JP2006255565A - Method and apparatus for stirring and defoaming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for stirring and defoaming capable of stirring and defoaming at high precision compared with conventional ones by achieving high vacuum. <P>SOLUTION: A method for stirring and defoaming a material to be mixed and kneaded K comprises a first step for applying a centrifugal force to the material to be mixed and kneaded K while revolving a container 15 containing the material to be mixed and kneaded K, and a second step for defoaming the material to be mixed and kneaded K in the state where pressure in the container 15 is reduced to 400 Pa or less, and preferably 66 Pa or less while applying a centrifugal force to the material to be mixed and kneaded K. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum type stirring and defoaming method and a stirring and defoaming apparatus.

  In general, there is known a stirring and defoaming device configured to revolve on a revolution orbit while holding a container holding a material to be kneaded on a container holder and revolving (see, for example, Patent Document 1). In this type of stirring and defoaming device, the material to be kneaded is pressed against the inner wall of the container by centrifugal force acting by the revolution of the container, and bubbles contained in the material to be kneaded are released to the outside, and the container is rotated by the rotation of the container. The product to be kneaded is stirred. Specifically, it has been clarified that when the revolution speed of the container is high, the defoaming performance of the material to be kneaded is improved, and when the rotation speed is high, the stirring performance is improved.

  When the stirring and defoaming device described in Patent Document 1 is used under normal pressure, the defoaming performance varies depending on the physical properties of the material to be kneaded, the rotational speed of rotation, the rotational speed of revolution, etc., but gold, silver, solder paste, For dental impression materials (alginic acid) and the like, it is recognized that the defoaming performance is practically sufficient. However, when the bubbles are observed in detail, the diameter of the remaining bubbles is small and the distribution is biased to several hundred μm or less. Therefore, inconveniences have arisen in applications where micron and submicron level bubbles are a problem.

  Therefore, a method and apparatus for stirring and defoaming the material to be kneaded by rotating and revolving the container under vacuum (0.5 to 50 Torr) has also been proposed (see, for example, Patent Document 2). When a vacuum pressure is applied to the material to be kneaded, the fine bubbles present in the material to be kneaded expand and foam, and the separation from the material to be kneaded can be promoted. To be promoted.

That is, when the other conditions such as the rotational speed are the same, the amount of gas molecules present in the material to be kneaded is considered to decrease as the vacuum is further increased.
Japanese Patent Laid-Open No. 10-43568 (paragraphs 0013 to 0023, FIG. 1) Japanese Patent Laid-Open No. 11-104404 (Claim 1, FIG. 1)

  However, if the degree of vacuum is too high, the material to be kneaded will boil, resulting in the generation of new bubbles and changes in physical properties, so that it was practically impossible to achieve an ultra-high vacuum. For example, in a material manufacturer or the like, generally, it is a taboo to process a material to be kneaded in a high vacuum environment of 400 Pa (≈3 Torr) or less. Further, as described in Patent Document 2, even in the conventional stirring and defoaming process, it was not possible to evacuate to 67 Pa (≈0.5 Torr) or less. Therefore, at the present stage, the defoaming process can be performed only at a vacuum degree of 400 Pa as the limit, and the remaining of fine bubbles that do not disappear must be allowed.

  On the other hand, it is known that boiling occurs when the vapor pressure of the material to be kneaded becomes higher than the external pressure. That is, by operating (higher) the external pressure, boiling of the material to be kneaded can be suppressed, so that it is considered that a higher vacuum can be achieved.

  Therefore, the present invention has been made in view of the circumstances described above, and provides a stirring and defoaming method and a stirring and defoaming apparatus capable of performing stirring and defoaming with higher accuracy than before by realizing high vacuum. The issue is to provide.

The applicant of the present application paid attention to the centrifugal force acting on the material to be kneaded due to the revolution of the container, and conducted intensive studies for the purpose of stirring and defoaming the material to be kneaded with high accuracy.
In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is a method for stirring and defoaming, wherein a first step of causing a container containing the material to be kneaded to revolve and applying a centrifugal force to the material to be kneaded is provided. And a second step of defoaming the material to be kneaded by lowering the pressure in the container to 400 Pa or less in a state where centrifugal force is applied to the material to be kneaded.

  According to the first aspect of the present invention, since a large centrifugal force is applied to the material to be kneaded as a pseudo external pressure by applying rotation only to the container, even if the pressure is reduced to 400 Pa or less exceeding the conventional limit. (Even if the degree of vacuum is increased), the material to be kneaded does not boil. And defoaming is performed by revolving a container and making it high vacuum in this way. In other words, in the agitation and defoaming process, the object to be kneaded can be exposed to a high-vacuum environment that has been impossible in the past by revolving the container (without rotating). Combined with the action of, high-definition defoaming became possible.

  The invention according to claim 2 is the stirring and defoaming method according to claim 1, wherein in the second step, the pressure in the container is lowered to 66 Pa or less to defoam the material to be kneaded. .

  According to the invention which concerns on Claim 2, since the pressure in a container is lowered | hung to 66 Pa or less and a vacuum degree is raised, more highly accurate defoaming effect | action is obtained.

  The invention according to claim 3 is the stirring and defoaming method according to claim 1, characterized in that it has a third step of rotating the container after the pressure in the container has dropped to 66 Pa or less.

  According to the invention of claim 3, in addition to the action of the invention of claim 1, stirring and defoaming of the material to be kneaded is promoted by adding rotation to the container.

  The invention according to claim 4 is the stirring and defoaming method according to claim 1 or 3, wherein the material to be kneaded is a sealing paste material.

  The invention according to claim 4 specifically specifies the object of the material to be kneaded in the stirring and defoaming method according to claim 1 or claim 3. The sealing paste material has a problem of remaining fine bubbles because of its use. According to the invention which concerns on Claim 4, the stirring deaeration of such a sealing paste material is performed with high precision.

The invention according to claim 5 is the stirring and defoaming method according to any one of claims 1 to 4, wherein the centrifugal force applied to the kneaded material in the second step is 3000 m / s ² or more. It is characterized by that.

  The invention according to claim 5 specifically specifies the centrifugal force applied to the container in the stirring and defoaming method according to any one of claims 1 to 4. If the degree of vacuum is increased in a state where there is no centrifugal force or a low state, the material to be kneaded may be boiled. According to the invention of claim 5, since sufficient centrifugal force acts on the material to be kneaded, boiling caused by high vacuum is suppressed, and denaturation of the material to be kneaded is prevented.

  According to a sixth aspect of the present invention, there is provided a container for containing a material to be kneaded, a revolving table for rotatably supporting the container, a support member for rotatably supporting the revolving table, and the container on the revolving table. A rotation drive mechanism for rotation that rotates in rotation, a rotation drive mechanism for rotation that revolves the container by rotating the revolving table, a vacuum pump for decompressing the inside of the container, revolution and rotation of the container, and A stirring and defoaming device comprising a control unit for controlling the pressure in the container, wherein the control unit revolves the container and reduces the pressure in the container in a state in which centrifugal force acts on the material to be kneaded. Control is performed to lower the pressure to 400 Pa or less.

  The invention which concerns on Claim 6 is an apparatus which implement | achieves the stirring defoaming method of any one of Claim 1-5. According to the invention which concerns on Claim 6, a revolution table is rotated by the rotation drive mechanism for revolutions, a container is revolved and a centrifugal force is made to act on the to-be-kneaded material in a container. In this state, the pressure in the container is reduced to 400 Pa or less. As a result, the object to be kneaded is defoamed with high accuracy by the combined action of centrifugal force and high vacuum environment.

  According to the stirring and defoaming method of the present invention, the material to be kneaded is exposed to a high vacuum environment that has been impossible in the past, and the defoaming of the material to be kneaded is performed with high accuracy in combination with the action of centrifugal force. Can do. Moreover, after performing defoaming with high accuracy in this manner, sufficient agitation can be performed as usual by rotating the container. Moreover, according to the stirring and defoaming apparatus of the present invention, the stirring and defoaming method can be realized, and the material to be kneaded can be stirred and defoamed with high accuracy.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a longitudinal sectional view of a stirring and defoaming apparatus that performs the stirring and defoaming method of the present invention.
In the present embodiment, for example, a sealing paste material is assumed as an object to be kneaded. However, the object to be kneaded is not particularly limited, and can be any material.

First, a description will be given of a stirring and defoaming apparatus that performs the stirring and defoaming method of the present invention.
As shown in FIG. 1, the stirring and defoaming device 1 includes a housing 11, a support member 12, a motor 13, a revolving table 14, a container 15, a suction tube 16, a decompression unit 17, a rotation force applying shaft 18, and a rotation force transmission shaft 19. The main shaft 20, the electromagnetic brake 21 (braking means), and a controller (not shown) are mainly included, and in addition, a spring 22, a balance weight attaching portion 23, and the like are provided. The stirring and defoaming apparatus 1 rotates and rotates the container 15 on a predetermined trajectory, and stirs and degass the material to be kneaded K contained in the container 15. In FIG. 1, the revolution axis when the container 15 is revolved is represented by a symbol Y1, and the rotation axis when the container 15 is rotated is represented by a symbol Y2.

  The support member 12 is held horizontally in the housing 11 via a plurality of springs 22. The support member 12 is formed with a motor through hole 12a for inserting the rotating shaft 13b of the motor 13 on the right side of the paper surface and a cylindrical revolving table fixing portion 12b at the center of the paper surface, in the vicinity of the motor through hole 12a. The revolution table 14 is attached to the motor 13 and the revolution table fixing | fixed part 12b. The plurality of springs 22 absorb excitation vibration accompanying rotation of the motor 13 and the revolution table 14 and the like, and are not transmitted to the housing 11.

  The motor 13 includes a motor main body 13a fixed to the upper surface side of the support member 12, and a rotating shaft 13b that protrudes from the motor main body 13a through the motor through hole 12a of the support member 12 to the lower surface side. A pulley P1 that rotates in synchronization with the rotation shaft 13b is fixed to the tip of the rotation shaft 13b.

  The revolving table 14 is rotatably supported by the revolving table fixing part 12b via the bearing b1 in a state of penetrating the revolving table fixing part 12b. A pulley P <b> 2 is fixed to the lower part of the revolving table 14. A belt V1 is stretched between the pulley P2 and the pulley P1, and the rotation of the motor 13 is transmitted to the pulley P2 via the pulley P1 and the belt V1, thereby rotating the revolution table 14. . The pulley P1, the belt V1, the pulley P2, and the like correspond to the “revolution rotational drive mechanism” in the claims. The revolution table 14 has a through hole 14a penetrating the revolution center, a through hole 14b provided to be inclined to the through hole 14a, an outer peripheral side of the through hole 14b, and parallel to the through hole 14b. The through-hole 14c is formed, and the container 15, the balance weight attaching portion 23, and the like are disposed on the upper surface side thereof.

  The container 15 includes a container body 15a, an upper lid 15b that closes the opening of the container body 15a, an O-ring 15c that seals the container body 15a and the upper lid 15b, and a sample holder 15d that is accommodated in the container body 15a. Yes.

  The container body 15a is formed in a bottomed cylindrical shape with an open top, and the O-ring 15c is disposed in a groove formed at the edge of the opening. The peripheral surface of the lower surface of the upper lid 15b and the opening side end surface of the container main body 15a are pressed against each other via an O-ring 15c, thereby sealing the space between the two. Thereby, the sealed state inside the container 15 is maintained.

  The sample holder 15d accommodates the material K to be kneaded therein, and is accommodated in the container main body 15a so as not to rotate relative to the container main body 15a around the rotation axis Y2 and to be detachable. By making the container body 15a freely detachable, the sample holder 15d can be moved to the next step after the kneading and defoaming operation of the material to be kneaded K is completed. The sample holder 15d that has been used once can be washed and used repeatedly, or can be disposable.

The suction tube 16 is provided to evacuate the inside of the container 15, and one end 16 a is connected to the rotation axis Y <b> 2 of the upper cover 15 b of the container 15. The other end 16 b is fixed to a hose lead-out hole 11 a formed on the revolution axis Y <b> 1 in the housing 11 via a magnetic fluid seal 24. By using the magnetic fluid seal 24, the degree of vacuum in an ultra-high pressure vacuum (eg, 1.3 × 10 ⁻⁶ Pa (= 10 ⁻⁸ Torr)) can be maintained.

  The decompression means 17 is provided outside the housing 11, and includes a connection pipe 17a, a vacuum pump 17b, a vacuum gauge 17c for measuring the degree of vacuum, a shutoff valve 17d and a leak valve 17e provided in the connection pipe 17a. . The connection pipe 17a connects the vacuum pump 17b and the suction pipe 16, so that the inside of the container 15 can be evacuated by the vacuum pump 17b.

The rotation force applying shaft 18, the rotation force transmission shaft 19, the support shaft 20, and the electromagnetic brake 21 are a rotation drive mechanism for rotation for rotating the container 15 around the rotation axis Y2.
The rotation force applying shaft 18 is rotatably supported by a through hole 14a formed at the rotation center of the revolution table 14 via a bearing b2. An electromagnetic brake 21 to be described later is provided at the lower end portion of the rotation force applying shaft 18, and a rotation gear G1 that is a bevel gear is fixed to the upper end portion.

  The rotation force transmission shaft 19 is rotatably supported in the through hole 14b of the revolution table 14 via a bearing b3. A rotation gear G2, which is a bevel gear meshing with the rotation gear G1, is fixed to the upper end portion of the rotation force transmission shaft 19, and a rotation gear G3 is fixed to the lower end portion.

The support shaft 20 is rotatably supported in the through hole 14c of the revolving table 14 via a bearing b4. A rotation gear G4 that meshes with the rotation gear G3 is fixed to the lower end portion of the support shaft 20, and the container 15 is fixed to the upper end portion thereof. The upper end side of the support shaft 20 is inclined inward, whereby the rotation axis Y2 of the container 15 is inclined inward at a constant angle with respect to the revolution axis Y1. Since the rotation axis Y2 is tilted inward, even if the liquid level of the material K to be kneaded rises as shown in FIG. 1 due to the revolution of the container 15, it protrudes from the sample holder 15d and overflows into the container body 15a. There is no.
The number of teeth of the rotation gear G1 and the rotation gear G2, and the rotation gear G3 and the rotation gear G4 can be set as appropriate.

  The electromagnetic brake 21 is for braking the rotation force applying shaft 18 and is fixed to an attachment member 21 a attached to the support member 12. The electromagnetic brake 21 is an excitation actuated brake composed of an electromagnet, a link mechanism, a spring for urging the rotation force applying shaft 18 and the like. When the electromagnet is energized (ON state), the rotation force applying shaft 18 is braked by the force of the spring and cannot rotate relative to the support member 12. When energization of the electromagnet is stopped (OFF state), the rotation force applying shaft 18 is released from braking and becomes rotatable.

  In the rotation driving mechanism for rotation configured as described above, when the electromagnetic brake 21 is in the ON state, the rotation force applying shaft 18 is not rotatable. At this time, when the revolution table 14 rotates at, for example, the rotation speed x, the rotation force applying shaft 18 rotates relative to the revolution table 14 at the rotation speed x. The rotation of the rotation force applying shaft 18 is transmitted to the container 15 via the rotation force transmission shaft 19 and the support shaft 20. That is, the container 15 rotates (spins) with respect to the revolution table 14 so that the rotation speed x is the same as that of the revolution table and the rotation direction is reversed.

  On the other hand, when the electromagnetic brake 21 is in the OFF state, the rotation force applying shaft 18 is rotatable. At this time, when the revolution table 14 rotates, the support shaft 20, the rotation force transmission shaft 19, and the rotation force application shaft 18 are driven to rotate in accordance with the rotation, so that the container 15 rotates relative to the revolution table 14 (rotation). )do not do.

  The control unit (not shown) drives the motor 13 and the electromagnetic brake 21 to control the rotation / revolution of the container 15, controls the decompression means 17, and controls the vacuum pressure in the container 15.

  The balance weight attaching portion 23 is provided at a symmetrical position of the container 15 in the revolution table 14 around the revolution axis Y1. The balance weight mounting portion 23 includes a screw member 23a provided along the radial direction of the revolving table 14, and a balance weight 23b screwed to the screw member 23a, and moves the balance weight 23b in the radial direction. Thus, the weight balance on the revolution table 14 is maintained.

  Next, the stirring and defoaming method performed using this stirring and defoaming apparatus 1 will be described while explaining the operation of the stirring and defoaming apparatus 1 with reference to FIGS. 1 and 2 as appropriate. FIG. 2 is a flowchart for explaining the stirring and defoaming step.

First, the sample holder 15d containing the material K to be kneaded is placed on the container body 15a, and the electromagnetic brake 21 is turned off (step S1 in FIG. 2). Then, the motor 13 is driven by the controller, and the rotation is transmitted to the revolution table 14 via the pulley P1, the belt V1, and the pulley P2, thereby rotating the revolution table 14 (step S2 in FIG. 2). Thereby, the container 15 is revolved around the revolution axis Y1. At this time, the revolution speed of the container 15 is set to 1000 rpm or more, for example. Thereby, a centrifugal force of 3000 m / s ² or more is applied to the material K to be kneaded. In this embodiment, the revolution speed is set to 1000 rpm or more. However, the revolution speed is not limited, and the setting is appropriately changed as long as sufficient centrifugal force is applied to the material K to be kneaded in the container 15. can do.

  Then, it is determined whether or not the rotational speed has reached or exceeded a predetermined value (step S3 in FIG. 2). If it has not reached the predetermined value (No in step S3 in FIG. 2), the determination is repeated again. On the other hand, when the rotational speed becomes equal to or higher than the predetermined value (Yes in step S3 in FIG. 2), the controller depressurizes the inside of the container 15 with the vacuum pump 17b while the container 15 is revolved (step in FIG. 2) S4). The degree of vacuum in the container 15 is detected by the vacuum gauge 17c at regular intervals (step S5 in FIG. 2), and the control unit determines whether or not the detected value is a predetermined value or less, for example, 400 Pa or less (FIG. 2). 2 step S6). The predetermined value is not particularly limited, and may be any value as long as it is set to a value of 400 Pa or less. Preferably, the pressure is 66 Pa, and further 50 Pa, whereby a more suitable defoaming effect can be obtained.

  If the detected value is higher than the predetermined value (No in step S6 in FIG. 2), the process returns to step S3 and the decompression of the container 15 is continued. When the detected value is equal to or lower than the predetermined value (Yes in step S6 in FIG. 2), the container 15 starts to rotate (step S7 in FIG. 2). Specifically, the container 15 rotates with respect to the revolution table 14 by turning on the electromagnetic brake 21. The rotation speed at this time is 600 rpm, for example. Note that the rotation speed can be set and changed as appropriate.

  Then, the container 15 is rotated while revolving until a predetermined time (for example, 5 minutes) elapses (step S8 in FIG. 2). When the predetermined time elapses (Yes in step S8), the motor 13 is stopped. Then, the stirring defoaming operation is finished.

  As a result, the material to be kneaded K is pressed against the inner wall of the sample holder 15d by the centrifugal force generated by the revolution of the container 15, and the bubbles present in the material to be kneaded are discharged (defoamed) to the outside. Further, when the container 15 is depressurized to 400 Pa (preferably 66 Pa) or less, fine bubbles present in the material to be kneaded expand and foam, and separation from the material to be kneaded is promoted. That is, highly accurate defoaming is performed by evacuating the container 15 to 400 Pa (preferably 66 Pa) or less while revolving. Furthermore, the material K to be kneaded is stirred (kneaded) by the rotation of the container 15.

According to the stirring and defoaming method according to the present embodiment, the following effects can be obtained.
In the present embodiment, since a large centrifugal force is applied to the material K to be kneaded by rotating the container 15 only for revolution, even if the pressure is reduced to 400 Pa (preferably 66 Pa) or less exceeding the conventional limit (vacuum degree) Does not cause boiling of the material to be kneaded. And deaeration is performed by making the container 15 revolve in this way and making it highly vacuum. That is, in the stirring and defoaming step, the container 15 is revolved so that the material to be kneaded can be exposed to a high vacuum environment that has been impossible in the past. Thus, defoaming can be performed with high accuracy.

  Moreover, the kneaded material K can also be stirred as usual by rotating the container 15. Thereby, highly accurate stirring deaeration is promoted.

As mentioned above, although this embodiment was described, this invention is not limited to the said embodiment, It can implement with a various form.
The apparatus for carrying out the stirring and defoaming method according to the present invention is not limited to the stirring and defoaming apparatus 1.
In the embodiment, the stirring deaerator 1 using a gear is used as a rotation transmission mechanism for transmitting rotation to the container 15. For example, an agitating deaerator using a pulley or the like is used instead of a gear. May be.

  In the above-described embodiment, the rotation / revolution movement of the container 15 is realized by the single motor 13. However, a stirring and defoaming apparatus in which a motor for rotation and a rotation are separately provided can also be used. According to this, rotation speed or revolution speed can be arbitrarily changed. That is, the rotation ratio between the revolution table 14 and the container 15 can be changed as appropriate.

It is a longitudinal cross-sectional view of the stirring defoaming apparatus which performs the stirring defoaming method of this invention. It is a flowchart explaining a stirring defoaming process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stirring deaerator Y1 Revolving shaft Y2 Rotating shaft 11 Housing 12 Support member 13 Motor 14 Revolving table 15 Container 16 Suction pipe 17 Decompression means 18 Rotating force giving shaft 19 Rotating force transmission shaft 20 Support shaft 21 Electromagnetic brake 24 Magnetic fluid seal K Material to be kneaded

Claims (6)

  A first step of revolving a container containing the material to be kneaded to apply centrifugal force to the material to be kneaded, and reducing the pressure in the container to 400 Pa or less in a state where centrifugal force is applied to the material to be kneaded. And a second step of defoaming the material to be kneaded.   2. The stirring and defoaming method according to claim 1, wherein in the second step, the object to be kneaded is defoamed by lowering the pressure in the container to 66 Pa or less.   The stirring and defoaming method according to claim 2, further comprising a third step of rotating the container after the pressure in the container has decreased to 66 Pa or less.   The stirring and defoaming method according to claim 1, wherein the material to be kneaded is a sealing paste material. 5. The stirring and defoaming method according to claim 1, wherein in the second step, the centrifugal force applied to the material to be kneaded is 3000 m / s ² or more. A container for storing the material to be kneaded;
A revolving table that rotatably supports the container;
A support member for rotatably supporting the revolving table;
A rotation drive mechanism for rotation for rotating the container on the revolution table;
A revolving rotation drive mechanism for revolving the container by revolving the revolving table;
A vacuum pump for decompressing the inside of the container;
A stirring and defoaming device comprising: revolution and rotation of the container and a control unit for controlling the pressure in the container,
The said control part controls the pressure in the said container to reduce to 400 Pa or less in the state which revolved the said container and the centrifugal force acted on the said to-be-kneaded material, The stirring deaeration apparatus characterized by the above-mentioned.

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