JP2008285525A - Method for controlling liquefied gas-mixing timing in on site-spraying type foam maker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new method for controlling a liquefied gas-mixing timing, hardly causing problems wherein excessive feed or insufficient feed of carbon dioxide is sometimes caused because of the not synchronized feeding timing of the liquefied gas in a conventional spray foaming device in a site-spraying type using the liquefied gas such as carbon dioxide as a foaming agent. <P>SOLUTION: The method for controlling the liquefied gas-mixing timing includes feeding two or more kinds of plastic foam raw materials to a spray gun G while mixing the liquefied gas with at least one thereof, detecting the ejecting operation of the spray gun G and mixing the liquefied gas so as to be synchronized with the detection when ejecting all of the raw materials in a pressurized state from the spray gun G while mixing them. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for controlling liquefied gas mixing timing in an on-site blowing type foaming machine that uses liquefied gas as a foaming agent and sprays two or more kinds of plastic foam raw materials with a spray gun or the like.

  Plastic molded articles are widely used in the construction field, packing transportation field, and the like, and are also used as auxiliary materials for furniture, office equipment, and various machines. In particular, foamed molded products such as rigid polyurethane foam have excellent heat insulating properties, buffer properties, moldability, adhesive properties, etc., and thus heat insulating materials for houses and cold storage, materials and structures for construction and civil engineering, and home appliances. It is widely used as a frame body.

  Conventionally, a rigid polyurethane foam has been widely formed using an isocyanate component and / or a polyol component as a raw material and using a high-pressure injection foaming device or a spray foaming device. In addition, chlorofluorocarbons (hydrochlorofluorocarbon [HCFC] etc.) having an ozone depletion potential (ODP) as a blowing agent have been completely abolished in recent years, and alternative chlorofluorocarbons (hydrofluorocarbon [HFC]) having a large global warming potential (GWP) By restricting the amount of use, it has been proposed to use hydrocarbons such as pentane and liquefied carbon dioxide as a blowing agent in addition to carbon dioxide obtained by the reaction of water and an isocyanate component.

  Of these, foaming with only carbon dioxide obtained by the reaction of water and isocyanate components, that is, complete water foaming, the effect of reducing the amount of energy used due to inferior heat insulation performance is diminished, the adhesive force with the object to be bonded is reduced, There was a problem such as poor workability in the field foaming. Also, when using hydrocarbons such as pentane, hydrocarbons are dangerous flammable substances, and the capital investment for safety measures is extremely high, and sufficient safety measures are virtually impossible in the field foaming field. There is a problem, there is a big problem in terms of practicality.

  Therefore, at present, it is said that a foam manufacturing method using a spray foaming apparatus using liquefied carbon dioxide as a foaming agent is suitable for in-situ foaming. As a foam manufacturing method using such a spray foaming apparatus, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-82050) discloses a quantitative supply device that supplies liquid carbon dioxide quantitatively and liquid carbon dioxide supplied from this device. There has been proposed a spray foaming apparatus for foaming a polyurethane foam by using a foam. Among these, the quantitative supply device is a device for supplying a fixed amount of liquid carbon dioxide from a liquid carbon dioxide storage container with a carbon dioxide metering pump, and is a carbon dioxide flowing through a flow path connecting the liquid carbon dioxide storage container and the carbon dioxide metering pump. It has a configuration provided with a cooling means for keeping carbon in a liquid state.

  This is because carbon dioxide has a low boiling point and is easy to vaporize, so when trying to pump from a container filled with liquefied carbon dioxide such as a cylinder with a metering pump, the vaporized carbon dioxide is likely to be mixed and a predetermined amount is pumped. May not be possible. In particular, the pressure tends to decrease on the suction side of the metering pump, liquefied carbon dioxide is more likely to vaporize, and a predetermined amount may not be pumped. In order to suppress such vaporization of liquefied carbon dioxide, in the apparatus of Patent Document 1, liquid dioxide in which cooling means for keeping carbon dioxide in a liquid state is provided in a flow path connecting a container such as a cylinder and a metering pump. A carbon quantitative supply device is provided.

  Patent Document 2 (Japanese Patent Laid-Open No. 2005-200484) discloses an apparatus for manufacturing a polyurethane foam having a predetermined degree of foaming by mixing a predetermined amount of liquefied carbon dioxide with a polyol component as a foaming agent. A method for producing a polyurethane foam using the above has been proposed. The apparatus proposed in Patent Document 2 also uses, for example, an extremely low temperature liquefied carbon dioxide of about −20 ° C. as a foaming agent, thereby preventing vaporization during measurement of the liquefied carbon dioxide, and a predetermined amount of liquefaction. Carbon dioxide can be mixed with the foam raw material, and a foam having a predetermined degree of foaming or the like can be obtained.

In the apparatuses proposed in Patent Documents 1 and 2, the polyol component and the polyisocyanate component mixed with liquefied carbon dioxide are mixed by collision mixing in the gun head of the spray gun, and then discharged and reacted to form a foam. Although manufactured, since the spray gun is connected to the raw material supply device by a long hose, the operation by the spray gun is performed at a considerable distance from the raw material supply device. For this reason, it is difficult to synchronize the operation of the spray gun with the operation of the raw material supply pump and the operation of the carbon dioxide metering pump (supply unit), resulting in excessive supply of carbon dioxide or insufficient supply. There were many. For example, in a condominium construction site, when the spray gun is directed to the wall surface, to the ceiling, or to the floor surface, the pressure and flow velocity at the time of discharge differ, which is the supply of raw materials. Reflected in the operation of the pump, there was a problem that it became impossible to synchronize with the operation of the carbon dioxide supply unit, and air blowing and foaming were liable to occur. In addition, there is a problem that a time lag occurs between the activation of the spray gun trigger, the operation of the raw material supply pump, and the operation of the carbon dioxide supply unit, and the foam raw material is sprayed without sufficiently mixing carbon dioxide.
JP 2003-82050 A Japanese Patent Laid-Open No. 2005-200484

  In the conventional field spray type spray foaming apparatus using a liquefied gas such as carbon dioxide as a foaming agent, the supply timing of the liquefied gas is not synchronized, so the supply of carbon dioxide is excessive or insufficient. In view of the fact that the problem often occurs, it is an object of the present invention to provide a new liquefied gas mixing timing control method that does not cause such a problem.

  The constitution of the present invention made for the purpose of solving the above-mentioned problems is that two or more kinds of plastic foam raw materials are mixed into at least one of them and a liquefied gas is mixed and supplied to a spray gun, and these raw materials are When the mixture is discharged from the spray gun in a pressurized state, the discharge operation of the spray gun is detected, and the liquefied gas is mixed in synchronization with the detection.

  According to the present invention, in the configuration described above, the detection of the discharge operation of the spray gun is performed by detecting the trigger starting air pressure of the spray gun by a pressure sensor, or the detection of the discharge operation of the spray gun is performed by supplying air to the spray gun. When the pressure is supplied, the pressure or flow rate of the air path connected to the gun can be detected by the pressure sensor or the flow rate sensor.

  Another configuration of the present invention made for the purpose of solving the above problems is to supply two or more kinds of plastic foam raw materials to a spray gun with liquefied gas mixed in at least one of them. When these raw materials are mixed and discharged from the spray gun in a pressurized state, a pressure sensor or a flow velocity sensor is provided in the raw material supply path to detect a decrease in raw material pressure or a flow velocity change in the path, and the detection The liquefied gas is mixed in synchronization with the above.

  Furthermore, another configuration of the present invention made for the purpose of solving the above problems is to supply two or more kinds of plastic foam raw materials to a spray gun by mixing a liquefied gas into at least one of them. In addition, when these raw materials are mixed and discharged from the spray gun in a pressurized state, a detection sensor for operating the pump is provided in the raw material supply pump to detect the uneven operation of the pump, and the detection is performed. The liquefied gas is mixed in synchronization with the above.

  In each of the above-described configurations, the present invention can use two or more plastic foam raw materials as an isocyanate component raw material and a polyol component raw material for producing polyurethane foam. Further, carbon dioxide or supercritical and / or subcritical carbon dioxide can be used as the liquefied gas. The supercritical and / or subcritical carbon dioxide is preferably mixed in an amount of 0.3 wt% or more with respect to the plastic foam raw material mixture.

  In the present invention, since the control of the mixing timing of the liquefied gas, which is a foaming agent, into the plastic foam raw material is detected and synchronized with the detection of the discharge operation of the spray gun, the foam raw material is not sufficiently mixed with the liquefied gas. Will not be sprayed. Further, the present invention controls the mixing timing of the liquefied gas by providing a pressure sensor or a flow velocity sensor in the plastic foam raw material supply path to detect a decrease in the raw material pressure or a change in the flow velocity in the path, and synchronizes with the detection. Control of the mixing timing of liquefied gas or the timing of mixing the liquefied gas is performed by detecting a non-uniform operation of the pump by providing a detection sensor for the pump operating state in the plastic foam raw material supply pump. It can also be set as the structure made to synchronize and also in this case, foam raw material will not be sprayed, without liquefied gas being fully mixed.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an example of the present invention showing a configuration in which the control of the liquefied gas mixing timing is synchronized with the detected air pressure for trigger activation of the spray gun, and FIG. 2 shows the control of the liquefied gas mixing timing. FIG. 3 is a block diagram of another example of the present invention showing a configuration synchronized with the pressure of the air path to the spray gun detected by the pressure sensor, and FIG. 3 shows the control of the mixing timing of the liquefied gas detected in the raw material supply path. FIG. 4 is a block diagram of another example of the present invention showing a configuration synchronized with a decrease in raw material supply pressure or a change in flow rate, and FIG. 4 is used to control the mixing timing of the liquefied gas in the uneven operation of the detected raw material supply pump. It is a block diagram of another example of this invention which shows the structure to synchronize.

  In the embodiment shown in FIG. 1, an isocyanate component raw material and a polyol component raw material for producing polyurethane foam are used as the plastic foam raw material. 1 is a storage container for the polyol component raw material, 1a is a delivery pump for sending the polyol component raw material in the storage container raw material 1, 2 is a storage container for the isocyanate component raw material, 2a is an isocyanate component in the storage container raw material 2 This is a delivery pump for delivering raw materials.

  3 is a raw material supply pump that collectively feeds the polyol component raw material and isocyanate component raw material sent from the delivery pumps 1a and 2a, respectively, and 4 is a primary heater that warms the polyol component raw material and isocyanate component raw material in the raw material supply path. .

  5 is a mixing unit for mixing liquefied carbon dioxide, which is a liquefied gas, provided in the polyol component raw material supply path into the polyol component raw material, and 6 is a supply unit for supplying liquefied carbon dioxide to the mixing unit 5. is there. In the liquefied gas supply unit 6, liquefied carbon dioxide from the carbon dioxide cylinder 7 storing the cooled liquefied carbon dioxide is supplied to the mixing unit 5 by controlling the supply amount thereof. A control unit 6 a is provided in the liquefied gas supply unit 6. Here, liquefied carbon dioxide, which is a liquefied gas, is mixed in the polyol component raw material, but it may be mixed in the isocyanate component raw material, or liquefied carbon dioxide is mixed in both the polyol component raw material and the isocyanate component raw material. You may do it.

  G is a spray gun for on-site spraying composed of a component raw material collision mixing unit 8 and a gripping unit 9, and 8a is a polyol component raw material supply port provided in the collision mixing unit 8 of this spray gun G. 8b is a supply port for the isocyanate component raw material, and 8c is a discharge nozzle provided in front of the collision mixing unit 8. The polyol component raw material supplied via the raw material supply path L1 is supplied to the supply port 8a, and the isocyanate component raw material supplied via the raw material supply path L2 is supplied to the supply port 8b. The raw material supply paths L1 and L2 are appropriately heated from the outside (not shown) to the extent that liquefied carbon dioxide is not vaporized.

  T is a trigger provided in the grip 9 of the spray gun G, and 9a is an air supply port for trigger activation, also provided in the grip 9. Air is supplied from the air tank 10 through the air supply path L3 to the air supply port 9a.

  Next, S1 is a pressure sensor provided in the grip 9 of the spray gun G, and the air pressure when the trigger T is pulled and air is supplied into the grip 9 is detected by the pressure sensor S1. R1 is a signal line for electrically connecting the pressure sensor S1 and the control unit 6a of the liquefied gas supply unit 6 to send the detection signal to the control unit 6a when the pressure sensor S1 detects the air pressure for trigger activation. Is. Since the control unit 6a operates the liquefied gas supply unit 6 immediately upon receiving the detection signal, the mixing timing of the liquefied gas into the polyol component raw material can be controlled in synchronization with the operation of the spray gun G.

  In FIG. 2, air is supplied from the air tank 10 to the air supply port 9a of the grip portion 9, and a pressure sensor S2 is provided in the supply path L3, and the pressure in the air supply path L3 when air is supplied is shown. It is intended to be detected. A flow rate sensor may be provided in the middle of the air supply path L3 instead of the pressure sensor S2, and the flow rate of air flowing through the supply path L3 may be detected. R2 is a signal line that electrically connects the pressure sensor S2 and the control unit 6a of the liquefied gas supply unit 6. When the pressure in the air supply path L3 is detected by the pressure sensor S2, the detection signal is sent to the control unit 6a. Is for. Since the controller 6a immediately activates the liquefied gas supply unit 6 upon receiving the detection signal, the mixing timing of the liquefied gas into the polyol component raw material is synchronized with the fluctuation of the pressure in the air supply path L3 accompanying the operation of the spray gun G. Can be controlled.

  Next, FIG. 3 shows the pressure sensor S3 provided in the polyol component raw material supply path L1, and the pressure sensor S3 detects the pressure of the raw material flowing in the supply path L1. Note that a flow rate sensor may be provided in the supply path L1 instead of the pressure sensor S3, and the flow rate of the raw material flowing in the supply path L1 may be detected. R3 is a signal line that electrically connects the pressure sensor S3 and the control unit 6a of the liquefied gas supply unit 6. The pressure sensor S3 detects the pressure drop of the raw material flowing in the supply path L1, and the detection signal is sent to the control unit 6a. To send to. The control unit 6a operates the liquefied gas supply unit 6 as soon as the detection signal is received. This is the operation of the liquefied gas supply unit 6, that is, the control of the mixing timing of the liquefied gas into the polyol component raw material, and the pressure and flow velocity of the component raw material flowing in the supply path L1 when the foam raw material is discharged from the discharge nozzle 8c are reduced. This phenomenon is used to synchronize with the decline. The pressure sensor S3 or the flow rate sensor may be provided on the raw material supply path L2 side through which the isocyanate component raw material flows, or of course, may be provided on both of the raw material supply paths L1 and L2. In addition, the same code | symbol as the code | symbol shown in FIG. 1, FIG. 2 has shown the same member.

  In FIG. 4, a detection sensor S4 is provided in a raw material supply pump 3 that collectively feeds a polyol component raw material and an isocyanate component raw material, and the operating state of the raw material supply pump 3 is detected by this sensor S4. This is because a pump unit for supplying raw materials in a field blowing type foaming machine is usually a piston pump, and basically moves up and down or left and right. However, the movement of the pump is obviously uneven due to the difference in discharge amount and movement of work. If the operation of the liquefied gas supply unit 6 remains uniform despite the non-uniform movement of the pump, the amount of liquefied gas mixed in will be excessive and insufficient, and a homogeneous foam cannot be produced. Therefore, in the present invention, the control of the mixing timing of the liquefied gas by the operation of the liquefied gas supply unit 6 is synchronized with the uneven operation of the raw material supply pump 3. Specifically, the non-uniform operation of the raw material supply pump 3 is detected by the detection sensor S4, and this is sent by the signal line R4 that electrically connects the pressure sensor S4 and the controller 6a of the liquefied gas supply unit 6 to supply the liquefied gas. The operation of the unit 6 is controlled. In addition, the code | symbol same as the code | symbol shown in FIGS. 1-4 has shown the same member.

  Next, common matters in the present invention including Examples 1 to 4 described with reference to FIGS. First, in Examples 1 to 4, an isocyanate component raw material and a polyol component raw material for producing polyurethane foam are used as plastic foam raw materials. In addition, two liquids such as an epoxy resin, a phenol resin, and a methone resin are mixed. Any of the raw materials that can react can be used.

  Here, the polyol component raw material and the isocyanate component raw material which are urethane raw materials will be described in detail. Examples of the polyol component raw material include ester-based, adipate-based, ether-based, lactone-based, and carbonate-based polyol component raw materials. Examples of the ester-based and adipate-based polyol component raw materials include ethylene glycol, propylene glycol, butanediol, butenediol, hexanediol, pentanediol, neopentylglycol, 3-methyl-1,5-pentanediol, glycerin, triglyceride, and the like. At least one of polyhydric alcohols such as methylolpropane, sorbitol and bisphenol A, and at least one of dibasic acids such as adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, maleic acid and aromatic carboxylic acid Examples thereof include compounds obtained by condensation reaction with seeds.

  Examples of ether-based polyol component raw materials include polyethylene glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, dihydric alcohols such as bisphenol A, 3-methyl-1,5-pentanediol, and glycerin. , Trimethylolpropane, neopentyl glycol, tris (2-hydroxylethyl) isocyanurate, sucrose, glucose, sorbitol, methyl glucooxide, and other polyhydric alcohols, ethylenediamine, propylenediamine, diethylenetriamine, toluenediamine, metaphenylenediamine, diphenylmethane Examples include active hydrogen group-containing compounds such as amine compounds such as diamines. Further, those obtained by addition polymerization of alkylene oxide or the like using at least one of the active hydrogen group-containing compounds as an initiator are also used.

Examples of the lactone-based polyol component raw material include polycaprolactone glycol, polypropiolactone glycol, and polyvalerolactone glycol.
The carbonate-based polyol component raw material is obtained, for example, by a dealcoholization reaction between a polyhydric alcohol such as ethylene glycol, propylene glycol, butanediol, pentanediol, octanediol, or nonanediol and diethylene carbonate, dipropylene carbonate, or the like. Compounds and the like.

Next, as an isocyanate component raw material, carbon number (excluding carbon in the NCO group) 6-20 aromatic diisocyanate, carbon number 2-18 aliphatic diisocyanate, carbon number 4-15 alicyclic diisocyanate, carbon 4 to 15 araliphatic diisocyanates and modified products of these diisocyanates (urethane groups, carbodiimide groups, allophanate groups, urea groups, burette groups, uretdione groups, uretoimine groups, isocyanurate groups, oxazolidone group-containing modified products, etc.) Is mentioned. More specifically, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, dicyclomethane diisocyanate, isophorone diisocyanate, xylene diisocyanate, norbornane dimethyl isocyanate and the like can be mentioned.
Said polyol component raw material and isocyanate component raw material can be used individually by 1 type or in mixture of 2 or more types.

  Of these compounds, the polyol component raw material is often used as a polyol component liquid by mixing in advance with a catalyst, a foam stabilizer, a foaming agent, a flame retardant, a colorant, an antistatic agent, and the like during polyurethane production. Among these, a catalyst is added by the role which advances reaction of isocyanate and a polyol component raw material, and dimerization and trimerization of isocyanate, and can use a well-known catalyst. Specifically, triethylenediamine, 2-methyltriethylenediamine, tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, pentamethylhexanediamine, dimethylaminoethyl ether, trimethylaminopropylethanolamine, tridimethylaminopropylhexahydro Examples include tertiary amines such as triazine and tertiary ammonium salts, and organometallic compounds such as potassium acetate, potassium octylate, dibutyltin dilaurate, and lead octylate.

  A foam stabilizer, a foaming agent, a flame retardant, and other additives are not limited, and all those used in the production of polyurethane foam can be used. Specifically, examples of the foam stabilizer include ethylene oxide and propylene oxide addition polymers of dimethyl silicon. Examples of the blowing agent include HFCs such as 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1,2-tetrafluoroethane, and pentane. , Hydrocarbons such as cyclopentane, water and the like. Examples of the flame retardant include triethyl phosphate and tris (2,3 dibromopropyl) phosphate. Examples of other additives include fillers such as antimony trioxide and zeolite, and colorants such as pigments and dyes.

  Next, in the present invention, when carbon dioxide is used as the liquefied gas, the temperature of the raw material component when mixing the carbon dioxide is 0 ° C. to 60 ° C., preferably 20 ° C. to 40 ° C. When the temperature is 0 ° C. or lower, the viscosity of the component raw material becomes too high and carbon dioxide and the component raw material are not mixed uniformly. On the contrary, when the temperature is 60 ° C. or higher, the viscosity of the component raw material becomes too low, and the carbon dioxide mixed at the time of discharging the component raw material mixed with carbon dioxide is released. The mixing pressure of the component raw materials and carbon dioxide is 1 MPa or more, preferably 3 MPa or more, more preferably 7.4 MPa or more. Further, the viscosity of the component raw material mixed with carbon dioxide is 10 to 5000 mPa · s, preferably 1000 to 4000 mPa · s, although it depends on the type of the component raw material. When the viscosity is smaller than 10 mPa · s or larger than 5000 mPa · s, the carbon dioxide and the component raw materials are not mixed uniformly, and the cell diameter of the bubbles is also increased.

In the mixing unit 5 in FIGS. 1 to 4, when carbon dioxide in a supercritical or subcritical state is used as the liquefied gas, the carbon dioxide is mixed with the pressurized polyol component raw material, so that the diffusion coefficient of carbon dioxide is large. Also, since the viscosity coefficient is small, carbon dioxide can be uniformly and continuously dissolved in the polyol component raw material. In addition, the polyol component raw material in which carbon dioxide is mixed and dissolved is mixed with the isocyanate component raw material in the spray gun G, and after discharging, the viscosity is increased by the reaction and cured, so low density (50 kg / m ³ or less) and fine bubbles (200 μm) A polyurethane foam having the following) can be easily produced continuously and efficiently. In addition, carbon dioxide in a supercritical and / or subcritical state is preferably mixed in an amount of 0.3 wt% or more with respect to the polyurethane foam raw material mixture (mixture of polyol component raw material and isocyanate component raw material), and the pressure in the spray gun G is , 0.5 MPa or more is preferable.

  In the present invention, as described above, carbon dioxide in a subcritical state or a supercritical state can be used as the liquefied gas. Here, “subcritical carbon dioxide” means liquid carbon dioxide whose pressure is equal to or higher than the critical pressure of carbon dioxide and whose temperature is lower than the critical temperature, or whose pressure is lower than the critical pressure of carbon dioxide, and It means carbon dioxide in a gaseous state where the temperature is higher than the critical temperature, or a state where both the temperature and the pressure are less than the critical point but close to this. More specifically, carbon dioxide having a temperature of 20 ° C. to 31 ° C. and a pressure of 5 MPa or more is preferable. Further, “supercritical carbon dioxide” refers to carbon dioxide in a state where the pressure is not less than the critical pressure (7.38 MPa) of carbon dioxide and the temperature is not less than the critical temperature (31.1 ° C.). In order to bring carbon dioxide into a supercritical state, the temperature is preferably 31.1 ° C. or higher, the pressure is 7.38 MPa or higher, and the use state of the urethane foam raw material is preferably 35 to 50 ° C. and 8 to 20 MP. Subcritical or supercritical carbon dioxide is excellent in diffusibility and solubility, and has a characteristic that its density can be continuously changed greatly, and is therefore a solvent with excellent environmental properties.

  According to the present invention, the timing of mixing the component gas of the liquefied gas that becomes the foaming agent is controlled, the operation of the spray gun, specifically the detection of air pressure for trigger activation and the pressure in the air supply path, and the detection of the flow rate. Or detection of a drop in pressure or flow rate in the component raw material supply path, or synchronization with the detected operation of the raw material supply pump, so that there is no excess or deficiency in the mixing of the liquefied gas and the spray gun There is an advantage that a uniform foam can be produced in addition to the occurrence of air blow or the like.

The block diagram of an example of this invention which shows the structure which synchronizes control of the mixing timing of liquefied gas with the air pressure for trigger starting of the detected spray gun. The block diagram of another example of this invention which shows the structure which synchronizes control of the mixing timing of liquefied gas with the pressure of the air path | route to the spray gun detected by the pressure sensor. The block diagram of another example of this invention which shows the structure which synchronizes control of the mixing timing of liquefied gas with the fall of the raw material supply pressure or the flow velocity detected in the raw material supply path. The block diagram of another example of this invention which shows the structure which synchronizes control of the mixing timing of liquefied gas with the nonuniform operation | movement of the detected raw material supply pump.

Explanation of symbols

1 Polyol component raw material storage container
1a, 2a Delivery pump 2 Storage container for isocyanate component raw material 3 Raw material supply pump 4 Primary heater 5 Mixing unit 6 Liquefied gas supply unit
6a Control unit 7 Carbon dioxide cylinder 8 Collision mixing unit 9 Grasping unit
10 Air tank G Spray gun T Trigger
S1 ~ S4 Pressure sensor
L1, L2 material supply path
L3 air supply path
R1-R4 signal line

Claims (9)

  When two or more kinds of plastic foam raw materials are mixed into at least one of them with a liquefied gas and supplied to the spray gun, and these raw materials are mixed and discharged from the spray gun in a pressurized state, the spray gun A control method of the liquefied gas mixing timing in the on-site blowing type foaming machine, wherein the liquefied gas is mixed in synchronization with the detection.   2. The method for controlling a liquefied gas mixing timing according to claim 1, wherein the detection of the discharge operation of the spray gun is performed by detecting the trigger starting air pressure of the spray gun with a pressure sensor.   The detection of the discharge operation of the spray gun is performed by detecting the pressure or flow rate of the air path connected to the gun by the pressure sensor or the flow rate sensor when air is supplied to the spray gun. Control method.   When two or more kinds of plastic foam raw materials are mixed with liquefied gas in at least one of them and supplied to the spray gun, and these raw materials are mixed and discharged from the spray gun in a pressurized state, An on-site blowing type foaming machine characterized in that a pressure sensor or a flow rate sensor is provided in a supply path to detect a decrease in raw material pressure or a change in flow speed in the path, and the liquefied gas is mixed in synchronization with the detection. For controlling the timing of liquefied gas mixing into plastic foam raw materials in Japan.   When two or more kinds of plastic foam raw materials are mixed with liquefied gas in at least one of them and supplied to the spray gun, and these raw materials are mixed and discharged from the spray gun in a pressurized state, A plastic in an on-site blowing type foaming machine characterized in that a supply pump is provided with a detection sensor for operating the pump to detect non-uniform operation of the pump, and the liquefied gas is mixed in synchronization with the detection. A method for controlling the timing of mixing liquefied gas into the foam material.   The method for controlling the liquefied gas mixing timing according to any one of claims 1 to 5, wherein the two or more kinds of plastic foam raw materials are an isocyanate component raw material and a polyol component raw material for producing polyurethane foam.   The liquefied gas is carbon dioxide, The liquefied gas mixing timing control method according to any one of claims 1 to 6.   The liquefied gas mixing timing control method according to any one of claims 1 to 7, wherein the liquefied gas is carbon dioxide in a supercritical and / or subcritical state.   The supercritical and / or subcritical carbon dioxide is mixed in the plastic foam raw material mixture in an amount of 0.3 wt% or more.

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