bleached chemical pulp obtained by kraft pulping, sulfite pulping, alkali pulping, etc. of coniferous or hardwood, or GP, TMP (thermomechanical pulp) Mechanical pulp such as, or cotton pulp, linter pulp, water repellency, water resistance described in Japanese Patent Application No. 10-0322920,
Waste paper pulp, liquid ammonia-treated pulp, mercerized pulp, and curled fiber (manufactured by Warehauser, USA, trade name:
HBA-FF, NHB405, NHB416), cellulosic fibers such as hemp fibers described in Japanese Patent Application No. 10-377923, (2) protein fibers such as wool, silk, and collagen fibers, and (3) chitin. Complex sugar chain fibers such as chitosan fiber and alginic acid fiber are exemplified. Among them, cellulosic fibers are particularly preferable because they are excellent in performance and easy to procure. The natural organic polymer fiber is usually blended in the range of 35 to 100% by dry weight with respect to the composition.

When it is desired to increase the interlaminar strength of the molded product, it is necessary to mix fine fibers having a number average fiber length in the range of 0.01 to 0.80 mm obtained by mechanically treating natural pulp fibers with a sand grinder or the like. It is valid. The fine fibers are usually blended in a range of 2 to 40% by dry weight with respect to the composition.

Further, when synthetic fibers having thermoplasticity such as polyethylene fibers, polypropylene fibers, polyolefin sheath fibers, polyester sheath fibers, and biodegradable aliphatic polyester fibers are blended into the slurry composition, only heating is required. Thus, a molded article that can be joined to each other can be obtained. The synthetic fiber is usually 5 to 5% by dry weight with respect to the composition.
It is blended in the range of 60%.

The slurry composition may further contain an adhesive, a waterproofing agent, a water repellent, a dye, a pigment, a drainage improver, a pH adjuster, a slime control agent, a thickener,
Preservatives, fungicides, antibacterial agents, flame retardants, rodenticides, insecticides, humectants, freshness preservatives, oxygen scavengers, foaming agents, surfactants, electromagnetic shielding materials, antistatic agents, rust inhibitors, fragrances ,Deodorants,
Various microcapsules having foaming properties and aromatic properties can be selected and blended. These may be used in combination of two or more.

The slurry is usually prepared batchwise or continuously by 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. . 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.
Are preferred.

The obtained molded article can be made into a more complicated shaped article by joining the obtained molded article with the same or different molding die. Also, if necessary, after molding, a water-proofing agent, a water repellent, a dye, a pigment, a preservative, a fungicide, an antibacterial agent, a flame retardant, a rodenticide,
Spray and impregnate insect repellent, freshness preserving agent, deoxidizer, electromagnetic shielding material, antistatic agent, rust inhibitor, fragrance, deodorant, etc.
It can be contained using means such as coating. In addition, synthetic resin film, synthetic paper, synthetic resin plate, waterproof paper,
It can be bonded to other materials such as water-repellent paper, metal foil such as aluminum, metal plate and glass plate. Processing such as cutting and printing can also be performed. Hereinafter, the present invention will be described more specifically with reference to examples. However, needless to say, the present invention is not limited to these examples. In Examples and Comparative Examples, “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified.

<Example 1> A jute hemp bag was pulverized with a pulverizer (Atoms Model 14-1200, manufactured by Hyakuma Yamamoto Seisakusho), and then the fibers were softened with a grinder mill (GM4-25, manufactured by Glow Engineering). To obtain hemp fibers having a number average fiber length of 7 mm. The Canadian Standard Freeness of this fiber was measured to be 725 ml. Further, a 1.5-liter sand grinder filled with 80% glass beads having an average particle size of 2 mmΦ is prepared by using a water slurry of waste corrugated paper pulp having a solid concentration of 1% (Dynomill KDL-PIL manufactured by Shinmaru Enterprises).
OT) was introduced and passed at 350 ml / min to obtain fine fibers having a number average fiber length of 0.30 mm. Next, 90 parts of the hemp fiber (dry weight) and 5 parts of the fine fiber (dry weight) were further mixed with a copolyester-polyethylene terephthalate sheath core fiber (TSF. TJ04CN2.
2 × 5) A mixture of 5 parts (dry weight) was mixed with water to adjust the solid content concentration to 1%, and sufficiently stirred to obtain a slurry. The slurry composition was found to have a Canadian standard freeness of 695 ml. Subsequently, the open surface of the upper surface is a square of 250 mm x 100 mm and the deepest portion is 10 mm.
A mold 10 as shown in FIG. 1 (FIG. 2 is a cross-sectional view) having a 0 mm cavity and two cylindrical protrusions having a diameter of 30 mm (outer diameter of the bottom) and a height of 99 mm attached to the deepest portion. The hopper 22 was mounted on the mold 10 as shown in FIG. 3, and the slurry was supplied from a guide 23. Subsequently, as shown in FIG. 4, suction dehydration was performed from a suction port 21 provided at a lower portion of the molding die 10, and fibers were deposited so as to swell on the open surface of the molding die. Next, as shown in FIG. 5, the hopper was removed, and then unnecessary parts deposited so as to rise on the open surface of the mold as shown in FIG. Next, as shown in FIG. 7, a press-up mold 28 having a flat bottom surface and a plurality of small holes 29 for injecting hot air into the smooth surface of the wet molded product.
After lightly applying, the upper mold 2 is sucked through the suction port 21.
8, hot air was fed from the hot air inlet 30 and dried to obtain a fiber-based low-density molded body 31 as shown in FIG. At that time, suction was performed using hot air of 210 ° C. under a condition of −600 mmHg, and drying was possible in 3 minutes.

<Comparative Example 1> A molding die 10 as shown in FIG. 9 (FIG. 10 is a cross-sectional view), which is almost the same as FIG. 1 except that two cylindrical projections were not attached, was prepared. Molding and drying were performed in exactly the same manner as in Example 1 except that a mold was used, to obtain a fiber-based low-density body 31 as shown in FIG. It took 7 minutes and 30 seconds for drying.

[0028]

As described above, according to the present invention, the slurry is guided and dewatered on a mesh having a convex portion satisfying the following four conditions, and the deposited layer of small pore non-passing fine components in the slurry is formed on the mesh. And then drying by passing hot air from above and passing through the sedimentary layer for drying, so that drying is extremely quick and a thick molded article can be produced very efficiently. (1) It has a void that can be ventilated inside. (2) It has a wall at the bottom. (3) It has a hole at the top for taking in hot air connected to the gap. With holes

[Brief description of the drawings]

FIG. 1 is a perspective view showing a concave mold used for manufacturing a molded body according to an embodiment of the present invention, on which a convex portion for promoting drying is attached.

FIG. 2 is a sectional view of the concave mold of FIG. 1 taken along the line AA.

FIG. 3 is a cross-sectional view showing a state in which a hopper, which is an enclosure for slurry storage, is mounted on the concave mold of FIG. 2 and pulp slurry is supplied from an upper guide.

FIG. 4 is a cross-sectional view showing a state in which pulp is deposited in a mold by suction dehydration.

FIG. 5 is a cross-sectional view showing a state where a hopper is removed from the state of FIG. 4;

FIG. 6 is a cross-sectional view showing a state in which unnecessary portions accumulated on an open surface of a mold are cut off.

FIG. 7 is a cross-sectional view showing a state where hot air is injected into a wet pulp molded product and dried.

FIG. 8 is a cross-sectional view showing the dry molded product thus obtained.

FIG. 9 is a perspective view showing a concave mold used for manufacturing a molded body of a comparative example of the present invention.

10 is a cross-sectional view of the concave mold of FIG. 9 taken along the line BB.

11 is a cross-sectional view showing a state in which a hopper as an enclosure for slurry storage is mounted on the concave mold of FIG. 10, and pulp slurry is supplied from an upper guide.

FIG. 12 is a cross-sectional view showing a state in which pulp is deposited in a mold by suction dehydration.

13 is a cross-sectional view showing a state where the hopper is removed from the state of FIG.

FIG. 14 is a cross-sectional view showing a state in which unnecessary portions accumulated on the open surface of the mold are cut away.

FIG. 15 is a cross-sectional view showing a state where hot air is injected into a wet pulp molded product and dried.

FIG. 16 is a cross-sectional view showing the dry molded product thus obtained.

FIG. 17 shows a state in which a sink mold is set on the protrusion for promoting drying, a hopper serving as an enclosure for slurry storage is mounted on the concave mold, and pulp slurry is supplied from an upper guide. FIG.

FIG. 18 is a cross-sectional view showing a state in which pulp is deposited in a mold by suction dehydration.

FIG. 19 is a cross-sectional view showing a state where the hopper and the submerged mold are removed from the state of FIG. 18;

FIG. 20 is a cross-sectional view showing a state where unnecessary portions accumulated on the open surface of the mold are cut away.

FIG. 21 is a cross-sectional view showing a state where hot air is injected into a wet pulp molded product and dried.

FIG. 22 is a cross-sectional view showing the dry molded product thus obtained.

FIG. 23: A sinking die having a structure different from that of FIG. 17 is set on the drying-promoting protrusion, and a hopper serving as an enclosure for slurry storage is mounted on the concave-shaped forming die. It is sectional drawing which shows the state in which the pulp slurry was supplied.

FIG. 24 is a cross-sectional view showing a state in which an unnecessary portion deposited on an open surface of a mold is cut off, and then a deposited layer formed on a convex portion is removed using a cutting machine.

FIG. 25 is a sectional view of a mold having a structure in which an openable / closable valve is attached to the bottom surface of a convex portion of the mold of FIG. 2;

FIG. 26 is a cross-sectional view of a molding die having a structure in which a protrusion mounting position is shifted to an end.

[Explanation of symbols]

10: concave mold, 11: small hole, 12: bottom of mold, 1
3: permeable protrusion, 14: permeable void inside, 15:
Bottom wall of the projection, 16: upper part of the projection, 17: hole for taking in hot air, 18: lower part of the side wall of the projection, 19: hole for discharging hot air,
20: suction chamber, 21: suction port, 22: hopper, 23:
Guide, 24: Pulp slurry, 25: Pulp sediment,
26: water drop, 27: tip saw, 28: drying device (hot air type), 29: small hole, 30: hot air injection port, 31: dry molded product, 32: sinking type, 33: cutting machine, 34: open / close valve

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomoyuki Fukuda 3-6-4 Sotokanda, Chiyoda-ku, Tokyo F-term in Oji Bag Co., Ltd. 3E066 AA01 BA01 CA05 DA01 KA10 MA05 4L055 AA07 AA11 AF33 BF02 BF04 BF05 EA05 FA22 GA05

Claims (6)

[Claims] Claims 1. A slurry is guided and dehydrated on a mesh having a convex portion satisfying the following four conditions, and a deposition layer of small pore non-passing fine components in the slurry is formed on the mesh.
Thereafter, a hot air is supplied from above to pass through the deposition layer and is dried to produce a molded body. (1) It has a void that can be ventilated inside. (2) It has a wall at the bottom. (3) It has a hole at the top for taking in hot air connected to the gap. With holes 2. A slurry is supplied into a concave-shaped lower mold having a plurality of small holes on an inner wall surface, a suction chamber formed by double inner and outer walls, and a suction port attached to an outer wall, the one surface of which is open. And
By removing water, which is a medium of the slurry, from the small holes, the small components that do not pass through the small holes in the slurry are deposited in the lower mold to form a wet molded product, and then the upper mold is covered with the upper mold. The method for producing a molded article according to claim 1, wherein in the method for producing a molded article which is dried by supplying hot air from an upper mold, a convex part satisfying the following four conditions is provided on the bottom surface of the concave molded lower mold. (1) It has a void that can be ventilated inside. (2) It has a wall at the bottom. (3) It has a hole at the top for taking in hot air connected to the gap. With holes 3. The method for producing a molded body according to claim 1, wherein a surface of the formed deposited layer on a side that is not in contact with the mesh is sliced or polished. 4. When forming a molded article in a wet state, depositing is performed so as to exceed the opening surface of the lower molding die, and unnecessary portions accumulated beyond the opening surface of the lower molding die before the drying step are cut off. 3. The method for producing a molded article according to 2. 5. The method for producing a molded article according to claim 1, wherein a hole and / or a groove in a penetrating or non-penetrating state is provided in the wet deposited layer formed on the convex portion, and drying is performed. . 6. The method according to claim 1, wherein the slurry composition has a Canadian Standard Freeness (CSF) of 550 ml or more.