JP2005220468A - Method and apparatus for producing cylindrical body made by papermaking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a cylindrical body made by papermaking, suitable for producing the slender thin cylindrical body made by the papermaking. <P>SOLUTION: A sheet 10 in a wet state, made by the papermaking is wound on an expandable and shrinkable core body 3, and the wound sheet 10 with the core body 3 is arranged in a dehydrating mold 50. The core body 3 is expanded to press the sheet 10 onto the inner surface of the dehydrating mold 50, and to dehydrate and mold the sheet so as to form the cylindrical body made by the papermaking. Preferably, the dehydrated and molded cylindrical body 11 is arranged in a drying mold with the core body 3, and the core body 3 is expanded to press the cylindrical body 11 to the inner surface of the drying mold 60 to dry the cylindrical body 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for producing a cylindrical papermaking product.

As a prior art relating to the manufacture of a fiber tube, for example, a technique described in Patent Document 1 below is known.
This technique provides a fiber stream on two mesh belts that have apertures and can be moved continuously or intermittently along the inner surface of a tubular papermaking tube wall. The water in the fiber stream is removed by suction from a small hole provided in the tubular papermaking mold, and a seamless tubular papermaking body is continuously produced.

  By the way, this technique employs a mechanism that feeds a tubular paper product with a mesh belt along its length direction, so that a tubular paper product with a small diameter, particularly a thin paper product with a small diameter, can be manufactured. It is difficult.

JP 51-115319 A

  This invention is made | formed in view of the above-mentioned subject, and it aims at providing the manufacturing method and apparatus of a cylindrical papermaking body suitable also for manufacture of a thin and thin cylindrical papermaking body.

  The present invention wraps a paper sheet in a wet state around an expandable core, and places the paper sheet in a dewatering mold together with the core body, and then expands the core body to convert the paper sheet into the dewatering mold. The object is achieved by providing a method for producing a cylindrical paper-making body comprising a step of depressing the paper-making sheet into a tubular paper-making body and pressing the paper-making sheet into a cylindrical paper-making body.

  Further, the present invention is an apparatus for producing a cylindrical papermaking for carrying out the method for producing a cylindrical papermaking according to the present invention, comprising: a papermaking means for papermaking; and a papermaking sheet made by the papermaking means. A retractable core body to be wound, a winding means for winding the paper sheet around the core body, and the paper sheet wound around the core body together with the core body and cooperating with the core body The present invention provides an apparatus for producing a cylindrical papermaking body, which includes a dewatering mold for dewatering and molding the papermaking sheet into a cylindrical shape.

  According to the present invention, a thin and thin cylindrical paper-making body can also be suitably produced.

  Hereinafter, the present invention will be described based on preferred embodiments thereof.

  FIG.1 and FIG.2 shows one Embodiment of the manufacturing apparatus of the cylindrical papermaking body of this invention. In FIG. 1, the code | symbol 1 has shown the manufacturing apparatus (henceforth only a manufacturing apparatus) of a cylindrical papermaking body.

  As shown in FIG. 1, the manufacturing apparatus 1 of the present embodiment includes a papermaking means 2 for each papermaking sheet 10, a stretchable core body 3 around which the papermaking sheet 10 made by the papermaking means 2 is wound, and a core body. The papermaking sheet winding means 4 for winding the papermaking sheet 10 around the core body 3 in cooperation with the core body 3, and the papermaking sheet 10 wound around the core body 3 are accommodated together with the core body 3. The dewatering means 5 for dewatering and forming the papermaking sheet 10 into a cylindrical shape, and the drying means 6 for storing the cylindrical papermaking body 11 dehydrated and formed by the dewatering means 5 together with the core 3 and drying the cylindrical papermaking body 11. I have. In addition, the manufacturing apparatus 1 includes a supply unit 7 that supplies a stretchable sheet or net-like body 10 ″, which will be described later, to the conveyance path of the strip-shaped sheet 10 'formed by the sheet forming unit 2.

  The papermaking means 2 includes a storage tank 20 that stores a raw material slurry containing fibers, a papermaking drum 21 disposed in the storage tank 20, a transport unit 22 that transports a papermaking sheet 10 ′ made by the papermaking drum 21, And a cutting unit 23 for cutting the paper sheet 10 ′ into each leaf. The configurations of the storage tank 20 and the papermaking drum 21 are the same as those conventionally used in a papermaking sheet manufacturing apparatus using wet suction papermaking.

  The storage tank 20 is connected to the circulation path 202 together with the adjustment tank 200 and the pump 201. In the storage tank 20, the raw material slurry whose concentration is adjusted in the adjustment tank 200 is supplied by the pump 201, and a substantially constant amount of the raw material slurry is stored.

  The papermaking drum 21 is provided so as to rotate around the horizontal axis while a part of the outer peripheral surface thereof is immersed in the raw material slurry. The papermaking drum 21 is provided with a fluid flow passage (not shown) having one end opened on the outer peripheral surface thereof and the other end connected to a suction pump (not shown). A papermaking net 210 is disposed on the outer peripheral surface of the papermaking drum 21. The papermaking drum 21 rotates at a predetermined rotation speed. At that time, the suction pump sucks the raw slurry through the flow passage, discharges the liquid, and deposits the solid on the papermaking net 210. In this way, the papermaking sheet 10 'is continuously made.

  The transport unit 22 includes a drive pulley 220, a pulley 221, a transport belt 222 wound around these pulleys, and a suction box 223 disposed inside the transport belt 222. The papermaking sheet 10 ′ and the sheet or mesh 10 ″ (hereinafter also referred to as the papermaking sheet 10) are conveyed by the conveying belt 222. Is attracted to the surface of the conveyor belt 222. The conveyor belt 222 rotates as the drive pulley 220 is driven.

  The cutting unit 23 includes a cutter 230 and a pair of nip rollers 231 that grip the papermaking sheet 10 on both sides of the cutting position.

  As shown in FIG. 2, the core body 3 includes a hollow core tube 30 and an inflatable and shrinkable bag-like elastic pressing body 31 attached so as to partially contain the core tube 30. . The core body 3 is provided so as to rotate around its axis by a drive mechanism (not shown). Further, the core body 3 is moved by a reciprocating mechanism (not shown) from the installation position of the winding means 4 described later, through the installation positions of the dehydrating means 5 and the drying means 6, and the cylindrical papermaking body and the core body 3. It is provided so as to be able to reciprocate between the positions where the two are separated.

  The core tube 30 is provided with a flow hole 300 that communicates the inside and the outside. The rear end portion of the core tube 30 is connected to a suction pump (both not shown) via a flow passage 301. The other end of the flow passage 301 is connected to a fluid supply source and a suction pump via a switching valve (both not shown). When fluid is supplied from the fluid supply source into the elastic pressing body 31 through the flow passage 301 and the circulation hole 300, the elastic pressing body 31 expands, and the suction pump passes through the flow passage 301 and the circulation hole 300. When aspirated, it contracts. Examples of the material of the elastic pressing body 31 include urethane, fluorine rubber, silicone rubber, and elastomer. Examples of the fluid for expanding the elastic pressing body 31 include compressed air (heated air), oil (heated oil), and other various fluids. The core body 3 is arranged in a direction substantially perpendicular to the conveyance direction by the conveyance belt. The length of the elastic pressing body 31 is preferably longer than the length of the papermaking sheet or the like 10 cut every leaf (the width of the belt-shaped papermaking sheet 10 ').

  The winding means 4 includes a pair of swing arms 40 and 41 that swing around a horizontal axis so as to sandwich the core 3 at the winding position of the papermaking sheet 10 or the like from the side, an endless belt 42, A drive pulley 43 that drives the belt 42 and a tension pulley 44 that controls the tension of the belt 42 are provided.

  The swing arms 40 and 41 are arranged so that the rotation shafts are adjacent to each other, and are provided so as to swing in opposite directions from a substantially horizontal position to a substantially vertical position. In addition, a rotating shaft is an axis | shaft provided in the center of the pulley 400 and the pulley 410 (after-mentioned). A pair of pulleys 400 and 401 that rotate about a horizontal axis at a predetermined interval are attached to the swing arm 40. Similarly, a pair of pulleys 410 and 411 are attached to the swing arm 41. The drive pulley 43 is disposed at an intermediate position between the rotation shafts of the pulleys 400 and 410 and below the pulleys 400 and 410. The tension pulley 44 is attached to the front end portion of the swinging shaft, and the rear end portion of the swinging shaft is attached to a shaft disposed almost directly below the rotation shaft of the drive pulley 3. The drive pulley 43 is disposed outside the belt 42, and the pulleys of the swing arms 40 and 41 and the tension pulley 44 are disposed inside the belt 42.

  The dehydrating means 5 includes a dehydrating mold 50 constituted by a pair (in this embodiment, a pair) of split molds 500 and an opening / closing mechanism (not shown) that opens and closes the dehydrating mold 50. When these split molds 500 are combined and the dehydrating mold 50 is closed, a space is formed in which the core body 3 and the paper-making sheet 10 wound around the core body 3 are accommodated. A fluid flow passage 501 is connected to the split mold 500. Inside the split mold 500, there are provided a flow passage 502 having one end opened on the surface facing the papermaking sheet 10 and the other end and the other end communicating with the flow passage 501. In order to obtain a cylindrical paper-making body having a surface roughness as described later, the surface roughness (Ra) of the inner surface of the split mold 500 is preferably 15 μm or less, particularly 10 μm or less, more preferably 3 μm or less. The other end of the flow passage 501 is connected to a suction pump and a fluid supply source via a switching valve (both not shown). When sucked by the suction pump through the flow passages 501 and 502, the papermaking sheet 10 is adsorbed on the inner surface of the split mold 500, and fluid is supplied from the fluid supply source through the flow passages 501 and 502. When this occurs, the cylindrical papermaking body 11 is detached from the inner surface of the split mold 500.

  The drying means 6 includes a drying mold 60 constituted by a pair (in this embodiment, a pair) of split molds 600 and an opening / closing mechanism (not shown) for opening and closing the drying mold 6. When these split molds 600 are combined and the drying mold 60 is closed, a space in which the dewater-molded cylindrical papermaking body 11 is accommodated together with the core body 3 is formed. A fluid flow path 601 is connected to the split mold 600. Inside the split mold 600, there is provided a flow passage 602 having one end facing the cylindrical papermaking body 11 (hereinafter, this surface is also referred to as an inner surface) and opened in a slit shape and the other end communicating with the flow passage 601. It has been. In order to obtain a cylindrical paper-making body having a surface roughness as described later, the surface roughness (Ra) of the inner surface of the split mold 600 is preferably 15 μm or less, particularly 10 μm or less, and more preferably 3 μm or less. The other end of the flow passage 601 is connected to a suction pump and a fluid supply source via a switching valve (both not shown). A heater 603 is disposed inside the split mold 600, and the cylindrical papermaking body 11 is dried by heating the split mold 600 with the heater 603. When a fluid is supplied from the fluid supply source to the inside of the split mold 600 through the flow passages 601 and 602, the papermaking body is detached from the inner surface of the split mold 600.

  The manufacturing apparatus 1 includes a control unit (not shown) that operates the above-described means and the reciprocating mechanism of the core body 3 according to a predetermined sequence. Each means is actuated to produce a cylindrical papermaking.

  Next, the manufacturing method of the cylindrical papermaking body of this invention is demonstrated based on embodiment applied to manufacture of the cylindrical papermaking body used for manufacture of a casting using the manufacturing apparatus 1. FIG.

  First, as shown in FIG. 1, a wet strip-shaped sheet-making sheet 10 ′ is formed from the raw material slurry by the sheet-making means 2.

  The papermaking sheet 10 rotates a papermaking drum 21 having a part of the outer peripheral surface immersed in the raw material slurry, sucks the liquid content of the raw material slurry with the suction pump through the flow passage, and converts the solid component of the raw material slurry into the papermaking material. Paper is made by depositing on the net.

The components in the raw material slurry and the blending ratio thereof can be selected according to the use of the cylindrical paper to be produced.
Hereinafter, description will be made based on a case where the present invention is applied to the production of a cylindrical papermaking suitable for the production of a casting from a molten metal.

The cylindrical papermaking produced in this embodiment contains organic fibers, inorganic fibers, inorganic particles, and a thermosetting resin.
The compounding ratio of the organic fiber, the inorganic fiber, the inorganic particles, and the thermosetting resin is a reduction in the amount of gas generated from the cylindrical papermaking when casting using the produced cylindrical papermaking, From the viewpoints of ease of removal of the cylindrical papermaking after the end of casting, maintenance of heat resistance of the cylindrical papermaking itself and ease of molding, etc., the organic fiber / the inorganic fiber / the inorganic particle / the thermosetting resin. = 10 to 70/1 to 80/10 to 70/10 to 70 (weight ratio), 15 to 50/5 to 50/20 to 60/10 to 50 (weight ratio), particularly 20 to 40/5 30/30 to 60/10 to 40 (weight ratio) is preferable.

  The organic fiber is a component that mainly forms a skeleton in a state before being used for casting in a cylindrical papermaking body and improves the moldability of the cylindrical papermaking body. In addition, when used for casting, some or all of the molten metal is burned by the heat of the molten metal, forming a void inside the cylindrical papermaking after the casting is manufactured, and improving the removability of the cylindrical papermaking. is there.

  Examples of the organic fibers include paper fibers, fibrillated synthetic fibers, and recycled fibers (for example, rayon fibers). These organic fibers can be used alone or in combination of two or more. Among these, paper fibers are particularly preferable because they can be formed into various forms by papermaking and sufficient strength can be obtained after dehydration and drying.

  Examples of the paper fiber include wood pulp, cotton pulp, linter pulp, bamboo straw and other non-wood pulp. As the paper fiber, these virgin pulp or waste paper pulp can be used alone or in combination of two or more. The paper fiber is particularly preferably used paper pulp from the viewpoints of easy availability, environmental protection, and reduction of manufacturing costs.

  The organic fiber has an average fiber length of 0.3 to 2.0 mm, particularly 0.5 to 1.5 mm, considering the formability, surface smoothness, and impact resistance of the cylindrical papermaking product.

  The blending ratio of the organic fiber in the cylindrical papermaking product is preferably 10 to 70 wt%, particularly 10 to 50 wt%, considering the moldability of the cylindrical papermaking product and the removability of the cylindrical papermaking product after the production of the casting.

  The inorganic fiber is a component that mainly forms a skeleton in a state before being used for casting in a cylindrical paper-making body, and maintains its shape without being burned by the heat of molten metal when used for casting. In particular, it is a component that suppresses thermal shrinkage that occurs when an organic component such as a thermosetting resin used in the present embodiment is thermally decomposed by the heat of the molten metal.

  Examples of the inorganic fiber include carbon fiber, artificial mineral fiber such as rock wool, ceramic fiber, and natural mineral fiber. These inorganic fibers can be used alone or in combination of two or more. Among these, it is preferable to use pitch-based or polyacrylonitrile (PAN) -based carbon fibers having high strength even at high temperatures from the viewpoint of effectively suppressing shrinkage associated with carbonization of the thermosetting resin, and in particular, PAN-based carbon. Fiber is preferred.

  The inorganic fiber has an average fiber length of 0.2 to 10 mm, particularly 0.5 to 8 mm from the viewpoints of dewaterability when the cylindrical papermaking is made and dehydrated, moldability of the cylindrical papermaking, and uniformity. preferable.

  The said inorganic fiber has a function which suppresses the heat shrink accompanying the thermal decomposition of a cylindrical papermaking body.

  The inorganic fiber is preferably blended in an amount of 5 to 200 parts by weight, particularly 10 to 100 parts by weight, based on 100 parts by weight of the organic fiber. By mix | blending inorganic fiber in such a range, heat resistance of a cylindrical papermaking body is fully maintained, and generation | occurrence | production of the casting surface defect by gas generation | occurrence | production can be suppressed.

  The inorganic particles are components that soften by the heat of the molten metal to form a refractory film and prevent the carbon film formed by the thermal decomposition of the thermosetting resin by the heat from being dissolved in the molten metal with a low carbon equivalent. Yes, it is a component that further improves the surface smoothness of the casting obtained by preventing the sand from adhering to the casting surface when casting sand is disposed outside the cylindrical papermaking body or inside the hollow core. In consideration of the moldability of the cylindrical papermaking and the surface smoothness of the casting, the inorganic particles should be 50 to 400 parts by weight, particularly 100 to 300 parts by weight, based on 100 parts by weight of the organic fiber in the blending ratio. Is preferred.

Examples of the inorganic particles include silica, alumina, mullite, magnesia, zirconia, mica, graphite, obsidian, and other inorganic particles having a fire resistance of 800 to 2000 ° C., preferably 1000 to 1700 ° C., and a high viscosity at the time of softening, Obsidian and mullite powder are preferred because they have a particularly high effect of preventing the dissolution of the carbon film in the molten metal. These inorganic particles may be used alone or in combination of two or more. The particle diameter of the inorganic particles is preferably 200 μm or less. In particular, inorganic particles having a fire resistance of ± 300 ° C., particularly ± 200 ° C. with respect to the casting temperature of the molten metal to be cast are preferable. Here, the fire resistance of the inorganic particles depends on a measuring method (JIS R2204) using a Zeger cone.

  Examples of the thermosetting resin include thermosetting resins such as phenol resins, epoxy resins, and furan resins. The thermosetting resin is a component necessary for maintaining the normal temperature strength and the hot strength and improving the surface roughness of the casting, and a surface smoothness equivalent to that of a sand mold coated with a coating agent is obtained. It is not necessary to use a coating agent. This is an important performance for the tubular papermaking product of the present invention containing organic fibers and the like that are difficult to ignite and dry when using conventional alcoholic coating agents.

  In particular, the thermosetting resin having such performance has little generation of combustible gas, has a combustion suppressing effect, has a high residual carbon ratio of 25% or more after pyrolysis (carbonization), and has a carbon film at the time of casting. It is preferable to use a phenol-based resin from the viewpoint that a good casting surface can be obtained for the formation. The residual carbon ratio can be determined from the residual weight after heating to 1000 ° C. in a reducing atmosphere (under a nitrogen atmosphere) by an analytical thermal analysis.

  Examples of the phenolic resin include novolak phenol resins, resol type phenol resins, modified phenol resins modified with urea, melamine, epoxy, and the like, preferably novolak phenol resins or modified resins thereof.

  The thermosetting resins may be used alone or in combination of two or more, and may be used in combination with an acrylic resin, a polyvinyl alcohol resin, or the like. In particular, when the tubular papermaking product of the present invention is applied to a hollow core, a high hot strength can be obtained by using a thermosetting resin (particularly a residual carbon ratio of 15% or more, particularly 25% or more). And the function as a hollow core can be sufficiently exhibited.

  The thermosetting resin is preferably blended in an amount of 30 to 300 parts by weight, particularly 50 to 200 parts by weight, per 100 parts by weight of the organic fiber in the blending ratio. By blending the curable resin in such a range, the surface roughness and shape retention of the casting can be improved.

  The thermosetting resin is coated on the organic fiber, the inorganic fiber or the inorganic particle, or powdered or emulsified and added to the raw material slurry. What binds inorganic fibers and the inorganic particles, impregnates after forming the formed body, and dries or hardens it to increase the strength of the cylindrical paper body, and carbonizes it by the heat of the molten metal during casting to maintain the strength, etc. Any form may be used as long as it can be carbonized by the heat of the molten metal during the subsequent casting to form a carbon film and contribute to maintaining the strength of the cylindrical papermaking and improving the surface smoothness of the casting. Good.

  Since the curing agent required when the novolak phenol resin is used is easily dissolved in water, it is preferably applied after dehydration of the molded body, particularly in the case of wet papermaking. It is preferable to use hexamethylenetetramine or the like as the curing agent.

  In addition to the organic fiber, the inorganic fiber, the inorganic particle, and the thermosetting resin, the cylindrical papermaking manufactured in the present embodiment includes polyvinyl alcohol, carboxymethyl cellulose (CMC), and polyamidoamine as necessary. Other components such as a paper strength reinforcing material such as epichlorohydrin resin, a polyacrylamide-based flocculant, and a colorant can be added at an appropriate ratio.

  When the manufacturing apparatus 1 as shown in FIG. 1 is used as in this embodiment, the concentration of the raw slurry is adjusted in the adjustment tank through the circulation path, but has fluidity that can be supplied by the circulation pump. It is preferable.

  In this embodiment, a raw material slurry containing the organic fiber, the inorganic fiber, the inorganic particle, and the thermosetting resin at the predetermined blending ratio is prepared.

  Examples of the dispersion medium of the raw material slurry include water, white water, and solvents such as ethanol and methanol. Among these, from the viewpoints of papermaking / dehydration stability, quality stability, cost, ease of handling, etc. Water is particularly preferable.

  The total ratio of the fibers and inorganic particles to the dispersion medium in the raw slurry is 0.1 to 3 wt%, particularly 0.5 to 2 wt%, from the viewpoint of suppressing unevenness in the thickness of the papermaking and improving surface properties. % Is preferred.

  If necessary, additives such as the paper strength reinforcing material, the flocculant, and the preservative can be added to the raw material slurry at an appropriate ratio.

  Then, the raw slurry is sucked by the suction pump while the papermaking drum 21 is rotated, and the solid content is made to be volume on the papermaking net 210.

The liquid component content (weight content) of the paper sheet 10 ′ made by the paper making means 2 is preferably 20 to 90 wt%, particularly preferably 60 to 80 wt%, considering that it can maintain a sheet-like shape. The basis weight of the papermaking sheet, for the same reason as described above, 900~2000g / m ^2, in particular 1000~1200g / m ² is preferred. Furthermore, the width of the papermaking sheet 10 ′ (the length of the papermaking sheet 10 for each leaf) depends on the molding conditions of the cylindrical molded body, but is preferably 300 to 1000 mm, particularly 450 to 650 mm.

  Next, the sheet or net 10 ″ is supplied by the supply means 7 to the transport path of the paper-making sheet 10 ′, and the stretchable sheet or net 10 ″ is disposed on the back surface of the paper-making sheet 10 ′. . By arranging the stretchable sheet or the net-like body 10 ″ in this way, the wet papermaking sheet 10 ′ is protected, so that the papermaking sheet 10 ′ can be prevented from being damaged during conveyance and handling. In particular, when it is arranged on the back surface, it is possible to facilitate the conveyance and handling of the papermaking sheet 10 ′. For the same reason, the sheet or the net 10 ″ is arranged on the front surface or the back surface of the papermaking sheet 10 ′. You can also.

  Considering that the stretchability of the sheet or net 10 ″ is easy to follow the shape of the papermaking sheet 10, it is preferably 120 to 200%.

The basis weight of the sheet is preferably ²⁰ to 200 g / m ² , particularly 20 to 50 g / m ² for the same reason as described above.
The sheet preferably has air permeability in consideration of the volatility of the liquid from the papermaking sheet 10 ′. Examples of the material of the sheet include plant fibers including rayon, synthetic resin fibers such as nylon.

  The net-like body may be knitted so that the wire members constituting the mesh body are joined. Moreover, the wire itself may be knitted. Considering that the reticulate body easily follows the shape of the papermaking sheet 10, the wire diameter of the wire in an unstretched state is preferably 0.03 to 0.15 mm, and particularly preferably 0.05 to 0.1 mm. The opening area ratio in the state is 70 to 95%, more preferably 85 to 90%. Examples of the material of the net-like body include fibers similar to the material of the sheet. If importance is attached to biodegradability, plant-based fibers are preferably the main constituent, but this can also be said for the above-described sheet. That is.

  The sheet or net 10 ″ preferably has air permeability in consideration of the drying efficiency of the papermaking sheet 10. The mesh of the net is preferably about 7 to 10.

  Next, the paper sheet 10 ′ is transported to the cutting unit 23 by the transporting conveyor 222 of the transporting unit 22 together with the sheet or mesh body 10 ″ joined to the transporting path. Cut to a predetermined length to obtain a papermaking sheet 10 for each leaf.

Next, the papermaking sheet 10 is wound around the core body 3 by the winding means 4.
As shown in FIG. 3A, first, the swing arm 40 is placed in a substantially horizontal state (the winding means 4 operates from the substantially horizontal state), and the winding arm 10 is wound around the core 3. This is performed in a state where 41 is started. Then, the belt 42 is driven by the driving pulley 43, and the papermaking sheet 10 or the like cut by the cutting unit 23 is guided below the core body 3 by the belt 42. At this time, the core 3 is rotated counterclockwise around the axis in FIG.

  Next, as shown in FIG. 3B, the swing arm 40 is gradually raised, and the papermaking sheet 10 is wound between the core body 3 and a belt 42 that rotates around the core body 3. Then, as shown in FIG. 3 (c), the swing arms 40 and 41 are both raised, and the papermaking sheet 10 and the like 10 of the core body 3 in a state where the front end portion and the rear end portion overlap each other with a predetermined width. Wrap around the circumference.

  Next, as shown in FIG. 3D, the driving of the belt 42 by the driving pulley 43 and the rotation of the core body 3 are stopped, and both the swing arms 40 and 41 are brought into a fallen state. Then, the core 3 is moved to the dehydrating means 5 together with the papermaking sheet 10 by the reciprocating mechanism (see FIG. 1).

  Next, as shown in FIG. 4, the papermaking sheet 10 or the like is placed in the dehydrating mold 50, and fluid is supplied into the elastic pressing body 31 through the flow passage 301 and the flow hole 300 of the core body 3. The pressing body 31 is expanded. The papermaking sheet 10 wound around the core 3 is pressed against the inner surface of the dehydrating die 50, and the liquid content of the papermaking sheet 10 is discharged to the outside through the flow passages 502 and 501, so that the papermaking sheet 10 is cylindrically made. The body 11 is dehydrated.

  The pressing force of the papermaking sheet 10 by the core 3 at the time of dehydration is 0.4 to 1. considering the drying efficiency of the papermaking sheet 10, the surface properties, density, strength and other properties of the produced cylindrical papermaking pair 11. 2 MPa, particularly 0.6 to 1 MPa is preferred. The liquid component content of the cylindrical paper-made body 11 formed by dehydration is 70 to 95 weights in consideration of the shape being maintained, not being damaged when moving to the drying process, and the drying efficiency in the drying process. %, Particularly 60 to 80% by weight is preferred.

  After the dehydration is completed, the supply of fluid from the flow passage 301 is stopped, and the dewatering mold 50 is opened, and the tubular papermaking body 11 that has been dewatered and molded is detached from the dewatering mold 50 together with the core body 3. Then, the core 3 is moved to the drying means 6 together with the cylindrical papermaking body 11 by the reciprocating mechanism, and they are arranged in the drying mold 60 (see FIG. 1).

  Next, as shown in FIG. 5, the fluid is supplied into the elastic pressing body 31 through the flow passage 301 and the flow hole 300 of the core body 3, and the elastic pressing body 31 of the core body 3 is expanded to form the cylindrical papermaking body 11. While pressing against the inner surface of the drying mold 60, the liquid in the cylindrical papermaking body 11 is discharged to the outside through the flow passages 602 and 601, and the cylindrical papermaking body 11 is dried.

  The drying temperature (mold temperature) is preferably 100 to 200 ° C., particularly preferably 120 to 180 ° C. in consideration of the drying efficiency of the cylindrical papermaking, prevention of ignition thereof, and the like. Moreover, the pressing force of the cylindrical papermaking body by the core during drying is preferably 0.2 to 1.2 MPa, particularly 0.4 to 1 MPa for the same reason as described above.

  Next, the drying mold is opened, the cylindrical papermaking body 11 is detached from the drying mold 60 together with the core body 3, and the cylindrical papermaking body 11 is separated from the core body 3. The obtained cylindrical paper-making body 11 is subjected to post-processing such as trimming, coloring, printing, labeling, etc., after removing the sheet or the net-like body, if necessary, and the production is completed.

  The cylindrical papermaking produced in the present embodiment can have an inner diameter of 5 to 30 mm, particularly 6 to 20 mm, depending on the portion used.

  Further, the thickness of the cylindrical papermaking produced in the present embodiment can be appropriately set according to the portion used, but the thickness at least in the portion in contact with the molten metal is 0.2 to 5 mm, particularly 0. By setting the thickness to 4 to 2 mm, the strength required when molding by filling the foundry sand is sufficient, and the shape function of the cylindrical paper-making body, particularly the structure such as the core (described later) can be maintained. . In addition to suppressing an increase in the amount of gas generated during casting and preventing the occurrence of surface defects in the casting, the molding time can be shortened and the manufacturing cost can be kept low.

  The cylindrical papermaking produced in the present embodiment can have a bending strength of 5 MPa or more, particularly 10 MPa or more, in a state before being used for casting.

  The cylindrical papermaking produced in this embodiment preferably has a surface roughness (Ra) of 20 μm or less, particularly 3 to 15 μm, more preferably 5 to 10 μm. By setting it as such surface roughness, the smoothness of the surface of the casting obtained can be made more excellent. Here, the surface roughness can be measured with a commercially available measuring device.

  When the cylindrical papermaking produced in this embodiment is produced through a papermaking process using a raw material slurry using water as a dispersion medium, it is necessary to reduce the amount of gas generated during casting as much as possible before casting. In the state, the water content (weight water content) is preferably 10% or less, particularly preferably 8% or less.

  The cylindrical papermaking body manufactured in the present embodiment can be applied to a core used in a main mold having a casting product-shaped cavity on the inner surface, or a pouring system member such as a runner. In particular, it has excellent hot compressive strength, high shape retention, and excellent removability after casting. It is also possible to apply to hollow cores that do not require filling. Moreover, since it is possible to reduce the diameter of the pouring system member, the amount of hot water remaining in the runner can be reduced.

  Moreover, since the said cylindrical papermaking body is shape | molded by pressing on the inner surface of a dry mold with the said elastic press body from the inside, the smoothness of an inner surface and an outer surface is high. For this reason, when it uses for manufacture of a casting, the obtained casting becomes a thing excellent especially in surface smoothness.

  If necessary, the obtained cylindrical papermaking can be impregnated partially or entirely with a binder and heated to be thermally cured. Examples of the binder include colloidal silica, ethyl silicate, and water glass.

  Moreover, it is preferable that the cylindrical papermaking body is heat-treated in a reducing atmosphere at 150 to 300 ° C., particularly 200 to 250 ° C., to advance the curing of the thermosetting resin. By performing such a heat treatment, a cylindrical paper-making body having better shape retention can be obtained. In particular, it is also suitable when there are concerns about the occurrence of gas defects due to the material and shape of the casting. The degree of cure of the thermosetting resin by such heat treatment is preferably 30% or more, particularly 80% or more in terms of the amount of acetone insoluble in the thermosetting resin described below.

Specifically, the insoluble content of the thermosetting resin is determined as follows.
That is, about 5 g of a sample is taken from the cylindrical papermaking product, pulverized with a mill, and the weight (a) is precisely weighed. The ground sample is added to a container together with acetone and shaken sufficiently, and then left at room temperature. Next, the pulverized sample is sufficiently filtered with a filter paper (weight (c)) so that the pulverized sample does not remain in the container, and the filtered pulverized sample is dried together with the filter paper to obtain them (crushed sample and filter paper). ) (B) is precisely weighed. Then, based on the obtained weights (a) to (c) and the theoretical weight (d) of components other than the thermosetting resin in the pulverized sample, the insoluble content of the thermosetting resin ( %).
Insoluble content% = 100− (a− (b−d)) × 100 / (ad)

  As explained above, according to the manufacturing method of the cylindrical papermaking of this embodiment, a thin, thin-walled cylindrical papermaking can be manufactured with high mechanical strength.

  The present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

  FIG. 6 shows another embodiment of the paper sheet winding means in the tubular paper body manufacturing apparatus of the present invention. In FIG. 6, parts common to the winding means 4 of the embodiment are given the same reference numerals, and description thereof is omitted. Therefore, the description in the above embodiment is appropriately applied to a portion not particularly described.

  As shown in FIG. 6A, the winding means 4 includes a swing arm 40, an endless belt 42, a driving pulley 43 that drives the belt 42, and fixed pulleys 45 to 48. . The pulley 401, the drive pulley 43, and the pulleys 46 to 48 of the swing arm 40 are arranged inside the belt 42, and the pulley 400 and the pulley 45 of the swing arm 40 are arranged outside the belt 42. A belt 42 that drives on the pulleys 46 to 48 is disposed so as to have the same conveying height as the papermaking sheet 10 cut by the cutting unit 23.

  In the winding means 4 of the present embodiment, as shown in FIG. 6A, the belt 42 is driven by a driving pulley, and the leaf-making sheet 10 or the like 10 cut by the cutting unit 23 is cored by the belt 42. Guided below the body 3. At this time, the core body 3 is rotated counterclockwise around the axis in FIG.

  Next, as shown in FIG. 6B, the core body 3 is moved downward at substantially the center of the pulleys 46 and 47, and further moved downward so as to press the papermaking sheet 10 from above. Along with this, the swing arm 40 moves clockwise. Then, the papermaking sheet 10 is wound between the core body 3 and the belt 42 that rotates around the core body 3, and the papermaking sheet 10 has the core body 3 in a state where the front end portion and the rear end portion thereof overlap each other with a predetermined width. It is wound around the outer periphery of.

  When the papermaking sheet 10 is wound around the core 3, the core 3 is separated from the belt 42 together with the papermaking sheet 10 as shown in FIG. Along with this, the swing arm 40 returns to the original position. Then, after driving of the belt 42 by the driving pulley 43 and the rotation of the core body 3 are stopped, the core body 3 is moved toward the dewatering means 5 together with the papermaking sheet 10 by the reciprocating mechanism and arranged in the dewatering mold 50. To do. As shown in FIG. 3 (c), the winding means 4 of the present embodiment makes the core 3 and the papermaking sheet 10 and the like firmly held by the belt 42 by the movement of the swing arms 40 and 41. The papermaking sheet 10 or the like can be smoothly wound around the core 3.

  In the manufacturing method of the cylindrical papermaking body of this invention, raw material slurry is not restrict | limited to the said embodiment, The raw material slurry match | combined with the cylindrical papermaking body to be manufactured is used.

  Further, in the present invention, it is preferable to arrange a stretchable sheet or a net-like body as in the above embodiment, but these can be omitted. Moreover, there is no restriction | limiting in particular in how to arrange | position these sheets and nets. Like the said embodiment, a strip | belt-shaped sheet | seat and a net-like body may be distribute | arranged to the back surface of a strip | belt-shaped papermaking sheet | seat, and you may distribute | arrange on the surface or both surfaces. Further, the stretchable sheet or net-like body disposed on the front surface or the back surface of the papermaking sheet may be cut in advance.

  Moreover, although it is preferable that the manufacturing apparatus of the present invention is dehydrated with a dehydrating mold and then dried with a drying mold as in the previous embodiment, dehydration and drying may be performed with a single mold.

  Moreover, the curved cylindrical paper-making body can also be manufactured by making it the shape which curved the inner surface shape of the dry type | mold and the dehydration type | mold.

  In the present invention, depending on the use of the cylindrical paper to be produced, dry molding with a dry mold can be omitted.

  The manufacturing method and apparatus of the cylindrical papermaking of the present invention are also used for manufacturing the cylindrical papermaking used for various interior materials and various model materials in addition to the cylindrical papermaking used for the production of castings as described above. Preferably used. Further, the present invention is suitable for the production of a thin and thin tubular paper-making body, but a tubular paper-making body having a thickness of 0.5 to 3 mm, an inner diameter of 3 to 30 mm and a length of about 10 to 300 mm is also suitable. Can be manufactured.

It is a figure which shows typically one Embodiment of the manufacturing apparatus of the cylindrical papermaking body of this invention. It is a figure which shows typically the core in the manufacturing apparatus of the cylindrical papermaking body of the embodiment. It is a figure which shows typically operation | movement of the winding means in the manufacturing apparatus of the cylindrical papermaking body of the embodiment, (a) is a figure which shows the state which has introduced the papermaking sheet | seat of every leaf to the winding means, ( (b) And (c) is a figure which shows the state which has wound the papermaking sheet | seat around a core, (d) is a figure which shows the state which winding was completed. It is a fragmentary sectional view which shows typically the spin-drying | dehydration process in the manufacturing apparatus of the cylindrical papermaking body of the embodiment. It is a fragmentary sectional view which shows typically the drying process in the manufacturing apparatus of the cylindrical papermaking body of the embodiment. It is a figure which shows typically other embodiment of the winding means in the manufacturing apparatus of the cylindrical papermaking of this invention, and its operation | movement, (a) is the state which has introduced the papermaking sheet | seat of every leaf to the winding means (B) is a figure which shows the state which winds the papermaking sheet | seat around a core, (c) is a figure which shows the state which winding was completed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus of cylindrical papermaking 2 Papermaking means 3 Core body 4 Winding means 42 Belt 5 Dehydration means 50 Dehydration type 6 Drying means 60 Drying type 10, 10 'Papermaking sheet 10 "Stretchable sheet or net body 11 Cylindrical shape Papermaking

Claims (7)

  A wet paper sheet is wound around an expandable core, and the paper sheet is placed in a dewatering mold together with the core, and then the core body is expanded to press the paper sheet against the inner surface of the dewatering mold. And the manufacturing method of the cylindrical papermaking body which comprises the process of carrying out the spin-drying | dehydration shaping | molding of the said papermaking sheet | seat to a cylindrical papermaking body.   The method includes the steps of: placing the dewatered and formed cylindrical paper-making body together with the core body in a drying mold, expanding the core body, and pressing the paper-making body against the inner surface of the drying mold to dry it. A method for producing a cylindrical papermaking product according to 1.   The method for producing a cylindrical paper-making body according to claim 1 or 2, wherein a stretchable sheet or a net-like body is disposed on the front or back surface of the paper-making sheet, and the paper-making sheet is wound around the core body together with the sheet or the net-like body. .   The manufacturing method of the papermaking body of Claim 3 in which the said sheet | seat which can be expanded-contracted has air permeability.   A cylindrical papermaking apparatus for carrying out the method for producing a cylindrical papermaking product according to claim 1, comprising: a papermaking means for papermaking; and a telescopic core for winding the papermaking paper made by the papermaking means. A paper-making sheet winding means for winding the paper-making sheet around the core body; and the paper-making sheet wound around the core body is accommodated together with the core body, and the paper-sheet produced in cooperation with the core body Apparatus for producing a cylindrical paper-making body provided with a dewatering mold for dewatering into a shape.   The said core body is a manufacturing apparatus of the cylindrical papermaking body of Claim 5 provided with the hollow core pipe and the elastic press body which is attached to the outer side of this core pipe, a fluid is supplied inside, and expand | swells. The cylindrical papermaking apparatus according to claim 5 or 6, wherein the winding means includes an endless belt that is driven to rotate around the core body and winds the papermaking sheet around the core body.

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