JP2015182066A - Fluid mixture discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid mixture discharge device that can effectively be used for relatively shortening the time required from the start of the hardening reaction of a fluid mixture to the completion of casting.SOLUTION: This device comprises a first tank 10A that reserves a first fluid containing an inorganic powder and polyol for producing a binder (urethane resin), a second tank 10B that reserves a second fluid containing isocyanate, first pipelines 40A and 50A connected to the first tank, second pipelines 40B and 50B connected to the second tank, confluence pipelines 60 and 70 extending from a confluence part where the first pipeline end opposite the first tank joins with the second pipeline end opposite the second tank to make the end opposite the confluence part function as a discharge opening, a first pump 20A interposed between the first pipelines, a second pump 20B interposed between the second pipelines, and a static mixer 30 interposed between the confluence pipelines.

Description

  The present invention relates to a mixed fluid discharge apparatus, and in particular, a slurry containing at least inorganic powder and “a plurality of types of precursors for producing a urethane resin as a binder” is used as the mixed fluid. Related to things. Hereinafter, “injecting slurry into the mold” is referred to as “casting”, and removing the mold from the molded body cured in the mold is sometimes referred to as “release”. Further, in this specification, “numerical value A to numerical value B” indicating a range refers to “numerical value A or more and numerical value B or less”.

  Conventionally, a mixed fluid (slurry) prepared by mixing at least inorganic powder and “a plurality of types of precursors (typically polyol and isocyanate) for producing a urethane resin as a binder” ) Is cast, and the molded slurry is solidified by “reaction (curing reaction, gelation reaction) in which urethane resin is generated from the plurality of types of precursors” to obtain a molded body. It is known (see, for example, Patent Document 1). Such a method of obtaining a molded body using a curing reaction is also called a gel cast method.

  Usually, in the gel casting method, mixing of “inorganic powder and a plurality of types of precursors” as raw materials of the slurry is performed using a stirring blade or the like. When mixing is performed inside a bottomed cylindrical container using a stirring blade, etc., the slurry tends to stay in the region near the inner peripheral surface of the container, so that the slurry is uniformly mixed throughout the container. It was difficult to get. Moreover, the slurry obtained by the mixing was cast from the casting port of the mold using its own weight (water head pressure). In this method, a relatively long time is required until the casting is completed after the plural types of precursors are mixed (until the slurry is filled in the molding space of the molding die). This is mainly because the flow rate of the slurry to be injected is reduced due to a decrease in the water head pressure at the end of casting. Further, since the water head pressure is high at the initial stage of casting, the flow rate of the injected slurry tends to be excessively high. As a result, there is also a problem that bubbles are easily mixed in the mold.

  By the way, the said hardening reaction of a slurry is started from the time of mixing the said multiple types of precursor. In order to reliably fill the slurry in the molding space of the mold, it is necessary to maintain the fluidity of the slurry until the casting of the slurry is completed. This means that when the mixing and casting are performed using the above method, it is necessary to use a slurry having a relatively slow curing reaction. Therefore, when the above method is used, a situation in which a mold release operation is easily performed before the strength of the molded body reaches a level that can withstand the mold release is likely to occur. The problem of deformation occurred easily.

International Publication No. 2012/011359 Pamphlet

  The present invention has been made in order to cope with the above-described problems. The purpose of the present invention is to mix a plurality of types of precursors that are part of the raw material of the mixed fluid (the curing reaction of the mixed fluid is It is an object of the present invention to provide a mixed fluid discharge device that can be used effectively in order to relatively shorten the time required from completion of casting to completion of casting.

  The mixed fluid discharge device according to the present invention includes a first fluid including at least an inorganic powder and a first precursor that is a part of a plurality of types of precursors for generating a urethane resin as a binder. A first tank for storing; a second tank for storing a second fluid that includes at least a second precursor that is the remainder of the plurality of types of precursors; and a first tank that is connected to the first tank, A first pipe through which the first fluid passes, and a second pipe connected to the second tank and through which the second fluid in the second tank passes, and opposite to the first tank of the first pipe. A second end of the second pipe and an end opposite to the second tank of the second pipe are joined to the joining pipe extending from the joining section, and the first pipe is interposed in the middle of the first tank. The first fluid is sucked into the first pipe and sent to the joining pipe. And a second pump that is interposed in the middle of the second pipe, sucks the second fluid in the second tank and sends it to the merging pipe, and is interposed in the middle of the merging pipe. Or a static mixer connected to an end of the merging pipe opposite to the merging portion.

  Typically, the first precursor is a polyol and the second precursor is an isocyanate. Further, typically, the first fluid includes a dispersion medium, a dispersion aid, and the like. The second fluid may contain a dispersion medium, a dispersion aid, and the like. The second fluid may also contain inorganic powder. The inorganic powder is, for example, a ceramic powder or a metal powder.

  According to this device, when the first and second pumps are driven in a state where the first and second fluids are stored in the first and second tanks, respectively, the first and second pumps respectively send out the first and second pumps. The first and second fluids are merged by the merge pipe, and the merged first and second fluids are sufficiently stirred and mixed by the static mixer, and discharged as a mixed fluid (slurry) from the discharge port to the outside. Accordingly, when the first and second pumps are continuously driven in a state where the discharge port of this apparatus is connected to the casting port of the mold (liquid-tight), mixing of the first and second fluids (slurry of the slurry) Mixing of raw materials) and casting can be done at the same time.

  When this method is used, compared with the method described in the background art section described above, the time required to complete casting after a plurality of types of precursors are mixed can be significantly shortened. This means that a slurry having a relatively high curing reaction rate can be used. Therefore, when this method is used, it is difficult to cause a situation in which a mold release operation is performed before the strength of the molded body reaches a level that can withstand the mold release. Deformation is less likely to occur.

  In the above apparatus, it is preferable that the first and second pumps are Mono pumps or gear pumps. If the change in the discharge flow rate is gentle at the start and end of driving of the first and second pumps, a mixed fluid that is not sufficiently stirred and mixed is likely to be discharged from the discharge port. In other words, at the start and end of casting, a slurry that is not sufficiently stirred and mixed is easily cast.

  On the other hand, when the MONO pump and the gear pump are used, the discharge flow rate can be steeply increased from zero to a desired flow rate at the start of driving, and the discharge flow rate is steep from the current flow rate to zero at the end of driving. Can be reduced. Therefore, at the start and end of casting, it is difficult to cast a slurry that has not been sufficiently stirred and mixed.

1 is an overall schematic configuration diagram of an embodiment of a mixed fluid discharge apparatus according to the present invention. It is a figure which shows an example of the state which connected the discharge port of the apparatus shown in FIG. 1 to the casting port of a shaping | molding die liquid-tightly. FIG. 3 is a top view of the mold shown in FIG. 2.

  Hereinafter, an embodiment (this embodiment) of a mixed fluid discharge device according to the present invention will be described with reference to the drawings.

(Constitution)
As shown in FIG. 1, the present embodiment 100 includes a first tank 10A and a second tank 10B, a first pump 20A and a second pump 20B, and a static mixer 30. The first and second pumps 20A and 20B may be any type of pump as long as the pump can intermittently suck and discharge the fluid. The suction side of the first pump 20A and the first tank 10A are connected by a pipe 40A. The suction side of the second pump 20B and the second tank 10B are connected by a pipe 40B.

  The discharge side of the first pump 20A is connected to the pipe 50A, and the discharge side of the second pump 20B is connected to the pipe 50B. The end of the pipe 50A opposite to the first pump 20A and the end of the pipe 50B opposite to the second pump 20B merge, and the pipe 60 extends from this junction.

  The end of the pipe 60 opposite to the joining part is connected to the inflow side of the static mixer 30, and the outflow side of the static mixer 30 is connected to the pipe 70. The end of the pipe 70 opposite to the static mixer 30 functions as a discharge port of this apparatus. Note that the pipe 70 may be a part of the static mixer 30. Here, the pipes 40A and 50A correspond to the “first pipe”, the pipes 40B and 50B correspond to the “second pipe”, and the pipes 60 and 70 correspond to the “merging pipe”.

(Operation)
In the present embodiment 100, the first fluid is stored in the first tank 10A, and the second fluid is stored in the second tank 10B. Examples of the first fluid include inorganic powder, a dispersion medium, and a polyol (corresponding to the first precursor), and a dispersion aid and a catalyst as necessary. Specifically, as an inorganic powder, metal powder such as silver powder, platinum powder, gold powder, palladium powder, zirconia powder, alumina powder, barium titanate powder, ferrite powder, quartz powder, nickel oxide powder, yttria Ceramic powders such as powder, silicon nitride powder, aluminum nitride powder may be used. As a dispersion medium, a mixture of an aliphatic polyvalent ester and a polybasic acid ester can be used. As the polyol, ethylene glycol can be used. A polycarboxylic acid copolymer can be used as a dispersion aid. As catalyst, 6-dimethylamino-1-hexanol can be used.

  Examples of the second fluid include isocyanate (corresponding to the second precursor). Specifically, a modified product of polymethylene polyphenyl polyisocyanate can be used as the isocyanate.

  When the first and second pumps 20A and 20B are driven by a driving device (not shown) in a state where the first and second fluids are stored in the first and second tanks 10A and 10B, respectively, The first fluid is sucked into the first pump 20A through the pipe 40A and sent out from the first pump 20A to the pipe 50A. Similarly, the second fluid in the second tank 10B is sucked into the second pump 20B through the pipe 40B and sent out from the second pump 20B to the pipe 50B.

  The first fluid sent to the pipe 50 </ b> A and the second fluid sent to the pipe 50 </ b> B merge at the pipe 60. The merged first and second fluids are sent to the static mixer 30 via the pipe 60, and are sufficiently stirred and mixed in the static mixer 30. The fluid agitated and mixed by the static mixer 30 is discharged to the outside from the front end portion (discharge port) of the pipe 70 as a mixed fluid (slurry) through the pipe 70.

  The flow rate of the mixed fluid (slurry) discharged from the discharge port is, for example, 100 to 6000 μL / sec. The volume ratio of the first and second fluids in the mixed fluid (slurry) discharged from the discharge port is, for example, 8: 1 to 15: 1.

(Action / Effect)
The present embodiment 100 can be used, for example, in a state where the tip end portion (that is, the discharge port) of the pipe 70 is liquid-tightly connected to the casting port of the molding die. 2 and 3 show an example of the state. In the example shown in FIGS. 2 and 3, a cylindrical rubber stopper is provided in the casting port of the molding die. The outer peripheral surface of the rubber plug is press-fitted (clamped) into the cylindrical recess formed in the casting port, and the tip (discharge port) of the pipe 70 is press-fitted (clamped into the inner peripheral surface of the rubber plug). ) ・ "Liquid-tight connection" is achieved by being fixed.

  In the state shown in FIG. 2 and FIG. 3, the first and second pumps 20A and 20B are continuously driven to mix the first and second fluids (mixing of the raw materials of the slurry), and Casting of the mixed fluid (slurry) can be done at the same time.

  In the method shown in FIGS. 2 and 3, the mixing of the polyol and the isocyanate is started from the time when the driving of the first and second pumps 20A and 20B is started (therefore, in the reaction in which the urethane resin is generated). A certain curing reaction) is initiated. When this method is used, the time required from the start of mixing of the polyol and the isocyanate to the completion of the slurry casting can be remarkably shortened as compared with the method described in the background section above. . This means that a slurry having a relatively high curing reaction rate can be used. Therefore, when this method is used, it is difficult to cause a situation in which a mold release operation is performed before the strength of the molded body reaches a level that can withstand the mold release. Deformation is less likely to occur.

  Further, in this method, since the slurry is cast while the slurry receives the discharge pressure of the pump, the method described in the section of the background art described above (that is, using its own weight (water head pressure) from the casting port of the molding die). Compared with the method in which the slurry is cast), the pressure of the slurry in the mold during casting is large. However, as shown in FIGS. 2 and 3, the pressure is sufficiently low that a “liquid-tight connection” can be achieved using a rubber plug. Specifically, the pressure is 0.05 to 1.0 atm, and more preferably 0.1 to 0.5 atm. Therefore, as shown in FIG. 3, even if the position of the casting port of the mold (and thus the mounting position of the rubber plug) is determined so as to straddle the mating surfaces of the molds A and B, the mating surface of the mold And the slurry in a shaping | molding die does not leak from the contact surface of the outer peripheral surface of a rubber stopper, and a casting port.

  In the present embodiment 100, if the change in the discharge flow rate of the mixed fluid (slurry) is gradual at the start and end of driving of the first and second pumps 20A and 20B, they are not sufficiently stirred and mixed. The mixed fluid is easily discharged from the discharge port. In other words, at the start and end of casting, a slurry that is not sufficiently stirred and mixed is easily cast.

  In this regard, when a Mono pump and a gear pump are used as the first and second pumps 20A and 20B in the present embodiment 100, the discharge flow rate can be sharply increased from zero to a desired flow rate at the start of driving, and At the end of driving, the discharge flow rate can be sharply reduced from the current flow rate to zero. Therefore, at the start and end of casting, it is difficult to cast a slurry that has not been sufficiently stirred and mixed.

  10A, 10B ... 1st tank, 2nd tank, 20A, 20B ... 1st pump, 2nd pump, 30 ... Static mixer, 40A, 40B ... Piping, 50A, 50B ... Piping, 60 ... Piping, 70 ... Piping

Claims (4)

A first tank for storing a first fluid containing at least an inorganic powder and a first precursor that is a part of a plurality of types of precursors for producing a urethane resin as a binder;
A second tank for storing a second fluid containing at least a second precursor that is the remainder of the plurality of types of precursors;
A first pipe connected to the first tank and through which the first fluid in the first tank passes;
A second pipe connected to the second tank and through which the second fluid in the second tank passes;
A merging pipe extending from a merging portion where the end of the first pipe opposite to the first tank and the end of the second pipe opposite to the second tank merge;
A first pump that is interposed in the middle of the first pipe, sucks the first fluid in the first tank, and sends it out toward the merge pipe;
A second pump interposed in the middle of the second pipe, sucking the second fluid in the second tank and sending it out toward the merge pipe;
A static mixer that is interposed in the middle of the merging pipe, or connected to an end of the merging pipe opposite to the merging part;
A mixed fluid discharge device. The mixed fluid discharge device according to claim 1,
The mixed fluid discharge device, wherein the first and second pumps are Mono pumps. The mixed fluid discharge device according to claim 1,
The mixed fluid discharge device, wherein the first and second pumps are gear pumps. The mixed fluid discharge device according to claim 1,
One of the first and second pumps is a mono pump, and the other of the first and second pumps is a gear pump.

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