JP2015044402A - Extrusion molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion molding machine, even if a molding material is soft, capable of retaining a pressure-reduced state and removing bubbles while uniformly kneading the molding material.SOLUTION: Provided is an extrusion molding machine comprising: a first casing 21 having a feed port 4; a first screw 31 arranged at the inside of the first casing 21; a second casing 22 having an exhaust port 5 and formed so as to perform vacuum deaeration; and a second screw 32 arranged at the inside of the second casing 22. The first casing 21 and the second casing 22 are communicated with a cylindrically formed communication tube 6.

Description

  The present invention relates to an extrusion molding machine for extruding a molding material mainly composed of cement.

  An inorganic board is manufactured by extruding a molding material that is mainly composed of cement and mixed with fibers such as pulp, polypropylene fibers and vinylon fibers, silica components such as silica sand, silica powder, and fly ash and water using an extruder. This is used as a building member.

  Conventionally, various types of extrusion molding machines have been proposed.

  For example, Patent Document 1 describes a vacuum extrusion molding machine that supplies clay from a hopper, feeds it with a feed screw, and sends it to a deaeration chamber through a slit-shaped eye plate.

  In Patent Document 2, a kneading barrel with a kneading screw installed therein, and an auger barrel with an auger screw installed at the tip of the kneading barrel through a communicating portion are provided, and an extrusion port is provided at the tip of the auger barrel. The provided extruder is described. Then, the kneading screw is provided with a tapered portion, the screw protrusion is provided on the outer peripheral surface of the taper portion and the barrel protrusion is provided on the inner peripheral surface of the kneading barrel, and the screw protrusion and the barrel protrusion are different in the axial direction of the kneading screw. Formed in position.

  Patent Document 3 also describes an extrusion molding apparatus including an extruder and a die, in which a powder material passes through the extruder and then passes through the die, and the powder material is provided in the form of a mixture including a vehicle. Has been. And, having one gear pump between the extruder and the die, whereby the powder material is discharged from the extruder and passes through the gear pump having two or more sets of gears before entering the die, The gear set is arranged continuously with respect to the flow of the powder material.

JP-A-61-169208 JP 2008-179054 A Japanese Patent Laid-Open No. 5-220803

  In the vacuum extrusion molding machine described in Patent Document 1, if the clay closes the hole in the eye plate, the reduced pressure state of the vacuum deaeration chamber can be maintained to the extent that bubbles can be removed from the molding material. However, since a plurality of holes are usually formed in the eye plate, if the clay falls out from one hole, the vacuum deaeration chamber communicates with the outside air through these holes, and it is difficult to maintain the reduced pressure state.

  Further, in the extrusion molding machine described in Patent Document 2, an annular gap is formed between the outer peripheral surface of the ground portion and the inner peripheral surface of the kneading barrel, but it is difficult to completely close the gap with a molding material. The communication portion communicates with the outside air through an unblocked portion, and it becomes difficult to maintain a reduced pressure state.

  Also in the extrusion apparatus described in Patent Document 3, since an annular gap is formed between the outer peripheral surface of the auger screw and the inner peripheral surface of the barrel, a vacuum is passed through a portion that is not blocked by the plasticized mixture. The deaeration chamber communicates with the outside air, and it becomes difficult to maintain the reduced pressure state.

  Furthermore, in the conventional extrusion molding machines as described in Patent Documents 1 to 3, when the molding material becomes soft, there is a problem that it becomes more difficult to maintain a reduced pressure state and it is difficult to remove bubbles from the molding material. .

  The present invention has been made in view of the above points, and provides an extrusion molding machine capable of removing bubbles while maintaining a reduced pressure state and uniformly kneading the molding material even if the molding material is soft. For the purpose.

The extrusion molding machine according to the present invention is
A first casing having a supply port;
A first screw disposed in the first casing;
A second casing having a discharge port and formed to be vacuum degassable;
A second screw disposed in the second casing;
With
The first casing and the second casing are communicated with each other through a communication pipe formed in a cylindrical shape.

  In the extrusion molding machine, it is preferable that an opening on the second casing side of the communication pipe is narrower than an opening on the first casing side.

  In the extrusion molding machine, it is preferable that the length of the communication pipe is variable.

  In the extrusion molding machine, it is preferable that at least one cutting bar is provided so as to cross the opening on the second casing side of the communication pipe.

  In the extrusion molding machine, it is preferable that an inner surface of a distal end portion on the second casing side of the communication pipe is formed in a tapered surface shape so as to spread from the first casing side toward the second casing side. .

  According to the present invention, even if the molding material is soft, it is possible to remove bubbles while maintaining the reduced pressure state and uniformly kneading the molding material.

(A) is a schematic sectional drawing which shows an example of an extrusion molding machine, (b) is an AA line schematic sectional drawing in (a). (A) is an exploded cross-sectional view showing an example of a communication pipe, (b) is a bottom view showing an example of the tip of the communication pipe, (c) is a cross-sectional view showing an example of a short communication pipe, and (d) is a long communication pipe. It is sectional drawing which shows an example. (A) is an exploded sectional view showing another example of the communication pipe, (b) is a bottom view showing another example of the tip of the communication pipe, (c) is a sectional view showing another example of the short communication pipe, d) is a sectional view showing another example of a long communication pipe. (A) (b) is a bottom view which shows another example of the front-end | tip of a communicating pipe. It is a bottom view which shows another example of the front-end | tip of a communicating pipe. An example of the cutting bar is shown, (a) is a front view, (b) is a side view, and (c) is a plan view. Another example of the cutting bar is shown, (a) is a front view, (b) is a side view, and (c) is a plan view. Another example of the cutting bar is shown, (a) is a front view, (b) is a side view, and (c) is a plan view. A mode that a molding material passes the inside of a communicating pipe | tube is shown, (a) (b) is sectional drawing.

  Embodiments of the present invention will be described below.

  FIG. 1 shows an example of an extrusion molding machine 1 according to this embodiment. The extrusion molding machine 1 includes a first casing 21, a first screw 31, a second casing 22, and a second screw 32.

  The first casing 21 is formed in an elongated box shape. The first casing 21 has a supply port 4 (hopper) on the upper surface of one end, and a first opening 71 on the lower surface of the other end. A molding material can be supplied into the first casing 21 from the supply port 4.

  The first screw 31 (pug screw) is disposed in the first casing 21. The first screw 31 is configured to be rotationally driven by a rotational drive device (not shown). By rotating the first screw 31, the molding material in the first casing 21 can be fed from one end side (upstream side) to the other end side (downstream side) of the first casing 21 while being kneaded. The terms upstream and downstream are used based on the direction in which the molding material moves.

  A second casing 22 is provided below the first casing 21. The second casing 22 includes a vacuum deaeration chamber 8 and a storage chamber 9. The storage chamber 9 is formed in an elongated box shape. The vacuum deaeration chamber 8 is provided at an upper portion of one end of the storage chamber 9, and a base portion 10 is provided at the other end of the storage chamber 9. The vacuum deaeration chamber 8 communicates with the base 10 through the storage chamber 9. The vacuum deaeration chamber 8 has a second opening 72 on the upper surface, and the communication pipe 6 is provided in the second opening 72. The communication pipe 6 is formed in a cylindrical shape such as a cylindrical shape so as to protrude from the inner periphery of the second opening 72 to the vacuum deaeration chamber 8 side. The position of the second opening 72 coincides with the position of the first opening 71 of the first casing 21, and the first casing 21 and the second casing 22 are communicated with each other through the communication pipe 6. The base part 10 has a discharge port 5. The vacuum deaeration chamber 8 of the second casing 22 is formed so that it can be vacuum deaerated by a vacuum pump (not shown). Thus, the 2nd casing 22 has the discharge port 5, and is formed so that vacuum deaeration is possible. The higher the degree of vacuum in the vacuum deaeration chamber 8 is, the better. However, it is only necessary that the degree of vacuum in the vacuum deaeration chamber 8 can be reached so as to remove bubbles in the molding material.

  The inner surface 6a in the vicinity of the opening 61c on the first casing 21 side of the communication pipe 6 is preferably formed in a tapered surface shape that is wide on the outside and narrow on the inside as shown in FIG. Thereby, it becomes easy to draw the molding material kneaded by the first screw 31 into the communication pipe 6.

  The opening 63c on the second casing 22 side of the communication pipe 6 is preferably narrower than the opening 61c on the first casing 21 side. For example, as shown in FIG. 2 to be described later, in the vicinity of the opening 63c on the second casing 22 side of the communication pipe 6, a protrusion 6b can be provided in a direction to close the opening 63c to make the opening 63c narrow. In this way, the opening 63c on the second casing 22 side of the communication pipe 6 can be made narrower than the opening 61c on the first casing 21 side. The protrusion 6b may be provided on the entire inner peripheral surface of the communication pipe 6 near the opening 63c on the second casing 22 side, or may be provided on a part as shown in FIG. When the projection 6b is provided as described above, the molding material 20 is drawn by the projection 6b when the molding material 20 in the communication pipe 6 is drawn toward the vacuum deaeration chamber 8 as shown in FIG. 9A. The tip end portion of the vacuum deaeration chamber 8 on the side of 20 is easily sheared, and only this tip end portion easily falls into the vacuum deaeration chamber 8. Thereby, it can suppress that all the molding materials 20 in the communicating pipe 6 fall into the vacuum deaeration chamber 8 of the 2nd casing 22 at once.

  The second screw 32 (auger screw) is disposed in the storage chamber 9 of the second casing 22. The second screw 32 is configured to be rotationally driven by a rotational drive device (not shown). By rotating the second screw 32, the molding material in the second casing 22 is further kneaded, and from the vacuum deaeration chamber 8 on the one end side (upstream side) of the second casing 22 to the other through the storage chamber 9. It can be sent to the base part 10 on the end side (downstream side). In FIG. 1, the second screw 32 is illustrated as rotating in two different directions, but other screws may be used.

  Next, FIG. 2 shows a specific example of the communication pipe 6. As shown in FIG. 2A, the communication pipe 6 includes a base 61, an intermediate part 62, and a tip part 63. FIG. 2C shows a short communication pipe 6, which is composed of a base portion 61 and a tip portion 63. FIG. 2 (d) shows a long communication pipe 6, which is composed of a base part 61, an intermediate part 62, and a tip part 63. Thus, the intermediate part 62 may or may not be used.

  The base 61 is formed in a cylindrical shape, a flange portion 61a is provided at one end, and a male screw portion 61b is provided at the other end. The base 61 is fixed to at least one of the first opening 71 and the second opening 72 with a flange 61a so that the male screw 61b is located on the vacuum deaeration chamber 8 side. Thus, the base 61 may be a separate member that can be removed from the vacuum deaeration chamber 8, but may be integrated with the vacuum deaeration chamber 8.

  The intermediate part 62 is formed in a long cylindrical shape, and has an internal thread part 62a at one end and an external thread part 62b at the other end.

  The tip portion 63 is formed in a short cylindrical shape, and is provided with a female screw portion 63a at one end and a protrusion 6b on the inner peripheral surface at the other end. The protrusion 6b may not be provided, but is preferably provided.

  And the short communication pipe 6 as shown in FIG.2 (c) can be formed by joining the external thread part 61b of the base 61, and the internal thread part 63a of the front-end | tip part 63. FIG. In this case, the intermediate part 62 is not used. Further, by joining the male screw portion 61b of the base portion 61 and the female screw portion 62a of the intermediate portion 62, and further joining the male screw portion 62b of the intermediate portion 62 and the female screw portion 63a of the tip portion 63, FIG. It is also possible to form a long communication pipe 6 as shown in FIG. The intermediate part 62 may not be used as shown in FIG. 2C, or only one intermediate part 62 may be used as shown in FIG. 2D. However, if necessary, two intermediate parts 62 may be used. You may connect above. Thus, it is preferable that the length of the communication pipe 6 is variable. If the molding material is hard, the communication pipe 6 is shortened. If the molding material is soft, the communication pipe 6 is lengthened, so that the molding material remains in the communication pipe 6 for a relatively long time. Can do. In addition, the joining method of the base part 61, the intermediate part 62, and the front-end | tip part 63 is not limited to the above screwing type.

The cross-sectional area (area through which the molding material passes) of the communication tube 6 is adjusted according to the physical properties of the molding material, such as hardness and softness, but is 4.9 to 50 cm ² , for example, the inner diameter if the communication tube 6 is cylindrical. Is 2.5-8 cm. The portion having the cross-sectional area or the inner diameter is a portion that is not formed in a tapered surface shape and is not provided with the protrusion 6b. The length of the communication pipe 6 is, for example, 5 to 15 cm. If the molding material is hard, the cross-sectional area of the communication pipe 6 may be widened, the inner diameter may be longer, and the length may be shorter. If the molding material is softer, the cross-sectional area of the communication pipe 6 is narrower, the inner diameter is shorter, The length may be longer.

  Next, FIG. 3 shows another specific example of the communication pipe 6. As shown in FIG. 3A, the communication pipe 6 is also composed of a base portion 61, an intermediate portion 62, and a tip portion 63. FIG. 3C shows a short communication pipe 6, which includes a base 61 and a tip 63. FIG. 3D shows a long communication pipe 6, which is composed of a base part 61, an intermediate part 62, and a tip part 63. In this case, the intermediate portion 62 may be used or not used.

  The base 61 and the intermediate part 62 are formed in the same manner as shown in FIG.

  The tip portion 63 is formed in a short cylindrical shape. A female screw part 63 a is provided at one end of the tip part 63. At least one cutting bar 100 is provided at the other end of the tip portion 63 so as to cross the opening 63c. Furthermore, the inner surface 63b at the other end of the distal end portion 63 is formed in a tapered surface shape so as to spread from one end side (upstream side) toward the other end side (downstream side). When the cross-sectional area of the communication pipe 6 is constant, if the cutting bar 100 is provided in the opening 63c, the actual opening area (effective opening area) through which the molding material can pass is reduced accordingly. For example, in FIG. 3B, the effective opening area of the opening 63c is the total area of eight fan-shaped opening portions. Therefore, in order to increase the effective opening area, the inner surface 63b is formed in a tapered shape as described above. In particular, the effective opening area of the opening 63c is preferably substantially equal to the cross-sectional area of the communication pipe 6 on the upstream side of the tapered inner surface 63b. Thereby, it can suppress that a molding material retains or clogs without moving for a long time in the communicating pipe 6. FIG.

  The shape of the opening 63c of the tip 63 before providing the cutting bar 100 can be circular as shown in FIG. 5, but in this case, the center of the circular opening 63c is shown in FIG. 3B. The four cutting bars 100 intersect so that the opening 63c is divided into eight equal parts. The cutting bar 100 is formed in a long rectangular shape and has a blade portion 100a. The blade portion 100a is formed in a tapered surface shape that becomes thinner toward the tip. The cutting bar 100 is provided at the other end of the tip portion 63 with the blade portion 100a facing the female screw portion 63a. The number of cutting bars 100 provided at the tip 63 may be one or two. For example, in FIG. 4A, one cutting bar 100 is provided so as to divide the opening 63c into two equal parts through the center of the opening 63c. Further, in FIG. 4B, two cutting bars 100 are provided so as to intersect in a cross shape at the center of the opening 63c and divide the opening 63c into four equal parts. The upper limit of the number of cutting bars 100 is, for example, six although it depends on physical properties such as hardness and softness of the molding material.

  Here, an example of a method of providing the cutting bar 100 as shown in FIGS. 3B and 4A and 4B will be described.

  First, as shown in FIG. 5, a plurality of groove portions 63d are provided at radial positions from the center of the opening 63c at the edge of the other end of the tip portion 63. In FIG. 5, a total of four sets of one set of groove portions 63 facing each other through the center of the opening 63c are provided.

  On the other hand, FIGS. 6 to 8 show members constituting the cutting bar 100. In order to distinguish these members, the first cutting bar 101 shown in FIG. 6 and the second shown in FIG. The cutting bar shown in FIG. 8 is referred to as a third cutting bar 103.

  The first cutting bar 101 shown in FIG. 6 is formed in a long rectangular shape, has a blade portion 101a at one side edge in the long direction, and has a notch portion 101b at the center of the other side edge. . The blade portion 101a is formed in a tapered surface shape that becomes thinner toward the tip.

  The second cutting bar 102 shown in FIG. 7 is also formed in a long rectangular shape, but has a blade portion 102a at one side edge in the long direction and a notch portion 102b at the center of this side edge. doing. The blade portion 102a is formed in a tapered surface shape that becomes thinner toward the tip.

  The third cutting bar 103 shown in FIG. 8 includes two bar halves 113. The bar half body 113 is half the size of the cutting bar 100 and has a blade portion 113a on one side edge. The blade 113a is formed in a tapered surface shape that becomes thinner toward the tip. A butting portion 113b is provided on one side adjacent to the blade portion 113a. The butt portion 113b is formed in a V shape so that the apex angle is a right angle as shown in FIG.

  Then, as shown in FIG. 4A, a single cutting bar 100 is provided by spanning and inserting the first cutting bar 101 into a pair of opposing groove portions 63d and fixing by welding or the like. A distal end 63 can be formed. The blade portion 101a of the first cutting bar 101 is directed to the side where the groove portion 63d is present.

  Further, as shown in FIG. 4 (b), the second cutting bar 102 is bridged and inserted into the pair of opposed groove portions 63d so as to be orthogonal to the first cutting bar 101, and the first cutting bar 101d. The notch 101b of the cutting bar 101 and the notch 102b of the second cutting bar 102 are engaged with each other. Then, the front-end | tip part 63 in which the two cutting | disconnection bars 100 were provided can be formed by fixing by welding etc. In addition, the blade part 102a of the 2nd cutting | disconnection bar | burr 102 will face the side with the groove part 63d.

  Furthermore, the bar half body 113 is inserted into the remaining four groove portions 63d shown in FIG. The blade portion 113a of the bar half body 113 is directed toward the side where the groove 63d is present, and the butting portion 113b is abutted at a location where the first cutting bar 101 and the second cutting bar 102 intersect. Then, the front-end | tip part 63 in which the four cutting | disconnection bars 100 as shown in FIG.3 (b) were provided by fixing by welding etc. can be formed.

  Next, a method for producing a molded product by performing extrusion using the extruder 1 of the present embodiment will be described.

  First, a molding material containing cement as a main component is kneaded with a material kneading mixer (not shown). Molding materials include, for example, cement as a main component, silica material, pulp, organic fibers such as polypropylene fiber and vinylon fiber, inorganic fibers such as glass fiber, silica sand, silica powder, fly ash and other silica. Components, mica, light weight aggregates and the like can be appropriately selected and added, and further mixed with water. The hardness of the molding material can be evaluated with a viscosity hardness meter (“CRAY HARDNESS TESTER” manufactured by Nippon Choshi Co., Ltd.). The soft molding material has a needle penetration value of about 0 or more and less than 3 on the viscosity hardness meter, and the hard molding material has a needle penetration value of about 3 or more and about 6 or less on the viscosity hardness meter. A hard or soft material can be used.

  Next, this molding material is supplied into the first casing 21 from the supply port 4 of the extrusion molding machine 1. In the 1st casing 21, the 1st screw 31 is rotationally driven by the rotational drive apparatus, and while the molding material is uniformly kneaded by this 1st screw 31, it is sent to the other end side from the one end side of the 1st casing 21. .

  Then, the molding material sequentially enters the first opening 71, the second opening 72, and the communication pipe 6, and is filled and stays in the communication pipe 6. As described above, when the inner surface 6a in the vicinity of the opening 61c on the first casing 21 side of the communication pipe 6 is formed in a tapered surface shape, the molding material is easily drawn into the communication pipe 6. The inside of the vacuum deaeration chamber 8 of the second casing 22 is evacuated by a vacuum pump and is in a reduced pressure state. Therefore, the molding material in the communication pipe 6 is drawn to the vacuum deaeration chamber 8 side by the feeding by the first screw 31 and the vacuum deaeration chamber 8 being depressurized, and gradually falls into the vacuum deaeration chamber 8. Since the communication pipe 6 is formed in a cylindrical shape, even if the molding material in the communication pipe 6 is soft, it is easy to receive frictional resistance on the inner surface of the communication pipe 6, and all of the molding material in the communication pipe 6 is used. However, it is difficult to fall into the vacuum deaeration chamber 8 at a time. As described above, the molding material is stably supplied little by little into the vacuum deaeration chamber 8 so that the rotation speeds of the first screw 31 and the second screw 32 can be easily adjusted.

  Here, when the communication pipe 6 shown in FIG. 2 is used, since the projection 6b is provided in the vicinity of the opening 63c on the second casing 22 side of the communication pipe 6, the molding material 20 once from the communication pipe 6. Can be further suppressed as shown in FIG. 9 (a). If the length of the communication pipe 6 is variable as shown in FIGS. 2C and 2D, the length of the communication pipe 6 should be changed in advance according to the hardness or softness of the molding material. Thus, the reduced pressure state in the vacuum deaeration chamber 8 can be maintained.

  On the other hand, when the communication pipe 6 shown in FIG. 3 is used, at least one cutting bar 100 is provided so as to cross the opening 63c of the communication pipe 6 on the second casing 22 side. As shown in (b), the molding material 20 can be finely cut with the blade portion 100a of the cutting bar 100. As a result, the surface area of the molding material 20 increases, more bubbles in the molding material 20 can be removed in the vacuum deaeration chamber 8, and the deaeration efficiency can be improved. In particular, since the blade portion 100a is formed in a tapered surface shape, the molding material 20 is hardly caught by the cutting bar 100, and the cutting bar 100 is very likely to hinder the movement of the molding material 20 in the communication pipe 6. Lower.

  Further, compared with the case where there is no cutting bar 100, the case where the cutting bar 100 is provided further suppresses the molding bar 20 from dropping out of the communication pipe 6 all at once due to the resistance of the cutting bar 100. can do. If the cutting bar 100 becomes a resistance in this way, the molding material 20 can be kept in the communication pipe 6 for a longer time, so that even if the length of the communication pipe 6 is shortened, sufficient degassing is performed. be able to. If the communication pipe 6 is shortened, the distance from the opening 63c of the communication pipe 6 to the second screw 32 is increased, so that a sufficient deaeration time can be secured without increasing the vacuum deaeration chamber 8. The longer the degassing time, the more the degassing efficiency of the molding material 20 in the vacuum degassing chamber 8 can be improved. However, it is not necessary to make the communication pipe 6 short in general. In reality, physical properties such as hardness and softness of the molding material 20 may be taken into consideration. Even in such a case, if the length of the communication tube 6 is variable as shown in FIGS. 3C and 3D, the length of the communication tube 6 in advance depends on the hardness or softness of the molding material 20. By changing the length, the reduced pressure state in the vacuum deaeration chamber 8 can be maintained.

  Thus, the inner surface 63b of the tip 63 on the second casing 22 side of the communication pipe 6 is formed in a tapered surface shape so as to spread from the first casing 21 side toward the second casing 22 side. As described above, the flow rate of the molding material expands in the vicinity of the opening 63c on the second casing 22 side of the communication pipe 6, thereby suppressing a decrease in the moving speed of the molding material in the communication pipe 6. The taper angle of the inner surface 63b is not limited, but is, for example, 5 to 80 °.

  When the communication pipe 6 shown in FIG. 2 or FIG. 3 is used, the molding material continues to enter the communication pipe 6 from the first casing 21 even if the molding material falls from the communication pipe 6 to the vacuum deaeration chamber 8. Therefore, the inside of the communication pipe 6 is almost always closed with the molding material. Therefore, the molding material closing the communication pipe 6 makes it difficult for the air in the first casing 21 to flow into the vacuum deaeration chamber 8, and the decompressed state in the vacuum deaeration chamber 8 can be maintained. By maintaining the reduced pressure state in this way, the bubbles in the molding material sent into the vacuum deaeration chamber 8 can be sufficiently removed.

  In the storage chamber 9 of the second casing 22, the second screw 32 is rotationally driven by a rotational drive device. The molding material from which bubbles are removed in the vacuum deaeration chamber 8 as described above is then sent from one end side to the other end side of the storage chamber 9 while being further uniformly kneaded by the second screw 32. Since the gap between the second screw 32 and the storage chamber 9 is almost always closed with the molding material, the air in the storage chamber 9 or the base 10 is less likely to flow into the vacuum deaeration chamber 8, and vacuum deaeration The decompressed state in the chamber 8 can be maintained.

  The molding material sent to the other end side of the storage chamber 9 is continuously extruded as a green sheet from the discharge port 5 of the base part 10 and molded. The green sheet thus extruded is cut to a predetermined length by a cutting device (not shown), and then cured and cured, whereby a building member such as an inorganic board can be obtained as a molded product. Since the reduced pressure state in the vacuum deaeration chamber 8 is maintained, the bubbles in the molding material are sufficiently removed, and the occurrence of cracks due to rupture during curing can be suppressed. In addition, as a building member, an outer wall material, a flooring material, a ceiling material, a roofing material, an interior material, a brick block etc. can be mentioned, for example.

  Hereinafter, the present invention will be specifically described by way of examples.

  Cement, siliceous raw material, pulp, additives (extrusion aids such as methylcellulose) are blended in the blending amounts shown in Table 1, and 40 parts by mass of water is added to 100 parts by mass of these solids to obtain a molding material. Manufactured and kneaded with a material kneading mixer.

次に上記の成形材料を用いて図１に示す押出成形機１で押出成形を行って成形品を製造した。真空度はゲージ圧表記で−０．０８ＭＰａとした。成形品の寸法は、幅２００ｍｍ×長さ５００ｍｍ×厚さ２０ｍｍである。

Next, extrusion molding was performed using the molding material described above with an extrusion molding machine 1 shown in FIG. 1 to produce a molded product. The degree of vacuum was -0.08 MPa in terms of gauge pressure. The dimensions of the molded product are 200 mm wide × 500 mm long × 20 mm thick.

  Table 2 shows the forms of the communication pipe 6 of Examples 1 to 4 and Comparative Example 1. In the first and second embodiments, the length of the communication pipe 6 is different, and the cutting bar 100 is not provided in the communication pipe 6. In the third embodiment, two cutting bars 100 are provided in the communication pipe 6 as shown in FIG. In the fourth embodiment, four cutting bars 100 are provided on the communication pipe 6 as shown in FIG. In the third and fourth embodiments, the inner surface 63b of the distal end portion 63 of the communication pipe 6 is formed into a tapered surface, and the taper angle is 60 °. The inner diameters of the communication pipes 6 of Examples 3 and 4 in Table 2 are the inner diameters on the upstream side of the tapered inner surface 63b. In Comparative Example 1, the length of the communication pipe 6 is 0 mm, that is, the communication pipe 6 itself is not provided.

(Bubble observation)
The molded product was cut in the thickness direction, and the cross section was observed to check for the presence of bubbles. The presence or absence of bubbles was determined according to the following criteria.

  “◎”: No bubbles.

  “◯”: A thing with almost no bubbles.

  “△”: Some bubbles.

  "X": A thing with many bubbles.

(Specific gravity of molded product)
The specific gravity of the molded product of Example 4 was set to 100, and the specific gravity of the molded products of Examples 1 to 3 was obtained as a relative value. In addition, about the molded article of the comparative example 1, since there were many entrapment of bubbles, specific gravity was not calculated | required.

  The results are shown in Table 2.

表２から明らかなように、実施例１〜４では、比較例１に比べて、成形品から気泡を十分に除去することができることが確認された。

As is clear from Table 2, in Examples 1 to 4, it was confirmed that air bubbles could be sufficiently removed from the molded product as compared with Comparative Example 1.

  In addition, when the protrusion 6b was provided in the communicating pipe 6 like FIG.2 (b), the effect of bubble removal was able to be acquired similarly to lengthening the communicating pipe 6 without lengthening it.

DESCRIPTION OF SYMBOLS 1 Extruder 4 Supply port 5 Discharge port 6 Communication pipe 21 1st casing 22 2nd casing 31 1st screw 32 2nd screw 61c Opening 63 Tip part 63b Inner surface 63c Opening 100 Cutting bar

Claims (5)

A first casing having a supply port;
A first screw disposed in the first casing;
A second casing having a discharge port and formed to be vacuum degassable;
A second screw disposed in the second casing;
With
The extrusion molding machine, wherein the first casing and the second casing are communicated with each other by a communication pipe formed in a cylindrical shape. The extrusion molding machine according to claim 1, wherein an opening on the second casing side of the communication pipe is narrower than an opening on the first casing side. The extrusion molding machine according to claim 1, wherein a length of the communication pipe is variable. The extrusion molding machine according to any one of claims 1 to 3, wherein at least one cutting bar is provided so as to cross the opening on the second casing side of the communication pipe. The inner surface of the front end portion on the second casing side of the communication pipe is formed in a tapered surface shape so as to spread from the first casing side toward the second casing side. The extrusion molding machine according to any one of 4.

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