JP2891282B2 - Extrusion molding method for cement building materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extruding a cement building material, and more particularly to an improvement in a method for extruding a lightweight and high-strength product formed using an air entraining agent.

[0002]

2. Description of the Related Art Conventionally, an air entraining agent has been used as a means for extruding a lightweight and high-strength cement building material with an inorganic raw material such as cement, and the resulting micro-bubbles are uniformly dispersed in a cement matrix to obtain a porous structure. May be. In the above extrusion method, in order to further promote the generation rate and miniaturization of bubbles due to the air entraining agent, a powdery raw material such as cement, siliceous raw material, aggregate, reinforcing fiber, etc. and the air entraining agent and other liquid raw materials are separated into separate tanks. In some cases, the two materials are mixed with a kneader after the liquid material is sufficiently foamed with an air entraining agent.

[0003]

[Problems of the prior art] However, when the air entraining agent and water are mixed while being foamed in a stirring tank, even if foaming can be sufficiently performed at the time of stirring, when the stirrer is stopped to supply to the kneader, the foam and water are mixed. Is easily separated, water cannot be supplied with uniformly dispersed bubbles when supplied to the kneader, and there is a problem that it is difficult to form a homogeneous product.

On the other hand, when the liquid is poured into the kneader while the stirrer is driven to solve such a problem, the bubbles are scattered around by the stirring blades, so that the bubbles are wasted, and the bubbles in the latter half of the discharge gradually become coarse. However, there is a disadvantage that it is difficult to obtain a product having a uniform porous structure.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is capable of supplying air bubbles having a uniform particle size, thereby enabling the extrusion of a lightweight, high-strength inorganic product of a homogeneous material. The purpose of the present invention is to obtain a method of extruding a product having excellent explosion resistance and resistance to the product.

[0006]

That is, the method of extrusion molding of a cement building material of the present invention comprises kneading a cement, a siliceous raw material, an aggregate, and a reinforcing fiber by adding an extrusion aid, an air entraining agent, and a required amount of water. Then, in a method of extruding a lightweight and high-strength product by extruding a cement kneaded material containing microbubbles and extruding the same, the mixed powdered material previously dry-mixed is supplied to a kneader, and then air entrained. After the agent is added to a smaller amount of water alone than the predetermined amount of water and stirred and foamed uniformly, this is supplied to a chute to be charged into the kneader, and again in the charged chute by an air blow, a stirring means such as a stirring blade or the like. It is characterized in that foaming and washing of the inner wall of the charging chute with the remaining amount of water are supplied to the kneader while the whole is kneaded and then supplied to an extruder to extrude a product having a predetermined shape.

[0007]

In the present invention, cement, siliceous raw material,
As the cement extrusion molding compound itself, which is made by adding an extrusion aid, an air entraining agent, and a required amount of water to reinforcing fibers other than aggregate and asbestos, what is known as a conventional so-called extrusion compound is used. There is nothing special to note.

In the present invention, the compounding material is divided into an air entraining agent, water and other compounding materials. The former is sufficiently foamed by stirring, and the latter is a process of thoroughly dry-mixing and then mixing with a kneader. In the process, when stirring the air entraining agent and water, the air entraining agent is added to a smaller amount of water alone than the predetermined amount of water, stirred and foamed uniformly, and then supplied to a chute to be charged into the kneader. It is characterized in that foaming is again performed in the charging chute by a stirring means such as an air blow or a stirring blade, and the inner wall of the charging chute is supplied to the kneader while cleaning the inner wall with the remaining amount of water.

That is, water containing air bubbles obtained by stirring the air entraining agent and water is not directly supplied to the kneader, but is temporarily supplied to the charging chute, and further, separation of the foaming water and bubbles is prevented.
Promotes miniaturization of bubbles. Then, when the supply chute is supplied from the charging chute to the kneader, the foam adhering to the inner wall of the chute is supplied while being washed off with a residual amount of water. Therefore, the bubble-mixed water supplied to the kneader is in a state in which both are uniformly mixed, and the bubbles also have a small diameter, which contributes to the generation of a uniform cement matrix.

[0010]

Next, an embodiment of the present invention will be described. FIG. 1 is an explanatory view of an apparatus for implementing the method of the present invention.

Example 1 38% by weight of cement, 10% by weight of silica fume as raw material, 38% by weight of silica sand, 4% by weight of pulp fiber, and 10% by weight of aggregate such as sand were extruded to a total of 100% by weight. Methyl cellulose as an auxiliary agent 1
1% by weight of air entraining agent and 22% by weight of water. First, 20% by weight of water and 1% by weight of Kao Corporation as an air entraining agent: trade name "Mighty AE03" The mixture was put into the stirring tank 1 and stirred to foam uniformly. Next, the aerated water W is supplied to the input chute 2 while the stirring blade 1A of the stirring tank 1 is driven at a low speed, and the aerated water W is further foamed by the foam dispersing mixer 2A in the input chute 2 so that the remaining 2% by weight is obtained. The supply chute 2 was supplied to the kneader 4 while washing the inner wall of the chute 2 with the spray 3 using the water.

In FIG. 1, reference numeral 5 denotes a mixer for dry-mixing the water and the compounding material other than the air entraining agent. The mixer 5 extrudes the kneaded material after supplying the mixed powder material P and the aerated water W to the kneader 4 in its entirety. Supply to the molding device 6, thickness 20mm width 200mm length 50
A test plate of 0 mm / was extruded, and the obtained test plate was steam-cured at 60 ° C. for 6 hours and then autoclaved at 8 kg / cm ^{2 for} 12 hours to obtain a test piece.

[Embodiment 2] In the first embodiment, the stirring blade 1 is used to supply the aerated water W from the stirring tank 1 to the charging chute 2.
A test piece was obtained in the same manner as in Example 1 except that A was stopped.

Comparative Example 1 In the same compounding material as in Example 1, the entire amount of water to be added and the air entraining agent were stirred at a high speed in the stirring tank 1 and supplied directly to the kneader 4. A test piece was obtained in the same manner as described above. [Comparative Example 2] In the same compounding material as in Example 1, the whole amount of water to be added and the air entraining agent were stirred at a high speed in the stirring tank 1,
A test piece was obtained in the same manner as in Example 1 except that the aerated water W was supplied to the kneader 4 without cleaning the inner wall of the charging chute 2 through the charging chute 2.

The obtained test piece was subjected to a burst resistance test, a bending strength test, and a freeze-thaw test, and the results shown in Table 1 were obtained. The explosion-proof test was conducted by directly applying the flame of the gas burner adjusted to 950 ° C and observing the presence or absence of explosion or surface cracks after 10 minutes on 10 test plates. According to the measurement of the bending strength, the freeze-thaw test was based on the observation of the presence or absence of chipping after repeating 300 cycles in accordance with JIS A 5422.

[0016]

[Table 1]

In Table 1, in the column of the freeze-thaw test, ○ indicates that the surface condition was not changed at all, △ indicates that slight chipping was observed, and X indicates that many chippings were observed.

[0018]

As described above, according to the method of the present invention, when an air entraining agent is added to a predetermined amount of water and agitated and foamed, the mixture is stirred and supplied in two stages of a stirring tank and a charging chute. Therefore, it is possible to knead with other cement compounding materials in a state of uniform bubble diameter without separating water and foam, and as a result, it is possible to produce a cement matrix having a uniform porous structure, This makes it possible to extrude a cement building material having excellent explosive properties, freeze-thaw properties and flexural strength.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for implementing a method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stirrer tank 1A ... Stirrer blade 2 ... Input chute 2A ... Foam dispersing mixer 3 ... Spray 4 ... Kneader 5 ... Dry mixing mixer 6 ... Extrusion molding equipment W ... Air mixed water P ... Mixed powder material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B28B 3/20 C04B 38/10

Claims (1)

(57) [Claims] 1. An extrusion aid, an air entrainer and a required amount of water are added to cement, siliceous raw material, aggregate, and reinforcing fiber and kneaded to obtain a kneaded cement containing microbubbles, which is extruded. In the method of extruding a lightweight high-strength product by the above, the above mixed powdered raw material which has been dry-mixed in advance is supplied to the kneader, and then the air entraining agent is added to water of less than a predetermined amount of water alone and stirred. After uniformly foaming the mixture, the mixture is supplied to a charging chute into the kneader, and air is blown again in the charging chute with a stirring means such as a stirring blade, and the inner wall of the charging chute is washed with the remaining amount of water. A method for extruding a cement building material, comprising supplying the mixture to a kneader, kneading the whole, and then supplying the mixture to an extruder to extrude a product having a predetermined shape.