JPH09262815A - Manufacture of hydraulic inorganic molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add uniformly reinforcing fibers even for a hydraulic inorganic composition to which the reinforcing fibers of small specific gravity are added and manufacture a molded body of uniform strength and superior quality. SOLUTION: An extruder is constituted of a barrel 1 and a pair of continuous rotating bodies 2 rotating in the diameter direction of the barrel 1 and extruding a molding material in the barrel 1, and the extruder is provided with a first rotating section 3 with the function of feeding the molding material in the extrusion direction by the continuous rotating bodies 2, a second rotating section 4 with the function of kneading the molding material, a third rotating section 5 with the function of compressing the molding material and a fourth rotating section 6 for metering the molding material. Water is sprayed to a hydraulic inorganic composition composed of a hydraulic inorganic substance, reinforcing fibers and a water-soluble polymer mixed all together uniformly, and the water sprayed hydraulic inorganic composition is fed from a hopper communicated with the first rotating section 3, and extruded out of a discharge outlet 10 on the end of the barrel 1 through the kneading, compressing and metering processes.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a hydraulic inorganic molded body.

[0002]

2. Description of the Related Art Conventionally, a molded body made of a molding material using water and a hydraulic inorganic substance such as cement, mortar and gypsum has been often used as a preferable structural material. In order to produce a molded article composed of the above-mentioned molding material, extrusion molding is an excellent method, but in this extrusion molding, fluidity of the molding material is particularly required, and in order to secure this fluidity,
Conventionally, a large amount of water has been added to cement.

A molded product which is molded and hardened by adding a large amount of water in this manner has a problem that voids are formed by excess water and the strength and water resistance are inferior to those of a molded product when a small amount of water is added. there were. Further, when reinforcing fibers are added to the molding material, it is necessary to mix and knead the fibers so that the fibers are uniformly dispersed in the matrix.

As described above, a manufacturing method for obtaining a molded product of good quality by reducing the addition of water is proposed by the Japanese Patent Application No.
According to the present invention, regardless of the supply amount of the hydraulic inorganic composition, even if the reinforcing fiber is added, it is possible to shape with a small amount of water and to obtain a dense structure. Therefore, it is possible to obtain a high-strength molded product.

[0005]

However, when fibers such as pulp having a particularly low bulk specific gravity are used as reinforcing fibers, the difference in specific gravity between the hydraulic inorganic substance and the inorganic filler causes a large difference in the hydraulic inorganic substance, A hydraulic inorganic composition comprising an inorganic filler, a reinforcing fiber, and a water-soluble polymer substance, or a hydraulic inorganic composition comprising a hydraulic inorganic substance, an inorganic filler, and a reinforcing fiber is simultaneously prepared in the above-mentioned Japanese Patent Application No. 6-
Even when supplied to the first rotating part described in Japanese Patent No. 271078, a hydraulic inorganic substance having a large specific gravity or an inorganic filler is preferentially transferred to the second rotating part, and water containing less reinforcing fibers than a predetermined amount. It becomes a hard inorganic molded body.

The present invention has been made by paying attention to the above problems, and an object thereof is to solve these problems and to add a hydraulic inorganic material containing reinforcing fibers having a small specific gravity. Even in the case of a composition, the present invention provides a method for producing a hydraulic inorganic molded body, in which reinforcing fibers are uniformly added and a molded body of excellent quality having uniform strength can be obtained.

[0007]

In the method for producing a hydraulic inorganic molded body of the present invention, a barrel and a pair of long rotating bodies that rotate in the barrel radial direction to push out the molding material are provided. A first rotating part having a function of supplying the molding material in the extrusion direction by the long rotating body, a second rotating part having a function of kneading the molding material, and a function of compressing the molding material. In an extruder consisting of a third rotating part and a fourth rotating part for measuring a molding material, water is sprayed onto a hydraulic inorganic composition obtained by uniformly mixing a hydraulic inorganic substance, a reinforcing fiber and a water-soluble polymer. In addition, the hydraulic inorganic composition added with this water is supplied from a hopper provided in communication with the first rotating part, and is extruded from the tip of the barrel through kneading, compression, and measuring steps. To do.

In the present invention, as a method for quantitatively supplying the hydraulic inorganic composition to the above extruder, a screw feeder or a circle feeder which is a conventional technique is used. Further, the supply amount of the hydraulic inorganic composition varies depending on the barrel diameter of the extruder, but if the amount is too small or too large, the composition is not sufficiently kneaded.
r to 600 kg / hr is preferable.

In the present invention, when the amount of water added by spraying to the hydraulic inorganic composition is small, the hydraulic inorganic substance is not sufficiently cured, the dispersibility of the composition is lowered, and when the amount is large, the final amount is finally obtained. Since the strength of the molded product obtained in step 1) is reduced, it is 15 to 6 with respect to 100 parts by weight of the hydraulic inorganic substance.
It is preferably 0 parts by weight, more preferably 20 to 40 parts by weight.

When the amount of water added by spraying to the hydraulic inorganic composition quantitatively supplied to the first rotating part of the extruder used in the production method of the present invention is small, the reinforcing fiber and the hydraulic inorganic substance, or The inorganic filler separates and a uniform mixture cannot be obtained. When the amount of hydraulic inorganic composition supplied to the extruder is large, and the amount of water to be sprayed is too large, the hydraulic inorganic composition containing water is quantitatively transferred from the first rotating part to the second rotating part. Not supplied, making molding impossible.

Therefore, the water added by spraying to the hydraulic inorganic composition quantitatively supplied to the first rotating part is a uniform hydraulic inorganic composition quantitatively from the first rotating part to the second rotating part. It may be appropriately set within a range in which the water is transferred to the water-soluble inorganic substance and the amount is less than the amount of water with respect to the hydraulic inorganic substance.

When the amount of water to be sprayed is less than or equal to the amount of water for the desired hydraulic inorganic substance, the insufficient amount of water is supplied from the position of the second rotary section for kneading the molding material.
As a method of quantitatively supplying water to the second rotating portion,
It suffices to use a conventional technique, and for example, all of the pumps that can supply a fixed amount can be used.

The hydraulic inorganic substance used in the present invention may be any one that exhibits curability when kneaded with water. For example, plain portland cement, special portland cement, alumina cement, roman cement and other plain cement, acid resistant cement, fire resistant cement, water glass cement and other special cement, gypsum, lime, magnesia cement and other hard setting cement, etc. Particularly, Portland cement and alumina cement are preferably used in terms of strength and water resistance. These hydraulic inorganic substances may be used alone or in combination of two or more.

The reinforcing fibers used in the present invention include natural fibers such as pulp (bulk specific gravity of about 0.15) and hemp (bulk specific gravity of about 0.25), and vinylon (specific gravity of 1.3).
), Polyamide (specific gravity of about 1.2), polyester (specific gravity of about 1.3), polypropylene (specific gravity of about 0.9), aramid (specific gravity of about 1.4) and the like. The thickness of the reinforcing fiber is re-aggregated during mixing when it becomes thin, so that a so-called fiber ball is easily formed by entanglement, the strength of the finally obtained molded body is not improved, and becomes thicker or shorter. Since the reinforcing effect becomes smaller and the dispersibility and orientation of the fiber become lower as it becomes longer, the range of 0.5 denier to 40 denier is preferable, and the length of the fiber is preferably 1 mm to 15 mm.

When the amount of the reinforcing fiber added is small, the effect cannot be obtained, and when the amount is large, the dispersibility of the fiber is deteriorated. Therefore, 0.1 to 2 is added to 100 parts by weight of the hydraulic inorganic substance.
0 parts is preferred.

Further, the water-soluble polymer substance used in the present invention is dissolved in water to give a viscosity to enhance the fluidity of the composition obtained from the hydraulic inorganic substance and water to improve the shaping property. ,
Further, any material may be used as long as it can absorb excess water in the molded body and serve as a bonding agent that fills the voids between the cement particles. Examples of these water-soluble polymer substances include cellulose ethers such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and hydroxypropyl methyl cellulose, polyvinyl alcohol, polyacrylic acid, lignin sulfonate and the like. To be

If the amount of the water-soluble polymer substance added increases, the water resistance of the finally obtained molded article decreases, so 5 parts by weight or less is preferable with respect to 100 parts by weight of the hydraulic inorganic substance.

An inorganic filler may be added to the hydraulic inorganic composition used in the present invention. This inorganic filler may be one that does not dissolve in water, does not inhibit the curing reaction of the hydraulic inorganic substance, and does not inhibit the action of all molding materials used in the production method of the present invention, for example, silica sand. , Cement mortar aggregates such as river sand, fly ash, silica flower, silica fume, bentonite, mixed cement admixtures such as blast furnace slag, sepiolite, wollastonite, natural minerals such as mica, calcium carbonate, diatomaceous earth, etc. To be

Further, for the purpose of reducing the weight of the molded article, silica balloons, perlite, fly ash balloons, shirasu balloons, inorganic foams such as glass balloon foaming viscosity may be used alone or in combination of two or more kinds. Good.

If the average particle size of the above-mentioned inorganic filler is small, it becomes difficult to handle, and if it is large, the dispersibility is deteriorated. Therefore, the average particle size is preferably 0.03 μm to 500 μm. When the amount of the inorganic filler added is small, the dispersibility of the reinforcing fibers is low, and when it is large, the strength of the finally obtained molded product is low.
200 parts by weight are preferred.

An example of the extruder used in the present invention will be described below with reference to the drawings. FIG. 1 is a horizontal cross-sectional view of the extruder, and FIG. 2 is a cross-sectional view of FIG. 1 seen from the side. This extruder is composed of a barrel 1 and a pair of long rotating bodies 2 that rotate in the barrel 1 in the radial direction of the barrel 1 and continuously push out a molding material.

The long rotating body 2 has a first rotating portion 3 for supplying a molding material, a second rotating portion 4 for kneading, and a third rotating portion 5 for compressing, in the pushing direction of the tip. Further, it is composed of a fourth rotating portion which is lightweight. A nozzle 7 for supplying water is provided above the second rotating portion 4 of the barrel 1.

The hydraulic inorganic composition supplied from the hydraulic hopper supply hopper 8 to the first rotating part 3 is
By the water sprayed from the nozzle 9, the reinforcing fiber, the hydraulic inorganic substance, the inorganic aggregate, and the water-soluble polymer are integrated, and the long rotating body 2 having the flight 31 quantitatively transfers to the second rotating portion 4. Be transferred. When the amount of water supplied by spraying is insufficient, the required amount of water is simultaneously supplied from the nozzle 7.

In the second rotating section 4, the residence time and internal pressure of the hydraulic inorganic composition, to which a predetermined amount of water has been supplied, in the extruder are adjusted, and then transferred to the third rotating section 5. In the third rotating part 5, compressive stress and shear stress are applied to the hydraulic inorganic composition, the volume of the composition decreases toward the tip side of the extruder, and the filling rate in the barrel 1 is increased. It is transferred to the fourth rotating unit 6 and is quantitatively extruded from the discharge port 10 of the extruder.

In order to cure the molded product obtained as described above into a product, natural curing may be carried out for a long time, but a hydraulic inorganic substance having a slow curing reaction (for example, Portland cement). In this case, by subjecting this molded body to autoclave curing such as heating and humidification, it is possible to accelerate the curing reaction and improve the mechanical properties.

[0026]

In the method for producing a hydraulic inorganic molded article of the present invention, water is added by spraying to a hydraulic inorganic composition obtained by uniformly mixing a hydraulic inorganic substance, a reinforcing fiber, and a water-soluble polymer. Since the added hydraulic inorganic composition was supplied from the hopper and extruded from the tip of the barrel through the kneading, compression, and weighing steps, the reinforcing fiber, particularly natural fiber having a small bulk specific gravity such as pulp and hemp. Even in the case of using, it is possible to obtain a homogenous molded article having high strength and excellent quality.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to Examples and Comparative Examples. (Example 1) The extruder shown in Fig. 1 was used, a screw provided with a flight having a total length of 150 mm was used for the first rotating part 3, and the second rotating part was rotated on a paddle 41 as shown in Fig. 3. The shaft 2 is fitted, and has a length of 100 mm in the radial direction of the barrel 1, and it is a set of four pieces while changing the angle in 45 ° increments so that the apex becomes almost spiral in the extrusion direction. It was constructed and had a total length of 125 mm.

The paddle 41 rotates with a phase difference of 90 ° so that the top portion always slides on the other top portion,
A gap of 0.1 mm is provided between the paddle 41 and the barrel 1 so that the paddle 41 and the barrel 1 rotate in conjunction with the rotating shaft 2 and the screw of the first rotating portion 4.

The nozzle 7 provided above the barrel 1 of the second rotating portion 4 has a nozzle diameter of 10 mm outside the barrel 1 so that water can be quantitatively supplied into the barrel 1.
The paddle 41 side was set to 5 mm so that pressed water could be supplied.

Similar to the second rotating part 4, the third rotating part 5 is provided with a set of 10 paddles 51 and has a total length of 313 mm. The rotating shaft 2 is adapted to rotate in conjunction with the screw of the first rotating portion 3 and the rotating shaft 2 of the second rotating portion 4.

As with the second rotary unit 4, the fourth rotary unit 6 is provided with a set of nine paddles 61 and has a total length of 282 mm.
Further, the rotary shaft 2 is adapted to rotate in association with the screw of the first rotary unit 3, the rotary shaft 2 of the second rotary unit 4, and the rotary shaft 2 of the third rotary unit 5.

In the extruder having the above construction, first, 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda Cement Co., Ltd.), fly ash (average particle size 100 μm, true specific gravity 2.
3, bulk specific gravity 0.6 (according to JIS A 6201) 5
0 parts by weight, hydroxypropyl methylcellulose (20
2% by weight aqueous solution having a viscosity of 30000 cps at ℃) and 5 parts by weight of conifer bleached kraft pulp defibrated and pulverized in-house (bulk specific gravity of about 0.1) (Manufactured by K.K.) for 5 minutes to obtain a dry hydraulic inorganic composition.

120 kg / h of this hydraulic inorganic composition
The water is supplied to the first rotating part 3 at r, and at the same time 22.9 mist of water is supplied.
The hydraulic inorganic composition was sprayed at kg / hr.

The screw of the extruder is rotated at 60 rpm, and the distance between the fourth rotating portion 6 and the discharge port 10 is 100 mm.
Barrel 1 and a screw provided with a flight in the barrel 1 are inserted and connected, and further, at the outlet of the barrel 1,
A metal mold having a parallel portion of 100 mm in the extrusion direction, an outlet shape of 200 mm in width, and a height of 10 mm was continuously provided, and the extrusion pressure was set to 23 kg / cm ² , and a flat plate-shaped compact was continuously extrusion-molded.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

[0036]

[Table 1]

(Example 2) In the extruder having the above-mentioned structure, first,
Ordinary Portland cement (made by Chichibu Onoda Cement Co.)
100 parts by weight, fly ash (average particle size 100 μm,
True specific gravity 2.3, bulk specific gravity 0.6 (according to JIS A 6201) 50 parts by weight, hydroxypropyl methylcellulose (viscosity of 2% aqueous solution at 20 ° C. is 30,000c)
ps) 2 parts by weight, in-house bleached kraft pulp defibrated and crushed in-house (bulk specific gravity of about 0.1)
5 parts by weight of an Erich mixer (made by Japan Erich Co.)
And mixed for 5 minutes to obtain a dry hydraulic inorganic composition.

240 kg / h of this hydraulic inorganic composition
The water is supplied to the first rotating part 3 at r, and at the same time mist-like water is supplied by 15.3.
The hydraulic inorganic composition was sprayed at kg / hr.

Further, water was supplied at a rate of 30.6 kg / hr from a position of 50 mm in the extrusion direction from the start of the second rotary portion 4 using a uniaxial screw type pump (Homojin Equipment Co., Ltd. model Mono pump 3NE08H2). Except for the above, extrusion molding was performed under the same conditions as in Example 1 to obtain a flat plate-shaped molded body.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

The screw of the extruder is rotated at 60 rpm, and the distance between the fourth rotating part 6 and the discharge port 10 is 100 mm.
Barrel 1 and a screw provided with a flight in the barrel 1 are inserted and connected, and further, at the outlet of the barrel 1,
A metal mold having a parallel portion of 100 mm in the extrusion direction, an outlet shape of 200 mm in width, and a height of 10 mm was continuously provided, and the extrusion pressure was set to 23 kg / cm ² , and a flat plate-shaped compact was continuously extrusion-molded.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

(Example 3) In Example 2, the amount of water sprayed was 7.6 kg / hr, and the amount of water supplied to the nozzle 7 was 3
Extrusion molding was performed under the same conditions as in Example 2 except that the pressure was 8.2 kg / hr.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

(Example 4) In Example 3, cellulose powder (bulk specific gravity: 0.14) (produced by Kojinsha, Celltop HP) was used in place of the one obtained by defibrating and crushing the softwood bleached kraft pulp in-house. Example 106 except that -106) was used.
Extrusion was carried out under the same conditions as in.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

(Example 5) In Example 3, instead of crushed and crushed conifer bleached kraft pulp dried in-house, ramie hemp (bulk specific gravity 0.25) (CWS manufactured by Tosco)
Extrusion molding was performed under the same conditions as in Example 3 except that (5000R) was used.

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1 and were homogeneous and stable.

(Comparative Example 1) In Example 1, 22.9 kg / h was obtained by using a uniaxial screw type pump (model MONO pump 3NE08H2 manufactured by Hyojin Equipment Co., Ltd.) instead of supplying mist-like water.
Extrusion molding was performed in the same manner as in Example 1 except that rod-shaped water was supplied to the first rotating unit 3 at r. However, the hydraulic inorganic composition to which water is added stays in the first rotating part 3 and is not supplied to the second rotating part 4 and thereafter, so that a molded body cannot be obtained.

Comparative Example 2 In Example 1, only the hydraulic inorganic composition was supplied from the first rotating part 3 and the second rotating part 4 was used.
Then, extrusion molding was carried out in the same manner as in Example 1 except that water was quantitatively supplied at a rate of 22.9 kg / hr by using a uniaxial screw type pump (model MONO PUMP 3NE08H2 manufactured by Hyojin Equipment Co., Ltd.).

The above molded body was cured at 60 ° C. and 100% RH for 6 hours to obtain a cured molded body. Bending strength of the initial, middle, and late parts of this molded product (JIS A
(According to 1404) was measured to examine its homogeneity. The results are shown in Table 1, and there was a large variation in bending strength, and it was not possible to obtain a homogeneous and stable quality.

[0052]

In the method for producing a hydraulic inorganic molded article of the present invention, water is added by spraying to a hydraulic inorganic composition obtained by uniformly mixing a hydraulic inorganic substance, a reinforcing fiber and a water-soluble polymer, The hydraulic inorganic composition added with this water was supplied from a hopper, and kneaded, compressed, and extruded from the tip of the barrel through a metering process, so that the reinforcing fiber has a small bulk density such as pulp and hemp. Even when using natural fibers, it is possible to obtain a molded product that is homogeneous and has high strength and excellent quality. Therefore, it is suitable as a method for producing a hydraulic inorganic molded body.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view showing an example of an extruder in a method for producing a hydraulic inorganic molded body of the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

[Explanation of symbols]

 1 Barrel 2 Long Rotating Body 3 First Rotating Part 4 Second Rotating Part 5 Third Rotating Part 6 Fourth Rotating Part 7 Nozzle 8 Hopper 9 Water Spray Nozzle 10 Discharge Port 31 Flight 41, 51, 61 Paddle

Claims (1)

[Claims] 1. A barrel and a pair of long rotating bodies that rotate in a radial direction of the barrel to push out a molding material in the barrel, and the long rotating body supplies the molding material in a pushing direction. A first rotating part having a function of mixing, a second rotating part having a function of kneading the molding material, a third rotating part having a function of compressing the molding material, and a fourth rotating part for measuring the molding material. In an extruder, water is sprayed on a hydraulic inorganic composition obtained by uniformly mixing a hydraulic inorganic substance, a reinforcing fiber, and a water-soluble polymer, and the hydraulic inorganic composition sprayed with this water is the first rotating part. Is supplied from a hopper provided so as to communicate with, and is extruded from the tip of a barrel through a kneading, compression, and weighing process.