JPH06218722A - Production of hydraulic inorganic formed piece - Google Patents

Abstract

PURPOSE:To obtain a hydraulic inorganic formed piece production method in which even a series with a reinforcing fiber added can be shaped by a water quantity approximating a stoichiometric quantity in a hydration reaction of a cement, a texture of a formed piece is enhanced in denseness, and a cured piece of a high strength can be obtained. CONSTITUTION:In a barrel 10, a part having a kneading function in a continuous-length rotating body of an extruder is provided with a plurality of paddles 201, 211 securely fitted over rotating shafts 20, 21. The paddles 201, 211 are disposed in combination with a shift by an angle of 45 degrees between adjacent ones in the axial direction of the extruder so that the top parts are arranged in a nearly spiral form. A hydraulic inorganic substance, an inorganic filler, a reinforming fiber, and water are supplied to this extruder quantitatively and continuously to be extruded. The paired paddles 201, 211 each having a cross section of a convex lens form are rotated while keeping a phase difference of an approximately 90 degrees so that a top of one of the pair can always rub a top of the other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hydraulic inorganic molded body.

[0002]

2. Description of the Related Art Molded articles using water and a hydraulic inorganic substance such as cement, mortar, and gypsum have been suitably used for various structural materials since ancient times. The extrusion molding method is excellent in terms of productivity for producing these hydraulic inorganic moldings.
However, since fluidity is particularly required in the extrusion molding method, in order to secure fluidity, more than the stoichiometric amount of water in the hydration reaction of cement has been added. A cured product obtained by curing such a hydraulic inorganic molded product has voids formed by excess water, is molded with a water amount close to a stoichiometric amount, and has a higher strength than a cured product obtained by curing, There was a problem that the water resistance was low. Especially when reinforcing fibers are added, it is necessary to knead so that the fibers are uniformly dispersed in the matrix.

In order to obtain a high-strength fiber-reinforced inorganic cured product, 1) a hydraulic inorganic substance, a reinforcing fiber and a composition containing crystalline ultrafine silica stone are dry-mixed, and then water and a surfactant are added. Method of adding, kneading and extruding a solution containing
15335 publication). 2) 100 parts by weight of cement, 5 to 60 parts by weight of silica stone powder,
Wollastonite 5-60 parts by weight, fiber 0.1-10 parts by weight, high-performance water reducing agent 0.1-10 parts by weight, thickener 0.1-
A method in which an appropriate amount of water is added to and mixed with 4 parts by weight of the composition, and an extrusion step, a roll pressing step, and a flat pressing step are sequentially performed, followed by curing and curing (JP-A-2-289456). Is proposed.

[0004]

However, the methods 1) and 2) each have a plurality of steps, and it is necessary to carry out mixing in a batch process before introducing the raw materials into the kneading machine. As a result, In particular, in the system in which the reinforcing fiber is added, there are problems such as variation in product quality due to variation between batches and reduction in workability.

The object of the present invention is to solve the above-mentioned problems, and even in a system in which reinforcing fibers are added, it is possible to shape with a water amount close to the stoichiometric amount in the hydration reaction of cement, and to improve the structure of the molded body. It is an object of the present invention to provide a method for producing a hydraulic inorganic molded body that is highly densified and that can obtain a high-strength cured body.

[0006]

The hydraulic inorganic substance used in the present invention is not particularly limited as long as it is an inorganic substance which shows a hardening property when kneaded with water. For example, ordinary Portland cement, special Portland cement, alumina cement, Simple cement such as Roman cement, acid resistant cement, fire resistant cement, special cement such as water glass cement, gypsum,
Examples include air-hardening cements such as lime and magnesia cement, and particularly Portland cement and alumina cement are preferably used in terms of strength and water resistance. These may be used alone or in combination of two or more.

When the amount of water used in the present invention is small, the hydraulic inorganic substance is not sufficiently cured, and
Since the dispersibility of the composition decreases and the strength of the finally obtained cured product decreases when the composition increases, it is preferably 15 to 60 parts by weight, more preferably 20 to 40 parts by weight, relative to 100 parts by weight of the hydraulic inorganic substance. It is a department.

The inorganic filler used in the present invention does not dissolve in water, does not inhibit the curing reaction of hydraulic inorganic substances, and does not significantly inhibit the action of all the constituent materials used in the production method of the present invention. If not particularly limited, for example, silica sand, aggregate for cement mortar such as river sand, fly ash, silica flower, silica fume, bentonite, mixed material for mixed cement such as blast furnace slag, sepiolite, wollastonite, natural minerals such as mica, Examples include calcium carbonate and diatomaceous earth. For the purpose of further reducing the weight, silica balloon, perlite, fly ash balloon, shirasu balloon, glass balloon, inorganic natural foam such as foamed clay may be used. These may be used alone or in combination of two or more.

[0009] The above-mentioned inorganic filler is preferably manufactured in a range of 0.03 to 500 µm because it becomes difficult to manufacture when the average particle size is small, and it becomes difficult to disperse the particles of the inorganic filler when the average particle size is large. When the amount of the above-mentioned inorganic filler decreases, the dispersibility of the reinforcing fiber decreases, and when the amount of the inorganic filler increases, the strength of the finally obtained cured product decreases.
˜200 parts by weight is preferred.

As the reinforcing fiber used in the present invention, any reinforcing fiber can be used according to the performance to be imparted to the molded product, and examples thereof include synthetic fibers such as vinylon, polyamide, polyester, polypropylene, carbon and aramid, glass fiber and titanic acid. Inorganic fibers such as potassium and steel, pulp and the like can be used. Particularly when synthetic fibers are used, the flexibility is remarkably improved. The fiber diameter of the reinforcing fiber is reaggregated at the time of mixing when it becomes thin, fiber balls are easily formed by entanglement, the strength of the finally obtained cured product is not further improved, and when it becomes thick or short, the tensile strength is increased. Since the reinforcing effect such as improvement is small and the dispersibility and orientation of the fiber are reduced when it is long, the fiber diameter is preferably 0.5 to 40 denier and the fiber length is 1 to 15 mm. When the amount of the reinforcing fiber is small, the reinforcing effect cannot be obtained, and when it is large, the dispersibility of the fiber is deteriorated. Therefore, 0.1 to 20 parts by weight is preferable to 100 parts by weight of the hydraulic inorganic substance.

In the present invention, a water-soluble polymer substance may be added if necessary. The water-soluble polymer substance dissolves in water to impart viscosity, enhances fluidity of the composition obtained from the hydraulic inorganic substance and water, and improves shapeability, and
It is not particularly limited as long as it is a polymer substance which can absorb excess water in the hardened cement and serve as a binder to fill the voids between the cement particles, for example, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose and the like. Examples thereof include cellulose ether, polyvinyl alcohol, polyacrylic acid and lignin sulfonate. When the amount of the water-soluble polymer substance added increases, the water resistance of the finally obtained cured product decreases, so 5 parts by weight or less is preferable with respect to 100 parts by weight of the hydraulic inorganic substance.

The method for producing a hydraulic inorganic molded article of the present invention is an extruder for a hydraulic inorganic composition comprising the hydraulic inorganic substance, inorganic filler, reinforcing fiber, water and, if necessary, a water-soluble polymer substance. And extrusion molding.
It is preferable that these hydraulic inorganic compositions are quantitatively and continuously supplied.

The method for quantitatively and continuously supplying the hydraulic inorganic composition to the extruder is not particularly limited, and any conventionally known method can be used. For example, a screw feeder or a circle feeder is used. To be done. The supply amount of the hydraulic inorganic composition varies depending on the barrel diameter of the extruder. For example, in an extruder having a barrel diameter of 100 mm, the composition is not sufficiently kneaded even if the amount is small or large. / Hr is preferred.

The extruder is composed of a barrel and a pair of long rotating bodies that rotate in the barrel radial direction to continuously extrude the material. The long rotating body has a first rotating part having a function of supplying the material, a second rotating part having a function of kneading the material, and a third rotating part having a function of compressing the material in the extrusion direction. It comprises a rotating part and a fourth rotating part having a function of weighing the material.

The first rotating part has a function of supplying a material and quantitatively transfers the hydraulic inorganic composition to the second rotating part. The hopper and the barrel communicating with the hopper. It consists of a pair of screws that rotate inside. The screw is provided with any conventionally known flight. The rotation direction of the pair of screws may be the same direction or may be the opposite direction. When the rotation speed of the screw is low, the reinforcing fibers are not sufficiently defibrated, and the powder is discharged while agglomerated, and when it is large, the reinforcing fibers are scratched or broken, so that 30 to 150 rpm is preferable.

The second rotating part has a function of kneading materials, and disperses the reinforcing fibers supplied to the extruder uniformly with other compositions while sufficiently defibrating the fibers. The second rotating portion is formed by fitting and fixing a rotating shaft on a plurality of paddles. In the paddle, adjacent paddles in the axial direction of the extruder are mutually adjacent in the circumferential direction of the rotating shaft. The angle is different.

The paddle is for adjusting the residence time and internal pressure of the composition in the extruder by changing the composition according to the purpose of use, and is a metal flat plate having a cross-sectional shape with an acute-angled top. preferable. The pair of paddles always rotate so that the top of one rubs against the top of the other. If the minimum gap between the paddle and the barrel becomes large, the reinforcing fibers will not be sufficiently defibrated, so 0.5 mm or less is preferable.

The third rotating part has a function of compressing the material, and by applying compressive stress and shear stress to the material, the volume of the material is reduced as it goes in the feeding direction of the extruder, and the filling rate is increased. To give. The third rotating portion may be a screw provided with any conventionally known flight, or may be formed by fitting and fixing a rotating shaft on the plurality of paddles described above. The compression ratio is determined by the shape of the third rotating portion, the rotation amount, and the discharge amount. When a screw provided with a flight is used for the third rotating portion, for example, a screw in which the flight pitch is reduced as it moves in the screw feed direction, a screw in which the flight is discontinuous, or 10 to 50% of the flight is used. A screw and the like which are turned in the opposite direction are preferably used. When the rotating shaft is fitted and fixed to the plurality of paddles described above, the third rotating portion is assembled such that the adjacent paddles are perpendicular to each other in the circumferential direction of the rotating shaft. Is preferred.

The fourth rotating part has a function of measuring the material and quantitatively discharges the hydraulic inorganic composition from the extruder. The fourth rotating portion may be a screw provided with a conventionally known arbitrary flight, or may be formed by fitting and fixing a rotating shaft on the plurality of paddles described above. When the fourth rotating portion is formed by fitting and fixing the rotating shafts on a plurality of paddles, the top portion of the paddle is inclined so as to form a substantially spiral line in the extrusion direction,
It is preferably combined.

In the method for producing a molded article of the present invention, the hydraulic inorganic composition discharged from the fourth rotating part may be fed into an extrusion die having a desired shape to shape it. The hydraulic inorganic composition discharged from the rotating part may be fed into a press die having a desired shape for press molding.

FIG. 1 is a schematic view showing an example of an extruder used in the present invention. The extruder includes a barrel 10 and a pair of long rotating bodies that rotate in the barrel 10 in the radial direction of the barrel 10 to continuously extrude the material. The long rotator has a first rotating part 1 having a function of supplying the material and a second rotating part having a function of kneading the material in the extrusion direction.
Rotating part 2, a third rotating part 3 having a function of compressing a material, and a fourth rotating part 4 having a function of measuring a material.

The hydraulic inorganic composition supplied from the hopper (not shown) to the first rotary unit 1 is quantitatively transferred to the second rotary unit 2 by the screw 202 having a flight. In the second rotating part 2, the residence time and internal pressure of the hydraulic inorganic composition in the extruder are adjusted and supplied to the third rotating part 3. In the third rotating part 3, the hydraulic inorganic composition is subjected to compressive stress and shearing stress, the volume of the composition decreases as it goes in the feeding direction of the extruder, and the fourth rotation while increasing the filling rate. Sent to part 4. In the fourth rotating part 4, the hydraulic inorganic composition is quantitatively discharged from the discharge port 5 of the extruder.

FIG. 2 is a sectional view taken along the line AA 'in FIG. 1, showing an example of the second rotating portion used in the present invention. In the barrel 10 of the extruder, there are a plurality of paddles 201, 211.
The rotary shafts 20 and 21 are formed by being fitted and fixed.
Each of the pair of paddles 201 and 211 has a convex lens shape in cross section and has a phase difference of about 90 degrees, and always rotates so that one apex rubs the other apex.

The paddles 201 and 211 are assembled while changing their angles such that the paddles adjacent to each other in the axial direction of the extruder face each other in the extrusion direction so that the tops thereof have a substantially spiral shape. There are narrow gaps 31, 32, 33 between the paddles 201, 211 and the barrel 10, and the material supplied to the extruder passes through these gaps to impart an appropriate shear rate to the reinforcing fibers. Is sufficiently defibrated and is supplied to the third rotating section together with the other composition.

FIG. 3 is a sectional view showing another example of the second rotating part of the extruder used in the present invention. In the barrel 11 of the extruder, rotary shafts 22 and 23 are fitted and fixed to a plurality of paddles 221 and 231. Each of the pair of paddles 221 and 231 has a cross-sectional shape surrounded by three arcs having an outward convex shape, and always rotates so that one apex rubs the other without a phase difference.

The rotating shafts 22 and 23 are assembled such that the paddles adjacent to each other in the axial direction of the extruder are substantially spiral-shaped at their tops in the extrusion direction. Paddle 22
Narrow gaps 34, 3 between 1, 231 and barrel 10
The material to be fed to the extruder, which has 5, 36 and 37, passes through this gap to impart an appropriate shear rate, sufficiently defibrate the reinforcing fibers, and, together with the other composition, a third Is supplied to the rotating part of.

In order to obtain a cured product from the molded product of the present invention, natural curing may be carried out for a long time, but when a hydraulic inorganic substance such as Portland cement having a slow curing reaction is used. Curing reaction can be promoted and mechanical properties can be improved by carrying out curing by a conventionally known method such as heating and humidifying the molded body, and curing by autoclave.

[0028]

EXAMPLES The present invention will be described in more detail by way of examples.

Example 1 The extruder used in this example is the one shown in FIG. 1 and comprises a barrel 10 and a pair of members for continuously extruding material by rotating in the radial direction of the barrel 10 in the barrel 10. The long rotator has a first rotator 1, a second rotator 2, a third rotator 3, and a fourth rotator 4 in the direction of extrusion. They are provided in order.

The first rotating part is formed of a hopper and a screw having a total length of 150 mm, which rotates in a barrel communicating with the hopper. The screw is provided with a flight.

The second rotating portion is the paddle 20 shown in FIG.
The rotary shafts 20 and 21 are fitted and fixed to the first and second 211, respectively.
The paddles 201 and 211 are 1 in the radial direction of the extruder.
It has a length of 00 mm and is constructed by combining four sheets while changing the angle by 45 ° so that the apex becomes a substantially spiral line in the extrusion direction of the extruder, and the total length is 125 mm. The paddles 201 and 211 always rotate with a phase difference of 90 degrees so that one apex rubs the other apex, and the paddles 201 and 211 and the barrel 10 have a phase difference of 0.
It has gaps 31, 32, and 33 of 1 mm, and the rotating shaft rotates in conjunction with the screw of the first rotating portion.

In the third rotating portion, the rotating shafts 20 and 21 are fitted and fixed to the paddles 201 and 211 similar to those of the second rotating portion. The paddles 201 and 211 are configured by combining 10 sheets so that the tops thereof are alternately perpendicular to each other in the extrusion direction of the extruder, and have a total length of 313 mm. The rotating shaft rotates in conjunction with the screw of the first rotating unit and the rotating shaft of the second rotating unit.

The fourth rotating portion has the paddles 201 and 211 having the same sectional shape as the second rotating portion and the rotating shafts 20 and 2 respectively.
1 is fitted and fixed. The top of the paddle has a substantially spiral line in the extrusion direction, and the paddle is formed by combining nine sheets while changing the angle so that the top is continuous in the extrusion direction, and has a total length of 282 mm. The rotating shaft rotates in conjunction with the screw of the first rotating unit, the rotating shaft of the second rotating unit, and the rotating shaft of the third rotating unit.

In the hopper of the extruder, 102 kg / hr of ordinary Portland cement (manufactured by Onoda Cement Co., Ltd.), fly ash (average particle size 100 μm, true specific gravity 2.3, bulk specific gravity 0.6) by a screw feeder, JIS;
Polypropylene fiber with a fiber length of 6 mm (manufactured by Tesac Co., Ltd.) at a flow rate of 40 kg / hr (according to A 6201), 2.1 kg / hr of hydroxypropylmethylcellulose (having a viscosity of 2% aqueous solution at 20 ° C. of 30,000 cps) of 2.1 kg / hr. , Product name; 3F-EX)
At a flow rate of 2.1 kg / hr and water at a flow rate of 15 kg / hr, the screw of the extruder is rotated at a rotation speed of 100 rpm, and the hydraulic inorganic composition discharged from the fourth rotation unit is pressed. 20kg / cm ² supplied into the mold
Press molding was performed for 5 seconds under the pressure of 5 to obtain a molded body having a thickness of 5 mm.

The obtained molded body was cured at 60 ° C. and 90% RH for 6 hours to obtain a cured body. The bending strength of the obtained cured product was measured according to JIS A 1408 and was 286 kg / cm ² .

Example 2 A 100 mm barrel and a screw provided with a flight in the barrel were inserted and connected between the fourth rotating part of the extruder used in Example 1 and the discharge port 5, and the barrel was further connected. Example 1 except that a die having a parallel portion of 100 mm in the extrusion direction was continuously provided at the outlet and the extrusion pressure was set to 23 kg / cm ^2.
Extruding the hydraulic inorganic composition in the mold under the same conditions as,
A molded body was obtained.

The molded body thus obtained was cured in the same manner as in Example 1 to obtain a cured body. The bending strength in the extruding direction and the bending strength in the direction perpendicular to the extruding direction of the obtained cured product were measured according to JIS A 1
When measured according to 408, it is 293k in the extrusion direction.
g / cm ² , 277 kg / cm ^{2 in the} direction perpendicular to the extrusion direction
Met.

Comparative Example 1 100 parts by weight of ordinary Portland cement, 40 parts by weight of fly ash, hydroxypropyl methylcellulose 2
Parts by weight and 2 parts by weight of polypropylene fibers were mixed in a mixer having a capacity of 70 liters for 3 minutes, and further 20 parts by weight of water were supplied and mixed for 2 minutes. The obtained mixture is supplied to a kneading machine (manufactured by Miyazaki Tekko Co., Ltd., model: MP-100 type) and kneaded, and the obtained kneaded product has a die having a parallel portion of 100 mm in the extrusion direction as a discharge port. Connected screw diameter 100
mm extruder (manufactured by Miyazaki Iron Works, model; MV-FM-A-
(1 type) was extruded into the mold at an extrusion pressure of 23 kg / cm ² to obtain a molded body.

The obtained molded body was cured in the same manner as in Example 1 to obtain a cured body. The bending strength in the extruding direction and the bending strength in the direction perpendicular to the extruding direction of the obtained cured product were measured according to JIS A 1
408 in the extrusion direction when measured according to 408
g / cm ² , 260 kg / cm ^{2 in the} direction perpendicular to the extrusion direction
Met.

EFFECT OF THE INVENTION Since the method for producing a hydraulic inorganic molded article of the present invention is as described above, even if the addition amount of the water-soluble polymer substance conventionally used as a viscosity-imparting agent is reduced, the cement Even a material having poor fluidity, which has a water content close to the stoichiometric amount in the hydration reaction, can be shaped without mixing and kneading the composition, and a high-strength cured product can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an extruder used in the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 3 is a sectional view showing a second rotating portion of another extruder that can be used in the present invention.

[Explanation of symbols]

 1 1st rotating part 2 2nd rotating part 3 3rd rotating part 4 4th rotating part 10,11 Barrel 20,21,22,23 Rotating shaft 201,211,221,231 Paddle

Claims (1)

[Claims] 1. A barrel and a pair of elongate rotary members that rotate in the barrel radial direction to continuously extrude the material. The elongate rotary member pushes the material toward the extruding direction. A first rotating part having a function of supplying, a second rotating part having a function of kneading the material, a third rotating part having a function of compressing the material, and a fourth rotating part having a function of measuring the material. The second rotating part is formed by fitting and fixing the rotating shafts on a plurality of paddles, and the paddles are adjacent to each other in the axial direction of the extruder. In an extruder where matching paddles are installed at different angles in the circumferential direction of the rotating shaft, hydraulic inorganic substance, inorganic filler,
A method for producing a hydraulic inorganic molded body, which comprises supplying reinforcing fibers and water and performing extrusion molding.