JP6741418B2 - Raw material for casting manufacturing structure, container for the raw material, raw material slurry, casting manufacturing structure, and method for manufacturing the raw material - Google Patents

Description

The present invention relates to a raw material for a casting manufacturing structure. The present invention also relates to a raw material container for a casting manufacturing structure. The present invention also relates to a raw material slurry for a structure for producing a casting. The present invention also relates to a structure for producing a casting. The present invention also relates to a method for producing a raw material for a casting manufacturing structure.

When manufacturing a structure for producing a casting, a scrap material or a cutting waste is generated in the cutting process, and a defective product such as an excess or deficiency of mass or a product that fails the inspection is generated in the inspection process. A certain number of such waste materials are always generated, which has been a factor that hinders the improvement of the yield. Regarding the structure for producing a casting, the present applicant has previously proposed Patent Documents 1 and 2.

Patent Document 1 discloses a structure for producing a casting, which is obtained from a slurry composition containing organic fibers, inorganic fibers, inorganic particles and a thermosetting resin. Further, in Patent Document 2, a papermaking molded article that contains a fibrous material and a powder and is formed by wet papermaking, and includes a fiber having a frequency distribution of fiber lengths within a predetermined range. Is listed.

As a technique different from these, Patent Document 3 discloses a technique in which a waste glass fiber paper in a glass fiber paper containing glass fibers as a main fiber is made into a form that can be recycled or reused.

International publication 2014/104045 pamphlet JP, 2005-344274, A JP, 2004-313843, A

If the above-mentioned waste material is simply pulverized and mixed with a certain amount of water and reused as a raw material, the compressive strength of the obtained casting manufacturing structure will be lowered, and the function as a product will not be exhibited. ..
Here, Patent Document 1 does not describe anything about forming a structure for producing a casting by incorporating a waste material. Further, Patent Document 2 does not describe at all about forming a casting-manufacturing structure by incorporating waste material once made into a paper body as a raw material again.
Further, the pulverized glass fiber paper described in Patent Document 3 is limited to glass fiber paper, and is not suitable for a structure for casting production mainly containing inorganic powder and pulp fiber.

Therefore, the present invention provides a raw material for a casting manufacturing structure, a container for the raw material, a raw material slurry thereof, and a casting manufacturing structure obtained from the raw material slurry, which can solve the above-mentioned drawbacks of the conventional technology. Especially. Another object of the present invention is to provide a method for producing a raw material for a structure for producing a casting that can eliminate the drawbacks of the prior art.

The present invention is a raw material for a structure for producing a casting, comprising 84% by mass or more and less than 100% by mass of a virgin raw material, and a recycled raw material, wherein the virgin raw material has an organic fiber content of 10% by mass or more and 50% by mass or more. Mass% or less, content of inorganic fibers is 2 mass% or more and 50 mass% or less, content of inorganic particles is 20 mass% or more and 60 mass% or less, thermosetting resin content is 5 mass% or more and 50 mass% or less The total content of the organic fibers and the thermosetting resin that constitute the recycled raw material is 15% by mass or more and 78% by mass or less, and the content of the inorganic fiber that constitutes the recycled raw material is 2% by mass. And 50 mass% or less, the content of the inorganic particles constituting the regenerated raw material is 20 mass% or more and 60 mass% or less, and the regenerated raw material has a fiber length of 0.3 mm or more in the frequency distribution of the fiber length of 0.3 mm or more. Raw material for a structure for casting production, in which fibers in the range of less than 0 mm occupy 60% or more and 85% or less of the whole, and fibers in the range of fiber length less than 0.3 mm occupy 15% or more and 40% or less of the whole. Is provided.

The present invention also provides a container for a raw material for a casting manufacturing structure, which contains the raw material for a casting manufacturing structure in a water-soluble package.

In addition, the present invention contains the raw material for the casting manufacturing structure or a container for the casting manufacturing structural material at a ratio of 2.0% by mass or more and 4.0% by mass or less with respect to water. A raw material slurry for a structure for casting production is provided.

Further, the present invention is a casting manufacturing structure obtained from a raw material for the casting manufacturing structure, wherein the proportion of the recycled raw material in the casting manufacturing structure is more than 0 mass% and 16 mass% or less. A casting manufacturing structure is provided.

Further, the present invention is a method for producing a raw material for a casting manufacturing structure containing a virgin raw material of 84% by mass or more and less than 100% by mass, and a recycled raw material, wherein the recovered waste material of the casting manufacturing structure is A crushing step of dry crushing using a rotary crusher and a crushing step of collecting the crushed material obtained in the crushing step through a mesh having an opening having a diameter of 0.5 mm or more and 3 mm or less. The rotary crusher used in the step is a crusher that crushes with a plurality of rotary blades on a rotary shaft and a fixed blade fixed to the crusher body, and the rotary blades are arranged at intervals in the rotary axis direction, It is intended to provide a method for producing a raw material for a casting manufacturing structure, in which a space is provided between rotary blades adjacent to each other in the rotation axis direction.

According to the present invention, the compressive strength of a casting manufacturing structure obtained by using a recycled raw material does not easily decrease, and a casting manufacturing material that can be efficiently used as a casting manufacturing structure that can be sufficiently utilized as a product is a raw material for a casting manufacturing structure. A method of manufacturing the same is provided. Further, according to the present invention, there is provided a casting production structure which is not easily reduced in compressive strength of a casting production structure obtained by using a recycled raw material and which can be sufficiently utilized as a product.

FIG. 1 is a cross-sectional view for explaining the configuration of a rotary crusher used in the crushing process. FIG. 2 is an enlarged perspective view of a main part of the rotary crusher shown in FIG. FIG. 3 is a schematic view of a compressive strength measuring machine that measures the compressive strength of a structure for manufacturing a casting.

The present invention will be described below based on its preferred embodiments.

The raw material for the casting manufacturing structure of the present embodiment contains 84% by mass or more and less than 100% by mass of a virgin raw material and a recycled raw material. In the structure for casting production, first, the raw material of the structure for casting production containing organic fibers, inorganic fibers, inorganic particles and thermosetting resin in a predetermined mixing ratio is prepared in the state of a raw material slurry. Next, a fiber laminate having a predetermined shape is formed into a paper by a wet papermaking method using the raw material slurry, and dehydrated and dried. Then, after being cut into a predetermined shape, mass inspection or inspection such as inspection is performed to manufacture a casting manufacturing structure. Here, the virgin raw material is one which has not yet been prepared in a raw material slurry state and contains organic fibers, inorganic fibers, inorganic particles and a thermosetting resin in a predetermined mixing ratio. In addition, the recycled raw material means a raw material derived from the cut material after the above-mentioned drying, the cut waste, the excess and deficiency of the mass produced in the inspection, and the product not passed the inspection.

In this embodiment, the virgin raw material has an organic fiber content of 10% by mass or more and 50% by mass or less, an inorganic fiber content of 2% by mass or more and 50% by mass or less, and an inorganic particle content of 20% by mass or more and 60% by mass or more. The content of the thermosetting resin is 5 mass% or more and 50 mass% or less, the content of the organic fiber is 20 mass% or more and 40 mass% or less, and the content of the inorganic fiber is 3 mass% or more and 30 mass% or less. % Or less, the content of the inorganic particles is 30% by mass or more and 60% by mass or less, the content of the thermosetting resin is preferably 10% by mass or more and 30% by mass or less, and the content of the organic fiber is 25% by mass or more. 30% by mass or less, the content of inorganic fibers is 3% by mass or more and 10% by mass or less, the content of inorganic particles is 40% by mass or more and 55% by mass or less, and the content of the thermosetting resin is 15% by mass or more and 20% by mass or less. The following is more preferable.

The content of the organic fiber in the virgin raw material is 10% by mass or more from the viewpoint that the effect of the addition is sufficiently expressed, the moldability of the structure for casting production and the removability of the structure for casting production after casting are excellent. It is preferably 20% by mass or more, more preferably 25% by mass or more, particularly preferably 50% by mass or less, more preferably 40% by mass or less, 30 It is particularly preferably not more than 10% by mass, specifically preferably not less than 10% by mass and not more than 50% by mass, more preferably not less than 20% by mass and not more than 40% by mass, and not less than 25% by mass and not more than 30% by mass. % Or less is particularly preferable.

The content of the inorganic fiber in the virgin raw material is 2% by mass from the viewpoint of suppressing the heat shrinkage associated with the decrease in the heat resistance of the casting manufacturing structure to improve the shape retention of the casting, and from the viewpoint of suppressing the gas generation amount. It is preferably not less than 3% by mass, more preferably not less than 3% by mass, further preferably not more than 50% by mass, more preferably not more than 30% by mass, particularly preferably not more than 10% by mass. Preferably, specifically, it is preferably 2% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and particularly preferably 3% by mass or more and 10% by mass or less. ..

The content of the inorganic particles in the virgin raw material is preferably 20% by mass or more from the viewpoint of sufficiently expressing the effect of the addition of the inorganic particles and improving the hot strength during casting of the casting manufacturing structure. It is more preferably 30 mass% or more, particularly preferably 40 mass% or more, and preferably 60 mass% or less, more preferably 55 mass% or less, and specifically, The amount is preferably 20% by mass or more and 60% by mass or less, more preferably 30% by mass or more and 60% by mass or less, and particularly preferably 40% by mass or more and 55% by mass or less.

The content of the thermosetting resin in the virgin raw material is preferably 5% by mass or more from the viewpoint of obtaining the smoothness of the surface of the casting and improving the strength and shape retention of the structure for casting production. It is more preferably at least mass%, particularly preferably at least 15 mass%, preferably at most 50 mass%, more preferably at most 30 mass%, and at most 20 mass%. It is particularly preferable, specifically, 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 30% by mass or less, and 15% by mass or more and 20% by mass or less. Is particularly preferable.

Further, in the present embodiment, in the virgin raw material, in the frequency distribution of the fiber length, the fibers in the range of the fiber length of 0.3 mm or more and less than 5.0 mm occupy 80% or more and less than 100% of the whole, and less than 0.3 mm. It is preferable that the fibers in the range of 0 to more than 0% and 20% or less of the whole occupy, and the fibers in the range of 0.3 mm or more and less than 5.0 mm occupy 83% to 90% of the whole and 0 It is more preferable that the fibers in the range of less than 0.3 mm occupy 10% or more and 20% or less of the whole, and the fibers in the range of fiber length 0.3 mm or more and less than 5.0 mm occupy 85% or more and 90% or less of the whole. It is particularly preferable that the fibers in the range of less than 0.3 mm occupy 10% or more and 15% or less of the whole. The frequency distribution of the fiber length is measured by HiRes Fiber Quality Analyzer [Code LDA02] fiber length measuring device [OpTest Equipment Inc. Manufactured by the company).

Further, in the present embodiment, the regenerated raw material has a total content of the organic fibers and the thermosetting resin constituting the regenerated raw material of 15% by mass or more and 78% by mass or less, and the content of the inorganic fiber constituting the regenerated raw material is 2% by mass. % Or more and 50% by mass or less, the content of the inorganic particles constituting the recycled raw material is 20% by mass or more and 60% by mass or less, and the total content of the organic fibers and the thermosetting resin is 20% by mass or more and 67% by mass or less. The content of the inorganic fibers is preferably 3% by mass or more and 30% by mass or less, the content of the inorganic particles is preferably 30% by mass or more and 60% by mass or less, and the total content of the organic fibers and the thermosetting resin is 30% by mass. % To 57% by mass, the content of the inorganic fibers is 3% to 10% by mass, and the content of the inorganic particles is 40% to 55% by mass. The blending ratio of the recycled raw material is measured by thermogravimetric measurement TG using a thermal analyzer (product number TG8120 manufactured by Rigaku Corporation) under the conditions of a measurement temperature of 25 to 1000° C. and a heating rate of 20° C./min. The thermosetting resin in the recycled raw material has been subjected to a thermal history at least once and is partially cured, and has different properties from the thermosetting resin in the virgin raw material. Whether it is a virgin raw material or a recycled raw material is determined by observing a raw material for a casting manufacturing structure in water at 0.0001% by mass or less using, for example, a microscope to perform a pulverizing step. It is possible to determine by the presence or absence of uncrushed materials that are generated in no small amount.

The total content of the organic fiber and the thermosetting resin in the recycled material sufficiently expresses the effect of the addition of the organic fiber and the thermosetting resin, and the moldability of the structure for casting production and the structure for casting production after casting From the viewpoint of excellent removability, the surface smoothness of the casting, and the strength and shape retention of the casting manufacturing structure, it is preferably 15% by mass or more and 20% by mass or more. , More preferably 30% by mass or more, and 78% by mass or less, 67% by mass or less, further preferably 57% by mass or less, specifically, 15% by mass. Or more and 78 mass% or less, preferably 20 mass% or more and 67 mass% or less, and more preferably 30 mass% or more and 57 mass% or less.

The content of the inorganic fiber in the recycled raw material is 2% by mass from the viewpoint of improving the shape retention of the casting by suppressing thermal contraction due to the decrease in heat resistance of the casting manufacturing structure, and from the viewpoint of suppressing the gas generation amount. It is above, preferably 3% by mass or more, and 50% by mass or less, preferably 30% by mass or less, further preferably 10% by mass or less, and specifically 2 It is preferably from 50% by mass to 50% by mass, more preferably from 3% by mass to 30% by mass, still more preferably from 3% by mass to 10% by mass.

The content of the inorganic particles in the recycled raw material is 20% by mass or more and 30% by mass from the viewpoint of sufficiently expressing the effect of the addition of the inorganic particles and improving the hot strength at the time of casting of the casting manufacturing structure. It is preferably at least 40% by mass, more preferably at least 40% by mass, and at most 60% by mass, preferably at most 55% by mass. It is preferably 30% by mass or more and 60% by mass or less, and more preferably 40% by mass or more and 55% by mass or less.

Further, in the present embodiment, in the regenerated raw material, in the frequency distribution of the fiber length, the fibers in the range of the fiber length of 0.3 mm or more and less than 5.0 mm occupy 60% or more and 85% or less of the whole, and less than 0.3 mm. 15% or more and 40% or less of the whole range, fibers having a length of 0.3 mm or more and less than 5.0 mm occupy 62% or more and 83% or less of the whole, and less than 0.3 mm It is preferable that the fibers in the range occupy 17% to 38% of the whole, and the fibers in the range of fiber length 0.3 mm to less than 5.0 mm occupy 63% to 81% of the whole and 0.3 mm. It is more preferable that the fibers in the range of less than 19% occupy 37% or less of the whole. The frequency distribution of the fiber length is measured by HiRes Fiber Quality Analyzer [Code LDA02] fiber length measuring device [OpTest Equipment Inc. Manufactured by the company).

Examples of the organic fibers in the virgin raw material include fibers such as paper fibers, fibrillated synthetic fibers, and recycled fibers (for example, rayon fibers). These organic fibers may be used alone or in combination of two or more. Among them, it is preferable to use paper fibers, in particular, because they can be formed into various shapes by papermaking and have sufficient strength after dehydration and drying.

Examples of the paper fiber in the virgin raw material include wood pulp, cotton pulp, linter pulp, bamboo, straw and other non-wood pulp. As the paper fiber, these virgin pulps or waste paper pulps can be used alone or in combination of two or more. From the viewpoints of easy availability, environmental protection, reduction of manufacturing cost, etc., waste paper pulp is particularly preferable as the paper fiber.

The organic fiber in the virgin raw material has an average fiber length of 0.3 to 2.0 mm, particularly 0.5 to 1.5 mm, in consideration of the moldability, surface smoothness, and impact resistance of the structure for casting production. Is preferred.

Examples of the inorganic fibers in the virgin raw material include carbon fibers such as artificial mineral fibers such as rock wool, ceramic fibers, natural mineral fibers, glass fibers, silica fibers, and metal fibers. These inorganic fibers can be used alone or in combination of two or more. Among these, it is particularly preferable to use carbon fiber having high strength even at a high temperature at which the metal melts, from the viewpoint of suppressing heat shrinkage during casting.

As the carbon fiber in the virgin raw material, it is preferable to use pitch-based or polyacrylonitrile (PAN)-based carbon fiber having high strength even at high temperature from the viewpoint of effectively suppressing shrinkage due to thermal decomposition of the structure for casting production. Particularly, PAN-based carbon fiber is preferable.

The carbon fiber in the virgin raw material has an average fiber length of 0.2 to 10 mm, particularly 0 from the viewpoint of dehydration property when the casting manufacturing structure is formed into paper and dehydrated, formability of the casting manufacturing structure, and uniformity. It is preferably from 0.5 to 8 mm.

Examples of the inorganic particles in the virgin raw material include inorganic particles having a fire resistance of 800 to 4000° C., preferably 1000 to 4000° C., such as silica, alumina, mullite, magnesia, zirconia, mica, graphite, and obsidian. Graphite is preferable from the viewpoint of releasability at the time of molding the structural body for use. These inorganic particles may be used alone or in combination of two or more.

As the inorganic particles in the virgin raw material, when a casting is produced from a molten metal having a carbon equivalent of 4.2% or less, and further 4.0% or less, the heat contained in the casting production structure or the heat of the molten metal is used. The point of preventing the carbide film generated by decomposition from dissolving in the molten metal with a low carbon equivalent, and further, when casting sand is placed outside the casting manufacturing structure or inside the hollow core, In order to further improve the surface smoothness of the casting obtained by preventing the adhesion of sand, it is preferable to use inorganic particles having a fire resistance of 800 to 2000°C. When a casting is produced from a molten metal having a carbon equivalent of 4.2% or less, obsidian is preferable as the cast iron because the viscosity at the time of softening is high and the effect of preventing the dissolution of the carbon film in the molten metal is particularly high. Mullite powder is preferred for stainless steel.

The combined use of obsidian and mineral particles other than obsidian (hereinafter referred to as mineral particles) as the inorganic particles in the virgin raw material significantly improves the dimensional accuracy of the casting manufactured from the casting manufacturing structure using the same. .. As the mineral particles, those having a fire resistance of 1200° C. or higher are preferable, and silica (for example, fire resistance 1650° C. or higher), alumina (for example, fire resistance 1700° C. or higher), mullite (for example, fire resistance 1650° C. or higher), magnesia (for example Examples thereof include fire resistance of 2500° C.), zircon (for example, fire resistance of 2000° C. or higher), chromite (for example, fire resistance of 1950° C. or higher), graphite (for example, fire resistance of 3300° C. or higher). These mineral particles may be used alone or in combination of two or more. The combined use of obsidian and the above-mentioned mineral particles is more preferable when a casting is produced from a molten metal having a carbon equivalent of 4.2% or less, further 4.0% or less.

When obsidian and the above-mentioned mineral particles are used in combination as the inorganic particles in the virgin raw material, obsidian (1) and mineral particles other than obsidian (2) are considered based on the strength of the structure for casting production and the dimensional accuracy of the casting produced using the same. The compounding ratio of is a mass ratio of (1)/(2)=10/90 to 90/10, and more preferably 25/75 to 75/25.

The refractory degree of the inorganic particles in the virgin raw material is measured by a measuring method using a Zegel cone (JIS R2204). Note that the refractory level of general obsidian is 1200 to 1250°C.

The inorganic particles in the virgin raw material preferably have an average particle diameter of 200 μm or less. Even when obsidian and the above mineral particles are used in combination, it is preferable to use those having an average particle diameter of 200 μm or less. Further, in particular, inorganic particles having a refractory degree of ±300°C, particularly ±200°C, with respect to the casting temperature of the molten metal to be cast are preferable.

The average particle diameter of the inorganic particles in the virgin raw material is a laser diffraction type particle size distribution measuring device (average particle diameter of 50% in volume cumulative measured by using LA-920 manufactured by Horiba Ltd., analysis conditions are as follows. Is.
・Measurement method: Flow method ・Refractive index: Variation due to inorganic particles (see manual attached to LA-920)
-Dispersion medium: Ion-exchanged water + 0.1% sodium hexametaphosphate-Dispersion method: Stirring, built-in ultrasonic wave 3 minutes-Sample concentration: 2 mg/100 cc

Examples of the thermosetting resin in the virgin raw material include thermosetting resins such as phenol resin, epoxy resin and furan resin. The thermosetting resin is a component necessary for maintaining the room temperature strength and the hot strength and improving the surface roughness of the casting, and the surface smoothness equivalent to that of the sand mold coated with the mold coating agent is obtained, It is not necessary to use a coating agent. This is an important performance for the structure for producing castings of the present invention, which contains an organic fiber or the like that is difficult to ignite and dry when a conventional alcohol type coating agent is used.

The thermosetting resin in the virgin raw material has a particularly low generation of combustible gas, has an effect of suppressing combustion, has a high residual carbon rate of 25% or more after thermal decomposition or carbonization, and forms a carbon film during casting. It is preferable to use a phenolic resin from the viewpoint that a good casting surface can be obtained. The residual coal rate can be determined by the residual mass after heating to 1000° C. in a reducing atmosphere (nitrogen atmosphere) by a differential thermal analysis.

Examples of the phenol resin in the virgin raw material include novolac phenol resin, resole phenol resin, phenol resin of bisphenol A and bisphenol F, modified phenol resin modified with urea, melamine, epoxy and the like, but preferably novolac phenol resin, It is a resole phenol resin, a resole resin of bisphenol A, or a modified resin thereof.

As a thermosetting resin in a virgin raw material, a curing agent required when the novolac phenol resin is used in a phenol resin is easily soluble in water, so that it is applied after dehydration of a molded body particularly in the case of wet papermaking. It is preferable. Hexamethylenetetramine or the like is preferably used as the curing agent.

The thermosetting resin in the virgin material 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.

The raw material of the casting manufacturing structure of the present embodiment includes 84% by mass or more and less than 100% by mass of the above-mentioned virgin raw material and the above-mentioned recycled raw material. In the raw material of the structure for producing a casting of the present embodiment, particularly, in the frequency distribution of the fiber length of the recycled raw material, the fibers in the range of the fiber length of 0.3 mm or more and less than 5.0 mm occupy 60% or more and 85% or less of the whole. Further, the fibers in the range of less than 0.3 mm account for 15% or more and 40% or less of the whole. Therefore, the compressive strength of the structure for producing a casting obtained by using the recycled raw material does not easily decrease, and it can be sufficiently used as a product. From such a viewpoint, it is preferable that the above-mentioned virgin raw material is blended in the range of 85% by mass or more and 99% by mass or less, and the above-mentioned recycled raw material is blended in the range of 1% by mass or more and 15% by mass or less, It is more preferable that the above-mentioned virgin raw material is blended in a range of 89% by mass or more and 98% by mass or less, and the above-mentioned recycled raw material is blended in a range of 2% by mass or more and 11% by mass or less. By setting the lower limit value of the blending amount of the virgin raw material as described above, a sufficient compressive strength of the casting manufacturing structure can be obtained.

In addition to the above-mentioned virgin raw material and regenerated raw material, the raw material of the structure for producing a casting of the present embodiment includes, as necessary, polyvinyl alcohol, carboxymethyl cellulose (CMC), polyamidoamine epichlorohydrin resin, etc. for strengthening paper strength. Other components such as an agent, a coagulant such as polyacrylamide, and a coloring agent can be added at an appropriate ratio. The amount of the other components such as the above-mentioned paper-strengthening agent, coagulant, colorant, and the like added to the raw material of the structure for producing a casting is preferably 0.5% by mass or less. It is preferable to prepare the raw materials.

The raw material of the casting manufacturing structure of the present embodiment or the embodiment in which other components are mixed may be in the form of a container of the casting manufacturing raw material contained in a water-soluble package. As the water-soluble package containing the structure for casting production, a vinyl alcohol-based polymer, a carboxylic acid-based polymer, a polyester-based polymer, and a modified one of these, or at least one of them, and a cellulose derivative , Those formed from starch, and the like. With such a container form, dust does not scatter when the regenerated raw material is stored, stored, or used, and the regenerated raw material is dispersed without the need to open the container when preparing the raw material slurry described later. It can be mixed with water as a medium.

Next, a method for manufacturing a structure for manufacturing a casting according to the present invention will be described based on a method for manufacturing the structure for manufacturing a casting according to the above-described embodiment as a preferred embodiment.

In the manufacturing method of the present embodiment, first, a raw material slurry containing 84% by mass or more and less than 100% by mass of the above-mentioned virgin raw material and 16% by mass or less and more than 0% by mass of the above-mentioned recycled raw material is prepared. Then, after that, a fiber laminate having a predetermined shape is made into paper by a wet papermaking process using the raw material slurry, dehydrated and dried, and then, a structure for casting production is manufactured through a cutting process and an inspection process.

Water is used as a dispersion medium in the raw material slurry of the structure for casting production. From the viewpoint of improving the planar smoothness of the casting manufacturing structure, the raw material slurry of the casting manufacturing structure contains the raw material of the casting manufacturing structure in a proportion of 1% by mass or more and 5% by mass or less with respect to water. It is preferable that it is prepared by the above method, and it is preferable that it is prepared at a ratio of 2% by mass or more and 4% by mass or less with respect to water.

If necessary, additives such as the paper-strengthening agent, the aggregating agent, and the preservative can be added to the raw material slurry of the structure for producing a casting in an appropriate ratio.

In the wet papermaking process for the fiber laminate, for example, two split molds are butted to each other to have a shape substantially corresponding to the outer shape of the casting manufacturing structure and to open to the outside. A mold in which a cavity is formed is used. Each split mold is provided with a large number of communication holes for communicating the outside with the cavity, and the inner surface of each split mold is covered with a net having a mesh of a predetermined size. Then, a predetermined amount of the raw material slurry is injected into the cavity of the mold using a pressure pump or the like, while the liquid content is sucked and discharged through the communication hole to deposit the solid content of the raw material slurry on the net. The pressure of the raw material slurry under pressure is preferably 0.01 to 5 MPa, and more preferably 0.01 to 3 MPa.

Then, when a fiber laminate having a predetermined thickness is formed on the net by injecting a predetermined amount of the raw material slurry, the pressure injection of the raw material slurry is stopped, and air is pressed into the cavity to form the predetermined fiber laminated body. Dehydrate to a water content of.

Next, the dehydrated fiber laminate is dried and molded. In this dry molding step, a dry mold having a cavity corresponding to the outer shape of the casting manufacturing structure to be molded and having a cavity open to the outside is formed by abutting a pair of split molds. To use. Then, the dry mold is heated to a predetermined temperature, and the dehydrated fiber laminate is loaded into the dry mold.

Next, an elastic, stretchable and hollow core, that is, an elastic core, is inserted into the cavity, and a pressurized fluid is supplied into the core to move the core in the cavity. Inflate. Then, the fiber laminate is pressed against the surface on which the cavity is formed, and is dried while transferring the shape of the inner surface of the cavity. As the core, for example, one made of urethane, fluorine rubber, silicone rubber or elastomer is used.

Examples of the pressurized fluid that expands the core include compressed air or heated air, oil or heated oil, and various other liquids. The pressure for supplying the pressurized fluid is preferably 0.01 to 5 MPa, particularly 0.1 to 3 MPa.

The heating temperature of the drying mold, that is, the mold temperature is preferably 180 to 250° C., and particularly preferably 200 to 240° C. in consideration of the drying time and the deterioration of the surface property due to charring.

After the fiber laminate is dried, the pressurized fluid in the core is drained, the core is contracted, and the fiber laminate is taken out. Then, the drying mold is opened, and the precursor of the structure for casting production that has been dry-molded is taken out.

In the precursor of the structure for casting production obtained in this manner, the proportion of the recycled raw material in the structure for casting production is more than 0% by mass and 16% by mass or less. The proportion of the virgin raw material in the precursor of the structure for producing a casting is 84% by mass or more and less than 100% by mass. The precursor of the structure for producing a casting to be obtained contains the above-mentioned regenerated raw material, but in the frequency distribution of the fiber length of the regenerated raw material, the total number of fibers within the range of 0.3 mm to less than 5.0 mm is 60. % And 85% or less, and the fibers in the range of less than 0.3 mm occupy 15% or more and 40% or less of the whole, so that the compressive strength of the obtained structure for casting production does not easily decrease, and it is sufficient as a product. Available for From such a viewpoint, it is preferable that the obtained precursor of the structure for casting production has a ratio of the regenerated raw material in the structure for casting production of 1% by mass or more and 15% by mass or less, and The proportion of the virgin raw material in the precursor of the structure is preferably 85% by mass or more and 99% by mass or less, and the proportion of the regenerated raw material in the precursor of the structure for casting production is 2% by mass or more and 11% by mass or less. Is more preferable, and the ratio of the virgin raw material in the precursor of the structure for producing a casting is more preferably 89% by mass or more and 98% by mass or less.

The precursor of the casting manufacturing structure thus obtained is then cut into a predetermined shape in the cutting step, and the casting manufacturing structure is obtained through mass or inspection inspection in the inspection step. ..

The scraps and cutting scraps obtained in the cutting step, the excess and deficiency of the mass obtained in the inspection step, and the inspection-failed products are reused as the above-mentioned recycled raw materials.
A method of manufacturing a raw material for a casting manufacturing structure containing a recycled raw material will be described below.

In the method for producing a raw material for a casting manufacturing structure, the recovered waste material of the casting manufacturing structure is dry crushed using a rotary crusher (crushing step). Here, the waste material is an end material obtained in the cutting step, a cutting waste, an excess or deficiency in mass obtained in the inspection step, a product that fails inspection, and the like, which is formed after the dry molding step. Means The dry pulverization means pulverizing the waste material having a water content of 1% by mass or more and 20% by mass or less.

The rotary crusher used in the crushing step is, for example, a crusher as shown in FIGS. 1 and 2. The crusher 1 shown in FIGS. 1 and 2 is a crusher that crushes a rotary shaft with a plurality of rotary blades 2 and a fixed blade 3 fixed to a crusher body 10. The crusher 1 shown in FIGS. 1 and 2 has only one rotative shaft. The rotary blades 2 of the crusher 1 are arranged at intervals in the rotation axis direction, and a gap is provided between the rotary blades 2 and 2 adjacent to each other in the rotation axis direction. Here, the void means that a space not provided at all is provided. The rotary blades 2 are preferably arranged on the rotary shaft in an amount of 2 or more and 10 or less, and in the crusher 1 shown in FIGS. 1 and 2, three blades are arranged. Each rotary blade 2 is provided with three blades 22 on the peripheral surface of the rotor 21. The fixed blades 3 fixed to the crusher body 10 are arranged at the front and rear ends in the rotation direction in the vicinity of the bottom of the charging port 4 along the rotation axis direction. In the crusher 1 shown in FIGS. 1 and 2, the three rotary blades 2 are arranged at regular intervals in the rotation axis direction. The distance D between the rotary blades 2, 2 adjacent to each other in the rotation axis direction is preferably 0.5 times or more and 5 times or less, and 0.8 times or more and 2 times or less, with respect to the width d of the blade 22. Is more preferable. The width d of the blade 22 is preferably 1 mm or more and 100 mm or less, and more preferably 10 mm or more and 50 mm or less. The clearance between the blade 22 and the fixed blade 3 is preferably 0.01 mm or more and 10 mm or less, and more preferably 0.05 mm or more and 5 mm or less.

In the crushing step, the crusher 1 shown in FIGS. 1 and 2 is used, and the scrap material obtained in the cutting step, the cutting waste, the mass excess and deficiency obtained in the inspection step, the inspection rejected product, etc. Is charged and crushed by the rotary blade 2 and the fixed blade 3.

Next, the crushed material obtained in the crushing step is collected through a mesh having openings having a diameter of 0.5 mm or more and 3 mm or less (collecting step). In the method for producing a raw material for a structure for producing a casting, the pulverized product obtained in the pulverizing step is sucked and passed through a mesh having openings having a diameter of 0.5 mm or more and 3 mm or less.

In the method for producing a raw material for a structure for casting production, in the crushing step, since a gap is provided between the rotary blades 2, 2 adjacent to each other in the rotation axis direction, the end material obtained in the cutting step, Cut off scraps, excess or deficient mass obtained in the inspection step, rejected products, etc. by the rotary blade 2 and the fixed blade 3 rather than cutting them by the rotary blade 2 and the fixed blade 3. It is easy to become. Therefore, in the frequency distribution of the fiber length, 60% or more and 85% or less of the total fiber is in the range of 0.3 mm or more and less than 5.0 mm, and 15% of the total fiber is less than 0.3 mm. It is easy to obtain a recycled material that accounts for 40% or less.

As a pretreatment of the crushing step, it is desirable to have a compression step of compressing the recovered waste material of the casting manufacturing structure. By having the compression step, it is possible not only to reduce the bulk when storing the waste material of the casting manufacturing structure, but also to increase the pulverization efficiency in the pulverization step. As a means for the compression step, the casting structure may be manually stepped on, crushed by hand, or a pressing machine may be used.

Moreover, it is preferable to have a sorting step of sorting the crushed material collected in the collecting step according to the fiber length thereof. That is, it is preferable to have a sorting step as a step after the collecting step. By having the sorting step, the fiber length of the crushed product can be arbitrarily adjusted, and thus it becomes easy to suppress the decrease in the compressive strength of the casting manufacturing structure. A sieve or the like may be used as a means for selecting the pulverized material collected in the collecting step according to the fiber length thereof, or a difference in the flight distance of the pulverized material due to suction or blowing may be used.

The regenerated raw material thus formed is mixed with 84% by mass or more and less than 100% by mass of the above-mentioned virgin raw material to prepare the above-mentioned raw material slurry. Then, after that, in the same manner as above, a fiber laminate having a predetermined shape is formed into a paper through a wet papermaking process using the raw material slurry, dehydrated and dried, and then, a cutting process and an inspection process are performed to produce a casting. It becomes a structure.

The thickness of the manufactured casting production structure can be appropriately set depending on the portion used, but the thickness at least in the portion in contact with the molten metal is 0.2 to 5 mm, particularly 0.4 to 2 mm. Is preferred. When the thickness is 0.2 mm or more, sufficient strength required for molding with casting sand is obtained, and the shape function of the structure for casting production can be maintained, which is preferable. Further, if the thickness is 5 mm or less, the amount of gas generated during casting is reduced, surface defects of the casting are less likely to occur, the molding time can be shortened, and the manufacturing cost can be reduced, which is preferable.

In the state before being used for casting, the manufactured cast structure has a compressive strength of preferably 80 N or more, more preferably 100 N or more. Here, the compressive strength of the casting manufacturing structure means that the casting manufacturing structure 100 manufactured as shown in FIG. 3 is cut into a width of 300 mm, and the cut surface is placed in a horizontal state. In the compression strength measurement by a test stand (MODEL-1301F) manufactured by Co., Ltd., it means the strength measured by pushing down a position of 65 mm from the cut surface with a compression terminal 101 having a diameter of 31 mm at a compression speed of 20 mm/min.

From the viewpoint of suppressing the amount of gas generated during casting as much as possible, the manufactured casting structure preferably has a mass water content of 20% or less, particularly preferably 15% or less in a state before being used for casting.

As a casting manufacturing method using the manufactured casting manufacturing structure, the predetermined casting manufacturing structure obtained as described above is embedded in a predetermined position in the molding sand and molded. As the foundry sand, the usual ones conventionally used for the production of this kind of foundry can be used without particular limitation. The foundry sand may not be hardened with a binder, but may be hardened if necessary. When the structure for producing a casting is a hollow core, it is not necessary to fill the core with the molding sand, but it can be filled.

Then, the molten metal is poured from the pouring port to perform casting. Then, after the casting is finished, the casting is cooled to a predetermined temperature, the casting frame is disassembled to remove the casting sand, and the casting manufacturing structure is removed by blasting to expose the casting. Then, if necessary, the casting is subjected to post-treatment such as trimming to manufacture the casting.

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

As a rotary crusher for dry crushing the recovered waste material of the casting manufacturing structure, in addition to the crusher 1 shown in FIGS. 1 and 2, a gap is provided between the rotary blades 2 adjacent to each other in the rotation axis direction. Any crusher having a rotary blade 2 provided with and a fixed blade 3 fixed to the crusher main body 10 may be used.

Regarding the above-described embodiment, further, the following raw materials for a casting manufacturing structure, a raw material container for a casting manufacturing structure, a raw material slurry for a casting manufacturing structure, a casting manufacturing structure, a casting manufacturing structure Disclosed is a method of manufacturing a raw material for a body.

<1>
A virgin raw material of 84% by mass or more and less than 100% by mass, and a raw material for a casting manufacturing structure containing a recycled raw material, wherein the virgin raw material has an organic fiber content of 10% by mass or more and 50% by mass or less, The content of the inorganic fiber is 2% by mass or more and 50% by mass or less, the content of the inorganic particles is 20% by mass or more and 60% by mass or less, and the content of the thermosetting resin is 5% by mass or more and 50% by mass or less, and The regenerated raw material has a total content of organic fibers and thermosetting resins of 15% by mass or more and 78% by mass or less, and an inorganic fiber content of 2% by mass or more and 50% by mass of the regenerated raw material. The content of the inorganic particles constituting the recycled raw material is 20% by mass or more and 60% by mass or less, and the recycled raw material has a fiber length in the frequency distribution of 0.3 mm or more and less than 5.0 mm. 60% or more and 85% or less of all the fibers, and 15% or more and 40% or less of the fibers in the range of the fiber length of less than 0.3 mm are raw materials for the casting manufacturing structure.
<2>
The virgin raw material has a content of organic fibers of 20% by mass or more and 40% by mass or less, a content of inorganic fibers of 3% by mass or more and 30% by mass or less, a content of inorganic particles of 30% by mass or more and 60% by mass or less, The content of the thermosetting resin is preferably 10% by mass or more and 30% by mass or less, the content of the organic fiber is 25% by mass or more and 30% by mass or less, and the content of the inorganic fiber is 3% by mass or more and 10% by mass or less. Hereinafter, it is more preferable that the content of the inorganic particles is 40% by mass or more and 55% by mass or less, and the content of the thermosetting resin is 15% by mass or more and 20% by mass or less, for the casting production according to <1> above. Raw material for structures.
<3>
The content of the organic fiber in the virgin raw material is preferably 10% by mass or more, more preferably 20% by mass or more, particularly preferably 25% by mass or more, and 50% by mass or less. Is preferably 40% by mass or less, more preferably 30% by mass or less, particularly preferably 10% by mass or more and 50% by mass or less, and 20% by mass or more. 40% by mass or less is more preferable, and 25% by mass or more and 30% by mass or less is particularly preferable, and the raw material for the casting manufacturing structure according to <1> or <2>.
<4>
The content of the inorganic fiber in the virgin raw material is preferably 2% by mass or more, more preferably 3% by mass or more, and preferably 50% by mass or less, and 30% by mass or less. More preferably, it is particularly preferably 10% by mass or less, and specifically, it is preferably 2% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 30% by mass or less, The raw material for the casting manufacturing structure according to any one of <1> to <3>, which is particularly preferably 3% by mass or more and 10% by mass or less.
<5>
The content of the inorganic particles in the virgin raw material is preferably 20% by mass or more, more preferably 30% by mass or more, particularly preferably 40% by mass or more, and 60% by mass or less. It is preferable that it is 55% by mass or less, more preferably 20% by mass or more and 60% by mass or less, and further preferably 30% by mass or more and 60% by mass or less, The raw material for the casting manufacturing structure according to any one of <1> to <4>, which is particularly preferably 40% by mass or more and 55% by mass or less.
<6>
The content of the thermosetting resin in the virgin raw material is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 15% by mass or more, and 50% by mass. It is preferably not more than 30% by mass, more preferably not more than 30% by mass, particularly preferably not more than 20% by mass, and specifically preferably not less than 5% by mass and not more than 50% by mass. % Or more and 30% by mass or less, and particularly preferably 15% by mass or more and 20% by mass or less, for the casting manufacturing structure according to any one of <1> to <5>. material.
<7>
In the frequency distribution of the fiber length of the virgin raw material, fibers having a fiber length in the range of 0.3 mm or more and less than 5.0 mm account for 80% or more and less than 100% of the whole, and fibers having a fiber length in the range of 0.3 mm or less are the whole. It is preferable to occupy more than 0% and less than 20% of the total length, and the fibers having a fiber length of 0.3 mm or more and less than 5.0 mm occupy 83% or more and 90% or less of the whole and less than 0.3 mm. It is more preferable that the fibers occupy 10% or more and 20% or less of the whole, and the fibers having a fiber length of 0.3 mm or more and less than 5.0 mm occupy 85% or more and 90% or less of the whole and less than 0.3 mm. It is particularly preferable that the fibers in the range of 10% to 15% of the whole are the raw materials for the casting manufacturing structure according to any one of <1> to <6>.
<8>
The regenerated raw material has a total content of organic fibers and thermosetting resins constituting the regenerated raw material of 20% by mass or more and 67% by mass or less, a content of inorganic fibers of 3% by mass or more and 30% by mass or less, of inorganic particles. The content is preferably 30% by mass or more and 60% by mass or less, the total content of the organic fiber and the thermosetting resin is 30% by mass or more and 57% by mass or less, and the content of the inorganic fiber is 3% by mass or more and 10% by mass. % Or less, and the content of the inorganic particles is more preferably 40% by mass or more and 55% by mass or less, and the raw material for the casting manufacturing structure according to any one of <1> to <7>.
<9>
The total content of the organic fiber and the thermosetting resin in the recycled material is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 67% by mass or less, It is more preferably 57 mass% or less, specifically 20 mass% or more and 67 mass% or less, and further preferably 30 mass% or more and 57 mass% or less, <1> to <8> A raw material for a casting manufacturing structure according to any one of <8>.
<10>
The content of the inorganic fiber in the recycled raw material is preferably 3% by mass or more, more preferably 30% by mass or less, further preferably 10% by mass or less, and specifically 3% by mass or less. For the structure for casting production according to any one of <1> to <9>, which is preferably not less than 30% by mass and more preferably not less than 3% by mass and not more than 10% by mass. material.
<11>
The content of the inorganic particles in the regenerated raw material is preferably 30% by mass or more, more preferably 40% by mass or more, and preferably 55% by mass or less, specifically, 30% by mass. % Or more and 60% by mass or less, more preferably 40% by mass or more and 55% by mass or less, and the raw material for the structure for casting production according to any one of <1> to <10>. ..
<12>
In the regenerated raw material, in the frequency distribution of the fiber length, 62% or more and 83% or less of the total fiber is in the range of 0.3 mm or more and less than 5.0 mm, and the total fiber in the range of less than 0.3 mm is It is preferable to occupy 17% or more and 38% or less of the fiber length, and fibers having a fiber length of 0.3 mm or more and less than 5.0 mm occupy 63% or more and 81% or less of the whole and fibers having a fiber length of less than 0.3 mm. More preferably occupy 19% or more and 37% or less of the whole, the raw material for the casting manufacturing structure according to any one of <1> to <11>.
<13>
Examples of the organic fibers in the virgin raw material include fibers such as paper fibers, fibrillated synthetic fibers, and recycled fibers (for example, rayon fibers). The organic fibers are used alone or in combination of two or more. The raw material for the structure for producing a casting according to any one of <1> to <12>, which can be used and is particularly preferably paper fiber.
<14>
Examples of the paper fiber in the virgin raw material include wood pulp, cotton pulp, linter pulp, bamboo and straw and other non-wood pulp, and the paper fiber is one or more of these virgin pulp or waste paper pulp. The raw material for the structure for casting production according to <13>, in which waste paper pulp is preferably used.
<15>
The organic fiber in the virgin raw material preferably has an average fiber length of 0.3 to 2.0 mm, particularly 0.5 to 1.5 mm, and the casting according to any one of <1> to <14>. Raw material for manufacturing structures.
<16>
Examples of the inorganic fibers in the virgin raw material include carbon fibers, artificial mineral fibers such as rock wool, ceramic fibers, natural mineral fibers, glass fibers, silica fibers, fibers such as metal fibers, and the inorganic fibers include these. The raw material for the structure for producing a casting according to any one of <1> to <15>, which can be used alone or in combination of two or more kinds, and particularly preferably uses carbon fiber.
<17>
Pitch-based or polyacrylonitrile (PAN)-based carbon fibers are preferably used as the carbon fibers in the virgin raw material, and PAN-based carbon fibers are particularly preferable. For the casting manufacturing structure according to <16> above. material.
<18>
The carbon fiber in the virgin raw material preferably has an average fiber length of 0.2 to 10 mm, and particularly preferably 0.5 to 8 mm. The raw material for a casting manufacturing structure according to <16> or <17>. ..
<19>
Examples of the inorganic particles in the virgin raw material include silica, alumina, mullite, magnesia, zirconia, mica, graphite, obsidian, etc. having a fire resistance of 800 to 4000° C., preferably 1000 to 4000° C., and these inorganic particles. Can be used alone or in combination of two or more, and it is particularly preferable to use graphite, and the raw material for the structure for casting production according to any one of <1> to <18>.
<20>
As the inorganic particles in the virgin raw material, it is preferable to use inorganic particles having a fire resistance of 800 to 2000° C., cast iron is preferably obsidian, and cast steel and stainless steel are preferably mullite powder, <1> to <19. The raw material for the structure for casting manufacture of any one of >.
<21>
As inorganic particles in the virgin raw material, obsidian and mineral particles other than obsidian (hereinafter referred to as mineral particles) are used in combination, and the mineral particles preferably have a fire resistance of 1200° C. or higher, and silica (for example, fire resistance). 1650°C or higher), alumina (for example, refractory 1700°C or higher), mullite (for example, refractory 1650°C or higher), magnesia (for example, refractory 2500°C), zircon (for example, refractory 2000°C or higher), chromite (for example, refractory 1950). C. or higher), graphite (for example, a refractory degree of 3300.degree. C. or higher), and the like, and these mineral particles may be used alone or in combination of two or more kinds. <1> to <20> Raw material for the structure for manufacturing the foundry.
<22>
When obsidian and the mineral particles are used in combination as the inorganic particles in the virgin raw material, the compounding ratio of obsidian (1) and the mineral particles other than obsidian (2) is a mass ratio of (1)/(2)=10/ 90-90/10, 25/75-75/25 are preferable, The raw material for the structures for casting manufacture as described in said <21>.
<23>
The inorganic particles in the virgin raw material preferably have an average particle diameter of 200 μm or less, and even when the obsidian and the mineral particles are used in combination, it is preferable to use those having an average particle diameter of 200 μm or less. For the casting manufacturing structure according to any one of <1> to <22>, inorganic particles having a refractory degree of ±300°C, particularly ±200°C, with respect to the casting temperature of the molten metal to be cast are preferable. material.
<24>
Examples of the thermosetting resin in the virgin raw material include thermosetting resins such as phenol resin, epoxy resin, and furan resin, and it is particularly preferable to use a phenol resin, any of <1> to <23> above. 1. A raw material for a structure for producing a casting according to item 1.
<25>
It is preferable that the virgin raw material is blended in a range of 85% by mass or more and 99% by mass or less, and the recycled raw material is blended in a range of 1% by mass or more and 15% by mass or less, and the virgin raw material is 89% by mass or more and 98% by mass or more. The casting production according to any one of the above items <1> to <24>, wherein it is more preferable that the content of the recycled raw material is 2% by mass or more and 11% by mass or less. Raw material for the structure.
<26>
A container for a raw material for a casting manufacturing structure, wherein the raw material for a casting manufacturing structure according to <1> to <25> is contained in a water-soluble package.
<27>
The water-soluble package containing the raw material for the structure for casting production, vinyl alcohol-based polymer, carboxylic acid-based polymer, polyester-based polymer and any one or at least one of these modified The containing body of the raw material for the structure for casting manufacture of the said <26>, including the thing containing, a thing derived from a cellulose derivative, starch, etc.
<28>
A raw material slurry for a casting manufacturing structure containing the raw material container for a casting manufacturing structure according to <26> or <27> at a ratio of 2% by mass or more and 4% by mass or less with respect to water. ..
<29>
A raw material slurry for a casting manufacturing structure, containing the raw material for a casting manufacturing structure according to <1> to <25> in a ratio of 2% by mass or more and 4% by mass or less with respect to water.
<30>
The raw material slurry of the casting manufacturing structure uses water as a dispersion medium, and the raw material of the casting manufacturing structure is prepared at a ratio of 1% by mass or more and 5% by mass or less with respect to water. It is preferable that the raw material slurry for the casting manufacturing structure according to <29> is preferably prepared in a proportion of 2% by mass or more and 4% by mass or less with respect to water.
<31>
A casting manufacturing structure obtained from the raw material for a casting manufacturing structure according to <1> to <25>,
A casting manufacturing structure in which the proportion of recycled raw material in the casting manufacturing structure is more than 0 mass% and 16 mass% or less.
<32>
The precursor of the casting manufacturing structure, the proportion of the regenerated raw material in the casting manufacturing structure is preferably 1 mass% or more and 15 mass% or less, and in the precursor of the casting manufacturing structure The proportion of the virgin raw material is preferably 85% by mass or more and 99% by mass or less, and the proportion of the recycled raw material in the precursor of the structure for producing a casting is more preferably 2% by mass or more and 11% by mass or less, Further, it is more preferable that the ratio of the virgin raw material in the precursor of the casting production structure is 89% by mass or more and 98% by mass or less, and the casting production structure according to <31>.
<33>
What is claimed is: 1. A method for producing a raw material for a casting manufacturing structure, which comprises 84% by mass or more and less than 100% by mass of a virgin raw material, and a recycled raw material, wherein a rotary mill is used to collect the recovered waste material of the casting manufacturing structure. A rotary pulverization used in the pulverization step, which has a pulverization step of dry pulverization using the pulverization step and a pulverization step of pulverizing the pulverized product obtained through the pulverization step through a mesh having an opening having a diameter of 0.5 mm or more and 3 mm or less. The machine is a crusher that crushes a rotary shaft with a plurality of rotary blades and a fixed blade fixed to the crusher body, and the rotary blades are arranged at intervals in the rotary axis direction and are adjacent to each other in the rotary axis direction. A method for producing a raw material for a structure for producing a casting, wherein a gap is provided between rotary blades.
<34>
In the rotary crusher used in the crushing step, the interval between the rotary blades adjacent in the rotation axis direction is preferably 0.5 times or more and 5 times or less, and 0.8 times or more 2 times the blade width. The blade width is more preferably double or less, the width of the blade is preferably 1 mm or more and 100 mm or less, more preferably 10 mm or more and 50 mm or less, and the clearance between the blade and the fixed blade is 0.01 mm or more and 10 mm or less. Is preferable, and more preferably 0.05 mm or more and 5 mm or less. The method for producing a raw material for a structure for producing a casting according to <33> above.
<35>
The method for producing a raw material for a casting manufacturing structure according to <33> or <34>, which includes a compression step of compressing the recovered waste material of the casting manufacturing structure as a pre-step of the crushing step.
<36>
The method for producing a raw material for a structure for casting production according to any one of <33> to <35>, further including a sorting step of sorting the crushed material collected in the collecting step according to its fiber length.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited to the embodiments.

[Example 1]
<Preparation of raw materials>
(1) Blending of virgin raw material Organic fiber: Newspaper waste paper 26% by mass
Inorganic fiber: Carbon fiber (“NPS chopped fiber” manufactured by Nippon Polymer Sangyo Co., Ltd.) 8% by mass
Inorganic particles: Obsidian ("Nice Catch Flower #330" manufactured by Kinsei Matec Co., Ltd.) 48% by mass
Thermosetting resin: Phenolic resin (“Bellpearl (registered trademark) S-890” manufactured by Air Water Bell Pearl Co., Ltd.) 18% by mass
(2) As the recycled raw material, when manufacturing a structure for casting production with the virgin raw material of the above (1), mill ends and cutting scraps obtained in the cutting step, and excess and deficient mass products and inspection obtained in the inspection step A rejected product was used. Then, they were charged into the charging port 4 of the crusher 1 shown in FIGS. 1 and 2 and crushed. The ratio D/d of the distance D between the rotary blades 2 and 2 adjacent to each other in the direction of the rotary axis and the width d of the blade 22 was 1. Then, the pulverized product was recovered through a mesh having an opening with a diameter of 0.5 mm to obtain a recycled raw material.
The blending ratio of the obtained recycled raw material was as follows.
Total of organic fibers and thermosetting resin: 43.0% by mass
Inorganic fiber: 9.2 mass%
Inorganic particles: 47.8 mass%
Frequency distribution of recycled fiber length:
Fibers in the range of 0.3 mm to less than 5.0 mm: 71.6%
Fibers less than 0.3 mm: 28.4%
<Preparation of raw material slurry>
The above-mentioned virgin raw material (90% by mass) and the above-mentioned regenerated raw material (10% by mass) were mixed to prepare a raw material slurry which was dispersed in water at a ratio of 3% by mass.

<Paper forming of structure for casting production>
The papermaking mold is a pair of split molds having a cavity forming surface corresponding to φ50×350 mm, and a net having a predetermined opening is arranged on the cavity forming surface, and a large number of communication holes for communicating the cavity forming surface with the outside. Was used. Then, the raw material slurry was circulated by a mohno pump to inject a predetermined amount of the slurry into the papermaking mold under pressure and drained through the communication hole to deposit a predetermined fiber laminate on the surface of the net. After the injection of a predetermined amount of the raw material slurry was completed, 0.2 MPa of pressurized air was supplied into the papermaking mold in which the fiber laminate was deposited for about 30 seconds to dehydrate the fiber laminate. The fiber laminate obtained was taken out of the papermaking mold and transferred to a drying mold heated to 220°C. As the drying mold, a pair of split molds having a cavity forming surface corresponding to φ50×350 mm, in which a large number of communicating holes for communicating the cavity forming surface with the outside were used. In the dry molding step, a bag-shaped elastic core is inserted from the upper opening of the dry mold, and a pressurized fluid (compressed air, 0.2 MPa) is supplied into the elastic core in the closed dry mold. Then, the elastic core was inflated. Then, the fiber laminate was pressed against the inner surface of the dry mold to dry the fiber laminate while transferring the inner surface shape of the dry mold. After performing pressure drying for a predetermined time (90 seconds), the pressurized fluid in the elastic core was drained to shrink the elastic core, and the elastic core was retracted from the drying mold. Then, the obtained molded body was taken out from the drying mold, cooled, and the end portion was cut in a cutting step to obtain a structure for casting production of Example 1.

[Example 2]
<Preparation of raw materials>
(3) Blending of virgin raw material Organic fiber: Newspaper waste paper 26% by mass
Inorganic fiber: Carbon fiber ("Pyrofil (registered trademark) chopped fiber TCTR03245E" manufactured by Mitsubishi Rayon Co., Ltd.) 4% by mass
Inorganic particles: Obsidian (Kinsei Matech Co., Ltd. "Nice Catch Flower #330") 52% by mass
Thermosetting resin: Phenol resin (“Bellpearl S-890” manufactured by Air Water Bell Pearl Co., Ltd.) 18% by mass
(4) As the recycled raw material, when the structure for casting production is manufactured using the virgin raw material of the above (3), mill ends and cutting scraps obtained in the cutting step, and excess and deficient products and inspection obtained in the inspection step A rejected product was used. Then, they were crushed by charging them into the charging port 4 of the crusher 1 shown in FIGS. The ratio D/d of the distance D between the rotary blades 2 and 2 adjacent to each other in the rotation axis direction and the width d of the blade 22 was 1. Then, the pulverized material was collected through a mesh having openings having a diameter of 0.5 mm to obtain a regenerated raw material.
The blending ratio of the obtained recycled raw material was as follows.
Total of organic fibers and thermosetting resin: 45.9% by mass
Inorganic fiber: 3.1 mass%
Inorganic particles: 51.0% by mass
Frequency distribution of recycled fiber length:
Fibers in the range of 0.3 mm to less than 5.0 mm: 63.9%
Fibers less than 0.3 mm: 36.1%
<Preparation of raw material slurry>
The virgin raw material (90% by mass) described above and the regenerated raw material (10% by mass) described above were mixed to prepare a raw material slurry in which the raw material slurry was dispersed in water at a ratio of 3% by mass.
A casting manufacturing structure of Example 2 was obtained using the same papermaking mold and drying mold as the manufacturing method of the casting manufacturing structure of Example 1 except that the above-described raw slurry was used as the raw material slurry.

[Example 3]
The same virgin raw material as in Example 1 was used as the virgin raw material. The ratio D/d of the distance D between the adjacent rotary blades 2 and 2 of the crusher 1 for crushing the recycled material and the width d of the blade 22 was 1. Then, the pulverized material was collected through a mesh having an opening with a diameter of 1.0 mm to obtain a regenerated raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 77.5%
Fibers less than 0.3 mm: 22.3%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing the casting manufacturing structure of Example 1, and the same papermaking mold and drying mold as those in the method for manufacturing the casting manufacturing structure in Example 1 were used. The structure for casting production of Example 3 was obtained.

[Example 4]
The same virgin raw material as in Example 2 was used as the virgin raw material. The ratio D/d of the distance D between the adjacent rotary blades 2 and 2 of the crusher 1 for crushing the recycled material and the width d of the blade 22 was 1. Then, the pulverized material was collected through a mesh having an opening with a diameter of 1.0 mm to obtain a regenerated raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 68.4%
Fibers less than 0.3 mm: 31.6%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing the casting manufacturing structure of Example 1, and the same papermaking mold and drying mold as those in the method for manufacturing the casting manufacturing structure in Example 1 were used. The structure for casting production of Example 4 was obtained.

[Example 5]
The same virgin raw material as in Example 1 was used as the virgin raw material. The ratio D/d of the distance D between the adjacent rotary blades 2 and 2 of the crusher 1 for crushing the recycled material and the width d of the blade 22 was 1. Then, the pulverized material was collected through a mesh having an opening with a diameter of 2.0 mm to obtain a recycled raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 80.5%
Fibers less than 0.3 mm: 19.4%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing the casting manufacturing structure of Example 1, and the same papermaking mold and drying mold as those in the method for manufacturing the casting manufacturing structure in Example 1 were used. The structure for casting production of Example 5 was obtained.

[Example 6]
The same virgin raw material as in Example 2 was used as the virgin raw material. The ratio D/d of the distance D between the adjacent rotary blades 2 and 2 of the crusher 1 for crushing the recycled material and the width d of the blade 22 was 1. Then, the pulverized material was collected through a mesh having an opening with a diameter of 2.0 mm to obtain a recycled raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 76.3%
Fibers less than 0.3 mm: 23.7%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing the casting manufacturing structure of Example 1, and the same papermaking mold and drying mold were used as in the method for manufacturing the casting manufacturing structure in Example 1, The structure for casting production of Example 6 was obtained.

[Example 7]
The same virgin raw material as in Example 1 was used as the virgin raw material. The regenerated raw material obtained in Example 3 was used as the regenerated raw material.
The above-mentioned virgin raw material (97 mass %) and the above-mentioned regenerated raw material (3 mass %) were mixed to prepare a raw material slurry in which the raw material slurry was dispersed in water at a ratio of 3 mass %.
A casting manufacturing structure of Example 7 was obtained using the same papermaking mold and drying mold as the manufacturing method of the casting manufacturing structure of Example 1 except that the above-mentioned raw material slurry was used as the raw material slurry.

[Example 8]
The same virgin raw material as in Example 1 was used as the virgin raw material. The regenerated raw material obtained in Example 3 was used as the regenerated raw material.
The above-mentioned virgin raw material (85 mass %) and the above-mentioned regenerated raw material (15 mass %) were mixed to prepare a raw material slurry in which the raw material slurry was dispersed in water at a ratio of 3 mass %.
A casting manufacturing structure of Example 8 was obtained by using the same papermaking mold and drying mold as in the manufacturing method of the casting manufacturing structure of Example 1 as the raw slurry except that the above-mentioned raw slurry was used.

[Reference Example 1]
A raw material slurry was prepared using only the same virgin raw material as in Example 1, and the structure for casting production of Reference Example 1 was prepared using the same papermaking mold and drying mold as in the method for producing the structure for casting production of Example 1. Obtained.

[Reference Example 2]
A raw material slurry was prepared by using only the same virgin raw material as in Example 2, and the structure for casting production of Reference Example 2 was prepared using the same papermaking mold and drying mold as in the method for producing the structure for casting production of Example 1. Obtained.

[Comparative Example 1]
The same virgin raw material as in Example 1 was used as the virgin raw material. The regenerated raw material obtained in Example 3 was used as the regenerated raw material.
The above-mentioned virgin raw material (80% by mass) and the above-mentioned regenerated raw material (20% by mass) were mixed to prepare a raw material slurry in which the raw material slurry was dispersed in water at a ratio of 3% by mass.
As the raw material slurry, except that the raw material slurry was changed to the above-mentioned raw material slurry, the same papermaking mold and drying mold as in the method for producing the casting manufacturing structure of Example 1 were used to obtain a casting manufacturing structure of Comparative Example 1.

[Comparative Example 2]
The same virgin raw material as in Example 1 was used as the virgin raw material. As a crusher for crushing the recycled raw material, a uniaxial rotary crusher having no space between adjacent rotary blades was used. Then, the pulverized material was collected through a mesh having an opening with a diameter of 1.0 mm to obtain a regenerated raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 53.1%
Fibers less than 0.3 mm: 46.9%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing a structure for casting production of Example 1, and the same papermaking mold and drying mold as those in the method for manufacturing a structure for casting production in Example 1 were used for comparison. The structure for casting production of Example 2 was obtained.

[Comparative Example 3]
The same virgin raw material as in Example 1 was used as the virgin raw material. As a crusher for crushing the recycled raw material, a uniaxial rotary crusher having no space between adjacent rotary blades was used. Then, the pulverized material was recovered through a mesh having an opening with a diameter of 5.0 mm to obtain a recycled raw material. The frequency distribution of the fiber length of the obtained recycled raw material was as follows.
Fibers in the range of 0.3 mm to less than 5.0 mm: 59.3%
Fibers less than 0.3 mm: 40.7%
After that, a raw material slurry was prepared in the same manner as in the method for manufacturing a structure for casting production of Example 1, and the same papermaking mold and drying mold as those in the method for manufacturing a structure for casting production in Example 1 were used for comparison. The structure for casting production of Example 3 was obtained.

[Evaluation]
Regarding the casting production structures of Examples 1 to 8, the casting production structures of Reference Examples 1 and 2 and the casting production structures of Comparative Examples 1 to 3, for casting production, which is a defective phenomenon The presence or absence of protrusions on the inner surface of the structure was visually evaluated. In addition, the compressive strength was evaluated by the method described above (see FIG. 3). The results are shown in Table 1 below.

According to the results of Table 1, the casting-manufacturing structures of Examples 1 to 8 are similar to the casting-manufacturing structures of Reference Examples 1 and 2 and have projections on the inner surface of the casting-manufacturing structure. No occurrence can be confirmed, the appearance is good, and there is no influence when fitting the casting manufacturing structure. Moreover, the structures for casting production of Examples 1 to 8 are about the same degree as the structures for casting production of Reference Examples 1 and 2 as compared with the structures for casting production of Comparative Examples 1 to 3 The compressive strength of is obtained. Therefore, the casting-manufacturing structures of Examples 1 to 8 obtained by using the recycled material can be sufficiently used as a product.

1 crusher 10 crusher main body 2 rotary blade 21 rotor 22 blade 3 fixed blade 4 input port 100 casting manufacturing structure 101 compression terminal

Claims (3)

A crushing step of dry crushing the recovered waste material of the casting manufacturing structure using a rotary crusher,
The pulverized product obtained in the pulverizing step is recovered through a mesh having openings having a diameter of 0.5 mm or more and 3 mm or less, and is composed of only organic fibers, thermosetting resin, inorganic fibers and inorganic particles, and organic fibers and thermosetting Content of the organic resin is 15% by mass or more and 78% by mass or less, the content of inorganic fibers is 2% by mass or more and 50% by mass or less, the content of inorganic particles is 20% by mass or more and 60% by mass or less, and the organic fibers are And in the frequency distribution of the fiber length of the fibers in which the inorganic fibers are mixed , the fibers in the range of the fiber length of 0.3 mm or more and less than 5.0 mm occupy 60% or more and 85% or less of the whole, and the fiber length of less than 0.3 mm A recovery step for obtaining a recycled raw material in which the range of fibers accounts for 15% or more and 40% or less of the whole;
The regenerated raw material and the virgin raw material are more than 0 mass% and 16.0 mass% or less, and the virgin raw material is 84 mass% or more and less than 100 mass% with respect to the total of both. And a step of mixing,
The rotary crusher used in the crushing step is a crusher that crushes a rotary shaft with a plurality of rotary blades and a fixed blade fixed to the main body of the crusher, and the rotary blades are arranged at intervals in the rotary shaft direction. And, a gap is provided between the rotating blades that are adjacent to each other in the direction of the rotation axis,
The virgin raw material is composed of only organic fibers, thermosetting resins, inorganic fibers and inorganic particles, the content of organic fibers is 10% by mass or more and 50% by mass or less, and the content of inorganic fibers is 2% by mass or more and 50% by mass. In the following, the content of the inorganic particles is 20% by mass or more and 60% by mass or less, the content of the thermosetting resin is 5% by mass or more and 50% by mass or less, and the fiber length of the fibers in which the organic fibers and the inorganic fibers are mixed In the frequency distribution, fibers having a fiber length of 0.3 mm or more and less than 5.0 mm account for 80% or more and less than 100% of the whole, and fibers having a fiber length of less than 0.3 mm have a fiber length of more than 0% and 20%. A method for producing a raw material for a structure for producing a casting, which comprises: The method for producing a raw material for a casting manufacturing structure according to claim 1 , further comprising a compression step of compressing the recovered waste material of the casting manufacturing structure as a pre-process of the crushing process. The method for producing a raw material for a casting manufacturing structure according to claim 1 or 2 , further comprising a sorting step of sorting the crushed material collected in the collecting step according to a fiber length of a fiber in which organic fibers and inorganic fibers are mixed. ..

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