JP3851895B2 - Method and apparatus for foaming high viscosity material - Google Patents

Description

  The present invention relates to a method and apparatus for foaming a high-viscosity material, and is used, for example, for in-situ molded gaskets and filling in voids.

  FIG. 10 is a fluid circuit diagram of a conventional foaming apparatus 90 for a high viscosity material.

  In FIG. 10, the high-viscosity material stored in the storage can 91 is pumped by the primary pump 92 and fed into the power mixer 94. The compressed gas filled in the tank 93 is fed into the power mixer 94 after the pressure is adjusted.

  The power mixer 94 is rotationally driven by the motor M, and agitates the fed high-viscosity material and gas under high pressure. The high viscosity material stirred by the power mixer 94 is discharged from the nozzle 96 through the pipe line 95. Nitrogen gas, carbon dioxide gas, air, etc. are used as gas. Such a foaming device 90 is used as a coating device for a high-viscosity polymer material such as a hot-melt adhesive (Japanese Patent Laid-Open No. 63-264327).

  A hot-melt adhesive is composed of a thermoplastic polymer that is solid at room temperature, and melts and flows when heated. On the other hand, when the hot melt adhesive is heated and melted and then cooled to room temperature, it becomes a solid and exhibits adhesive strength and adhesive lump strength. The conventional foaming apparatus for such hot melt adhesives takes in the gas by utilizing the property of rapidly exerting strength after cooling before the gas mixed in the hot melt adhesive is dissipated. Form a foam.

However, in the conventional foaming device 90 described above, the high-viscosity material and gas must be heated and sent to the power mixer 94 or upstream thereof at high pressure. For example, when the viscosity of the high-viscosity material is 100,000 cps, the internal pressure of the power mixer 94 is considered to be 100 kg / cm ² or more, so that the gas is fed into the power mixer 94 simultaneously with the high-viscosity material. Needs to be higher than the pressure of the high viscosity material.

When the gas pressure is high, it is difficult to control the flow rate, and a slight error in the flow rate at high pressure appears as a large error at atmospheric pressure. For example, the error in flow rate at 50 kg / cm ² appears 50 times at atmospheric pressure. Therefore, a large variation occurs in the mixing ratio between the high viscosity material and the gas, the foaming state becomes unstable, and it is extremely difficult to obtain uniform foaming.
JP-A 63-264327 Japanese Patent Laid-Open No. 06-198152 Japanese Patent Laid-Open No. 50-159871

  The present invention has been made in view of the above-described problems, and allows gas to be mixed with a high-viscosity material at a low pressure, facilitating gas flow control, and reducing variations in the mixing ratio of the high-viscosity material and gas. An object is to stabilize the foaming state and obtain uniform foaming.

  That is, the present invention provides a method and an apparatus in which a gas can be mixed into a high-viscosity material at a low pressure, particularly a low pressure of about atmospheric pressure, and a foam can be easily obtained without using a power mixer. With the goal.

The method according to the present invention includes a first step of sending a mixture of the high-viscosity material and the gas by mixing the supplied gas into the high-viscosity material by a first pump; A second step of pressurizing the mixture of the high-viscosity material and the gas delivered from the step by a second pump; and passing the pressurized mixture in a dispersion line, A third step of dispersing the gas in the high-viscosity material; and a fourth step of foaming the mixture that has passed through the dispersion conduit by discharging it through the discharge conduit. In the first step, the amount of the high-viscosity material sucked and the amount of gas supplied by the first pump are set as the pressure and density of the high-viscosity material in the discharge pipe in the fourth step. By controlling each according to Controlling the mixing ratio of the degree the material and the gas.

In the method according to the second aspect of the present invention, a mechanical suction type pump is used as the first pump.

The method according to the invention of claim 3 uses carbon dioxide gas as the gas.

In the method according to the fourth aspect of the invention, carbon dioxide and nitrogen gas are used in combination as the gas.

The method according to the invention of claim 5 uses a piston pump as the second pump.

In the method according to the sixth aspect of the present invention, the delivery pressure from the first step is 100 kg / cm ² or less, and the pressure is increased to 100 kg / cm ² or more in the second step.

According to a seventh aspect of the present invention, in any one of the second step, the third step, and the fourth step, a static mixer is used so that the mixture passes through the static mixer. To.

The method according to the invention of claim 8 uses a power mixer in any one of the second step, the third step, and the fourth step so that the mixture passes through the power mixer. To.

In the method according to the ninth aspect of the present invention, a pressure regulating valve is provided on the downstream side of the dispersion pipe, and the pressure of the mixture in the dispersion pipe is maintained at a predetermined pressure or higher.
According to a tenth aspect of the present invention, an on-off valve is provided in the flow path of the mixture in the fourth step, the second pump is operated in conjunction with the on-off valve, and the on-off valve is opened. Sometimes the second pump is operated at an earlier timing.

An apparatus according to the present invention includes a first pump that mixes a gas into a high-viscosity material and delivers a mixture of the high-viscosity material and the gas, and the high-viscosity material that is delivered from the first pump. A second pump for pressurizing the mixture with the gas; a dispersion pipe for dispersing the gas in the high-viscosity material by passing the pressurized mixture; and the dispersion pipe A discharge device for discharging the mixture that has passed through the passage, a flow rate control device for controlling the flow rate of the gas, and a control drive for controlling the suction amount of the high-viscosity material of the first pump An apparatus, a measuring device for measuring the pressure and density of the high-viscosity material in the discharge device, and giving instructions to the flow rate control device and the control driving device based on the measured pressure and density. Foaming state to control foaming state And a control unit,.

The apparatus according to claim 12 is provided with a pressure regulating valve for regulating the pressure of the mixture in the dispersion pipe.

An apparatus according to the invention of claim 13 is provided on the downstream side of the dispersion pipe and opens and closes the flow path, and closes the open / close valve when stopping the pressurization by the second pump, A pressure maintaining control unit for maintaining the pressure of the mixture in the dispersion pipeline in a pressurized state by operating the second pump at an earlier timing when opening the on-off valve; Have

A device according to the invention of claim 14 is provided with a curing agent supply device for supplying a curing agent for curing the high-viscosity material, and a curing provided at a tip portion of the discharge device and supplied from the curing agent supply device. A mixing device for mixing the agent with the mixture.

  High-viscosity materials include adhesives, gap filling sealants, coating materials, and in-situ foam-forming gasket materials, including moisture curable materials, thermosetting materials, reaction curable materials, and hot melt materials. . In any case, in the method and apparatus of the present invention, it is desirable to cure or solidify immediately after foaming, and to cure or solidify in a state where a gas is dispersed in a high-viscosity material.

  Carbon dioxide, nitrogen gas, air, etc. can be used as the gas.

  A uniaxial screw pump, a gear pump, a trochoid pump, a plunger pump, a follower pump, or the like is used as the first pump. As the pump or the second pump, a piston pump, a plunger pump, a gear pump, a trochoid pump, or the like is used. A piston pump that can obtain a constant flow rate is used as the piston pump.

  For example, a long pipe of about several meters to several tens of meters is used as a dispersion pipe for dispersing gas in a high viscosity material. Such a pipe is used, for example, as a distribution pipe unit that is wound in a straight line, or in an arc shape or a spiral shape, and is attached to a frame for supporting the pipe. The mixture of the high-viscosity material and the gas passes through the dispersion pipe line in a pressurized state, whereby the gas is refined by shearing force and the refined gas is dispersed in the high-viscosity material.

Carbon dioxide (carbon dioxide) is liquefied when a pressure of 70 kg / cm ² or more is applied at 20 ° C. Therefore, when carbon dioxide is used as the gas, carbon dioxide is mixed into the high-viscosity material at low pressure and then the pressure is increased. By pressurization, the carbon dioxide in the mixture is liquefied and simultaneously dissolved in the high viscosity material. As a result, the carbon dioxide gas is dispersed in the high viscosity material. In addition, the mixing ratio between the high viscosity material and the gas can be controlled with high accuracy.

  Further, when carbon dioxide gas and nitrogen gas are used in combination, the carbon dioxide gas is easily liquefied and the nitrogen gas is not easily liquefied. Since the pressure for liquefaction is different in this way, when the pressure is released and the pressure is returned to the normal pressure, the previously vaporized nitrogen gas is uniformly fired, and the nitrogen gas cavity (gas The carbon dioxide gas that vaporizes toward the nucleus) tends to concentrate, and the effect that the firing ratio can be increased while the foamed state remains uniform is obtained.

  According to the present invention, the gas can be mixed with the high-viscosity material by an apparatus having a low pressure and a simple structure, the flow rate of the gas is easily controlled, the variation in the mixing ratio of the high-viscosity material and the gas is reduced, and the foamed state It is possible to obtain uniform and fine foaming. Since a high-viscosity material and a gas are not mixed with a power mixer or a gear pump as in the past, it can be simply configured with a simple and inexpensive apparatus. The high-viscosity material does not generate heat due to frictional heat and does not adversely affect the foam.

  In addition, the mixing ratio of the high-viscosity material and the gas can be controlled more easily, and a more appropriate expansion ratio can be obtained.

According to the ninth and twelfth aspects of the invention, the inside of the dispersion pipe can be more reliably maintained at a high pressure, and the gas dispersion is more stable.

According to the invention of claims 11 to 14, it is possible to disperse the gas into the high-viscosity material with a simple structure, a high-viscosity material can be stably foamed.

According to the invention of claim 14 , a two-component curable high-viscosity material can also be used, and the curing speed of the high-viscosity material can be increased.

  1 is a circuit diagram of a foaming apparatus 1 according to the present invention, FIG. 2 is a cross-sectional view showing a suction portion of a uniaxial screw pump 42, FIG. 3 is a cross-sectional view showing a main portion of a piston pump 51, and FIG. FIG.

  The foaming device 1 includes a compressed gas supply device 11 and a mixing device 12 provided corresponding to the first step of the present invention, a pressurizing device 13 provided corresponding to the second step, and a third step. It comprises a dispersion device 14 provided correspondingly, a discharge device 15 provided corresponding to the fourth step, and a control device 19 for controlling these as a whole.

  The compressed gas supply device 11 includes a tank 31, a pressure adjustment valve 32, a flow rate control device 33, a three-way valve 34, throttle valves 35 and 36, a check valve 37, and a pressure adjustment valve 38.

The tank 31 is filled with high-pressure nitrogen gas or carbon dioxide gas. The pressure regulating valve 32 is set within a range of about 1 to 10 kg / cm ² and maintains the pressure of the gas supplied from the tank 31 at a constant low pressure. When air is used as the gas, a compressor is used instead of the tank 31. The flow rate control device 33 measures the gas flow rate Qg, displays the measured value on the display 33a, and controls the gas flow rate based on the control signal S5 from the control device 19.

  The three-way valve 34 is provided to reduce a control error of the flow rate control device 33 due to a difference in flow rate between when the gas is supplied to the mixing device 12 and when the supply is stopped. The flow path is switched by the three-way valve 34 between the direction in which the gas is supplied to the mixing device 12 and the direction in which the gas is released to the atmosphere. When supplying gas to the mixing device 12, gas is supplied via the three-way valve 34, and when not supplying gas to the mixing device 12, the three-way valve 34 is switched to release the gas to the atmosphere. As a result, the differential pressure in the flow rate control device 33 between when the mixing device 12 is operating and when it is not operating is made constant, the operation of the flow rate control device 33 is stabilized, and variations in the mixing ratio are suppressed.

  A low pressure gas having a predetermined flow rate and a predetermined pressure is supplied to the mixing device 12 by the compressed gas supply device 11.

  The mixing device 12 supports a storage can 41 for storing the high-viscosity material MV, a uniaxial screw pump 42 as a first pump, a motor M1 that rotationally drives the uniaxial screw pump 42, a uniaxial screw pump 42, and the motor M1 movably in the vertical direction. And a cylinder device 43 that presses the bottom surface of the uniaxial screw pump 42 against the high-viscosity material MV, and a conduit 44. The high-viscosity material MV is, for example, 30,000 cps or more.

In FIG. 2, the uniaxial screw pump 42 includes a stator 421, a rotor 422, a plate 423, and the like, and a distal end portion 425 of a gas pipe 424 for supplying gas from the compressed gas supply device 11 is provided at the suction port SP1. It is open. When the rotor 422 is rotated by the motor M1, the high-viscosity material MV is sucked from the suction port SP1, and at the same time, the gas supplied from the tip 425 enters the suction port SP1 and is mixed into the high-viscosity material VM. As a result, inside the rotor 422, the high-viscosity material MV and the gas are mixed and transferred in a mixed state, and the mixture is delivered to the pipe 44. Delivery pressure of the conduit 44 is at 100 kg / cm ² or less, usually carried out at about 50 to 100 / cm ^2. Since the pressure in the vicinity of the suction port SP1 is as low as about 1 kg / cm ² or less, the gas can be introduced into the single screw pump 42 at a low pressure. The rotational speed of the motor M1 is controlled by a signal S4 from the control device 19, and the flow rate (intake amount) of the uniaxial screw pump 42 is thereby controlled.

  In FIG. 3, the pressurizing device 13 includes a piston pump 51 as a second pump, a motor M2 for driving the piston pump 51, on-off valves 52 and 53, a pressure gauge 54, a pressure sensor 55, and the like.

The piston pump 51 includes a cylinder 511, a piston 512, a packing 513, and the like. When the piston 512 moves upward while the on-off valve 52 is open and the on-off valve 53 is closed, a mixture of the high-viscosity material MV and gas sent from the mixing device 12 is sucked into the cylinder 511. When the piston 512 moves downward while the on-off valve 52 is closed and the on-off valve 53 is open, the mixture in the cylinder 511 is pushed out to be in a pressurized state. The pressure in the cylinder 511 is detected by the pressure sensor 55 and sent to the control device 19. The extrusion pressure from the piston pump 51 is 150 kg / cm ² or more. When the pressure gauge 54 detects a preset pressure, it outputs a contact signal. The rotational speed of the motor M2 is controlled by a signal S3 from the control device 19, and the suction and extrusion of the piston pump 51 and the flow rate (extrusion amount) thereof are thereby controlled.

  In FIG. 1, the dispersion device 14 includes a dispersion line unit 61, pressure regulating valves 62 and 63, pressure gauges 64 and 65A, and the like.

  In FIG. 4, the dispersion pipe unit 61 includes plates 611, 612 arranged at both ends connected and fixed by rods 613, 613, and a pipe wound spirally between the plates 611, 612. 614 is mounted, and each end thereof is connected to ports 615 and 616 provided on the plates 611 and 612 via piping members. The pipe 614 corresponds to the dispersion conduit of the present invention. In addition, as a pipe line unit for dispersion | distribution, the thing which only made the pipe just helical form may be sufficient.

The pipe 614 is made of steel, for example, and has a total length of, for example, 10 to 5 m when the nominal diameter is 3/8, and a total length of, for example, 10 to 2 m when the nominal diameter is 1/4. Mixed form of the high-viscosity material MV and the gas, for example pressure 150 kg / cm ² or more, for example by 200~250kg / cm ^2, the flow rate is passed through the dispersing pipe unit 61 at 200 cc / min, gas For example, it becomes fine with an average diameter of about 0.01 mm and is dispersed in the high viscosity material MV.

  The phenomenon of gas dispersion is considered as follows. That is, in the pipe line such as the pipe 614, the gas flowing together with the high-viscosity material MV has a remarkably lower specific gravity and lower viscosity than the high-viscosity material MV, and therefore moves toward the pipe wall having a low flow velocity. The material is dispersed in the high-viscosity material MV by a shearing force generated between the tube wall and the high-viscosity material MV. Since the volume of the gas is reduced by pressurization, the dispersion effect increases as the pressurization is performed. In other words, large bubbles first move toward the tube wall and are shredded by shearing forces into small bubbles. When the bubble diameter is made ultrafine and mixed in the high-viscosity material MV, the specific gravity difference and the viscosity difference from the high-viscosity material MV alone are reduced, so that the bubble returns to the center part away from the tube wall in the pipe line. A phenomenon occurs. As the pressure in the duct decreases, the volume of the bubble increases and the bubble moves to the tube wall where it is sheared again. Such a phenomenon is repeated, and the gas is sheared and dispersed in the high viscosity material MV.

  Further, the phenomenon of gas dispersion can be estimated as follows. That is, when the mixture of gas and high-viscosity material is passed through the dispersion conduit in a pressurized state, a pressure gradient is generated in the dispersion conduit due to pressure loss that occurs toward the atmosphere. As the pressure decreases, the gas mass expands, but at the same time it expands and collapses and splits. As described above, the gas lump mixed in the high-viscosity material is dispersed into fine bubbles (gas lump) by continuously causing expansion and collapse in the dispersion pipe. By discharging this into the atmosphere, a foam can be obtained.

  Therefore, what is necessary is just to set the pressure inside the pipe 614, a pipe diameter, and a pipe length according to the viscosity characteristic of the high-viscosity material MV, specific gravity, and required discharge amount.

The pressure regulating valves 62 and 63 are for maintaining the high-viscosity material MV in the dispersion pipe unit 61 at a high pressure. For example, the pressure regulating valve 62 is 150 to 350 kg / cm ² or more, 63 is set to about 50 to 250 kg / cm ² , respectively.

  In FIG. 1 again, the discharge device 15 discharges the mixture of the high-viscosity material MV and the gas sent from the dispersion device 14 to normal pressure, thereby foaming. The discharge device 15 includes a discharge pipe 71, a discharge opening / closing valve 72, a nozzle 73, a density meter 74, a pressure sensor 75, and the like.

  The mixture sent from the dispersion device 14 gradually returns to normal pressure by flowing through the discharge pipe 71, and the gas expands accordingly. When the discharge opening / closing valve 72 is open, a mixture of the high-viscosity material MV and gas is discharged from the nozzle 73 and foams when discharged. By moving the nozzle 73 along a predetermined locus, the foamed high-viscosity material MV is applied or molded into a predetermined shape.

  The density meter 74 continuously measures, for example, the mass of the high-viscosity material MV in circulation online. The measurement signal S 1 from the density meter 74 and the detection signal S 2 from the pressure sensor 75 are input to the control device 19.

  The control device 19 calculates the expansion ratio A based on the measurement signal S1 and the detection signal S2, outputs signals S3 to S5 so that the expansion ratio A becomes a predetermined value, the gas flow rate Qg, and the uniaxial screw pump 42. Control the amount of inhalation. As a result, the entire foaming apparatus 1 is controlled, and a series of processes for discharging the high-viscosity material VM so that the foaming ratio becomes a predetermined value is controlled online. The expansion ratio A is defined by the following formula.

Foaming ratio A = V ₁ / V ₀
However, V _1: volume per unit mass of the high-viscosity material after foaming (when air open) V _0: the volume expansion device 1 per unit mass of the foam prior to the high viscosity material, the expansion ratio A for example 1 It can be set in the range of about 4, and in the case of an in-situ foam molded gasket, it is usually set to an appropriate value in the range of 2-4.

  According to the foaming device 1 described above, the gas in the tank 31 can be supplied to the suction port SP1 of the uniaxial screw pump 42 at a low pressure of about atmospheric pressure and mixed with the high-viscosity material MV, so the gas flow rate Qg is controlled. By doing so, the mixing ratio can be controlled with high accuracy, and the foaming ratio A of the high-viscosity material MV can be accurately controlled to obtain uniform foaming. Since the gas pressure is low, it is possible to supply low-pressure compressed air, for example, by a compressor without using the high-pressure tank 31.

  In the present invention, the gas can be miniaturized and the dispersion efficiency can be improved by circulating the inside of the dispersion pipe unit 61 in a state where the mixture is pressurized. Since the distribution pipe unit 61 has a simple structure, maintenance is easy and cost can be reduced. In addition, the dispersion | distribution pipe line unit 61 and normal mixers, such as a power mixer (power mixer) or a static mixer, can also be used together. These ordinary mixers may be provided in any of the second step, the third step, and the fourth step.

  Next, a modified example of the foaming apparatus 1 will be described.

  FIG. 5 is a diagram showing a pressurizing device 13a, a dispersing device 14a, and a discharge device 15a in another example of the foaming device 1a, and FIG. 6 is a diagram showing the operation timing of the foaming device 1a. In FIG. 5, the elements having the same functions as those in FIG. The same applies hereinafter.

  In the foaming apparatus 1a, an opening / closing valve 65 is provided between the dispersion line unit 61 and the discharge line 71a in place of the pressure regulating valve 63. That is, in the foaming apparatus 1 described above, the pressure regulating valve 63 is provided to maintain the inside of the dispersion pipe unit 61 at a predetermined pressure. However, in the foaming apparatus 1a of this example, the discharge pipe 71a is provided. The diameter of the pipe is reduced to increase the pipe resistance, and the opening / closing timing of the opening / closing valve 65 is controlled to generate and maintain a predetermined pressure inside the dispersing pipe unit 61. is there.

5 and 6, the pressure sensor 55 detects the extrusion pressure of the piston pump 51, and outputs a signal S6 when the detected pressure is equal to or higher than a set pressure (150 to 350 kg / cm ² ). When the maximum allowable pressure of the apparatus is 400 kg / cm ² or more, a danger signal S7 is output. The extrusion signal is a signal for instructing the extrusion of the high-viscosity material VM. When the ejection signal is on and the discharge is possible, the on-off valves 65 and 72 are opened to discharge the high-viscosity material MV. Foam. While the high-viscosity material MV is being extruded, pressure is generated by the pipe resistance of the discharge pipe 71a, and a predetermined high pressure is generated inside the dispersion pipe unit 61. Even when the push-out signal is on, the piston pump 51 automatically switches to the suction process when the bottom dead center signal in the push-out process is output by the proximity sensor attached to the piston pump 51. In addition, since the discharge is impossible during the suction process, the on-off valves 65 and 72 are closed. When the signal S7 is output from the pressure sensor 55, it is determined that an abnormality such as clogging of the pipe has occurred, and an emergency stop is performed and an alarm is output.

  When the push-out signal is turned off, the on-off valves 53, 65, 72 are closed, the on-off valve 52 is opened, and the piston pump 51 performs the suction process. Thereafter, the on-off valves 65, 72 remain open and are opened and closed. The valve 53 is opened, the on-off valve 52 is closed, and the piston pump 51 performs the extrusion process for a short time. As a result, the high-viscosity material MV is extruded, and the signal S6 of the pressure sensor 55 is output. Thereafter, the on-off valves 52, 53, 65, 72 maintain the previous state, the piston pump 51 stops, and the standby It becomes a state. In the standby state, the inside of the dispersion pipe unit 61 is maintained in a predetermined pressurized state. Next, when the discharge signal is turned on and the piston pump 51 performs the extrusion process, The pressure is continuously maintained without causing a pressure drop. As a result, the gas dispersion by the dispersion line unit 61 is always performed normally.

  In the foaming apparatus 1a, the pressure adjustment valve 63 is not necessary, so that the cost can be reduced accordingly.

  FIG. 7 is a view showing still another example of the foaming apparatus 1b. In the foaming apparatus 1b, a curing agent supply device 16 is provided in order to use a two-component curable high viscosity material. The curing agent supply device 16 injects and mixes the curing agent MS into the high-viscosity material MV at the distal end portion of the discharge pipe 71b. A manifold 76 incorporating a check valve is connected to the distal end portion of the discharge pipe 71b. The injected curing agent MS merges with the high-viscosity material MV in the manifold 76, and is sufficiently mixed and discharged by the power mixer or the static mixer 77.

  The curing agent supply device 16 includes a supply pipe 86, a flow meter, on-off valves 88 and 89, and the like.

  Curing agent MS in curing agent tank 82 flows into supply manifold 86 through supply line 86 where it merges with high viscosity material MV. Since the amounts of the high-viscosity material MV and the curing agent MS are determined by the operating states of the piston pump 51 and the curing agent pump 83, respectively, their mixing ratio can be freely set.

  According to the foaming apparatus 1b, since the two-component curable high viscosity material MV can be used, the curing speed can be increased. Since the curing agent MS is merged at the distal end portion of the discharge pipe 71b, the portion to be cleaned is small.

  In the foaming apparatus 1b shown in FIG. 7, the high-viscosity material MV, which is the main agent, is configured to foam, but the high-viscosity material MV and the curing agent MS may be replaced to foam the curing agent MS. . Moreover, you may comprise so that both the high-viscosity material MV and the hardening | curing agent MS may be foamed.

  Next, the case where carbon dioxide gas is used as the gas will be described.

Carbon dioxide gas is in a gaseous state at low pressure, and is liable to be liquid at high pressure (20 ° C., 70 kg / cm ² ). Therefore, when gas is mixed with a high-viscosity material, gas flow control is easy, The mixing ratio of the viscous material and the gas can be controlled with high accuracy, and the foamed state can be stabilized and a uniform foam can be obtained.

In the foaming apparatus 1 shown in FIG. 1, the tank 31 of the compressed gas supply apparatus 11 is filled with high-pressure carbon dioxide gas. The pressure regulating valve 32 is set to a pressure of 10 kg / cm ² or less, for example, about 7 kg / cm ² , and maintains the pressure of the carbon dioxide gas supplied from the tank 31 at a constant low pressure.

  A low pressure carbon dioxide gas having a predetermined flow rate and a predetermined pressure is supplied to the mixing device 12 by the compressed gas supply device 11.

By the mixing device 12, the high-viscosity material MV and carbon dioxide are mixed and transferred as a mixed material, and are sent to the pipe 44. The delivery pressure to the pipe 44 is, for example, about 50 kg / cm ² . This mixture is supplied to the pressure device 13.

  The mixture is pressurized to a high pressure by the pressurizing device 13, and the carbon dioxide gas in the mixture is liquefied and dissolved in the high viscosity material MV. Carbon dioxide gas (liquefied gas) dissolved in the high-viscosity material MV is easily dispersed in a pipe line or the like.

The extrusion pressure from the piston pump 51 of the pressure device 13 is 100 kg / cm ² or more is set to a pressure in the range for example of 150~300kg / cm ^2. This set pressure is adjusted by, for example, the pressure adjustment valve 62.

  The discharge device 15 returns the high-viscosity material MV and gas mixture delivered from the pressurization device 13 to normal pressure and discharges them, and vaporizes the liquefied carbon dioxide gas to obtain a foam.

  In addition, when the carbon dioxide gas that is liable to be liquefied at high pressure and the nitrogen gas that is in the gaseous state at the pressure at which the carbon dioxide gas is liquefied are used as the gas, the gas is added to the gaseous nitrogen gas dispersed in the high-viscosity material. The carbon dioxide gas liquefied under pressure evaporates and concentrates with a slight delay and expands the cell, so that the expansion ratio can be increased.

  FIG. 8 is a view showing still another example of the foaming apparatus 1c. In the foaming apparatus 1c shown in FIG. 8, the illustration of the pressure device 13 in the second step and the dispersion device 14 in the third step of the foaming device 1 shown in FIG. 1 is omitted.

  In the foaming apparatus 1c shown in FIG. 8, a normal follower plate pump 42A for feeding high-viscosity material is used as a first pump for delivering high-viscosity material, and gas is supplied to the high-viscosity material sent from the follower plate pump 42A. As a first piston pump, two piston pumps 45A and 45B are used.

  The follower plate pump 42 </ b> A sends the high-viscosity material taken out by being pressed by pressing the high-viscosity material stored in the storage can to the pipe 39 </ b> A. The piston pumps 45A and 45B are interposed between the pipe line 39A and the pipe line 44A, and mix the gas sent from the tank 31A into the high viscosity material sent from the follower plate pump 42A.

The cylinder capacities of the piston pumps 45A and 45B are determined by the moving distance of the piston. In the suction process of each piston pump 45A, 45B, first, gas is supplied into each cylinder at a pressure of 10 kg / cm ² or less from the tank 31A until a predetermined amount corresponding to the capacity of the cylinder is reached. Next, a high-viscosity material is supplied into the cylinder filled with gas from the follower plate pump 42A at a predetermined pressure of 10 kg / cm ² or more. At this time, the ratio between the pressure of the gas and the pressure of the high-viscosity material corresponds to the mixing ratio of the gas and the high-viscosity material. Therefore, control of these mixing ratios is easy.

  The pressure of the high-viscosity material supplied to the piston pumps 45A and 45B is adjusted by a control valve (for example, a piston valve, etc.) provided in the conduit 39A, with the follower plate pump 42A always kept in a pressure-feed state.

The pressure of the gas supplied to the piston pumps 45A and 45B is adjusted by a pressure regulating valve provided in the gas conduit 39B. In particular, the pressure of this gas can be supplied to the cylinders of the piston pumps 45A and 45B without increasing the pressure, but in this embodiment, the pressure is adjusted to a constant pressure of 10 kg / cm ² or less. .

  After the gas and the high-viscosity material have been sucked into the cylinders of the piston pumps 45A and 45B, the discharge process is started. In the discharge process of each piston pump 45A, 45B, a mixture of gas and high-viscosity material passes through a flow rate control valve such as a piston valve or a check valve provided in the discharge-side pipe line 44A, and the second piston. It is sent out to a piston pump 51 (see FIG. 1) which is a pump. By keeping the capacity (volume) of each of the piston pumps 45A and 45B as small as possible, the amount of the high-viscosity material MV and gas delivered in one discharge process is reduced, resulting in a discontinuous and pulsed state. . By doing in this way, dispersion | distribution in a subsequent dispersion | distribution process is performed more effectively.

  The mixture is fed from the piston pump 51 to a pipe 614 that is a pipe for dispersion, and passes through the pipe 614 to be dispersed, that is, the gas is dissolved and mixed in the high viscosity material.

  As shown in FIG. 8, by using two piston pumps 45A and 45B as the first piston pump, the discharge amount from the first piston pump can be increased, and continuous quantitative discharge can be performed. it can. Moreover, you may use three or more piston pumps instead of two. The plurality of piston pumps may be operated alternately or with a time difference. When two piston pumps are used, continuous discharge can be achieved by increasing the operation speed of the suction process relative to the operation speed of the discharge process.

  In the foaming apparatus 1c shown in FIG. 8, there are two operation modes, an alternate operation mode in which two piston pumps 45A and 45B are operated alternately, and an individual operation mode in which only one piston pump is operated independently. It is possible to switch the operation mode.

  FIG. 9 is a diagram showing the timing of the operating state when the two piston pumps 45A and 45B are used in the operation mode of operating alternately as the first piston pump.

  In FIG. 9, the control timing of the piston pumps 45A and 45B is interlocked with the suction signal of the second piston pump for pressurization. In this specification or the drawings, the piston pump 45A may be referred to as a pump 1 and the piston pump 45B may be referred to as a pump 2.

  During the first discharge process in which the piston of one piston pump 45A descends, the piston of the other piston pump 45B stands by at the top dead center with the gas and high-viscosity material sucked in. When the piston of one piston pump 45A reaches the bottom dead center and ends the discharge, the piston of the other piston pump 45B descends to perform the discharge process.

  Next, while the other piston pump 45B is performing the discharge process, the one piston pump 45A sucks the gas and the high-viscosity material and waits for the next discharge process.

  The control valves for supplying the gas and the high-viscosity material to the piston pumps 45A and 45B open and close according to the set time of the timer. For example, while the piston pump 45A is in the suction process and the piston is moving up, the gas control valve V3 is on for a set time. During this time, gas is supplied into the cylinder. When the set time elapses, the control valve V3 is turned off and the control valve V1 for the high viscosity material is turned on. When the control valve V1 is turned on, a high-viscosity material is supplied to the cylinder.

  Similarly, while the piston pump 45B is in the suction process and the piston is moving up, the gas control valve V4 is turned on. After the gas is supplied into the cylinder, the control valve V2 for the high viscosity material is turned on, and the high viscosity material is supplied to the cylinder. The set time of the timer is determined according to the viscosity of the high viscosity material.

  Thus, when the discharge process of the piston of one piston pump 45A is completed, the other piston pump 45B starts the discharge process, and the discharge process is performed alternately thereafter. Thus, the mixture is continuously discharged from the first piston pump.

  In the foaming apparatuses 1, 1a, 1b, and 1c described above, a gear pump, a trochoid pump, or the like may be used instead of the uniaxial screw pump 42. Instead of the piston pump 51, a gear pump, a plunger pump, or the like may be used. The dispersion line unit 61 may be used in combination with a power mixer or a static mixer. The parts of the foaming device 1, 1a, 1b, 1c or the dispersing device 14 or the entire configuration, shape, dimensions, material, quantity, timing of operation, etc. may be changed as appropriate in addition to those described above in accordance with the gist of the present invention. Can do.

Next, an experimental example using the foaming apparatus 1c will be described.
(Example 1)
As the high-viscosity material MV, a moisture-curing urethane-based sealing material (RD-4161 manufactured by Sunstar Giken Co., Ltd.) with a viscosity of 200,000 cps is used. Carbon dioxide and nitrogen gas are used as the gas, and the gas flow rate Qg is various. Experiments were performed with variable. The experimental results are shown in Table 1.

  According to Table 1, it is understood that very uniform foaming was obtained at a high foaming ratio by using carbon dioxide as the gas.

When the foaming state is evaluated under the same conditions using carbon dioxide gas and nitrogen gas, even if the gas is supplied at a low pressure and the flow rate is controlled, the carbon dioxide gas is easily liquefied at a high pressure. It can be dissolved and mixed at a precision rate, and a high foaming ratio A can be obtained.
(Example 2)
An experiment was conducted in the same manner as in Example 1 using a thermosetting urethane sealant (manufactured by Sunstar Giken Co., Ltd.) as the high-viscosity material MV and using carbon dioxide gas and nitrogen gas as the gas. The supply pressure of carbon dioxide gas was 7 kg / cm ² , the gas flow rate Qg was 0.22 NL / min, and the pressurization pressure was 280 kg / cm ² . Experiments were also conducted on an example in which moisture-curing room temperature curing urethane was used as the high-viscosity material MV. The experimental results are shown in Table 2.

  According to Table 2, it is understood that the thermosetting high-viscosity material MV that is rapidly cured at a relatively low temperature has obtained a stable expansion ratio A.

  That is, normally, in the foam having a high expansion ratio A, the internal gas escapes into the atmosphere during the curing process of the material, and the expansion ratio A is significantly reduced. If the curing rate is increased, the gas can be retained, so that a foam having a high expansion ratio A can be obtained.

  This is applied to the case where a packing or gasket is produced by foaming a high-viscosity material or the gap is filled.

It is a circuit diagram of the foaming apparatus which concerns on this invention. It is sectional drawing which shows the suction | inhalation part of a uniaxial screw pump. It is sectional drawing which shows the principal part of a piston pump. It is sectional drawing of the pipe line unit for dispersion | distribution. It is a one part circuit diagram of the foaming apparatus of another example. It is a figure which shows the operation | movement timing of the foaming apparatus of FIG. It is a one part circuit diagram of the foaming apparatus of another example. It is a one part circuit diagram of the foaming apparatus of another example. It is a figure which shows the operation | movement timing in the alternate operation mode of the foaming apparatus of FIG. It is a fluid circuit diagram of the conventional foaming apparatus.

Explanation of symbols

1, 1a, 1b, 1c Foaming device 16 Hardener supply device 19 Control device (pressure maintenance control unit, foaming state control unit, control drive device)
33 Flow control device 39A Pipe line 42 Single screw pump (first pump)
42A follower plate pump (first pump)
44, 44A Pipe lines 45A, 45B Piston pump (first piston pump)
51 Piston pump (pump, second pump, second piston pump)
61 Dispersion line unit 63 Pressure regulating valve 65 On-off valve 71, 71a, 71b Discharge line (discharge device)
73 nozzle (discharge device)
74 Density meter (measuring device)
75 Pressure sensor (measuring device)
76 Manifold (mixing device)
614 pipe (distribution pipeline)
M1 motor (control drive unit)
VM High viscosity material MS Curing agent

Claims (14)

A first step of mixing a supplied gas into a high-viscosity material by a first pump and delivering a mixture of the high-viscosity material and the gas;
A second step of pressurizing a mixture of the high-viscosity material and the gas delivered from the first step with a second pump;
A third step of dispersing the gas in the high-viscosity material by passing the pressurized mixture through a dispersion line;
A fourth step of foaming the mixture that has passed through the dispersion pipeline by discharging the mixture through the discharge pipeline;
In the first step, the suction amount of the high-viscosity material and the gas supply amount by the first pump are set according to the pressure and density of the high-viscosity material in the discharge conduit of the fourth step. Controlling the mixing ratio of the high-viscosity material and the gas, respectively,
A method for foaming a high-viscosity material. A mechanical suction pump is used as the first pump.
The foaming method of the high-viscosity material according to claim 1 . Carbon dioxide is used as the gas.
The foaming method of the high-viscosity material according to claim 1 or 2 . Carbon dioxide and nitrogen gas are used in combination as the gas,
The foaming method of the high-viscosity material according to claim 1 or 2 . A piston pump is used as the second pump.
Foaming method of the high viscosity material according to any one of claims 1 to 4. The delivery pressure from the first step is 100 kg / cm ² or less, and the pressure is increased to 100 kg / cm ² or more by the second step.
Foaming method of the high viscosity material according to any one of claims 1 to 5. The second step, in any of the third step or the fourth step, using a static mixer, the mixture like object to pass through the static mixer, claims 1 to 6 A method for foaming a high-viscosity material according to any one of the above. In any of the second step, the third step, or the fourth step, a power mixer is used so that the mixture passes through the power mixer.
Foaming method of the high viscosity material according to any one of claims 1 to 6. A pressure regulating valve is provided on the downstream side of the dispersion pipeline, and the pressure of the mixture in the dispersion pipeline is maintained at a predetermined pressure or higher.
Foaming method of the high viscosity material according to any one of claims 1 to 8. Providing an on-off valve in the flow path of the mixture in the fourth step,
The second pump is operated in conjunction with the on-off valve, and when the on-off valve is opened, the second pump is operated at an earlier timing.
Foaming method of the high viscosity material according to any one of claims 1 to 9. A first pump for mixing a gas into the high viscosity material and delivering a mixture of the high viscosity material and the gas;
A second pump for pressurizing a mixture of the high-viscosity material and the gas delivered from the first pump;
A dispersion line for dispersing the gas in the high viscosity material by passing the mixture in a pressurized state;
A discharge device for discharging the mixture that has passed through the dispersion pipe;
A flow rate control device for controlling the flow rate of the gas;
A control drive device for controlling the amount of suction of the high viscosity material of the first pump;
A measuring device for measuring the pressure and density of the high-viscosity material in the discharge device;
A foaming state control unit for controlling the foaming state of the high-viscosity material by giving a command to the flow rate control device and the control drive device based on the measured pressure and density;
A foaming device for a high-viscosity material comprising: A pressure adjusting valve is provided for adjusting the pressure of the mixture in the dispersion pipe;
The high-viscosity material foaming apparatus according to claim 11 . An on-off valve provided on the downstream side of the dispersion pipe to open and close the flow path;
When the pressurization by the second pump is stopped, the on-off valve is closed, and when the on-off valve is opened, the second pump is operated at an earlier timing, thereby mixing in the dispersion pipe A pressure maintenance control unit for maintaining the pressure of the object in a pressurized state;
The foaming apparatus for a high-viscosity material according to claim 11 or 12, comprising: A curing agent supply device for supplying a curing agent for curing the high viscosity material;
A mixing device for mixing a hardener supplied from the hardener supply device with the mixture, provided at a tip portion of the discharge device;
Foaming device with a high viscosity material according to any one of claims 11 to 13 having a.

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