JPH08281619A - Manufacture of high design molding - Google Patents

Abstract

PURPOSE: To prevent the generation of defective surface such as breakage by dehydrating until the given concentration is provided by a pressing means with an emboss sheet, forming a cake formed into the final shape or the shape similar to the final, and then dehydrating until the given concentration is provided by the pressing means with an emboss sheet and molding a product into the final shape. CONSTITUTION: Dehydration is carried out until the concentration of 43-53% is provided by preliminary pressing by a pressing means 17 with an emboss sheet 16 under the pressure of 0.5-10kgf/cm<2> of cement slurry of concentration of 15-30% to prepare a cake 23 formed into the final shape or the shape similar to the final. As another process, the pressing means only is lifted as the emboss sheet 16 remains mounted on the cake 23 after the completion of primary pressing, and the primary pressing is released. In the secondary pressing, the cake 23 provided in the preliminary pressing is carried out by the pressing means 17 with the emboss sheet 16 under the pressure of 30-70kgf/cm<2> , and dehydration is carried out until the concentration is 60-70% and a product is formed into the final shape.

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 high design molded article having a deeply carved design on its surface, and more particularly to a method for producing a high design molded article useful as an outer wall material of a house.

[0002]

2. Description of the Related Art

Conventionally, in the case of producing a highly designed molded product by dewatering a cement slurry, the cement slurry is put into a mold and then the cement slurry is pressed with an embossing plate to be dehydrated and molded. Was there. In this method, since it is necessary to convey the molded cement slurry to the next step or the like before it is hardened to some extent, if a deeply carved design such as stone cutting is applied, there is a problem that the design is deformed during conveyance. there were. In order to prevent such deformation, conventionally, a method such as performing a long-time dehydration press time to sufficiently dehydrate the cement slurry or adding a fluidization inhibitor to the cement slurry has been used. . However, such a prevention method has drawbacks such as slow production speed and increased production cost.

As another method for producing a highly designed molded product, a so-called precast method is used in which a cement slurry is put on an embossed plate, and after the cement slurry is hardened, the mold is removed to obtain a highly designed molded product. Is also known. By using the precast method, it is possible to manufacture a molded product having a design that is similar to the surface shape of the embossed plate to some extent.
However, the precast method has a drawback that it takes too much time to complete the molding and that the obtained molded product is defective because it entraps air when the cement slurry is charged. Furthermore, since the dehydration in the precast method is performed only from any one of the upper and lower surfaces or both surfaces, the cement slurry near the four peripheral surfaces of the form becomes a high water content state due to its nature, resulting in a shortage of materials, There was also a defect that the molded product thus obtained was damaged.

In addition to the above method, for example, Japanese Patent Publication No.
There is also known a method for producing a highly designed molded product using a press molding apparatus described in Japanese Patent Publication No. 73849. In the press molding apparatus described in this publication, a pattern plate is set on a lower mold, cement slurry is supplied onto the pattern plate, and press molding is performed together with the upper mold on a flat plate. The press molding apparatus has an advantage that the mold can be manufactured at low cost because the mold and the pattern plate are separate bodies. However, it has a drawback that a large amount of pattern plates are required to mass-produce a molded body. Further, there is a drawback that the pattern board cannot be removed until the molded body is completely cured.

[0006] Therefore, an object of the present invention is to provide a method capable of preventing a surface defect such as a defect from occurring and producing a cement molded product having a deep carved design in a short time and at a low cost.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors focusing on the fluidity characteristics of cement slurry under press, the fluidity characteristics of the cement slurry in press molding are defined as specific conditions. It was found that the above objects can be achieved by controlling.

The present invention has been made based on the above-mentioned findings, and after the cement slurry is put into a mold, the cement slurry is pressed by a pressing means having an embossing plate to dehydrate and mold it. In the method for producing a highly designed molded product, a cement slurry having a concentration of 15 to 35% is primarily pressed by a pressing means having an embossing plate under a pressure of 0.5 to 10 kgf / cm ² , and a concentration of 43 to
Dewatering to 53% and obtaining a cake molded into the final shape or a shape similar to it, then, after depressurizing the primary press, the cake is 30 to 70 kgf / cm 2.
A method for producing a high-design molded article, which comprises secondary pressing with a pressing means having an embossing plate under the pressure of ² to dehydrate until the concentration reaches 60 to 70% and molding into a final shape. By providing it, the said objective was achieved.

[0009]

In the method of the present invention, by the primary press,
The material in the cement slurry is made to reach every corner of the embossed irregularities, and then a secondary press is used to complete the dehydration and give the final shape.

The method of the present invention will be described in detail below.

According to the method of the present invention, after the cement slurry is put into the mold, the cement slurry is pressed by a pressing means having an embossing plate for dehydration and molding, so that the surface has a deeply engraved uneven shape. The method for producing a high-design molded product is characterized by a cement slurry dehydration step in press molding. The dewatering step includes a primary pressing step and a secondary pressing step. Hereinafter, with reference to the drawings, the primary pressing process and the secondary pressing process will be described in detail by taking a batch process as an example. Here, FIG. 1 is a schematic view showing a step of the method of the present invention, FIG. 2 is a schematic view showing a cross section of a press molding apparatus, and FIG. 3 is a transfer step from a primary press to a secondary press. 4 is a schematic diagram showing an alternative method of FIG.
FIG. 1 is a schematic diagram showing an apparatus for carrying out the method of the present invention in continuous steps.

As shown in FIG. 1A, in the method of the present invention, first, the mold 12 is placed on the perforated plate 10,
Cement slurry 15 from the hopper 14 into the mold 12
Input. In this case, the cement slurry 15 has a concentration of 15 to 35%. If the concentration is less than 15%, bleeding (a phenomenon in which the material and water are separated in the cement slurry and the water floats) occurs, and a cement slurry having a uniform concentration cannot be obtained. If it exceeds the above range, the cement slurry, which will be described later, cannot be properly smoothed, and a cement slurry having a uniform concentration cannot be obtained. The concentration of the cement slurry 15 is preferably 15 to 30%.

The composition of the cement slurry 15 is not particularly limited, and the composition may be appropriately determined according to the purpose of use of the molded product obtained by the method of the present invention. For example, when the molded product obtained by the method of the present invention is used as an outer wall material for a house, the cement slurry is typically slag, gypsum, perlite, mica, in addition to cement and water.
It contains pulp, vinylon fiber, polymer flocculant, etc. as its components. The content of these components is typically 15 to 50% by weight of cement, 30 to 70% by weight of slag, 3 to 10% by weight of gypsum, 3 to 10% by weight of perlite, and 2 of mica.
-10 wt%, pulp 3-6 wt%, vinylon fiber 0.
5 to 1.5% by weight, polymer flocculant 0.1 to 0.5% by weight
However, the present invention is not limited to this.

In the present invention, the cement slurry 15 can be put into the mold 12 until the thickness thereof becomes 65 mm. This thickness is extremely large as compared with the conventional method for manufacturing a cement molded product. As a result, according to the method of the present invention, it is possible to manufacture a cement molded product having a deep engraving, that is, a design with a large difference in unevenness.

After the cement slurry 15 has been charged, as shown in FIG.
As shown in (c), the pressing means 17 having the embossing plate 16 is lowered to perform the primary pressing of the cement slurry 15. Prior to performing such a primary press, it is preferable to smooth the cement slurry 15 charged in the mold 12 by using a doctor blade 18 or the like as shown in FIG. 1B. The reason for this is
As shown in FIG. 1 (a), the cement slurry 15 that has been put into the mold 12 has a surface 20 that is not smooth and has a recessed portion 20. The water in the cement slurry exudes into such a portion and is in a state of being accumulated. This is because if the primary pressing is immediately performed from this state, a material shortage will occur in the portion where water is accumulated, resulting in surface defects such as defects. Therefore, it is preferable to smooth the cement slurry 15 put in the mold 12 as shown in FIG. 1B before performing the primary pressing.

Next, the primary pressing step shown in FIG. 1 (c) will be described in detail. In the primary pressing step, the cement slurry 15 is applied to the embossed plate 16 under a pressure of 0.5 to 10 kgf / cm ^2. The cake is molded into the final shape or a shape similar to that of the cake 23, which is dehydrated until the concentration reaches 43 to 53% by the pressing means 17 that it has.

The pressure during the primary press is as described above.
It is 0.5 to 10 kgf / cm ² . If the pressure of the primary press is less than 0.5 kgf / cm ² , the cake 23 will be significantly deformed during transfer to the secondary pressing process, which is the next process, and if it exceeds 10 kgf / cm ² , the pressure of the secondary press will be reduced. Even if it is raised, the material does not move and the molded product is rounded and cracks occur, so it is within the above range. The pressure of the primary press is preferably ¹ to 5 kgf / cm ² .

By the pressure as described above, the cake 23 is obtained by dehydrating the cement slurry 15 to a concentration of 43 to 53%. If the concentration is less than 43%, the cake 23 will be significantly deformed and the material will be blown out during the secondary pressing. On the other hand, if the above concentration exceeds 53%, material transfer does not occur, the secondary press-formed product is rounded, and in some cases cracked, so it is within the above range. The above concentration is preferably 44 to 48%.

The thickness of the cake 23 in the mold 12 is preferably 20 to 30 mm by this primary press. By setting the thickness of the cake 23 within the above range, a cake that is not significantly deformed is molded, which is preferable.

The primary press will be described in more detail with reference to FIG.
As shown in FIG. 3, the pressing means 17 having the embossing plate 16 is lowered from above the cement slurry 15 put in the mold 12 to make the cement slurry 1
Dewater press 5. In order to effectively perform dehydration, the embossed plate is provided with a large number of dehydration holes 21. The dewatering hole 21 communicates with the dewatering hole 21 'of the pressing means, and the dewatering hole 21' is connected to a pump 22 to dewater the cement slurry 15. At this time, it is preferable to interpose a filter cloth 24 between the cement slurry 15 and the embossed plate 16. As a result, the cement slurry 15 can be dehydrated more effectively. The filter cloth 24 has a thickness of 0.5 to 1.0 mm and an air permeability of 10,000 to 40, for example.
A plain weave or a twill weave made of synthetic fiber having a density of 000 cm ³ / min · cm ² is preferably used, but not limited thereto.

The dewatering holes 21 and 21 'and the pump 22 not only dewater the cement slurry 15 but also remove air from the air pool generated between the cement slurry 15 and the embossing plate 16. It also works as a pullout.

It is more effective to perform dehydration from the lower portion of the cement slurry 15, that is, from the porous plate 10 together with dehydration through the embossing plate 16. More specifically, as shown in FIG. 2, the perforated plate 10 is provided with a large number of dehydration holes 26, which are connected to a pump 28 so that the cement slurry 15 can be dehydrated from below as well. Done. At this time, it is preferable to interpose a filter cloth 30 between the cement slurry 15 and the porous plate 10. As a result, the cement slurry 15 can be dehydrated more effectively. The filter cloth 24 has, for example, a thickness of 1.0 mm or more and an air permeability of 10,000 to 40,000 cm ³ / min.
A synthetic fiber twill weave or a twill weave woven fabric having a size of cm ² is preferably used, but not limited thereto.

As described above, in the primary press, the cement slurry 15 is dehydrated by the cement slurry 1 described above.
It is preferable to perform dehydration from the upper and lower surfaces of No. 5, but it is more preferable to dehydrate from the side surface of the cement slurry 15. That is, in addition to the dehydration from the embossed plate 16 and the perforated plate 10, it is desirable to perform dehydration from at least one side surface of the mold 12, preferably from all four side surfaces. More specifically, as shown in FIG.
A large number of dehydration holes 32 are provided on the side surface of the mold 12, the dehydration holes 32 are connected to a pump 34, and the cement slurry 15 is also dehydrated from the side surface.
Thus, by dehydrating the cement slurry 15 also from its side surface, the dehydration press time can be further shortened and the occurrence of surface defects such as defects can be effectively prevented. The reason is that when the cement slurry 15 is dehydrated only from the upper and lower surfaces, the side surface of the cement slurry 15, that is, the portion in contact with the mold 12 is in a high water content state due to the nature of the cement slurry 15. ,
In many cases, the resulting molded product lacks in materials and may be damaged, but such dehydration can be prevented by dehydrating the cement slurry 15 from its side surface. Is. Also in the dehydration from the mold 12, it is preferable to interpose the filter cloth 36 between the mold 12 and the cement slurry 15. As a result, the cement slurry 15 can be dehydrated more effectively. Examples of the filter cloth 24 include the porous plate 10 and the cement slurry 1
The filter cloth 24 interposed between the filter cloth 5 and the filter cloth 5 may be used, but is not limited thereto.

The dehydration of the cement slurry 15 in the primary press has been described above in detail. In the primary press, the cement slurry 15 is molded into a final shape or a shape similar thereto in addition to the dehydration of the cement slurry 15. Make cake 23. Here, the reason for including "similar shape" is that perfect molding to the final shape is
This is because it is carried out in a secondary press described later, so that it is not necessary to completely mold the cake 23 in the primary press into a final shape. The molding in the primary press can be performed by a pressing means 17 having an embossing plate 16 as shown in FIG. 2, for example. In this case, the embossing plate 16 and the pressing means 1
It may be integral with or separate from 7. The surface of the embossing plate 16 has an uneven shape, and such a shape is a shape that can give a final shape to the surface of the molded product, or a shape similar thereto. In addition, as an example of the final shape of the surface of the molded product, when the molded product is used as an outer wall material of a house, it may be, for example, a deeply carved tile-like shape or a stone-tone-like shape, but is not limited thereto.

When the primary press is completed in this way, as shown in FIG. 1D, the embossing plate 16 is raised together with the pressing means 17 to release the pressure of the primary press. Next, the cake 23 is transferred to the secondary press, and the cake 23 shown in FIG.
Secondary pressing is performed as shown in (e).

As an alternative to this, as shown in FIG. 3, after the primary press is completed, the embossing plate 16 is still placed on the cake 23 and only the pressing means is raised to raise the primary press. It is also preferable to decompress. This prevents air from entering between the embossing plate 16 and the cake 23 when pressing the cake 23 with the embossing plate 16 again in the secondary pressing, and Due to the surface tension of the cake 23 when the embossing plate 16 rises, the embossing plate 1
The cake 23 adheres to the surface of the
It is possible to prevent the shape of the item from breaking. Then, at the time of secondary pressing, the pressing means 17 is lowered and the embossing plate 16 is pressed to perform pressing.

When the primary press is decompressed and transferred to the step of the secondary press, the form 12 may be attached or removed.

Next, the secondary press will be described. In the secondary press, the cake 2 obtained in the primary press
3 is secondarily pressed by a pressing means having an embossing plate under a pressure of 30 to 60 kgf / cm ² , and the concentration is 60 to 70.
It is dehydrated until it reaches 100% and molded into the final shape.

The pressure during the secondary pressing is 3 as described above.
It is 0 to 60 kgf / cm ² . The pressure of the secondary press is 3
If it is less than 0 kgf / cm ² , it takes a long time to make the above-mentioned cake 23 into a design conforming to the embossed shape, which is 60 k.
If it exceeds gf / cm ² , it is difficult to control the thickness and it takes a long time to reach the maximum pressure, so the content is set within the above range. The pressure of the secondary press is 45 to 55 kgf / cm ^2.
It is preferred that

By the pressure as described above, the cake 23
Is dehydrated until its concentration reaches 60-70%. If the above concentration is less than 60%, the surface hardness of the secondary press molded product is low, and the design collapses or sags when stacked,
If it exceeds 70%, the specific gravity becomes high, that is, a heavy molded product will be obtained. The above concentration is 62 to 6
It is preferably 5%.

The thickness of the cake 23 in the mold 12 is preferably 9 to 22 mm by this secondary pressing. By setting the thickness of the cake 23 within the above range, it is possible to obtain a target molded article having a high design property, which is preferable.

The secondary press can be used by using the same device as the primary press. That is, the dehydration in the secondary press may be performed from the upper and lower surfaces of the cake 23, or in addition to this, from the side surface. In the secondary press, it is preferable to dehydrate with a filter cloth,
In view of the high pressure of the secondary press, the filter cloth used at that time preferably has high strength. For example, the filter cloth has a thickness of 1.0 mm or more and an air permeability of 10,000 to 4000.
A synthetic fiber twill woven or cedar twill woven fabric having a density of 0 cm ³ / min · cm ² may be used, but is not limited thereto.

The cake 23 in the secondary press
The surface shape of the embossed plate 16 used for molding
It has such a shape as to give a final shape to the obtained molded product. The specific shape is the same as that of the embossed plate used in the primary press.

When the secondary press is completed, as shown in FIG. 1 (f), the embossing plate 16 is raised together with the pressing means 17 to release the pressure of the secondary press. Then, the target molded product is obtained by curing and curing by a known method.

According to the method of the present invention, the thickness of the molded product can be set to 22 mm at the maximum, and the difference in surface irregularities can be set to 10 mm at the maximum. As a result, it is possible to obtain a molded product with a realistic feeling that is closer to the surface shape of the embossed plate.

Although the method of the present invention has been described based on the batch process, the method of the present invention is not limited to such a batch process, and may be carried out by the continuous process shown in FIG. 4, for example. it can. Therefore, the continuous method will be described below. It should be noted that, of the steps and conditions in the continuous step, those similar to those in the batch step will not be described in detail, but the detailed description in the batch step is appropriately applied. Further, regarding the members and materials in FIG. 4 showing the continuous process, the same numbers are given to the same members, materials and the like in FIGS. 1 to 3 showing the batch process.

FIG. 4 is a schematic diagram showing an apparatus for carrying out the method of the present invention in continuous steps. This apparatus includes a primary press section 40 for performing a primary press, a cutting section 42 for cutting the cake obtained by the primary press into a predetermined size, a transfer section 44 for transferring the cake cut into a predetermined size, and a transfer section 44. Secondary press section 46 that secondarily presses the cake transferred from
Have and. Each part will be described below.

First, the primary press section 40 will be described. In the primary press section, the cement slurry 15 is supplied from the hopper 14 onto the moving felt 40. The cement slurry 15 supplied onto the felt 48 is leveled by a leveling roll 50 and pre-dewatered. Then, the cement slurry 15 is added to the upper dewatering box 52 and the lower dewatering box 5.
4 is pressed first, and the cake 23 is dehydrated to a predetermined concentration and given a predetermined surface shape. Although the mold is not shown in the primary press section 40, a mold may of course be used. When a mold is used, dehydration may be performed from the side surface of the mold.

Next, the cutting section 42 will be described. In the cutting part 42, the cake 23 obtained by the primary pressing part 40 is cut into a predetermined size. The cutting means is not particularly limited, and for example, water jet, scraping, guillotine cutting, and the like can be used, but the cutting means is not limited thereto.

Next, the transfer section 44 will be described. In the transfer unit 44, the cake 23 cut into a predetermined size
Is placed on the standby conveyor 56 and is transferred to the secondary press section 46 which is the next step. Further, the transfer unit 44 has a role of adjusting a process speed difference between the primary press unit 44 and the secondary press unit 46.

Next, the secondary press section 46 will be described. In the secondary press section 46, the cake 23 transferred from the transfer section 44 is pressed by the pressing means 17 having the embossing plate 16 to dehydrate it to a predetermined concentration and give the surface its final shape. When the secondary pressing is completed, the embossing plate 16 is pressed onto the pressing means 17
And the secondary press is released. Then, the target molded product is obtained by curing and curing by a known method.

Although the method of the present invention has been described above based on the typical embodiment of the batch process and the continuous process, the present invention is not limited to such embodiment, and various modifications can be made. It is possible. For example, by making the secondary press multi-stage with two or more stages and changing the embossing shape of each stage, it is possible to produce small quantities of various kinds, and it is also possible to further shorten the embossing die changing time and the dehydration time.

[0043]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Unless otherwise specified,% means% by weight.

Example 1 A concentration of 1 was obtained from the formulation shown below.
A 5% cement slurry was prepared. Next, this cement slurry was put into the press molding apparatus shown in FIG. 2, and the surface thereof was smoothed to a thickness of 62 mm. Then, using a pressing means having an embossed plate having a stone-tone surface, primary pressing was performed for 14 seconds under a pressure of 3 kgf / cm ² to obtain a cake having a concentration of 44%. At this time, dehydration was performed from the upper and lower surfaces and each side surface of the cement slurry. The thickness of the cake obtained is 30
mm.

After completion of the primary press, the primary press was depressurized by raising only the pressing means while the embossed plate was still placed on the cake. The formwork was still attached. Then, the pressing means is lowered to press the embossing plate to remove the cake by 55 k.
Secondary pressing was performed for 15 seconds under a pressure of gf / cm ² to dehydrate until the concentration became 62 to 63%, the thickness was 11 mm, and the final shape was formed.

Then, it was cured and cured to obtain a molded product.
The time required for the above-mentioned primary press and secondary press is
Is until the time to reach a pressure 0 kgf / cm ² to a maximum pressure 3 kgf / cm ² or 55 kgf / cm ^2. Further, the obtained molded product had an average thickness of 11 mm, a difference in unevenness of 7 mm at the maximum, and no defects were observed on the surface.

<Composition of cement slurry> Slag 60% Cement 18% Dihydrate gypsum 6% Perlite 6% Mica 5% Pulp 4% Vinylon fiber 1% Slurry concentration 15% (Material: water = 15: 85)

Comparative Example 1 Cement Slurry Thickness 62
A molded product was obtained in the same manner as in Example 1 except that the dehydration press molding was carried out at a stretch from mm to 11 mm under a pressure of 30 kgf / cm ² . The time required for dewatering press molding was more than 3 minutes. In addition, the obtained molded product has an overall thickness of 11.3.
mm, the difference between the unevenness is up to 5 mm, and
Defects were observed on the surface.

[0049]

As described above in detail, according to the method of the present invention, the dewatering press time is shortened by performing the dewatering press step in the two steps of the primary press and the secondary press, and a large amount of the dewatering press can be performed in a short time. A molded product can be manufactured at low cost. Further, it is possible to manufacture a molded product having an extremely deeply engraved design as compared with the conventional molded product. Furthermore, by performing dehydration not only from the upper and lower surfaces of the cement slurry but also from the side surface, the time for dehydration press is further shortened,
The occurrence of surface defects such as defects is also effectively prevented.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the steps of the method of the present invention.

FIG. 2 is a schematic view showing a cross section of a press molding device.

FIG. 3 is a schematic view showing another method of the transfer step from the primary press to the secondary press.

FIG. 4 is a schematic diagram showing an apparatus for carrying out the method of the present invention in a continuous process.

[Explanation of symbols]

 10 Perforated Plate 12 Formwork 14 Hopper 15 Cement Slurry 16 Embossing Plate 17 Pressing Means 23 Cake

Claims (6)

[Claims] 1. A method for producing a high-design molded article by introducing cement slurry into a mold, and then pressing the cement slurry by a pressing means having an embossing plate to dehydrate and mold the cement slurry. ~ 35% cement slurry 0.5 ~ 10k
Primary pressing with a pressing means having an embossing plate under a pressure of gf / cm ² is performed to dehydrate until the concentration reaches 43 to 53%, and a cake molded into a final shape or a shape similar thereto is obtained, and then, After decompressing the primary press, the cake is 30 to 70 kg.
A high design molded product characterized by being subjected to secondary pressing under a pressure of f / cm ² by a pressing means having an embossing plate, dehydration until the concentration reaches 60 to 70%, and molding into a final shape. how to. 2. The method according to claim 1, wherein the primary dewatering is performed after smoothing the cement slurry charged in the mold. 3. The method according to claim 1, wherein dehydration in the primary press and / or the secondary press is performed from the upper and lower surfaces and side surfaces of the cement slurry. 4. The method according to claim 1, wherein after the completion of the primary press, only the pressing means is lifted to release the pressure of the primary press with the embossed plate still mounted on the cake. the method of. 5. The method according to claim 1, wherein the primary pressing and the secondary pressing are performed in a batch process. 6. The method according to claim 1, wherein the primary pressing and the secondary pressing are performed in a continuous process.