JP2023026211A - Foam production method and foam production apparatus - Google Patents

Abstract

To provide a method for producing a foam which is excellent in homogeneity, and a foam production apparatus for producing a foam which is excellent in homogeneity.SOLUTION: A foam production method includes the steps of: supplying a mixed liquid containing a resin raw material and a foaming agent to inside of a container 2 for transmitting microwaves; and heating the mixed liquid by irradiating the mixed liquid with microwaves, and thereby curing the mixed liquid while foaming. In the foaming step, an inner pressure control member 3 moving while directly or indirectly pressing the surface of the mixed liquid controls the inner pressure of the mixed liquid. The inner pressure of the mixed liquid can be preferably controlled by its own weight of the inner pressure control member 3.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a foam manufacturing method and a foam manufacturing apparatus.

Foams such as melamine foam are known. Such foams are used, for example, in thermal insulation, sound absorption, or sponges for washing dishes.

Patent Literature 1 discloses a method for producing melamine foam. In the manufacturing method, the raw material of the melamine foam is heated by irradiation with microwaves, thereby allowing the curing reaction to proceed while foaming the raw material. Further, in the method for producing melamine foam described in Patent Document 1, raw materials for melamine foam are supplied into a mold having a predetermined internal contour shape. As the foaming of the raw material progresses, the raw material spreads throughout the inside of the mold, and as a result, a melamine foam having an outer contour shape that matches the inner contour shape of the mold is obtained.

JP 2003-191255 A

However, although the manufacturing method described in Patent Document 1 can manufacture a foam having a desired contour shape, the behavior of the raw material during foaming is not controlled at all, so the specification in Patent Document 1 Contrary to the description in the book, there is a problem that it is actually difficult to produce a foam with excellent homogeneity.

An object of the present invention is to provide a method for producing a foam with excellent homogeneity and a foam production apparatus for producing a foam with excellent homogeneity.

A method for producing a foam according to one aspect of the present invention includes the steps of supplying a mixed liquid containing a resin raw material and a foaming agent to the inside of a microwave-permeable container, and irradiating the mixed liquid with microwaves. A step of heating the mixed liquid to harden the mixed liquid while foaming the mixed liquid, and in the foaming step, an internal pressure control member that moves while directly or indirectly pressing the surface of the mixed liquid. The internal pressure of the liquid mixture is controlled.

A method for producing a foam according to one aspect of the present invention includes the steps of supplying a mixed liquid containing a resin raw material and a foaming agent to the inside of a microwave-permeable container, and irradiating the mixed liquid with microwaves. By heating the mixed solution, the mixed solution is cured while foaming, and in the foaming step, the amount of foaming of the mixed solution is measured, and microwaves are applied according to the amount of foaming. Control output.

A foam manufacturing apparatus according to an aspect of the present invention contains a mixed liquid containing a resin raw material and a foaming agent, a container that transmits microwaves, a microwave oscillator that generates microwaves, and a heating of the mixed liquid. A microwave irradiation unit that irradiates the mixed liquid with microwaves so as to harden while foaming, and a microwave irradiation unit that directly or indirectly presses the surface of the mixed liquid and moves along with the foaming of the mixed liquid. an internal pressure control member that controls the internal pressure of the liquid.

A foam manufacturing apparatus according to an aspect of the present invention contains a mixed liquid containing a resin raw material and a foaming agent, a container that transmits microwaves, a microwave oscillator that generates microwaves, and a heating of the mixed liquid. a microwave irradiation unit that irradiates the mixed liquid with microwaves so as to harden the mixture while foaming; a measuring means that measures the amount of foaming of the mixed liquid; and a microwave that controls the output of microwaves according to the amount of foaming. and a control unit.

According to the present invention, a foam having excellent homogeneity can be produced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structural example of the foam manufacturing apparatus which concerns on embodiment. 2 is a block diagram of the foam manufacturing apparatus shown in FIG. 1; FIG. FIG. 2 is a cross-sectional view of the housing shown in FIG. 1; FIG. 2 is a cross-sectional view of the housing shown in FIG. 1; FIG. 2 is a cross-sectional view of the container and internal pressure control member shown in FIG. 1; FIG. 2 is a plan view of the container and internal pressure control member shown in FIG. 1; It is a figure which shows the flow of the manufacturing method of the foam which concerns on embodiment. It is explanatory drawing of a foaming process. It is explanatory drawing of a foaming process. FIG. 11 is a plan view of a housing in a modified example; FIG. 10 is a cross-sectional view for explaining a container and an internal pressure control member in a modified example; FIG. 10 is a cross-sectional view for explaining a container and an internal pressure control member in a modified example; FIG. 10 is a cross-sectional view for explaining a container and an internal pressure control member in a modified example; FIG. 10 is a cross-sectional view for explaining a container and an internal pressure control member in a modified example;

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings are appropriately different from the actual ones, and some parts are shown schematically for easy understanding. Moreover, the scope of the present invention is not limited to these forms unless there is a description to the effect that the present invention is particularly limited in the following description.

Before describing a foam manufacturing apparatus according to an embodiment and a method for manufacturing a foam according to an embodiment, first, a foam manufactured by the manufacturing method and a mixed liquid as a raw material thereof will be described.

1. Foam A foam manufactured by a manufacturing method using microwaves, which will be described later, is a porous body having a plurality of cells. The foam is made of thermosetting resin such as urethane resin or melamine resin. Moreover, the foam may have open cells in which cells are continuous, or may have independent cells in which cells are not continuous. However, it is preferred that the foam has open cells. Physical properties such as density, average pore size, void content and expansion ratio of the foam are not particularly limited. Moreover, the shape of the foam is not particularly limited, and examples thereof include a columnar shape and a flat plate shape.

Such foams are used, for example, as heat insulating materials, sound absorbing materials, cushioning materials, sealing materials, cushioning materials, sports mats, sponges for washing dishes, and the like. Note that the use of the foam is not particularly limited and is arbitrary. The foam can be used for any purpose by adjusting the void content and the like.

2. Mixed Liquid The aforementioned foam can be obtained by irradiating a liquid mixed liquid (hereinafter also simply referred to as a “mixed liquid”) as a raw material with microwaves to foam and cure the mixed liquid. The mixed liquid contains a main agent containing a resin raw material and a foaming agent. Furthermore, the mixed liquid contains, for example, a foaming aid and a curing agent, if necessary.

The main agent contains a resin raw material, a surfactant, and an additive such as a pH adjuster. Examples of resin raw materials include thermosetting resin monomers such as urethane and melamine. Note that the resin raw material may include a condensate of melamine or formaldehyde, or the like. Examples of foaming agents include non-fluorinated solvents such as hydrofluorocarbons, and water. Foaming aids include alcohol compounds such as methanol or ethanol, and hydrocarbons. Curing agents include, for example, acidic catalysts such as formic acid.

The respective contents of the main agent, foaming agent, foaming assistant and curing agent are not particularly limited, and are arbitrarily set according to, for example, physical properties such as density of the foam to be produced. Moreover, the liquid mixture may contain materials other than these in addition to the main agent, foaming agent, foaming aid and curing agent. Moreover, the mixed liquid may be in the form of a paste.

3. Foam production device 100
FIG. 1 is a schematic diagram showing a configuration example of a foam manufacturing apparatus 100 according to an embodiment. In FIG. 1, X-axis, Y-axis and Z-axis are illustrated as three axes orthogonal to each other. The XY plane is parallel to the horizontal plane and the direction along the Z axis is parallel to the vertical direction. For convenience of explanation, one direction along the X-axis is hereinafter referred to as the X1 direction, and the opposite direction to the X1 direction is referred to as the X2 direction. Similarly, one direction along the Y axis is called the Y1 direction, and the opposite direction to the Y1 direction is called the Y2 direction. One direction along the Z axis is called the Z1 direction, and the direction opposite to the Z1 direction is called the Z2 direction. Also, hereinafter, the Z1 direction will be referred to as "upward" and the Z2 direction will be referred to as "downward."

3-1. Overall Configuration of Foam Production Apparatus 100 The foam production apparatus 100 shown in FIG. 1 is an apparatus for producing the aforementioned foam. The foam production apparatus 100 is an apparatus for producing a foam from the liquid mixture by irradiating the liquid mixture with microwaves to heat the liquid mixture. By using a heating method using microwaves, the mixture can be heated more uniformly than when other heating methods are used, so that the homogeneity of the foam can be improved. For example, by using microwaves, it is possible to reduce the variation in the distribution of the void content in the foam.

As shown in FIG. 1, a foam manufacturing apparatus 100 includes a housing 1, a container 2, an internal pressure control member 3, a transport mechanism 4, a mixed liquid supply section 5, a position sensor 6, a plurality of microwave It has irradiation units 7 a and 7 b and a control device 8 . The microwave irradiation section 7a and the microwave irradiation section 7b have the same configuration. When the microwave irradiation units 7a and 7b are not distinguished from each other, they are referred to as the microwave irradiation unit 7. FIG. Each part will be briefly described below.

The housing 1 is a box-shaped housing that accommodates the container 2 . The inner wall of the housing 1 is reflective to microwaves, and the housing 1 is configured so that the microwaves do not leak to the outside. The housing 1 is made of a non-magnetic metal material such as stainless steel, aluminum or copper. At least the inner wall of the housing 1 needs to be reflective to microwaves, and the housing 1 may include a portion that is not reflective to microwaves. Further, the housing 1 may be provided with an observation window (not shown) for observing the inside.

Further, in the illustrated example, the outer shape of the housing 1 is elongated along the X-axis. A loading port 102 through which the container 2 is loaded is provided at one of both ends in the longitudinal direction of the housing 1 (the end in the X2 direction), and a loading port 103 through which the container 2 is unloaded is provided at the other end (the end in the X1 direction). is provided. During microwave irradiation, the loading port 102 is closed by an openable loading door 12, and the loading port 103 is closed by an openable unloading door 13. As shown in FIG. In addition, the outer shape of the housing 1 is not limited to a long shape along the X axis, and may be a long shape along the Y axis, for example, or other shapes. The size of the housing 1 is not particularly limited, and is determined according to, for example, the distribution of microwaves irradiated inside the housing 1, the production scale of the foam, and the like.

The container 2 is a case that accommodates the liquid mixture. The container 2 is made of a material and thickness that is transparent to microwaves. The container 2 is made of, for example, glass or resin. An internal pressure control member 3 for controlling the internal pressure of the liquid mixture is arranged in the container 2 . The internal pressure control member 3 is a flat member. The internal pressure control member 3 may be film-like. Like the container 2, the internal pressure control member 3 is made of a material and thickness that transmits microwaves. The housing 1, the container 2, and the internal pressure control member 3 will be detailed later.

The transport mechanism 4 is a mechanism that transports the container 2 . The transport mechanism 4 mainly transports the container 2 in the X1 direction, but may be capable of transporting in both the X1 direction and the X2 direction. In addition, below, the X1 direction which is the direction in which the container 2 is conveyed is also called "conveyance direction."

The transport mechanism 4 has multiple conveyors 40 , 41 and 42 . Conveyor 40 is arranged between conveyor 41 and conveyor 42 . , a part of the conveyor 40 is located inside the housing 1 . Conveyors 40, 41 and 42 each convey the container 2 in the X1 direction. The container 2 is conveyed from the conveyor 41 onto the conveyor 40 , passes through the housing 1 , and then conveyed onto the conveyor 42 . Conveyors 41 and 42 are not particularly limited as long as they can convey container 2 in the X1 direction. Also, one or both of the conveyors 41 and 42 may be provided as required or may be omitted.

Conveyor 40 includes plate 45 , driving pulley 401 , driven pulley 402 , belt 403 , multiple rollers 404 , motor 405 , encoder 406 and proximity sensor 407 . Belt 403 is stretched over drive pulley 401 and driven pulley 402 . A portion of the belt 403 runs through the housing 1 and supports a plate 45 arranged within the housing 1 . Note that elements other than the part of the belt 403 and the plate 45 among the elements constituting the conveyor 40 are positioned outside the housing 1 . Belt 403 is formed of a material and thickness that is transparent to microwaves. The belt 403 is made of, for example, resin. The plate 45 is a member for transporting the container 2 , and the container 2 is placed on the plate 45 . Plate 45 is formed of a material and thickness that is transparent to microwaves. The plate 45 is made of glass, resin, or the like, for example.

Motor 405 is, for example, various DC motors or various AC motors. A drive pulley 401 is connected to the rotating shaft of the motor 405 . A driving force generated by the motor 405 is transmitted to the driving pulley 401 to run the belt 403 . As the belt 403 runs, the plate 45 moves in the X1 direction or the X2 direction. By this movement of the plate 45, the container 2 is conveyed in the X1 direction or the X2 direction.

Encoder 406 is, for example, a pulse generator. In the example shown in FIG. 1, encoder 406 is attached to driven pulley 402 . The encoder 406 outputs a signal corresponding to the rotation angle, rotation speed, etc. of the driven pulley 402 . Based on the signal, the direction and amount of movement of the plate 45 can be detected. Also, the proximity sensor 407 is, for example, a limit switch. The proximity sensor 407 detects the movement limit position of the plate 45 in the X1 direction and the movement limit position in the X2 direction.

It should be noted that the movement of the container 2 by the transport mechanism 4 described above may be continuous movement or non-continuous movement combining movement and stoppage. For example, while the container 2 is being irradiated with microwaves, the movement of the container 2 by the transport mechanism 4 may be stopped. Further, the moving speed of the container 2 by the transport mechanism 4 may be constant or may vary. Also, the transport speed is controlled to a predetermined speed, for example.

The mixed liquid supply unit 5 is installed outside the housing 1 and is a device that measures the mixed liquid and supplies a required amount of the mixed liquid into the container 2 . In the illustrated example, the mixed liquid supply unit 5 is located above the conveyor 41 , but may be arranged at a location other than above the conveyor 41 . Moreover, the liquid mixture supply part 5 may be equipped with a stirrer. The liquid mixture supply unit 5 may function as a generation unit that mixes various materials in required amounts to generate a liquid mixture.

A position sensor 6 is installed in the housing 1 . In the example shown in FIG. 1 , the position sensor 6 is attached to the housing 1 so as to be positioned above the internal pressure control member 3 . The position sensor 6 is, for example, a photosensor or the like using light such as infrared rays. Specifically, the position sensor 6 has a light-emitting element that irradiates the internal pressure control member 3 with light and a light-receiving element that receives light reflected by the internal pressure control member 3 . Moreover, when the position sensor 6 is an infrared sensor, the internal pressure control member 3 has reflectivity to infrared rays. The position sensor 6 measures the distance to the internal pressure control member 3 and detects the position (height) of the internal pressure control member 3 in the Z-axis direction based on the measurement result. For example, the position of the internal pressure control member 3 in the Z-axis direction is the height of the internal pressure control member 3 from the bottom surface of the container 2 .

The number of position sensors 6 is not limited to one, and may be plural. The installation location of the position sensor 6 may not be the upper part of the housing 1, and may be installed on the conveyor 40, for example. In this case, for example, the position sensor 6 is covered with a member having microwave reflectivity so that the position sensor 6 is not affected by microwaves. Further, the position sensor 6 may be a sensor other than the photosensor as long as it can detect the position of the internal pressure control member 3 in the Z-axis direction.

A microwave irradiation unit 7 is installed in the housing 1 . The microwave irradiation unit 7 irradiates the inside of the housing 1 with microwaves. The microwave irradiation units 7a and 7b are spaced apart from each other and arranged side by side along the X-axis. That is, the microwave irradiation unit 7 is arranged along the conveying direction of the container 2 . The microwave irradiation unit 7a is positioned closer to the carrying-in side of the container 2 than the exhaust unit 15, which will be described later, and the microwave irradiation unit 7b is positioned closer to the unloading side of the container 2 than the exhaust unit 15, which will be described later. The microwave irradiation unit 7a irradiates microwaves obliquely downward to the right in FIG. 1, and the microwave irradiation unit 7b irradiates microwaves obliquely downward to the left in FIG.

FIG. 2 is a block diagram of the foam manufacturing apparatus 100 shown in FIG. As shown in FIG. 2, the microwave irradiation unit 7 has a microwave oscillator 71 that generates microwaves. For example, the microwave oscillator 71 is a magnetron, klystron, gyrotron, semiconductor type oscillator, or the like. The microwave frequency is not particularly limited, but is, for example, 915 MHz or 2.45 GHz. Although not shown, the microwave irradiation unit 7 has a transmission unit that transmits microwaves generated by the microwave oscillator 71 and irradiates the microwaves into the container 2 . The transmission unit is, for example, a waveguide or a coaxial cable that transmits microwaves.

Note that the microwave output is determined according to the scale of the foam manufacturing apparatus 100 and the like, and is not particularly limited. However, in this embodiment, the microwave output from the microwave irradiation section 7a is different from the microwave output from the microwave irradiation section 7b. Specifically, the microwave irradiation unit 7a is controlled by the control device 8 so that the output of microwaves is greater than the output of microwaves from the microwave irradiation unit 7b. Moreover, although it is preferable that the frequency of the microwave output from the microwave irradiation section 7a and the frequency of the microwave output from the microwave irradiation section 7b are the same, they may be different.

The control device 8 is a computer that controls the operation of the transport mechanism 4 and the output of the microwave irradiation section 7 . Specifically, the control device 8 has a processing device 81 and a storage device 82 . The processing device 81 is a processor such as a CPU (Central Processing Unit). The storage device 82 is a memory such as a semiconductor memory. The storage device 82 stores a control program P1. The processing device 81 functions as a transport control unit 811, a position calculation unit 813, and a microwave control unit 812 by executing the control program P1.

The transport control unit 811 controls the operation of the motor 405 of the transport mechanism 4 to transport the container 2 along the X axis. Specifically, the transport control unit 811 controls the position of the plate 45 along the X axis calculated based on the information output from the encoder 406 and the information output from the proximity sensor 407 to be the predetermined position. Also, it controls the operation of the motor 405 .

The position calculator 813 calculates the amount of change in the position of the internal pressure control member 3 in the Z1 direction per unit time (that is, the movement speed of the internal pressure control member 3 in the Z1 direction) based on information output from the position sensor 6, for example. calculate. The position sensor 6 and the position calculator 813 described above are "measuring means" that detect the position of the internal pressure control member 3 in the Z1 direction and measure the amount of change in the position per unit time as the amount of bubbling per unit time.

The microwave control unit 812 controls the output of each microwave irradiated by the microwave irradiation units 7a and 7b. Specifically, the microwave control section 812 controls the output of the microwave irradiation section 7 based on information output from the position sensor 6 . More specifically, the microwave control unit 812 changes the intensity of the microwave output from the microwave irradiation unit 7 in accordance with the amount of change in position per unit time, so that the degree of bubbling of the mixed liquid can be set as a target. Feedback control is performed on the output of the microwave so that the value For example, if the moving speed of the internal pressure control member 3 in the Z1 direction is faster than the target speed, the intensity of the microwave is decreased, and if the moving speed is slower than the target speed, the intensity of the microwave is increased. . By controlling the microwave output based on the information output from the position sensor 6 in this way, the physical property value such as the expansion ratio can be made to match or approach the target value.

In addition to or instead of controlling the microwave output, the processing device 81 may also control the transport speed or transport direction of the transport mechanism 4 based on the information output from the position sensor 6. good. Further, when a plurality of position sensors 6 are provided, the microwave control unit 812 controls the microwave irradiation unit 7a using one position sensor 6 out of the plurality of position sensors 6, and controls the other one position sensor 6. The sensor 6 may be used to control the microwave irradiation section 7b.

The foam manufacturing apparatus 100 having the above configuration includes the housing 1, the container 2, the internal pressure control member 3, the transport mechanism 4, the mixed liquid supply unit 5, the position sensor 6, the microwave irradiation unit 7a, the microwave irradiation unit 7b, and the control It may have elements other than the device 8 . For example, in addition to the position sensor 6, the foam manufacturing apparatus 100 may have a sensor that acquires information about the conditions inside the housing 1 such as temperature and humidity. In this case, not only the information output from the position sensor 6 but also the information output from the sensor may be used to control the driving of the microwave irradiation units 7a and 7b. In addition to or instead of the position sensor 6, the foam manufacturing apparatus 100 may include a sensor that acquires information on the pressure in the Z1 direction applied to the internal pressure control member 3 due to foaming of the mixed liquid. In this case, the driving of the microwave irradiation section 7a, the microwave irradiation section 7b, etc. may be controlled based on the information output from the position sensor 6 together with or alone with the information output from the position sensor 6. FIG. Therefore, the "measuring means" may have a pressure sensor and measure the amount of change in pressure per unit time as the amount of foaming per unit time.

3-2. housing 1
3 and 4 are cross-sectional views of the housing 1 shown in FIG. 1, respectively. FIG. 3 shows a cross section of the housing 1 cut along the XZ plane. As shown in FIG. 3 , the housing 1 has a box-shaped main body 11 that accommodates the container 2 and an exhaust section 15 . The loading door 12 and the unloading door 13 described above are attached to the main body 11 . FIG. 4 also shows a cross section of the housing 1 cut along the YZ plane. As shown in FIG. 4 , the housing 1 has an intake section 14 . The inside of the housing 1 is filled with air, but may be filled with, for example, nitrogen gas.

As shown in FIG. 4 , the intake section 14 is connected to the main body 11 . In the illustrated example, the intake section 14 is connected to a portion of the main body 11 in the Z2 direction (downward in the vertical direction). The suction unit 14 is an elongated cylindrical member whose longitudinal direction is the X1 direction. In the example shown in FIG. 4 , the intake section 14 is arranged in the Y2 direction with respect to the main body 11 . As shown in FIGS. 3 and 4, the length of the intake section 14 in the longitudinal direction is substantially equal to the length of the main body 11 in the X1 direction. Two open ends 106a and 106b are provided at both ends of the intake portion 14 in the longitudinal direction. Two open ends 106 a and 106 b introduce outside air into the interior of intake section 14 . A space inside the intake portion 14 communicates with an intake port 104 formed on the lower side of the side wall of the main body 11 . The intake port 104 is an elongated hole whose longitudinal direction is the X1 direction. The length of the intake port 104 in the X1 direction is substantially equal to the length of the intake section 14 in the longitudinal direction. A perforated plate 161 is arranged at the intake port 104 to prevent leakage of microwaves to the outside. The perforated plate 161 is a plate member having a plurality of fine holes, and is arranged over the entire area of the intake port 104 . Note that the perforated plate 161 is configured to allow air to flow.

As shown in FIG. 3 , the exhaust portion 15 is connected to the main body 11 . The exhaust part 15 is a cylindrical member that protrudes from the main body 11 in the Z1 direction. The exhaust unit 15 is located between the microwave irradiation unit 7a and the microwave irradiation unit 7b when viewed from the Z1 direction. As shown in FIG. 4, the exhaust part 15 is located in the center of the housing 1 in the Y1 direction. Although not shown, the microwave irradiation units 7a and 7b are also located at the center of the housing 1 in the Y1 direction. Further, the internal space of the exhaust portion 15 communicates with an exhaust port 105 formed on the upper surface of the main body 11 . The exhaust port 105 is a circular hole. A perforated plate 162 is arranged at the exhaust port 105 to prevent leakage of microwaves to the outside. The perforated plate 162 is a plate member having a plurality of fine holes and is arranged over the entire area of the exhaust port 105 . Note that the perforated plate 162 is configured to allow air to flow. An exhaust mechanism having an exhaust fan (not shown) is connected to the exhaust unit 15 . The exhaust mechanism generates an airflow from the intake port 104 to the exhaust port 105 inside the main body 11 .

As described above, the exhaust unit 15 and the intake unit 14 circulate air along the inner wall surface of the housing 1 from the intake port 104 toward the exhaust port 105 by the operation of the exhaust mechanism (not shown). For example, the exhaust mechanism circulates air along the direction indicated by arrow A1 in FIG. Therefore, steam such as water generated by foaming from the mixed liquid in the container 2 can be released to the outside of the housing 1 . Therefore, vapor can be prevented from liquefying on the inner wall of the main body 11 . Therefore, it is possible to prevent microwaves from being absorbed by water or the like. Therefore, compared to the case where such evacuation is not performed, it is possible to control the distribution of the microwaves irradiated to the mixed liquid 10a, and the output of the microwaves for producing the foam can be increased more than necessary. You don't have to make it big. Therefore, a homogeneous foam can be produced efficiently.

Further, as shown in FIG. 4, the length T1 of the open end 106a in the Z1 direction is longer than the length T2 of the intake port 104 in the Z1 direction. Similarly, the length of the open end 106b in the Z1 direction is longer than the length T2. Therefore, the air introduced from the open ends 106a and 106b can be distributed uniformly over the entire area of the intake port 104. As shown in FIG. Therefore, it is possible to evenly generate an airflow from the intake port 104 toward the exhaust port 105 over the entire area of the main body 11 .

3-3. Container 2 and internal pressure control member 3
FIG. 5 is a cross-sectional view of the container 2 and internal pressure control member 3 shown in FIG. FIG. 6 is a view corresponding to the AA line cross section in FIG. The container 2 shown in FIGS. 5 and 6 is a box-shaped case that opens in the Z1 direction. As shown in FIG. 5, the mixed liquid 10a is placed in the container 2 . A mixed liquid 10a shown in FIG. 5 is the raw material of the aforementioned foam. In the illustrated example, the length of the container 2 in the X1 direction is longer than the length in the Y1 direction, but the shape of the container 2 is not particularly limited and is arbitrary. From another point of view, the shape of the container 2 is a longitudinal shape that is long along the conveying direction, but the shape of the container 2 may be, for example, a longitudinal shape that is long along a direction different from the conveying direction. good. Further, for example, the container 2 may be square or the like when viewed from the Z2 direction.

As shown in FIG. 5, the container 2 has a bottom portion 21 and frame-shaped side walls 22 . The shape of the bottom portion 21 when viewed from the Z2 direction is a square shape. The inner surface of the bottom portion 21, that is, the bottom surface 211 is a flat surface. Moreover, the side wall 22 is a wall extending from the bottom 21 in the Z1 direction. Note that the bottom portion 21 and the side walls 22 may be integrally molded, or the separately molded bottom portion 21 and the side walls 22 may be adhered to each other. Moreover, the inner wall surface of the side wall 22 is a flat surface. In addition, the inner wall surface of the side wall 22 and the bottom surface 211 may not be flat. Moreover, although the thickness of the side wall 22 is constant, the thickness of a part of the side wall 22 may be thicker than the thickness of the other part.

As shown in FIG. 5, the internal pressure control member 3 is movable inside the container 2 . As shown in FIG. 6, the planar area of the internal pressure control member 3 viewed from the Z1 direction, that is, the planar area on the XY plane, is smaller than the planar area of the inside of the internal pressure control member 3 viewed from the Z1 direction. Further, the size and arrangement of the internal pressure control member 3 when viewed from the Z1 direction are set so that a gap d1 is formed between the internal pressure control member 3 and the container 2 over the entire circumference of the internal pressure control member 3 . Note that the interval d1 may be constant over the entire circumference of the internal pressure control member 3, or may vary. A part of the internal pressure control member 3 may be in contact with the container 2 .

Since the gap d1 exists between the internal pressure control member 3 and the container 2, the movement of the internal pressure control member 3 inside the container 2 becomes easier than when there is no gap d1. In addition, by providing the gap d1, steam such as water generated from the liquid mixture 10a can be efficiently discharged to the outside of the container 2. As shown in FIG. That is, the gap d1 functions as a discharge portion that discharges steam to the outside of the container 2 .

For example, the internal pressure control member 3 is made of the same material as that of which the container 2 is made. However, the material of the internal pressure control member 3 may differ from the material of the container 2 . Moreover, the thickness of the internal pressure control member 3 may be the same as or different from the thickness of the container 2 . The thickness of the internal pressure control member 3 is determined, for example, by the type of foam. The weight of the internal pressure control member 3 can be set according to the thickness of the internal pressure control member 3 . Further, when the density of the internal pressure control member 3 is ρa and the density of the mixed liquid 10a before foaming is ρb, the internal pressure control member 3 is set so that ρa<ρb. Due to this density relationship, the internal pressure control member 3 can be floated on the mixed liquid 10a before foaming.

As shown in FIG. 5, the internal pressure control member 3 contacts the surface of the liquid mixture 10a. Here, the liquid mixture 10a tries to expand in the direction of the arrow A2 due to foaming. At this time, the internal pressure control member 3 controls the internal pressure of the liquid mixture 10a, that is, the internal pressure of bubbles generated in the liquid mixture 10a. Specifically, the internal pressure control member 3 applies pressure to the liquid mixture 10a by its own weight in the direction opposite to the arrow A2. This restricts expansion due to bubbling of the mixture 10a. However, the pressure by the internal pressure control member 3 is smaller than the pressure generated by the bubbling of the liquid mixture 10a. It is smaller than the internal pressure in the direction of arrow A2. Therefore, the internal pressure control member 3 moves in the direction of the arrow A2 as the mixed liquid 10a foams while contacting the mixed liquid 10a. As shown in FIG. 5, the internal pressure control member 3 gradually moves in the Z1 direction. As a result, the liquid mixture 10a gently expands in the Z1 direction while keeping its internal pressure constant.

Here, the internal pressure control member 3 uniformly contacts and presses the bubbling liquid mixture 10a over substantially the entire area along the XY plane. For this reason, even if expansion of bubbles at a certain position of the mixture 10a progresses locally due to, for example, a bias in the electromagnetic field distribution of the microwave during bubbling of the mixture 10a by the internal pressure control member 3, the volume of the mixture 10a does not change rapidly. is suppressed. As a result, not only can the foaming process and the final shape be controlled to a desired shape, but during the gradual volume change, convection and stress differences between the walls of each cell cause fragmentation of the cells and agitation of the entire liquid. It has been confirmed that the variation in bubble diameter is actually reduced and the bubbles are homogenized. Such an effect becomes more remarkable as the foaming of the mixture 10a progresses and the volume of the foam increases. This is because the larger the volume of the foam, the greater the bias and variation in the electromagnetic field distribution inside the mixed liquid 10a, and allowing expansion in random directions makes it difficult to homogenize the shape and bubbles. According to the configuration, it is considered that the entire liquid mixture is uniformly heated by ensuring the overall fluidity of the liquid and bubbles.

On the other hand, when the mixed solution 10a is foamed in a container with a fixed lid as in the conventional art, a large pressure difference is generated in the mixed solution 10a between the portion in contact with the lid and the portion not in contact with the lid. Due to this pressure difference, variations occur in the bubble diameter and the bubble arrangement density.

Further, the internal pressure control member 3 controls the internal pressure of bubbles generated in the liquid mixture 10a by its own weight. Therefore, variation in bubble diameter can be suppressed with a simple configuration. The internal pressure control member 3 of this embodiment is formed of a flat plate having a uniform thickness. Therefore, it is easier to uniformly apply pressure to the upper portion of the liquid mixture 10a due to the weight of the internal pressure control member 3, as compared with the case where a member having a non-uniform thickness is used.

The thickness and constituent materials of the internal pressure control member 3 are set according to, for example, the type of material contained in the liquid mixture 10a, the content of each material contained in the liquid mixture 10a, and the like. In this embodiment, the internal pressure control member 3 controls the internal pressure of the liquid mixture 10a by its own weight. good. Moreover, although the pressure by the internal pressure control member 3 is constant over time in this embodiment, it may change over time. Further, the pressure applied by the internal pressure control member 3 is uniform over the range of the internal pressure control member 3 along the XY plane, but it does not have to be uniform. Moreover, although the thickness of the internal pressure control member 3 is constant, it does not have to be constant.

4. Foam Production Method FIG. 7 is a diagram showing the flow of the foam production method according to the embodiment. As shown in FIG. 7, the method for manufacturing a foam includes a supply step S11 and a foaming step S12. Each step will be described below.

4-1. Supply step S11
In the supply step S11, the liquid mixture 10a is supplied into the container 2 as shown in FIG. In the supply step S11, for example, a predetermined amount of the mixed liquid 10a is supplied from the mixed liquid supply unit 5 into the container 2 while the container 2 is placed on the conveyor 41 shown in FIG. Further, for example, after the liquid mixture 10a is supplied to the container 2, the internal pressure control member 3 is placed on the liquid mixture 10a from above the container 2 so as to come into contact with the liquid mixture 10a.

4-2. Foaming step S12
8 and 9 are explanatory diagrams of the foaming step S12, respectively. In the foaming step S12, the mixed liquid 10a is heated by irradiating the mixed liquid 10a with microwaves. Due to the heating, the mixed liquid 10a is cured while foaming. The foaming step S12 can also be said to be a heating step of heating the liquid mixture 10a with microwaves.

Specifically, first, as shown in FIG. 8, the container 2 is conveyed from the conveyor 41 onto the conveyor 40 . That is, the container 2 is arranged inside the housing 1 . When the container 2 is placed in the housing 1, the loading door 12 of the housing 1 is opened and closed.

Next, when the container 2 is placed inside the housing 1 , the microwave irradiation units 7 a and 7 b start irradiating the inside of the housing 1 with microwaves under the control of the microwave control unit 812 . The microwave irradiation is performed with the loading door 12 and the unloading door 13 closed. Since the housing 1 has microwave reflectivity as described above, it is possible to prevent microwaves from leaking to the outside.

The mixture 10a is heated by irradiating the mixture 10a with microwaves. When the liquid mixture 10a is heated, foaming of the liquid mixture 10a is started. Specifically, gas is generated by vaporizing the heated portion of the liquid mixture 10a, and the generated gas expands the liquid mixture 10a from the inside. In addition, the curing reaction is started along with the foaming.

Here, as described above, the internal pressure control member 3 is placed on the liquid mixture 10a in the supply step S11. Therefore, at the start of microwave irradiation, the internal pressure control member 3 is in contact with the liquid mixture 10a. However, the internal pressure control member 3 may be arranged in the container 2 so as to come into contact with the liquid mixture 10a after the start of microwave irradiation. That is, the internal pressure control member 3 is arranged on the liquid mixture 10a between the supply step S11 and the foaming step S12 or during the foaming step S12.

Next, when microwave irradiation by the microwave irradiation units 7a and 7b is started, the conveyor 40 conveys the container 2 in the X1 direction under the control of the conveyance control unit 811. FIG. Therefore, the transportation of the container 2 and the irradiation of the mixed liquid 10a with microwaves are simultaneously performed in parallel. By irradiating the container 2 with microwaves while being transported, the distribution of the microwaves can be controlled with respect to the liquid mixture 10a compared to the case of irradiating the microwaves without moving the container 2 . As a result, the homogeneity of the produced foam can be enhanced. Further, by moving the container 2 with respect to the housing 1, the configuration of the foam manufacturing apparatus 100 can be simplified compared to the configuration in which the microwave irradiation units 7a and 7b are moved with respect to the housing 1. .

The microwave irradiation and the transport of the container 2 by the conveyor 40 may be started at the same time, or the microwave irradiation may be started after the transport of the container 2 by the conveyor 40 is started. Further, the microwave irradiation units 7a and 7b may start microwave irradiation at the same time. For example, after only the microwave irradiation unit 7a irradiates the mixed liquid 10a with microwaves, may irradiate the mixed liquid 10a with microwaves. Each irradiation start timing by the microwave irradiation units 7a and 7b may be determined according to, for example, the conveying speed and conveying direction of the container 2 .

By the conveyance of the conveyor 40, the container 2 moves from a position closer to the loading door 12 than the loading door 13 as shown in FIG. 8 to a position closer to the loading door 13 than the loading door 12 as shown in FIG. move to During this movement, the mixture 10a continues to be irradiated with microwaves. Then, the mixed liquid 10a expands in the Z1 direction while the curing reaction progresses. While the foaming and curing reactions are in progress, the mixed liquid 10a includes a mixture of cured and uncured portions. In the description of this specification, both the state before the start of curing and the state in which the cured portion and the uncured portion are mixed are described as the mixed liquid 10a.

Further, as described above, before the container 2 is arranged in the housing 1, the internal pressure control member 3 is placed on the liquid mixture 10a. Therefore, the internal pressure control member 3 is in contact with the liquid mixture 10a during microwave irradiation. Therefore, when the mixed liquid 10a hardens while foaming, the internal pressure control member 3 controls the internal pressure of the bubbles generated in the mixed liquid 10a. Therefore, the mixed liquid 10a expands in the Z1 direction while expansion due to foaming is restricted to a predetermined condition.

In this way, when the liquid mixture 10a hardens while foaming, the internal pressure of the liquid mixture 10a is controlled by the internal pressure control member 3 . Therefore, during bubbling, the variation in the pressure applied to the entire circumference of the liquid mixture 10a by the container 2 and the internal pressure control member 3 can be reduced. As a result, it is possible to suppress the occurrence of a difference in the degree of expansion of the generated bubbles. In addition, since the internal pressure control member 3 can move along with the foaming, it is possible to reduce the variation in the diameter of the bubbles due to the difference in the generation time of the bubbles. For this reason, it is possible to suppress variation in cell diameter in the foam.

In particular, the internal pressure control member 3 preferably controls the internal pressure of the liquid mixture 10a before starting to irradiate the liquid mixture 10a with microwaves. As a result, compared to the case where the internal pressure of the liquid mixture 10a is controlled after the start of microwave irradiation, it is possible to achieve uniform cell diameters in the foam.

Further, the internal pressure control member 3 controls the internal pressure of bubbles generated in the liquid mixture 10a due to its own weight during foaming of the liquid mixture 10a. Therefore, in the present embodiment, the internal pressure control member 3 directly contacts the surface of the liquid mixture 10a and applies pressure thereto. Therefore, the internal pressure control member 3 contacts the surface of the mixed liquid 10a while the mixed liquid 10a is bubbling, and moves while directly pressing the mixed liquid 10a, thereby controlling the internal pressure of the mixed liquid 10a. By controlling the internal pressure of the bubbles generated in the mixture 10a by the weight of the internal pressure control member 3 as in the present embodiment, it is possible to suppress variations in bubble diameter with a simple configuration.

Further, as described above, the microwave irradiation unit 7a emits microwaves obliquely downward to the right in FIG. 1, and the microwave irradiation unit 7b emits microwaves obliquely downward to the left in FIG. Irradiate. Therefore, compared with the case where the container 2 is irradiated with microwaves from directly above, for example, the central portion of the liquid mixture 10a placed in the container 2 can also be effectively irradiated with microwaves.

Further, as shown in FIG. 8, when the container 2 is arranged at a position closer to the loading door 12 than to the loading door 13, the mixed liquid 10a in the container 2 is exposed to more microwaves than the microwave irradiation unit 7b. It is strongly affected by microwaves from the irradiation section 7a. On the other hand, as shown in FIG. 9, when the container 2 is arranged closer to the unloading door 13 than to the loading door 12, the mixed liquid 10a in the container 2 receives more microwaves than the microwave irradiation unit 7a. It is strongly affected by microwaves from the irradiation section 7b. As described above, the microwave irradiation unit 7a outputs microwaves having a higher intensity than the microwaves output from the microwave irradiation unit 7b. Therefore, the intensity of the microwaves irradiated to the liquid mixture 10a in the initial stage of production is higher than the intensity of the microwaves irradiated to the liquid mixture 10a in the final stage of production.

By decreasing the output of the microwaves irradiated to the mixed liquid 10a over time, it is possible to reduce variations in the distribution of the arrangement of the bubbles in the foam, compared to the case where the output is not changed over time. By increasing the output of microwaves immediately after the start of microwave irradiation to the mixed liquid 10a, foaming can be rapidly progressed. In addition, it is preferable to maintain the temperature of the foam in order to maintain the shape during the period after the mixed liquid 10a is foamed to the target foam shape. In addition, it is considered that the change in the output is effective even in a configuration that does not have the internal pressure control member 3 .

Next, for example, when it is determined that the preset irradiation time has been reached, under the control of the microwave control unit 812, the microwave irradiation units 7a and 7b stop the microwave irradiation. A foam is manufactured from the liquid mixture 10a by the above. In addition, after irradiation with microwaves, drying treatment may be performed as necessary.

Next, after the foam is manufactured, the container 2 is conveyed from the conveyor 40 onto the conveyor 42 . Then, the manufactured foam is removed from the container 2 and molded into a predetermined shape by removing unnecessary portions with a cutting machine or the like.

The method for producing a foam has been described above. For example, when treating a plurality of containers 2 continuously, when the mixture 10a is supplied to one container 2, the mixture 10a in the other container 2 is irradiated with microwaves. . Although a plurality of containers 2 may be arranged within the housing 1, it is preferred that one container 2 is arranged within the housing 1 in order to sufficiently enhance the homogeneity of the foam. In the above description, the mixed liquid 10a was irradiated with the microwaves while the container 2 was being transported.

5. Modifications The embodiments illustrated above can be modified in various ways. Specific modification aspects that can be applied to the above-described embodiment are exemplified below. Two or more examples arbitrarily selected from the following examples can be combined as appropriate within a mutually consistent range.

In the above-described embodiment, the foam manufacturing apparatus 100 has two microwave irradiation units 7a and 7b, but the number of "microwave irradiation units" may be one or three or more. FIG. 10 is a plan view of housing 1 in a modified example.

For example, the housing 1 shown in FIG. 10 has nine microwave irradiation units 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h and 7i. The microwave irradiation units 7c, 7d and 7e are arranged in the Y1 direction with respect to the housing 1 and are separated from each other. The microwave irradiation units 7f, 7g and 7h are arranged in the Y2 direction with respect to the housing 1 and separated from each other. These microwave irradiation units 7c, 7d, 7e, 7f, 7g, and 7h irradiate the mixed liquid 10a placed in the container 2 with microwaves along the Y1 direction or the Y2 direction. The arrangement of the microwave irradiation units 7c, 7d, 7e, 7f, 7g, and 7h in the Z1 direction is not particularly limited, but it is preferable that they are arranged above the container 2 as well. Thereby, the mixed liquid 10a in the container 2 can be evenly irradiated with microwaves. Further, the microwave irradiation unit 7i is installed so as to be able to irradiate the mixed liquid 10a in the container 2 from below the housing 1 with microwaves. The arrangement of the microwave irradiation units 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h and 7i is not limited to the example shown in FIG. Also, only one of these may be installed in the foam manufacturing apparatus 100 .

In the above-described embodiment, the container 2 has an opening that opens in the Z1 direction, but the position of the opening is not limited to this. The container 2 may have an opening open in the X1 direction, for example. For example, the example shown in FIG. 11 is given. FIG. 11 is a cross-sectional view for explaining a container 2A and an internal pressure control member 3A in a modified example. A container 2A shown in FIG. 11 differs from the container 2 described above in that it has an opening that opens in the X1 direction. Further, the internal pressure control member 3A shown in FIG. 11 differs from the internal pressure control member 3 described above in that it moves in the X1 direction as the mixture 10a foams.

As shown in FIG. 11, the internal pressure control member 3A is arranged to block the opening of the container 2A opened in the X1 direction. However, a space d2 exists between the upper portion of the internal pressure control member 3A and the container 2A. The space d2 has a size such that the liquid mixture 10a does not flow out from the space d2. A support rod 35 is attached to the internal pressure control member 3A to support it. The support rod 35 is inserted through a through hole formed in the unloading door 13, for example. The support rod 35 is slidably supported by the carry-out door 13 by being inserted through the through hole. The through hole is designed so that the microwave MW leaks to the outside while the support rod 35 is inserted.

Also, the container 2 may have an opening that opens in the Z2 direction, for example. For example, the example shown in FIG. 12 is given. FIG. 12 is a cross-sectional view for explaining a container 2B and an internal pressure control member 3B in a modified example.

A container 2B shown in FIG. 12 differs from the container 2 described above in that it has an opening that opens in the Z2 direction. Further, the internal pressure control member 3B shown in FIG. 12 is different from the internal pressure control member 3 described above in that it is a tray and moves in the Z2 direction as the mixed liquid 10a foams.

As shown in FIG. 12, the internal pressure control member 3B is a tray having a bottom and side walls. A liquid mixture 10a is placed inside the internal pressure control member 3B. The depth of the tray is such that the mixed liquid 10a before hardening does not flow out. A space d3 exists between the side wall of the internal pressure control member 3B and the container 2B. The space d3 has a size such that the liquid mixture 10a does not flow out from the space d3. A plurality of elastic members 36 are attached to the internal pressure control member 3B to support it. Each elastic member 36 is, for example, a coil spring. One end of each elastic member 36 is connected to the internal pressure control member 3B, and the other end of each elastic member 36 is connected to the plate 45 . In addition, the plate 45 has, for example, a frame shape so as to ensure air circulation into the container 2 . Also, the container 2B is detachably connected to the plate 45 . The internal pressure control member 3B described above moves in the Z2 direction against the elastic force of each elastic member 36 as the liquid mixture 10a foams.

Thus, the direction in which the container 2 is opened is not limited to the Z1 direction as described above, and may be any direction other than the Z1 direction. However, when the liquid mixture 10a has high fluidity, it is preferable to open in the Z1 direction.

Moreover, although the internal pressure control member 3 has a flat plate shape in the above-described embodiment, it may have a film shape. For example, the examples shown in FIGS. 13 and 14 are given. 13 and 14 are cross-sectional views for explaining a container 2C and an internal pressure control member 3C in modified examples. An internal pressure control member 3C shown in FIGS. 12 and 13 is made of a film. A plurality of rollers 38 for feeding the internal pressure control member 3C are attached to the container 2 . A plurality of stopper members 37 having a function as a roller and a function as a stopper are attached to the container 2 . For example, the end of the internal pressure control member 3C is configured to be hooked on each stopper member 37 . The internal pressure control member 3C is pulled up in the Z1 direction by the foaming of the liquid mixture 10a. At this time, the plurality of stopper members 37 and the plurality of rollers 38 restrict the internal pressure control member 3C from being sent in the Z1 direction.

Also, in the above-described embodiment, the internal pressure control member 3 is in direct contact with the surface of the liquid mixture 10a, but it does not have to be in direct contact. The internal pressure control member 3 may directly contact the surface of the liquid mixture 10a to apply pressure, or may apply pressure via gas.

Although the foam manufacturing apparatus and foam manufacturing method of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to these. Also, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same functions as those of the above-described embodiments, and any configuration can be added. Each process in the manufacturing method of the present invention can be replaced with any process that exhibits the same functions as those of the above-described embodiments, and any process can be added.

DESCRIPTION OF SYMBOLS 1... Case, 2... Container, 2A... Container, 2B... Container, 3... Internal pressure control member, 3A... Internal pressure control member, 3B... Internal pressure control member, 3C... Internal pressure control member, 4... Transfer mechanism, 5... Mixed liquid Supply unit 6 Position sensor 7 Microwave irradiation unit 7a Microwave irradiation unit 7b Microwave irradiation unit 7c Microwave irradiation unit 7d Microwave irradiation unit 7e Microwave irradiation unit 7f... Microwave irradiation part 7g... Microwave irradiation part 7h... Microwave irradiation part 7i... Microwave irradiation part 8... Control device 10a... Mixed liquid 11... Main body 12... Carry-in door 13... Carry-out door 14 Suction part 15 Exhaust part 21 Bottom part 22 Side wall 35 Support rod 36 Elastic member 37 Stopper member 38 Roller 40 Conveyor 41 Conveyor 42 Conveyor 45 Plate 71 Microwave oscillator 81 Processing device 82 Storage device 100 Foam production device 102 Inlet 103 Outlet 104 Inlet 105 Exhaust port DESCRIPTION OF SYMBOLS 106a... Opening end 106b... Opening end 161... Perforated plate 162... Perforated plate 211... Bottom surface 401... Driving pulley 402... Driven pulley 403... Belt 404... Roller 405... Motor 406... Encoder 407 Proximity sensor 811 Conveyance control unit 812 Microwave control unit 813 Position calculation unit A1 Arrow A2 Arrow P1 Control program S11 Supply step S12 Foaming step d1 ... gap, d2 ... space, d3 ... space, T1 ... length, T2 ... length.

Claims (8)

a step of supplying a mixture containing a resin raw material and a foaming agent to the inside of a microwave-permeable container;
A step of curing the mixed liquid while foaming the mixed liquid by heating the mixed liquid by irradiating the mixed liquid with microwaves;
In the foaming step,
A method for producing a foam, wherein an internal pressure control member that moves while directly or indirectly pressing the surface of the liquid mixture controls the internal pressure of the liquid mixture. 2. The method for producing a foam according to claim 1, wherein in the foaming step, the internal pressure of the liquid mixture is controlled by the weight of the internal pressure control member. a step of supplying a mixture containing a resin raw material and a foaming agent to the inside of a microwave-permeable container;
A step of curing the mixed liquid while foaming the mixed liquid by heating the mixed liquid by irradiating the mixed liquid with microwaves;
In the foaming step,
A method for producing a foam, comprising measuring the amount of foaming of the mixed liquid and controlling the output of microwaves according to the amount of foaming. In the foaming step,
An internal pressure control member that moves while directly or indirectly pressing the surface of the mixed liquid controls the internal pressure of the mixed liquid,
4. The method for producing a foam according to claim 3, wherein the amount of change in the position of said internal pressure control member is measured as said amount of foaming. a container containing a mixed liquid containing a resin raw material and a foaming agent and transmitting microwaves;
a microwave oscillator for generating microwaves;
a microwave irradiation unit that irradiates the mixed liquid with microwaves so as to heat and foam the mixed liquid to harden the mixed liquid;
an internal pressure control member that controls the internal pressure of the liquid mixture by directly or indirectly pressing the surface of the liquid mixture and moving along with the foaming of the liquid mixture. . The foam production apparatus according to claim 5, wherein the internal pressure control member controls the internal pressure of the liquid mixture by its own weight. a container containing a mixed liquid containing a resin raw material and a foaming agent and transmitting microwaves;
a microwave oscillator for generating microwaves;
a microwave irradiation unit that irradiates the mixed liquid with microwaves so as to heat and foam the mixed liquid to harden the mixed liquid;
measuring means for measuring the foaming amount of the mixed liquid;
and a microwave control unit that controls output of microwaves according to the amount of foaming. further comprising an internal pressure control member that directly or indirectly presses the surface of the mixed liquid and moves with the foaming of the mixed liquid to control the internal pressure of the mixed liquid,
8. The foam manufacturing apparatus according to claim 7, wherein the measuring means has a position sensor for detecting the position of the internal pressure control member, and measures the amount of change in the position of the internal pressure control member as the amount of foaming.

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