KR20120063978A - Ceramics extrusion die structure and manufacture method thereof for internal crack prevention of large size honeycomb compacts - Google Patents

Abstract

PURPOSE: A ceramics extrusion casting mold structure and a manufacturing method of a large size honeycomb molding using thereof are provided to prevent the generation of inner cracks on the large size honeycomb molding. CONSTITUTION: A ceramics extrusion casting mold structure comprises the following: an outer wall molding discharge unit(130) formed on one side of a body for forming outer walls of a large size honeycomb molding by extruding raw materials; an inner wall molding discharge unit(140) formed on the inside of the outer wall molding discharge unit for molding the inner walls of the large size honeycomb molding by extruding the raw materials; and more than two cell blocks(150) separately located inside spaces divided by the inner wall molding discharge unit for extruding the raw materials through intervals among the cell blocks.

Description

Ceramics Extrusion Die Structure and Manufacturing Method for Internal Crack Prevention of Large Size Honeycomb Compacts

The present invention is a ceramic extrusion mold structure for preventing internal cracks of a large honeycomb molded body, and a method of manufacturing a large honeycomb molded body using the same, and more particularly, a mold to prevent internal cracks generated during the manufacturing process of a large ceramic honeycomb molded body. The present invention relates to a ceramic extrusion mold structure for preventing internal cracking of a large honeycomb molded body to be designed, and a method of manufacturing a large honeycomb molded body using the same.

In general, ceramic honeycomb refers to a porous ceramic structure in which a myriad of holes (cells) in a honeycomb shape are drilled, and is used in various fields by using the structural characteristics of the honeycomb and the physical characteristics of the ceramic. The ceramic honeycomb is characterized by a large specific surface area, excellent air permeability, low pressure loss, high thermal insulation effect, and excellent durability and corrosion resistance.

In particular, ceramic honeycomb has been widely used as a three-way catalyst carrier for automobiles, a catalyst carrier for denitrification, a filter for molten metal, and the like, and has recently been used as a material for ceramic filters for various hot gases, including a filter for removing smoke from diesel vehicles.

Materials used in ceramic honeycomb include cordierite, spodumene, alumina, mullite, silicon nitride (Si3N4), silicon carbide (SiC), and the like.

On the other hand, various methods have been introduced and attempted as a method of manufacturing a ceramic honeycomb. Among them, an extrusion molding method is known to be the best in terms of reliability and efficiency. Progress has been made. Production through the extrusion method is first prepared by mixing the raw material powders and the additives for molding aid such as binders, and then extrusion molding, followed by a drying and firing process.

In particular, in the mold used for extrusion of the honeycomb molded body, a plurality of cell blocks are vertically and laterally disposed at predetermined intervals in the front center of the matrix made of stainless steel, iron, or the like, Slits are formed adjacent to each other along the outermost cell block, and a back hole communicating with the slits is formed on the rear surface of the mother body. Here, the extruded raw material passed through the slit forms a partition wall surrounding each cell, and the cell block blocks the flow of the raw material, thereby forming a hollow portion that becomes a cell. Here, the slits are the outer wall surface of the honeycomb molded body as the ceramic raw material is extruded through the gap during the molding of the honeycomb molded body, and the partition wall is the inner wall surface of the honeycomb molded body as the ceramic raw material is extruded through the gap during the molding of the honeycomb molded body.

However, in the case of a mold for forming a honeycomb molded body of the prior art, the width of the partition wall is thinner than the width of the slit, so that the pressure distribution applied to the ceramic raw material due to the frictional stress with the ceramic raw material applied to the mold wall during extrusion molding. Since it is not dispersed smoothly, the pressure of the slit is formed lower than the partition wall of the mold, so that the extrusion conveyance direction of the ceramic raw material is formed on the outer wall surface of the molded body.

In addition, the pressure distribution formed on the raw material by the torque of the raw material extrusion conveying screw in contact with the mold due to the structure of the extrusion molding machine also has a higher raw material extrusion pressure toward the slit surface rather than the partition wall, and the raw material conveying speed of the slit is formed relatively fast. do.

Therefore, the relative pressure is increased due to the frictional stress formed on the partition walls of the mold, so that the difference in density between the molded body formed in the slit and the raw materials formed on the partition walls is formed while the movement of the ceramic raw materials is not smooth. That is, since the relative density of the ceramic raw material formed on the partition wall is lower than that of the ceramic raw material formed on the slit, when the drying is completed, the shrinkage of the inner wall surface occurs more than the outer wall surface of the molded body. In this way, a large shrinkage of the inner wall surface of the molded body causes an internal crack to be formed.

Moreover, internal cracks that are not identified by the naked eye shorten the life of the product in use, and the cracks of the molded product which are visually confirmed have disadvantages in terms of manufacturing cost because they increase the product defect rate.

An object of the present invention is to solve the problems of the prior art as described above, since the width of the outer wall molding discharge portion formed in the mold and the width of the inner wall molding discharge portion are the same or within the set range, the pressure distribution applied to the raw material is dispersed The ceramic extrusion mold structure for preventing the internal crack of the large honeycomb molded body to prevent the internal gradient of the molded body to prevent the occurrence of the density gradient, thereby extending the service life and to reduce the defective rate during the manufacturing process and using the same It is to provide a method for producing a large honeycomb molded body.

In addition, the object of the present invention is to simplify the honeycomb mold design, and compared with the existing mold design and manufacturing process, it does not require a new device, and ceramic extrusion mold for preventing the internal crack of the large honeycomb molded body made easy to manufacture It is to provide a structure and a method for producing a large honeycomb molded body using the same.

In addition, an object of the present invention is a ceramic extrusion mold for preventing the internal crack of a large honeycomb molded body that can produce a large area product regardless of the size and product quality of the honeycomb molded body when manufacturing the molded body using the designed mold. It is to provide a structure and a method for producing a large honeycomb molded body using the same.

In addition, an object of the present invention is a ceramic extrusion mold structure for preventing the internal crack of the large honeycomb molded body to be formed evenly over the entire molded body regardless of the outer wall surface, the molding density, porosity and strength for the large honeycomb filter carrier product And a method for producing a large honeycomb molded body using the same.

According to a feature of the present invention for achieving the object as described above, the present invention, the outer wall forming discharge portion is formed on one side of the body and the raw material is extruded so that the outer wall surface of the large honeycomb molded body is molded; An inner wall molding discharge part which is formed inside the outer wall molding discharge part and extrudes raw materials so that the inner wall surface of the large honeycomb molded body is molded; And at least two cell blocks spaced apart from each other in the space divided by the inner wall molding discharge part, wherein the raw materials are extruded into adjacent gaps between the cell blocks, and the width of the inner wall molding discharge part is the outer wall molding discharge part. Equal to the negative width, or the difference in width is formed larger in the range of 0.1 mm to 2 mm, or smaller in the range of 0.1 mm to 2 mm.

The inner wall molding discharge part may be formed in any one of a straight, cross, well sperm, and lattice.

The honeycomb cell size by the cell block is 50 × 50 mm to 100 × 100 mm when the inner wall molded discharge part is cross-shaped, and the honeycomb cell size by 101 × 101 mm to 150 × 150 mm by the cell block when the inner wall molded discharge part is well sperm type. When the inner wall molding discharge part is crossed, the honeycomb cell size of the cell block may be formed to be 151 × 151 mm to 200 × 200 mm.

The large honeycomb molded body is a honeycomb molded body for selective catalytic reduction device filter (SCR), a honeycomb molded body for diesel engine exhaust gas reducing filter (DPF), silicon carbide ceramics honeycomb molded body for silicon carbide (SiC) solar absorber, mullite (Mullite) The ceramic honeycomb molded body and the silicon nitride (Si3N4) ceramic honeycomb molded body may be characterized in that either.

In addition, the present invention, the cell size of the honeycomb molded body, and the width of the inner wall molding discharge portion in the mold is equal to the width of the outer wall molding discharge portion, or the difference in the width is formed larger in the range of 0.1mm to 2mm, or 0.1mm to 2mm range A first step of designing the mold to be made smaller with a mold; A second step of mixing the ceramic raw material powder used for the production of the honeycomb molded body, the main binder and the auxiliary binder which is a surfactant; A third step of kneading the ceramic raw material powder, the main binder and the auxiliary binder at least once; A fourth step of extruding the large honeycomb molded body by supplying the kneaded extrusion raw material to a mold; A fifth step of drying the extruded large honeycomb molded body; A sixth step of removing the binder from the dried large honeycomb molded body using a heat treatment; And a seventh step of baking the honeycomb molded body from which the binder is removed at different temperatures according to the intended use.

According to the present invention, since the width of the outer wall molding discharge portion formed in the mold and the width of the inner wall molding discharge portion are the same or are formed within a predetermined range, the pressure distribution applied to the raw material is dispersed and the density is blocked, thereby preventing the internal crack of the molded body. By preventing the occurrence, the service life is extended and the defective rate during the manufacturing process is reduced. In addition, the honeycomb mold design is simple, does not require any new device compared to the existing mold design and manufacturing process, can be easily manufactured, and when manufacturing a molded body using the designed mold, the size and quality of the honeycomb molded body Irrespective of the size, the large-area product can be manufactured, and the molding density, porosity, and strength of the large honeycomb filter carrier product can be produced evenly on the entire molded body regardless of the outer wall surface.

1 is an exploded perspective view showing a state in which a ceramic extrusion mold structure for preventing internal cracking of a large honeycomb molded body according to a first embodiment of the present invention is mounted on a portable device.
2 is a front view showing the structure of a ceramic extrusion die structure for preventing internal cracking of a large honeycomb molded body according to a first embodiment of the present invention.
3 is a perspective view illustrating a large honeycomb molded body molded by a ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body according to the first embodiment of the present invention.
4 is an exploded perspective view showing a state in which a ceramic extrusion mold structure for preventing internal cracking of a large honeycomb molded body according to a second embodiment of the present invention is mounted in a portable device.
5 is a front view showing the structure of a ceramic extrusion die structure for preventing internal cracking of a large honeycomb molded body according to a second embodiment of the present invention.
FIG. 6 is a perspective view illustrating a large honeycomb molded body formed by a ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body according to the second embodiment of the present invention.
7 is a block diagram showing a method for manufacturing a large honeycomb molded body using a ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body according to the present invention.

Hereinafter, with reference to the drawings will be described in detail the configuration of each embodiment of the ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body according to the present invention.

First Embodiment

1 is an exploded perspective view of a ceramic extrusion mold structure for preventing internal cracking of a large honeycomb molded body according to a first embodiment of the present invention, and FIG. 2 is a large honeycomb constituting a first embodiment of the present invention. The configuration of the ceramic extrusion die structure for preventing the internal crack of the molded body is shown in front view, Figure 3 is a large size molded by the ceramic extrusion die structure for preventing the internal crack of the large honeycomb molded body according to the first embodiment of the present invention Honeycomb molded bodies are shown in perspective view.

According to these drawings, the ceramic extrusion mold structure 100 for preventing the internal crack of the large honeycomb molded body is largely the support 110, the honeycomb extrusion die 120, the outer wall molded discharge portion 130, the inner wall molded discharge portion 140 , A cell block 150 and an extrusion raw material injection mold 160.

The support 110 is made of stainless steel, iron or the like material so that the mounting hole 112 is formed so that the honeycomb extrusion die 120 can be mounted in the center portion of the support 110 and the edge of the ceramic extrusion machine (not shown). It is fastened to the tip by a bolt or the like, in the present embodiment it is illustrated as a rectangular plate shape.

The honeycomb extrusion mold 120 is mounted at the center of the support 110 to penetrate the outer wall molding discharge part 130 and the inner wall molding discharge part 140, and arrange the cell block 150, and insert the extrusion raw material injection mold 160. The large honeycomb molded body 10 is molded while the raw material injected through the feeding hole 162 of the extruding die is extruded. At this time, the raw material is extruded into the gap between the outer wall shaping discharge portion 130, the inner wall shaping discharge portion 140 and the cell block 150. Here, ceramics and the like are used as the raw material.

The outer wall molding discharge part 130 is a passage through which the raw material is extruded so as to penetrate the body surface of the honeycomb extrusion die 120 to form the outer wall surface 12 of the large honeycomb molded body 10. According to the shape of the outer surface of 10) may be formed in a square or a circle, etc., in the present embodiment is illustrated as a rectangular shape.

The inner wall molding discharge part 140 is formed at the center of the body surface of the honeycomb extrusion die 120, which is the inner side of the outer wall molding discharge part 130, so that the inner wall surface 14 of the large honeycomb molded body 10 is molded into a partition wall shape. Is a passage through which is extruded, it may be formed in any one of a straight, cross-shaped, well sperm-shaped and lattice, the shape is not limited to this can be changed, but may be formed in a symmetrical or asymmetrical, or the like. On the other hand, the inner wall molding discharge portion 140 in the present embodiment will be described by exemplifying the case of a cross. If the shape of the inner wall shaping discharge portion 140 is a straight line, the outer wall shaping discharge section 130 is divided into two spaces. In the cross shape, the outer wall shaping discharge section 130 is divided into four spaces. The discharge part 130 is divided into nine spaces, and in the case of a lattice shape, the outer wall molded discharge part 130 is divided into nine or more spaces.

At this time, when the inner wall shaping discharge portion 140 is formed in the cross (+) shape, the honeycomb cell size formed by the cell block 150 is included in the range of 50 × 50mm ~ 100 × 100mm, the inner wall shaping discharge portion ( If the 140 is a well sperm (#) type, the honeycomb cell size by the cell block 150 is included in the range 101 × 101mm ~ 150 × 150mm, if the inner wall molded discharge 140 is cross-type, the cell The honeycomb cell size by the block 150 is included in the range of 151 x 151 mm-200 x 200 mm. In this case, the honeycomb cell size by the cell block 150 reflects the experimental results according to the degree of arrival of the raw material reaching the inner and outer sides of the large honeycomb molded body 10 according to the size of the honeycomb cell size.

In addition, the shape of the inner wall molding discharge part 140 depends on the size of the large honeycomb molded body, and the cell size is independent of the size of the molded body because it is a gap between the cell wall and the wall to be manufactured. The cell size can be produced with.

As a result, the honeycomb structure of the large-size honeycomb molded body 10 can be adjusted according to the honeycomb cell having different sizes according to its shape. Furthermore, the honeycomb cell size refers to the space distance between the cell wall and the wall. The honeycomb cell size is divided into 50 cells, 100 cells, 200 cells, 300 cells and 500 cells according to the cell density of the honeycomb molded body, and the honeycomb according to the purpose of using the ceramic honeycomb carrier. The overall size of the molded body is determined and the honeycomb inner cell size is manufactured in various sizes from 1 mm to 10 mm.

On the other hand, the outer wall shaping discharge portion 130 and the inner wall shaping discharge portion 140 has a width W2 of the inner wall shaping discharge portion 140 to distribute the pressure distribution applied to the raw material. Is equal to the width W1 or the width W2 of the inner wall molding discharge part 140 is greater than the width W1 of the outer wall molding discharge part 130 in a range of 0.1 mm to 2 mm, or the inner wall The width W2 of the molding discharge part 140 is smaller than the width W1 of the outer wall molding discharge part 130 in a range of 0.1 mm to 2 mm.

The cell block 150 is spaced apart in the divided space through the inner wall molding discharge part 140 which partitions the outer wall molding discharge part 130 from the inside of the outer wall molding discharge part 130, thereby forming a large honeycomb molded body 10. It is a passage through which raw materials are extruded into adjacent gaps to have a honeycomb structure inside. In this case, the cell block 150 is illustrated as having a square pillar shape, but may be changed to a circular pillar or a polygonal pillar.

Extrusion raw material injection mold 160 is made of stainless steel, iron or similar material is installed on the front end of the extrusion molding machine, it is mounted on the rear of the honeycomb extrusion die 120 in a shape corresponding to the honeycomb extrusion die 120. A plurality of feeding holes 162 into which the extruded raw material is input is formed. Meanwhile, the feeding hole 162 is formed on a cell wall whose center is an intersection point or an edge of the cell block 150.

The large honeycomb molded body 10 includes honeycomb molded body for selective catalytic reduction device filter (SCR), honeycomb molded body for diesel engine exhaust gas reducing filter (DPF), silicon carbide ceramic honeycomb molded body for silicon carbide (SiC) solar absorber, mullite (Mullite) ceramic honeycomb molded body, silicon nitride (Si3N4) ceramic honeycomb molded body, alumina (Al2O3) honeycomb molded body, cordierite (Cordierite) honeycomb molded body can be applied to various structural ceramic honeycomb molded body.

On the other hand, the ceramic extrusion mold structure for preventing the internal crack of the large honeycomb molded body is that the honeycomb extrusion mold 120 and the extrusion raw material injection mold 160 is inserted and supported in the mounting hole 112 formed in the center of the support (110). Although illustrated, the honeycomb extrusion mold 120 and the extrusion raw material injection mold 160 may be used after being mutually fastened without a support.

Second Embodiment

4 is an exploded perspective view showing the structure of a ceramic extrusion mold for preventing internal cracking of a large honeycomb molded body according to a second embodiment of the present invention, and FIG. 5 is a large honeycomb constituting a second embodiment of the present invention. The configuration of the ceramic extrusion die structure for preventing the internal crack of the molded body is shown in front view, Figure 6 is a large-size molded by the ceramic extrusion die structure for preventing the internal crack of the large honeycomb molded body according to the second embodiment of the present invention Honeycomb molded bodies are shown in perspective view.

According to these drawings, the ceramic extrusion mold structure 100 for preventing internal cracks of the large honeycomb molded body is largely supported by the support 210, the honeycomb extrusion die 220, the outer wall molding discharge part 230, and the inner wall molding discharge part 240. , A cell block 250 and an extrusion raw material injection mold 260, and in this embodiment, the support base 210, the honeycomb extrusion mold 220, the outer wall molding discharge part 230, the cell block 250, and the extrusion raw material Since the injection mold 260 has the same structure and function as that of the foregoing embodiment, a detailed description thereof will be omitted.

The inner wall molding discharge part 240 is formed at the center of the body surface of the honeycomb extrusion die 220 which is the inner side of the outer wall molding discharge part 230 so that the inner wall surface 14 of the large honeycomb molded body 10 is molded into a partition wall shape. Is a passage through which is extruded, it may be formed in any one of a straight, cross-shaped, well sperm-shaped and lattice, the shape is not limited to this can be changed, but may be formed in a symmetrical or asymmetrical, or the like. On the other hand, the inner wall molded discharge portion 240 in the present embodiment will be described by exemplifying the case of a well sperm. If the shape of the inner wall shaping discharge part 240 is a straight line, the outer wall shaping discharge part 230 is divided into two spaces, and if the cross is shaping, the outer wall shaping discharge part 230 is divided into four spaces. The discharge part 230 is divided into nine spaces, and in the case of a lattice shape, the outer wall molded discharge part 230 is divided into nine or more spaces.

On the other hand, the outer wall shaping discharge portion 230 and the inner wall shaping discharge portion 240 has a width W2 of the inner wall shaping discharge portion 240 to distribute the pressure distribution applied to the raw material. Is equal to the width W1, or the width W2 of the inner wall shaping discharge portion 240 is larger than the width W1 of the outer wall shaping discharge portion 230 in a range of 0.1 mm to 2 mm, or the inner wall The width W2 of the molding discharge part 240 is smaller than the width W1 of the outer wall molding discharge part 230 in a range of 0.1 mm to 2 mm.

Reference numeral 212, which is not described in the drawings, is a mounting hole, and 262 is a feeding hole.

large Honeycomb Molded  Manufacturing method

A method of manufacturing a large honeycomb molded body using a ceramic extrusion mold structure for preventing an internal crack of the large honeycomb molded body of the present invention will be described with reference to FIGS. 1 to 3 and 7.

Method for producing a large honeycomb molded body using a ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body of the present invention is a mold design step (S300), raw material mixing step (S310), raw material mixing step (S320), extrusion molding step ( S330), drying step (S340), binder removal step (S350) and firing step (S360).

The mold designing step (S300) is a step of designing a mold according to the size (cell size) of the large honeycomb molded body 10, and the forming width W1 of the outer wall molding discharge part 130 formed in the honeycomb extrusion mold 120. The forming widths W2 of the inner wall shaping discharge parts 140 are the same, or the width W2 of the inner wall shaping discharge parts 140 is 0.1 mm to 2 mm greater than the width W1 of the outer wall shaping discharge parts 130. The width W2 of the inner wall molded discharge part 140 may be smaller than the width W1 of the outer wall molded discharge part 130 in a range of 0.1 mm to 2 mm.

Further, in the mold design step (S300), as described above, since the cell size may be changed according to the shape of the inner wall molding discharge part 140, it is possible to manufacture the large honeycomb molded body 10.

The raw material mixing step (S310) is a step of mixing the ceramic raw material powder used in the production of the large honeycomb molded body 10, the main binder and the auxiliary binder which is a surfactant, the raw material powder is 60 to 80% by weight, the main binder is 10 ~ 20 wt%, the auxiliary binder has 5 to 10 wt%. In particular, when the ceramic raw material powder, the main binder, and the auxiliary binder, which is a surfactant, are too high in content, mechanical and chemical properties of the honeycomb molded body are lowered, and when too small, plastic processing becomes difficult.

And the raw material mixing step (S310) is a honeycomb molded body for selective catalytic reduction device filter (SCR), honeycomb molded body for diesel engine exhaust gas reduction filter (DPF), silicon carbide ceramics honeycomb molded body for silicon carbide (SiC) solar absorber, mullite Ceramic raw material powder and methyl cellulose (methyl ceiiulose) used in the manufacture of various structural ceramic honeycomb bodies such as (Mullite), silicon nitride (Si3N4), alumina (Al2O3), cordierite, and carbokisir Methycerose (CMC), methyl cellulose (MC), hydroxy propyl methyl cellulose (HPMC), hydroxy ethyl methyl cellulose (HEMC), etc. are used as the main binders, and as auxiliary binders, dispersants, plasticizers, humectants, Stearic acid, behenic acid, oleic acid, polyethylene glycol (PEG), Using a surface active agent, such as wax Lapin (Paraffine wax), stearic acid (Steric acid) is subjected to a ceramic raw material powder and mixed.

The raw material kneading step (S320) is a step of kneading a plurality of raw materials consisting of a ceramic raw material powder, a main binder and an auxiliary binder, and performing at least a second kneading operation for homogeneous mixing of the ceramic raw material and the added binder. In this case, the more the kneading operation is performed, the more homogeneous mixing of the raw materials can be achieved.

Extrusion step (S330) is a step of manufacturing the large honeycomb molded body 10 by the extrusion molding method through the honeycomb extrusion mold 120, when the raw material is input into the extrusion molding machine through a feed (Feeder), through the feed screw inside the equipment The raw material is smoothly discharged. The extruded raw material disposed of is cast into a honeycomb form through the honeycomb molding die 120, and is cut according to the size of the product and transferred to the next drying process.

That is, in the extrusion molding step (S330), when the extrusion raw material is supplied from the extrusion machine, the extrusion raw material is simultaneously discharged to the outer wall molding discharge part 130 and the inner wall molding discharge part 140 of the honeycomb extrusion die 120 to form the outer wall. The raw material discharged through the discharge unit 130 forms the outer wall surface 12 of the large honeycomb molded body 10, and the raw material discharged through the inner wall molded discharge unit 140 is formed in the large honeycomb molded body 10. The wall 14 is formed, and as the raw material is extruded into the gap of the cell block 150, a cell is formed between the inner wall surface 14 and the outside of the large honeycomb molded body 10.

As such, when the widths of the outer wall molding discharge part 130 and the inner wall molding discharge part 140 are the same or are formed within a predetermined range, not only the molding density formed on the large honeycomb molded body 10 due to the same molding pressure and speed, Since the shrinkage after drying occurs at the same time, it is possible to prevent the occurrence of internal cracks. And since the internal crack of the large honeycomb molded body 10 is not formed even after the heat treatment process through the step (S330) of heat-treating the dried large honeycomb molded body to be described later there is an advantage that can minimize the defective rate of the product. At this time, it is possible to assure the stable quality of the product after the drying and firing process of the large honeycomb molded body 10 manufactured has the advantage of lowering the manufacturing cost of the process compared to the existing manufacturing mold.

However, when the width of the outer wall shaping discharge portion 130 is larger than the width of the inner wall shaping discharge portion 140 as in the conventional method, the inner wall shaping discharge portion (rather than the speed of the raw material extruded through the outer wall shaping discharge portion 130) The raw material extrusion speed through 140 is fast. Therefore, the density of the molded body is dense on the outer wall surface of the honeycomb molded body, which has a high extrusion speed, whereas the inner body of the honeycomb molded body has a low density of the molded body, and an internal crack is formed due to the large shrinkage of the inner wall surface during drying. In addition, the honeycomb molded body in which the presence of the internal crack is not confirmed is heat-treated as it is in the firing process. Therefore, there is a disadvantage that the manufacturing cost increases considerably because the defective rate generated during drying and the defective rate after the heat treatment firing process are combined.

Hereinafter, the effects of the invention to be achieved in the present invention through the existing method as follows.

That is, the inner wall surface 14 of the large honeycomb molded body 10 formed by discharging the outer wall surface 12 cell thickness of the large honeycomb molded body 10 discharged from the outer wall molded discharge unit 130 is discharged from the inner wall molded discharge unit 140. Since it is thicker than the cell thickness, the extrusion raw material is first discharged to the outer wall-forming discharge part 130. Therefore, the cells formed on the outer wall surface 12 of the large honeycomb molded body 10 have a high density, but the cells of the inner wall surface 14 having a narrow cell thickness have a slow discharge rate and discharge rate of the extruded raw material due to the frictional force during the raw material discharge process. As a result, the cell density is relatively low.

Therefore, after the large honeycomb molded body 10 is dried in the step S320 of manufacturing the manufactured large honeycomb molded body, a lot of defects due to internal cracks occur due to the low density inside the molded body in the shrinking process. Here, the reason why the cell thickness of the inner and outer wall surfaces 12 of the large honeycomb molded body 10 cannot be the same is that when the thickness of the molded cell becomes thick, smooth flow of air through the cell is prevented, and the efficiency of removing environmental inhibitors is increased. Because of the fall, the size of the inner wall surface 14 cell thickness is limited. As a result, the outer wall surface 12 is designed to be about twice as thick to support the inner cell walls.

The drying step (S340) is a step of drying the extruded large honeycomb molded body, and drying using microwave (MW) waves and heat, or performing primary and secondary drying while varying heat.

In more detail, the drying step (S340) is a case of a ceramic extruded molded body of a complex structure such as a honeycomb molded body, so that the first method is present in the body of the large honeycomb molded body 10 in a short time using microwave (MW). There is a method of removing more than about 70% of the moisture and drying the remaining moisture at about 90 ~ 110 ℃ (preferably 100 ℃) using a dryer, this method is used when drying a honeycomb that is not very large to be. The second method is the drying method of the large-sized ceramic honeycomb molded body 10, and after primary drying at 50 to 60 ° C. for 24 hours using a dryer, it is about 90 to 110 ° C. (preferably 100 ° C.) using a dryer. This is a method of performing secondary drying for a long time over 72 hours. At this time, the drying step (S340) is carried out at a constant temperature and humidity so as to dry slowly so as to make a homogeneous drying of the inside and outside of the molded body. At this time, the secondary drying may be carried out for a long time, but if the drying is small, its properties are deteriorated due to moisture, it is preferable to dry at least 72 hours. Alternatively, drying is possible through a process in which the temperature of the dryer is gradually lowered after the honeycomb molded body is put on the dryer during the second drying.

Binder removal step (S350) is a step of removing the binder by heat treatment of the dried large honeycomb molded body 10, in the case of the binder used in the extrusion molding, since the complete decomposition and removal occurs at about 400 ~ 500 ℃ The binder is removed using a furnace. In particular, the heat treatment furnace temperature of the binder removal step (S350) is commonly applied.

Firing step (S360) is a step of firing the large honeycomb molded body 10, the binder is removed to express the strength by varying the temperature according to the intended use, the large honeycomb molded body 10 is a selective catalytic reduction device filter (SCR) Honeycomb molded body, honeycomb molded body for diesel engine exhaust gas reduction filter (DPF), silicon carbide ceramic silicon honeycomb molded body for silicon carbide (SiC) solar absorber, mullite, silicon nitride (Si3N4), alumina (Al2O3), Various structural ceramics such as cordierite have various firing temperatures according to ceramic raw materials used for manufacturing honeycomb molded articles.

That is, the honeycomb molded body for the selective catalytic reduction device filter (SCR) is heat treated at a temperature of about 500 to 600 ° C., and the honeycomb molded body for the diesel engine exhaust gas reducing filter (DPF) and the silicon carbide ceramic honeycomb molded body are about 1300. Heat treatment at a temperature of 1500 ℃, the Cordierite honeycomb molded body is heat-treated at a temperature of 1200 ~ 1300 ℃, the Mullite ceramic honeycomb molded body, silicon nitride (Si3N4) ceramic honeycomb molded body, alumina ( Al2O3) honeycomb molded body is heat-treated at a temperature of 1200 ~ 1500 ℃.

At this time, in the firing step (S360), the heat treatment temperature is different depending on the ceramic raw materials used, and even if the honeycomb molded body for the same selective catalytic reduction device filter (SCR) is used, the firing temperature is varied depending on the raw material size of the ceramics and the content of the sintering additive. Is changed.

For example, the main raw material of the same selective catalytic reduction device filter (SCR) is TiO2, the raw material size is used in a variety of sizes, the use of very small TiO2 temperature is lowered, and the use of coarse particles, the temperature is increased. There are also various kinds of catalysts to be added here. Typically, when the amount of vanadium (V2O5), which is a kind of catalyst, increases, the heat treatment temperature decreases, and when used less, the heat treatment temperature increases. In the case of silicon carbide ceramics, since the sintering additive is used in the range of heat treatment temperature, the ceramic raw material is not used alone, but the sintering additive is used in the main raw material. It is decided.

On the other hand, the temperature is too high in the drying step (S340), the binder removal step (S350) and the firing step (S360), such as deterioration occurs if the temperature is too high, if it is too low, because the plastic processing is not performed in the experimental value Result.

10: large honeycomb molded body 12: outer wall surface
14: inner wall surface 110, 210: support
112, 212: mounting holes 120, 220: honeycomb extrusion mold
130, 230: outer wall molded discharge part 140, 140: inner wall molded discharge part
150, 250: cell block 160, 260: extrusion raw material injection mold
162, 262: feeding hole

Claims (5)

An outer wall molding discharge part formed on one surface of the body and extruded from the raw material to mold the outer wall surface of the large honeycomb molded body;
An inner wall molding discharge part which is formed inside the outer wall molding discharge part and extrudes raw materials so that the inner wall surface of the large honeycomb molded body is molded; And
And at least two cell blocks spaced apart from each other in the divided space through the inner wall molding discharge part.
Raw materials are extruded into adjacent gaps between the cell blocks,
The width of the inner wall molded discharge portion is the same as the width of the outer wall molded discharge portion, the difference in the width is formed larger in the range of 0.1mm to 2mm, or smaller in the range of 0.1mm to 2mm of the large honeycomb molded body, characterized in that Ceramic extrusion mold structure to prevent internal cracking.
The method of claim 1,
The inner wall molding discharge portion is formed of any one of a straight, cross-shaped, well sperm-shaped and lattice-shaped ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body.
The method of claim 2,
When the inner wall molded discharge part is cross-shaped, the honeycomb cell size by the cell block is 50 × 50 mm to 100 × 100 mm,
When the inner wall molded discharge part is well sperm type, the honeycomb cell size by the cell block is 101 × 101 mm to 150 × 150 mm,
The honeycomb cell size by the cell block is 151 × 151 mm to 200 × 200 mm when the inner wall molded discharge part is crossed, the ceramic extrusion mold structure for preventing internal cracking of a large honeycomb molded body.
The method of claim 1,
The large honeycomb molded body is a honeycomb molded body for selective catalytic reduction device filter (SCR), a honeycomb molded body for diesel engine exhaust gas reducing filter (DPF), silicon carbide ceramics honeycomb molded body for silicon carbide (SiC) solar absorber, mullite (Mullite) Ceramic honeycomb molded body, silicon nitride (Si3N4) ceramic honeycomb molded body, alumina (Al2O3) honeycomb molded body, cordierite (Cordierite) honeycomb molded body characterized in that the ceramic extrusion mold structure for preventing internal cracks of large honeycomb molded body. .
The cell size of the honeycomb molded body and the width of the inner wall molding discharge portion in the mold are the same as the width of the outer wall molding discharge portion, or the difference in width is formed to be larger in the range of 0.1 mm to 2 mm or smaller in the range of 0.1 mm to 2 mm. Designing the first step;
A second step of mixing the ceramic raw material powder used for the production of the honeycomb molded body, the main binder and the auxiliary binder which is a surfactant;
A third step of kneading the ceramic raw material powder, the main binder and the auxiliary binder at least once;
A fourth step of extruding the large honeycomb molded body by supplying the kneaded extrusion raw material to a mold;
A fifth step of drying the extruded large honeycomb molded body;
A sixth step of removing the binder from the dried large honeycomb molded body using a heat treatment; And
Manufacturing a large honeycomb molded body using a ceramic extrusion mold structure for preventing internal cracks of the large honeycomb molded body, characterized in that it comprises a; seventh step of firing the large honeycomb molded body from which the binder is removed at different temperatures depending on the intended use; Way.

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