JPH0517005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a coat hanger type extrusion mold for extrusion molding a wide cement-based molded product.

[Background Art] When a wide molded product such as a cement board used for construction is manufactured by extrusion molding, the molding is usually performed using a cord hanger type mold (T die). As shown in FIG. 3, this mold A has a material inlet 1 connected to an extrusion molding machine communicated with a material passage part 3 having a manifold 11, and the tip of the material passage part 3 is opened as an extrusion port 2. Cement-based molding material flows in from the material inlet 1, is spread in the width direction by the manifold 11, passes through the material passage section 3, and is extruded from the extrusion port 2 to form a wide material. A plate-shaped molded product can be obtained. However, in the case of such a coat hanger type mold A, materials such as synthetic resins can be spread well in the material passage part 3 and wide molded products can be molded without problems, but cement-based materials can be molded without any problem. Such materials are difficult to spread due to their viscosity, and the material passing section 3
If the flow at both ends of the mold becomes poor, the material will stay in this area (arrow a in Figure 3) and harden.Therefore, when using cement-based materials, wide molded products must be formed. This is extremely difficult, and generally only molded products with a width of 2 to 2.5 times the diameter of the material inlet 1 can be molded.

[Object of the Invention] The present invention has been made in view of the above points, and provides an extrusion mold for cement-based molded products that can perform wide extrusion molding even with cement-based materials. The purpose is to

[Disclosure of the Invention] The extrusion molding die for cement-based molded products according to the present invention has a material inlet 1 connected to the tip of the extruder and a width wider than the material inlet 1, and is suitable for molding cement-based products. The extrusion port 2 is located between the slit-shaped extrusion port 2 through which the material of
A material passing portion 3 having a slit-like cross section with approximately the same width as
A central projecting part 4 is made to protrude from the inner wall surface of the material passage section 3 near the entrance from the material inflow port 1, so that a central projecting part 4 is formed between both sides of the central projecting part 4 and the side wall surface of the material passing part 3. Branch flow passages 5, 5 are formed respectively, and end protrusions 6, 6 are respectively protruded from both sides of the inner wall surface of the material passage section 3 on the side of the extrusion port 2 from the central protrusion 4. End flow passages 7, 7 communicating with the branch flow passages 5, 5, respectively, are formed between the outer side surfaces of the protrusion parts 6, 6 and the side wall surface of the material passage part 3, and the pair of end protrusion parts Communication flow passages 8, 8 communicating with the branch flow passages 5, 5 are formed between the portions 6, 6 and the central protrusion portion 4, respectively, and both communication flow passages 8, 8 are formed between the protrusion portions 6, 6 at both end portions. 8 join together to form a central flow passage 9 which communicates with the projecting base parts 4 and 6 in the material passage part 3.
are provided to distribute the material for molding into each flow path 5, 7, 8, 9.
The above object is achieved by dividing the flow into two parts, and the present invention will be described in detail below with reference to Examples.

Mold A is formed by matching a pair of split molds 12, 12, and inside mold A there is a material inlet 1 that opens at one end and an extrusion port 2 that opens at the other end. and a material passage section 3 which acts as a manifold between the material inlet 1 and the extrusion port 2. The extrusion port 2 is formed in the shape of a slit with a width several times wider than the diameter of the material inlet 1. The material passage section 3 is formed into a slit-like cross-section with a width that is almost the same as the width of the extrusion port 2, but the width is narrowed in the vicinity of the entrance from the material inflow port 1 so that the entire material is coated as shown in FIG. Formed into a hanger shape. Then, near the entrance from the material inlet 1, a central protrusion 4 is attached to the inner surface of each split mold 12, 12 (i.e., the inner wall surface of the material passage section 3).
4 are made to protrude, respectively, and the split molds 12, 12
The heights of the central protrusions 4, 4 are set so that the front end surfaces of the central protrusions 4, 4 are in close contact with each other as shown in FIG. By making the central protrusion part 4 protrude in the material passage part 3 in this way, the central part of the material passage part 3 near the entrance from the material inlet 1 becomes a part through which the material cannot pass.
The material branches and flows into branch flow passages 5, 5 formed between the side surfaces on both sides of the central protrusion section 4 and the side wall surfaces of the material passage section 3. Further, end protrusions 6, 6 are respectively protruded on both sides of the inner surface of each split mold 12, 12 at a position on the side of the extrusion port 2 from the central protrusion 4. The height is split type 1
2 and 12 are set to such an extent that a gap 13 is formed between the tip surfaces of the opposing end protrusions 6 and 6 as shown in FIG. By providing the end protrusions 6, 6 in the material passage section 3 in this way, the above-mentioned End flow passages 7, 7 communicating with the branch flow passage 5 are formed, and the respective side faces of the end protrusions 6, 6 facing the central protrusion 4 and the side faces of the central protrusion 4 An end flow path 6 is branched between the end flow path 6 and a branch flow path 5.
A central flow passage 9 is formed in which the communication flow passages 8, 8 are connected to each other, and the communication flow passages 8, 8 are joined between the opposing side surfaces of the respective end protrusions 6, 6 to form a central flow passage 9 in communication with each other. It is designed so that it will be done. These end flow passages 6 and central flow passage 9 are formed in a runner portion 1 whose slit thickness is thinner than that of the material passage portion 3.
4 to the extrusion port 2.

However, for example, when extruding a wide plate-shaped product using a cement-based molding material containing blast furnace slag cement as a cement component, methylcellulose as a thickener, and silica sand or wollastonite as a filler, Finally, the material inlet 1 is connected to an extrusion molding machine, and a cement material is extruded from the material inlet 1 into the mold A. In this way, the material flows from the material inlet 1 to the material passage section 3.
When the material flows inward, the material is prevented from flowing in the center by the central protrusion 4 and is spread out into branch flow passages 5 on both sides of the central protrusion 4 as shown by the arrows in FIG. It flows in two parts. The material flowing into each of the branch flow passages 5, 5 flows out from the outlet of the branch flow passage 5 toward the end protrusion 6, but the end protrusion 6 becomes a gap 13. Because the flow path is narrow, a part of the material passes through the end protrusion 6, but because the flow resistance is large in this part, the other part of the material is in communication with the end flow path 7. The stream is divided into 8 streams. Furthermore, the materials flowing through each of the communicating flow passages 8,8 merge and flow into the central flow passage 9. The material branched and spread on both sides by the central protruding part 4 is divided into a pair of end protruding parts 6, 6.
The flow is further branched to make the flow uniform. In this way, from the material passage part 3 to the runner part 14, from the central flow passage 9 at the center, from the end protrusions 6, 6 on both sides of the center, and from the end flow passage at the end. 7,
The material flows uniformly from each of the runners 7, and in particular at the ends, the material is forcibly branched into the end flow passages 7, 7 and is supplied to the ends of the runner section 14. The material flowing into the runner section 14 is extruded from the extrusion port 2 into a wide plate shape, thereby making it possible to form a cement-based wide molded product. At this time, the material is forcibly fed into both side portions of the runner portion 14 from the end flow passages 7, 7, so there is no fear that the material will stagnate and harden in these portions. By using the mold A, it becomes possible to extrude a wide molded product having a diameter more than four times the diameter of the material inlet 1.

[Effects of the Invention] As described above, according to the extrusion mold of the present invention, the central protrusion and the end protrusion are provided in the material passage section, so that the cement-based molding material can be passed through the branch flow path or the end. Since the flow is divided into a partial flow passage, a communication flow passage, and a central flow passage, when cement-based molding material flows into the material passage part from the material inlet, the material is concentrated in the center by the central protrusion. It is divided into two parts so that the flow of the fluid is blocked and spread out to branch flow passages on both sides, and further branched by the end protrusions into a communication flow passage with the end flow passages and a central flow passage. As a result, the flow of the material is made uniform, the flow of the material is forced at the end by the end flow path, and the material can be extruded from the extrusion port, so that the material stagnates at the end. This makes it possible to extrude a wide molded product without any problems.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a plan view of the same split mold, and FIGS. 3 a and 3 b are a cross-sectional view and a vertical cross-sectional view of a conventional example. 1 is a material inlet, 2 is an extrusion port, 3 is a material passage part, 4 is a central protrusion, 5 is a branch flow passage, 6 is an end protrusion, 7 is an end flow passage, and 8 is a communication flow passage. ,9
is the central flow path.

Claims (1)

[Claims] 1. Between the material inlet connected to the tip of the extrusion molding machine and the slit-shaped extrusion port, which is wider than the material inlet and through which the cement-based molding material is extruded, there is a cross section with approximately the same width as the extrusion port. forms a slit-shaped material passage part, and a central protrusion protrudes from the inner wall surface of the material passage part near the entrance from the material inflow port, thereby forming a connection between both sides of the central protrusion part and the side wall surface of the material passage part. Branch flow passages are formed in between, and end protrusions are made to protrude from both sides of the inner wall surface of the material passage section on the extrusion port side from the central protrusion, and the outer side surfaces of each end protrusion are formed. An end flow passage that communicates with the branch flow passage is formed between the side wall surface of the material passage part, and a communication that communicates with the branch flow passage between the pair of end protrusions and the central protrusion. 1. An extrusion molding mold for a cement-based molded product, characterized in that flow passages are formed respectively, and a central flow passage is formed in which the two communication passages merge and communicate between the protrusions at both ends.