JPS60186453A - Manufacture of ceramic fiber sleeve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a ceramic fiber sleeve comprising a combination of ceramic W4 fibers, an inorganic filler, an inorganic binder, and a forming aid, and more specifically, Water is added to an inorganic binder and a molding aid and kneaded, which is then continuously formed into a hollow pipe using an extrusion molding machine with a circular nozzle at the tip with circular balls arranged concentrically, and then dried. The present invention relates to a method for manufacturing a ceramic fiber sleeve having characteristics.

Ceramic fiber sleeves are widely used in casting feeder combustion tubes, high-temperature duct linings, thermocouple protection tubes, etc., and are mainly used for insulation purposes. However, in recent years, 151 high-density products (0.6 to 0.9 f
/d) is becoming required. My sister told me that in the steel industry, high-density ceramic fiber sleeves (0,6 ~0.9) is required. When used as a protective sleeve for the sensor sleeve, strength and penetration resistance are required due to the harsh conditions of use, and since the sensor sleeve is set inside the ceramic fiber mW sleeve, a highly accurate one is required. requested.

Incidentally, as a conventional method for manufacturing ceramic fibrous sleeves, a mold suction dehydration molding method is mainly used. This manufacturing method is used not only for sleeve-shaped molded products but also for most of the generally known ceramic fibrous molded products. In the above manufacturing method, a mixture of ceramic fibers, organic and inorganic binders, etc. is made into a slurry solution of about 0.5 to 3%, stirred uniformly in a vat with a constant volume, and a mold directly connected to a vacuum pump is placed in the slurry solution. After the mixture is adsorbed onto the surface of the mold to a certain thickness, the mold is removed and dehydrated, followed by release and drying.

However, in the above manufacturing method, the adhesion of inorganic and organic binders is poor (and it is difficult to internally add inorganic fillers, so
The bulk density of the molded product molded by the above manufacturing method is 0.4 g/d
There is a limit to the degree of oxidation, and the strength of the molded product is also low.

If high bulk density and high strength are required, a method of forming the product using the above manufacturing method, drying it once, then impregnating it with an inorganic or organic binder solution (for example, silica sol, alumina sol, etc.) and drying it again is recommended. I'm taking it.

However, these manufacturing methods are said to have very low productivity because continuous production is not possible and labor is required, and the yield of binders and the like is also poor. In addition, in terms of quality, since the method involves depositing ceramic m-fibers on the surface of the mold, the dimensional accuracy of the molded product is poor, and there are many drawbacks such as uneven impregnation of the binder or uneven density.

Therefore, in the present invention, in order to eliminate these drawbacks all at once, water is added to ceramic fibers, an inorganic filler, an inorganic binder, and a forming aid, and then they are kneaded, and then a circular ball is formed with circular beads arranged concentrically. The object of the present invention is to provide a method for manufacturing a safe mink fibrous sleeve, which is characterized in that it is continuously formed into a hollow pipe using an extrusion molding machine having a nozzle at its tip and dried. That is, the ceramic fiber is 70 to 90% by weight, and the total solid content of the inorganic filler and inorganic binder is 5% by weight.
Water is added and kneaded so that the total water content is 70 to 130 parts by weight to 100 parts by weight of a blended composition consisting of ~25% by weight and a molding aid of 0.5 to 10% by weight as a solid content. Then, a hollow pipe is continuously formed using an extrusion molding machine having a circular nozzle at the tip with circular balls arranged concentrically, and dried. Also, the circular nozzle V at the tip of the extrusion molding machine
A far-infrared heater is installed at the outlet to continuously dry the surface layer of the hollow pipe extruded from the extruder, and then perform main drying.

The ceramic fibrous sleeve thus obtained is
Ceramic fiber 70-90% by weight, inorganic filler and inorganic binder total 5-25% by weight, molding aid 0.5-10%
% by weight, the ceramic fibers are partially defibrated and uniformly dispersed in the refractory composition mainly composed of the inorganic filler and the inorganic binder, and the remainder is granular. The granules have a diameter of 5 ff or less, and have a structure in which the granules are covered with a refractory composition in which a portion of the ceramic fibers are uniformly dispersed, and the bulk density thereof is 0.6 to 0.9.
It is 9M.

The ceramic fibrous sleeve according to the present invention has extremely good dimensional accuracy compared to the ceramic fibrous sleeve obtained by conventional methods because it is formed by regulating the inside and outside of the sleeve with a mold. Since it has the above-mentioned structure, it has a high bulk density, and has extremely excellent strength and corrosion resistance.

Furthermore, in terms of productivity, the yield of materials is improved, and process automation becomes possible, resulting in a significant improvement in productivity.

Next, a method for manufacturing a ceramic fibrous sleeve according to the present invention will be specifically explained.

The ceramic fiber used in the present invention is alumina fiber.
Although it is mainly composed of silica-based ceramic fibers, some of it may be replaced with crystalline alumina fibers, crystalline mullite fibers, and various other types of highly heat-resistant ceramic fibers.

As the inorganic filler used in the present invention, powders of AIV mina, mullite, and chamotte are particularly effective.Other examples include generally known refractory fillers such as zirconia, chromium oxide, fugilite, silicon carbide, magnesia, and silica. Powders of the materials can also be used, and any one type or two or more types selected from these can be used.

The inorganic binders used in the present invention are particularly effective, such as alumina sol, silica sol, and clay. In addition, generally known inorganic binders such as monoammonium phosphate, basic aluminum lactate, and aluminum hydroxychloride can also be used. , one kind or two or more kinds selected from these can be used.

The molding aids used in the present invention are particularly effective, such as methyl cellulose, boxymethine cellulose, and polymacrylamide; polyvinyl alcohol.

Polyethylene oxide, sodium alginate.

Ammonium alginate, vinyl acetate, gelatin.

Natural resins, synthetic resins, stearic acid, and other commonly known thickeners, lubricants, plasticizers, and other molding aids can also be used.
Any one type or two or more types selected from these can be used.

The above-mentioned ceramic fibers are cut into chips of 10 mm or less using a cutter mill, a feather mill, etc., which is a type of crusher, a shear mill, a roll crusher, etc., and are processed into chips of 10 mm or less, if necessary. A total of 5 to 25% by weight (solid content) of 7090% by weight of granules granulated using a transfer granulator such as a pan type, drum type, vibrating conveyor type, or horizontal vibrating plate, and an inorganic filler and an inorganic binder. The total water content is 70 to 13 parts per 100 parts by weight of a compounded composition consisting of 0.5 to 10% (solid content equivalent) of a molding aid (converted) and a molding aid.
A predetermined amount of water is added to make the composition 0 parts by weight, and the composition is uniformly kneaded using a mixer such as a mortar mixer or a kneader to obtain a plastic composition.Then, the composition is concentrically arranged with circular medium beads. A hollow pipe is continuously formed using an extrusion molding machine having a circular nozzle M at the tip, and dried using a commonly known dryer such as an electric heat dryer, a microwave dryer, or a kerosene burning dryer.

In addition, bulk ceramic fibers, inorganic fillers, inorganic binders, forming aids, and water are blended within the above-mentioned ratios to produce kneaders, paddle mixers, cutter mixers, all-purpose mixers, etc. The bulk ceramic fibers are chipped or granulated using a blade-type mixer and simultaneously kneaded uniformly to form a plastic composition, which is then formed into a hollow pipe using an extruder as described above (9) and dried. Plastic compositions made by simply mixing ceramic fibers, inorganic fillers, inorganic binders, molding aids, and water generally have better uniformity and fluidity than compositions mainly composed of ceramic powders that are subjected to extrusion molding. Due to the lack of flexibility, when continuously extruding hollow pipes using an extrusion molding machine, the hollow pipes tend to be bent.

By uniformly dispersing a portion of the ceramic fibers in a defibrated state in a composition consisting of an inorganic filler, an inorganic binder, a forming aid, and water, the fluidity and shape retention of the composition are improved. Therefore, bending of the hollow pipe during extrusion molding can be prevented. In addition, most of the ceramic fibers tlO
Ar or less, preferably Fi5fi or less, a part of the above-mentioned ceramic fiber is uniformly dispersed in a composition consisting of an inorganic filler, an inorganic binder, a forming aid, and water, which are uniformly dispersed. Since the overall fluidity is further improved, it is suitable for preventing bending of hollow pipes during molding.

(10) The blending ratio of ceramic fiber is 70 to 900 to 90% by weight.
The reason for this limitation is that if the amount is less than 70I, the bulk density of the ceramic fiber sleeve will be too high, and the original purpose of adding aged ramic fibers, which is to reduce the weight and heat insulation of the sleeve, will not be sufficient. If the amount of the inorganic filler and inorganic binder is exceeded, the amount of inorganic filler and inorganic binder will be relatively small, and the fluidity and shape retention of the mixed wire composition used for molding will decrease, making it difficult to extrude the hollow pipe continuously during molding, and making it difficult to extrude the sleeve. This is because the strength and corrosion resistance of the steel will not be sufficient.

The reason why the blending ratio of the inorganic filler and the inorganic binder is limited to a range of 5 to 25% by weight in terms of solid content is that if it is less than 5% by weight, the fluidity and shape retention of the mixed wire composition used for molding will decrease. It is difficult to extrude the hollow pipe continuously during molding, and the strength and corrosion resistance of the sleeve are insufficient. On the other hand, if it exceeds 25% by weight, the amount of ceramic fiber blended is relatively too small, making it difficult to reduce the weight and heat insulation of the sleeve. Because it's not enough.

The blending ratio of the molding aid is 0.5 to IO weight% in terms of solid content.
The reason for limiting it to the range is that if it is less than 0.5% by weight (11), the original purpose of adding the molding aid, such as the plasticity, shape retention, and lubricity of the mixed wire composition used for molding, will not be sufficiently achieved. If the amount exceeds -10 M%, problems such as smoke generation or scattering of molten iron will occur when the sleeve is used.

The reason why the amount of water in the plastic composition consisting of ceramic fibers, inorganic filler, inorganic binder, molding aid, and water is limited to 70 to 130% by weight based on 100 parts by weight of solid content is as follows: If it is less than 70% by weight, the fluidity of the mixed wire composition used for molding will decrease, making it difficult to continuously extrude hollow pipes during molding, while if it exceeds 130% by weight, the shape retention of the mixed wire composition used for molding will deteriorate. This is because it becomes difficult to extrude the hollow pipe continuously during molding, and only water is squeezed out from the circular nozzle outlet of the molding machine.

As mentioned above, a plastic composition obtained by blending and kneading ceramic fibers, an inorganic filler, an inorganic binder, a forming aid, and water within a predetermined range is continuously molded into a hollow pipe using an extrusion molding machine (12). When extruding, a far-infrared heater is provided at the exit of the circular nozzle at the tip of the extrusion molding machine to continuously dry the surface layer of the hollow pipe extruded from the molding machine, which improves the strength of the hollow pipe. However, this is preferable because it prevents deformation when the hollow pipe is transported to the main drying stage.

Next, examples of the method for manufacturing a ceramic fibrous sleeve according to the present invention will be described with reference to comparative examples.

Example 1 Alumina-silica fibers were cut into chips with a size of 10 or less using a cutter mill.
Silica-based mtta, crystalline alumina fiber, inorganic filler, inorganic binder, forming aid, and water were mixed as shown in A, B, and C in Table 1 and kneaded using a mortar mixer. next,
Inside the circular nozzle with an inner diameter of 61 wg, an outer diameter of 50 wg is placed concentrically.
It was continuously extruded into a hollow pipe shape using an extrusion molding machine having an extrusion port equipped with circular medium balls of MM, cut into a length of 300 ffjll, and then dried using an electric heat dryer. Thus obtained (13) Outer diameter 601Eml, m, Inner diameter 50 mm, Length 30
The quality of the ceramic fibrous sleeves with zero resistance is shown in Table 1, corresponding to formulations A, B, and C.

Example 2 Alumina-silica W4 fibers, an inorganic filler, an inorganic binder, a molding aid, and water were mixed as shown in Table 1 and E, and kneaded in a kneader. Next, it is continuously extruded into a hollow pipe shape using an extrusion molding machine having an extrusion outlet in which a circular medium ball with an outer diameter of 5 (lx) is arranged concentrically inside a circular nozzle with an inner diameter of 81 jff. A far-infrared heater was provided nearby to continuously dry the surface layer of the hollow pipe, and then it was cut into a length of 3001f!1, and then dried in a microwave dryer.The outer diameter thus obtained was 6Qwmp
(Table 1 shows eight ceramic fiber guest sleeves with inner diameters of 59 mm and 59 mm and length of 300 mm, corresponding to formulations C, D, and E.

Comparative Example Alumina, silica fibers, an inorganic binder, a forming aid, and water were mixed as shown in F, G, and H in Table 2 (14), defibrated with a pulper to form a slurry, and added to the slurry wobatt. A suction mold with an outer diameter of 5,000 mm connected to a vacuum pump was put into the mold, and the material was adsorbed and deposited on its surface, and then the mold was taken out, dehydrated, released from the mold, and dried. Thus obtained outer diameter 60M110, inner diameter 50
Table 2 shows the quality of ceramic fiber sleeves with a length of 300 mm, corresponding to the formulations G, 1 (, ■).

(15) Table 1 (16) Table 2 As shown above, according to the present invention, a plastic composition consisting of ceramic fibers, an inorganic filler, an inorganic binder, a molding aid, and water is molded using an extrusion molding machine. By continuously extruding it as a hollow pipe and then drying it, a ceramic fibrous sleeve with very good dimensional accuracy, high bulk density, and extremely excellent strength and corrosion resistance can be manufactured with high productivity.

(17) Procedural amendment (voluntary) May 28, 1985 1, Case description 1989 Patent Application No. 089968 2, Title of invention Method for manufacturing ceramic fibrous sleeve 8, Person making the amendment Relationship: Applicant's residence Address: 2-1-4 Kanda-cho, Ogaki-shi, Gifu 508
Subject of amendment (1) Entire specification 5, Contents of amendment As per the attached amended specification - 1 piece\, 't) (60゜ square dimension /T?X 41 Amended specification 1, Title of invention Ceramic fibrous sleeve Manufacturing method 2, claims (1) The ceramic fiber is 70 to 90% by weight, the total of the inorganic filler and the inorganic binder is 5 to 25% by weight as a solid content, and the forming aid is 0.5% as a solid content. For 100 parts by weight of a blended composition consisting of ~10% by weight, the total moisture content is 7% by weight.
Water is added and kneaded so that the amount is 0 to 180 parts by weight, and then a hollow pipe is continuously formed using an extrusion molding machine having a nozzle /l/ with circular balls arranged concentrically at the tip, and dried. A method for manufacturing a ceramic fibrous sleeve, characterized by:

(2) A far-infrared heater is installed at the exit of the circular nozzle,
2. The manufacturing method according to claim 1, wherein the surface layer portion of the hollow pipe extruded from the extrusion molding machine is continuously dried and then main drying is performed.

(3) The manufacturing method according to claim 1 or 2, wherein the inorganic filler is one or more selected from powders of alumina, mullite, and cypress powder.

(4) The manufacturing method according to claims 1 to 8, wherein the inorganic binder is one or more selected from alumina sol, silica sol, and clay.

(5) The manufacturing method according to claims 1 to 4, wherein the molding aid is one or more selected from methylcellulose, carboxymethylcellulose, and polyacrylamide.

8. Detailed Description of the Invention The present invention relates to a method for producing a ceramic fibrous sleeve comprising a combination of ceramic fibers, an inorganic filler, an inorganic binder, and a forming aid, and more specifically, Water is added to the binder and molding aid and kneaded, which is then continuously formed into a hollow pipe using an extrusion molding machine with a circular nozzle /l/ with concentric circular balls arranged at the tip, and then dried. Ceramic l characterized by
This invention relates to a method for manufacturing a fibrous sleeve.

Ceramic fibrous sleeves are used for casting riser cylinders, combustion pipes,
It is widely used as linings for high-temperature ducts and protective tubes for thermocouples, and is primarily used for insulation purposes.

However, in recent years, high-density products (0.6 to 0.9 f/
cJ) is becoming increasingly required. In particular, in the steel industry, high-density products made of ceramic fiber sleeves (0
, 6 to 0.9) is required. When used as a protective sleeve for a sensor, strength and penetration resistance are required due to the harsh conditions of use, and since the sensor is set inside the ceramic fiber sleeve, high precision is required. ing.

Incidentally, as a conventional method for manufacturing ceramic fibrous sleeves, a mold suction dehydration molding method is mainly used. This manufacturing method is used not only for sleeve-shaped molded products but also for most of the generally known ceramic fibrous molded products. In the above manufacturing method, a slurry solution containing a mixture of ceramic fibers, organic and inorganic binders, etc. with a total concentration of about 0.5 to 8% is made, stirred uniformly in a vat of a fixed volume, and a mold directly connected to a vacuum pump is placed into the slurry solution. After the mixture has been adsorbed onto the surface of the mold to a certain thickness, the mold is removed and dehydrated, followed by release and drying.

However, in the above manufacturing method, the adhesion of inorganic and organic binders is poor, and it is difficult to internally add inorganic fillers.
The bulk density of the molded product molded by the above manufacturing method is 0.49/l
The limit is about 21 degrees, and the strength of the molded product is also low. When high bulk density and high strength are required, a method of forming the molded material using the above manufacturing method, drying it once, then completely impregnating it with an inorganic or organic binder solution (for example, silica P, alumina sol, etc.) and drying it again is recommended. I'm taking it. However, in these manufacturing methods, continuous production is impossible and labor is required, and the yield of the binder and the like is also poor, resulting in extremely low productivity. In addition, in terms of quality, the dimensional accuracy of the molded product is poor because the method involves depositing ceramic fibers on the mold surface.
There were many drawbacks such as uneven binder impregnation or density unevenness.

Therefore, in order to eliminate these drawbacks all at once, the present invention has been developed by adding water to ceramic fibers, an inorganic filler, an inorganic binder, and a forming aid, kneading them, and then forming a circular ball with concentrically arranged circular beads. It is an object of the present invention to provide a method for producing a ceramic fibrous sleeve, which is characterized in that it is continuously formed into a hollow pipe using an extrusion molding machine having a nozzle at its tip and dried. That is, 70 to 90% by weight of ceramic fibers
, the total of inorganic filler and inorganic binder is 5 to 5 as solid content.
25% by weight, molding aid 0.5-10 as solid content] (
Water f is added and kneaded so that the total water content becomes 70 to 180 parts by weight to 100 parts by weight of the blended composition consisting of A hollow pipe is continuously formed using an extrusion molding machine in the department and dried. Furthermore, a far-infrared heater is disposed at the exit of the circular nozzle at the tip of the extrusion molding machine, and the surface layer of the hollow pipe extruded from the extrusion molding machine is continuously dried, and then main drying is performed.

The ceramic fibrous sleeve thus obtained is
Ceramic fiber M 70-90% by weight, total of inorganic filler and inorganic binder 5-25% by weight, molding aid 0.5-1
The ceramic fibers are partially defibrated and uniformly dispersed in the refractory composition mainly composed of the inorganic filler and the inorganic binder, and the remainder is It is a granular material with a particle size of 5 or less, and has a structure in which the granular material is covered with a refractory composition in which a part of the ceramic fibers are uniformly dispersed, and its bulk density is 0.6 to 0.9.
It is.

The ceramic fibrous sleeve according to the present invention has extremely high dimensional accuracy compared to ceramic fibrous sleeves obtained by conventional methods because it is formed by regulating the inside and outside of the sleeve with a mold. Because of its structure, it has a high bulk density, and has extremely excellent strength and corrosion resistance.

Furthermore, in terms of productivity, the yield of materials is improved, and process automation becomes possible, resulting in a significant improvement in productivity.

Next, a method for manufacturing the ceramic LLR fibrous sleeve according to the present invention will be specifically explained.

The ceramic fiber used in the present invention is alumina fiber.
Although silica-based ceramic fibers are used as the main material, some of them can be replaced with crystalline alumina fibers, crystalline mullite fibers, and various other types of highly heat-resistant ceramic fibers.

As the inorganic filler used in the present invention, powders of alumina, mullite, and chamotte are particularly effective, and in addition, commonly known refractory materials such as zirconia, chromium oxide, kojitite, silicon carbide, magneur, and silica are effective. Powders can also be used, and any one selected from these can be used.
A species, or two or more species, can be used.

As the inorganic binder used in the present invention, alumina sol, silica sol, and clay are particularly effective, and in addition, generally known inorganic binders such as monoammonium phosphate, basic aluminum lactate, and aluminum hydroxychloride may also be used. Any one selected from these that can be used
A species, or two or more species, can be used.

Particularly effective molding aids used in the present invention include methylcellulose, carboxymethylcellulose, and polyacrylamide.Other examples include hydroxyethylcellulose, starch, gum arabic, wax emulsion, lignin, dextrin, polyvinyl, polyvinyl alcohol, and polyethylene oxide. , sodium alginate, ammonium alginate, vinyl acetate, gelatin, natural resins, synthetic resins, stearic acid, etc. Generally known thickeners, lubricants, plasticizers, and other molding aids can also be used, and the molding aids selected from these can be used. Any one type or two or more types can be used.

The ceramic fibers mentioned above are cut into chips of 10 mm or less in size using a cutter mill, a feather mill, etc., which is a type of crusher, a shear mill, or a roll crusher, etc., and if necessary, they are processed using a granulator. A total of 70 to 90% by weight of granules granulated using a transfer granulator such as a pan type, drum type, vibrating conveyor type, or horizontal vibrating plate, and a total of 5 to 25N amount of inorganic filler and inorganic binder ( 100ij of a blended composition consisting of 0.5% to 10% (in terms of solids content) of a forming aid (in terms of solid content) [total water content per part of 70 to 1%]
A predetermined amount of water is added to a heavy sea urchin and kneaded uniformly with a kneader such as a mortar mixer or kneader to obtain a plastic composition (2. Next, the composition is concentrically mixed into a circular mold. It is continuously formed into a hollow pipe using an extrusion molding machine having a circular nozzle with a ball at its tip, and then dried using a commonly known dryer such as an electric dryer, a microwave dryer, or a kerosene-burning dryer.

Additionally, bulk ceramic fibers, inorganic fillers, inorganic binders, forming aids, and water can be blended within the above-mentioned ratios to produce kneaders, paddle mixers, cutter mixers, all-purpose mixers, etc. The bulk ceramic fibers are chipped or granulated into pieces with a size of 10 mm or less using a blade-type mixing machine, and at the same time kneaded uniformly to form a plastic composition. Eve and pear dry. Plastic compositions made by simply mixing ceramic fibers, inorganic fillers, inorganic binders, molding aids, and water generally have better uniformity and fluidity than compositions mainly composed of ceramic powders that are subjected to extrusion molding. Due to the lack of flexibility, when continuously extruding hollow pipes using an extrusion molding machine, the hollow pipes tend to be bent.

By uniformly dispersing a portion of the ceramic fibers in a defibrated state in a composition consisting of an inorganic filler, an inorganic binder, a forming aid, and water, the fluidity and shape retention of the composition are improved. This prevents the hollow pipe from bending during extrusion molding. In addition, the remainder of the ceramic fibers are made into granules with a size of 1Qjlffi or less, preferably 5+u+ or less, and are made of an inorganic filler, an inorganic binder, a forming aid, and water in which a portion of the ceramic fibers described above are uniformly dispersed. Uniform dispersion in the composition further improves the overall fluidity, which is suitable for preventing hollow pipes from bending during molding.

The reason why the blending ratio of ceramic fibers is limited to 70 to 90% by weight is that if it is less than 70% by weight, the bulk density of the ceramic fiber sleeve becomes too high, so the original purpose of blending ceramic fibers is to reduce the weight of the sleeve. On the other hand, if it exceeds 90%, the amount of the inorganic filler and inorganic binder will be relatively too small, and the fluidity and shape retention of the mixed wire composition used for molding will decrease. This is because it is difficult to extrude the hollow pipe continuously during molding, and the strength and corrosion resistance of the sleeve are insufficient.

The reason why the blending ratio of the inorganic filler and the inorganic binder is limited to a range of 5 to 25% by weight in terms of solid content is that if it is less than 5% by weight, the fluidity and shape retention of the kneaded composition used for molding will decrease. It is difficult to extrude the hollow pipe continuously during molding, and the strength and corrosion resistance of the sleeve are insufficient. On the other hand, if it exceeds 25% by weight, the amount of ceramic fiber blended is relatively too small, making it difficult to reduce the weight and heat insulation of the sleeve. Because it's not enough.

The blending ratio of the molding aid is 0.5 to 10% by weight in terms of solid content.
The reason for limiting the amount to this range is that if it is less than 0.5% by weight, the original purpose of blending the molding aid, such as plasticity, shape retention, and lubricity of the kneaded composition for molding, will not be sufficiently exhibited. This is because it becomes difficult to extrude the hollow pipe continuously during molding, and on the other hand, if the content exceeds 10% by weight, problems such as smoke generation or molten iron scattering occur when the sleeve is used.

The reason why the amount of water in the plastic composition consisting of ceramic fibers, inorganic filler, inorganic binder, molding aid, and water is limited to 70 to 180 parts by weight per 100 parts by weight of solid content is 70. If it is less than 18 parts by weight, the fluidity of the mixed wire composition used for molding will decrease, making it difficult to continuously extrude hollow pipes during molding, while if it exceeds 18 parts by weight, the shape retention of the mixed wire composition used for molding will decrease. This is because it is difficult to extrude the hollow pipe continuously during molding, and only water is squeezed out from the circular nozzle outlet of the molding machine.

As mentioned above, when a hollow pipe is continuously extruded using an extrusion molding machine, a plastic composition obtained by mixing and kneading ceramic fibers, an inorganic filler, an inorganic binder, a forming aid, and water within a predetermined range. By disposing a far-infrared heater at the exit of the circular nozzle at the tip of the extrusion molding machine to continuously dry the surface layer of the hollow pipe extruded from the molding machine, the strength of the hollow pipe is improved and the main drying process is improved. This is suitable because it prevents deformation when transporting the hollow pipe.

Next, an example of the tM manufacturing method of a ceramic rib fibrous sleeve according to the present invention and a comparative example will be described.

Example 1 Bulk alumina-silica fibers are cut into chips with a size of 10 mm or less using a cutter mill, and the chip-shaped alumina/silica fibers/crystalline alumina fibers, an inorganic filler, and an inorganic bond are formed. The agent, molding aid and water are A in Table 1.
The mixtures were mixed as shown in B and C and kneaded using a Morta μ mixer. Next, it was continuously extruded into a hollow pipe shape using an extrusion molding machine having an extrusion port in which a circular medium ball with an outer diameter of 50 mm was arranged concentrically inside a circular nozzle with an inner diameter of 60 mm.
It was cut into 11 lengths and then dried in an electric dryer.

Thus obtained outer diameter 601EIIφ, inner diameter 50
Table 1 shows the quality of the ceramic fiber sleeve with m+31φ and length of 8001u in correspondence with the formulations A and B%C.

Example 2 Balek-shaped alumina-silica fiber and inorganic filler,
An inorganic binder, a forming aid, and water were mixed as shown in D and E in Table 1 and kneaded in a kneader. Next, it is continuously extruded into a hollow pipe shape using an extrusion molding machine having an extrusion port in which a circular medium ball of silk with an outside diameter of 50 mm is arranged concentrically inside a circular nozzle with an inside diameter of 61 fins. A far-infrared heater is provided nearby to continuously dry the surface layer of the hollow pipe.
It was then cut into lengths of aoo*s+, and then dried in a microwave dryer. Outline 60U obtained in this way
The quality of the ceramic fiber sleeve with Iφ, inner diameter 5Q*gφ, and length 800mm is listed in Table 1 and shown in correspondence with H.

Comparative Example Bulk alumina-silica yarn fibers, an inorganic binder, a forming aid, and water were mixed as shown in F%G and H in Table 2, defibrated with a pulper to form a slurry, and the slurry was processed into a vat. into which the outer diameter 5 is connected to the vacuum pump.
(A suction mold of 1 + * φ was put in, and after the suction mold was adsorbed and deposited on its surface, the mold was taken out, dehydrated, released, and dried. Inner diameter 501
Table 2 shows the quality of ceramic fiber sleeves with a diameter of 111 mm and a length of 800 mm, corresponding to formulations F, G, and H.

As described above, according to the present invention, a plastic composition consisting of ceramic fibers, an inorganic filler, an inorganic binder, a forming aid, and water is continuously extruded into a hollow pipe using an extrusion molding machine, and then dried. By doing so, a ceramic fibrous sleeve with very good dimensional accuracy, high bulk density, and extremely excellent strength and corrosion resistance can be manufactured with good productivity.

patent applicant IBIDEN Co., Ltd. Representative Jun Taga

Claims (5)

[Claims] (1) Ceramic m-fiber is 70 to 90% by weight, and the total of inorganic filler and inorganic binder is 5 to 25% by weight as solid content.
, the total water content is 70 parts by weight for 100 parts by weight of a blended composition consisting of 0.5 to 10% by weight of the molding aid as a solid content.
Water is added and kneaded to a total of ~130 parts by weight, and then a hollow pipe is continuously formed using an extrusion molding machine having a nozzle with circular balls arranged concentrically at the tip, and then dried. A method for manufacturing a ceramic W4 fibrostomy sleeve. (2) A far-infrared heater is disposed at the exit of the circular nozzle to continuously dry the surface layer of the hollow pipe extruded from the extrusion molding machine, and then perform main drying. Manufacturing method described. (3) The manufacturing method according to claim 1 or 2, wherein the inorganic filler is one or more selected from powders of alumina, mullite, and chamotte. (4) The manufacturing method according to claims 1 to 3, wherein the amorphous binder is any one selected from alumina sol, silica sol, and clay, or 2 rrli or more. (5) The manufacturing method according to claims 1 to 4, wherein the molding aid is one or more selected from methylcellulose, carboxymethylcellulose, and polyacrylamide.