CN114311487A - Polymer supercritical fluid mixing foaming system and method - Google Patents
Polymer supercritical fluid mixing foaming system and method Download PDFInfo
- Publication number
- CN114311487A CN114311487A CN202210157774.XA CN202210157774A CN114311487A CN 114311487 A CN114311487 A CN 114311487A CN 202210157774 A CN202210157774 A CN 202210157774A CN 114311487 A CN114311487 A CN 114311487A
- Authority
- CN
- China
- Prior art keywords
- supercritical fluid
- pressure
- foaming
- gas source
- reaction kettle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
The invention relates to a polymer supercritical fluid mixing foaming system and a polymer supercritical fluid mixing foaming method, wherein the system comprises a supercritical fluid gas source I, a supercritical fluid gas source II, a gas source I pressurization control pump, a gas source II pressurization control pump, a first high-pressure electromagnetic valve, a second high-pressure electromagnetic valve, a reaction kettle and a pressure relief pipeline, wherein the supercritical fluid gas source I is sequentially connected with the gas source I pressurization control pump and the first high-pressure electromagnetic valve and then is connected with a gas inlet of the reaction kettle, the supercritical fluid gas source II is sequentially connected with the gas source II pressurization control pump and the second high-pressure electromagnetic valve and then is connected with a gas inlet of the reaction kettle, and the gas inlet of the reaction kettle is connected with the pressure relief pipeline. The prepared polymer microporous material has high foaming multiplying power, small internal cell size and high density. The controllable and adjustable cellular structure of the polymer cellular material is realized.
Description
Technical Field
The invention belongs to the technical field of polymer microporous material forming, and particularly relates to a polymer supercritical fluid mixing foaming system and a polymer supercritical fluid mixing foaming method.
Background
The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.
The polymer microporous material mainly obtains an internal cell structure through a foaming process, and the polymer microporous foaming process using the supercritical fluid as the physical foaming agent has the advantages of sufficient foaming power, high foaming rate, good cell stability, no chemical substance residue, environmental friendliness and the like, so the polymer microporous material is widely concerned by the industry.
The conventional supercritical fluid comprises supercritical carbon dioxide, supercritical nitrogen and the like, and the microcellular foaming technical method mainly comprises intermittent foaming, extrusion foaming, injection foaming and the like. As the existing polymer supercritical fluid foaming process mostly only uses one supercritical fluid foaming agent, the essential defect is caused in the aspect of comprehensive regulation and control of the cellular structure of the polymer cellular material: for example, the polymer porous material prepared by single supercritical carbon dioxide has high foaming ratio but low cell density and large size, and for example, the polymer porous material prepared by single supercritical nitrogen has high cell density and small size but relatively low foaming ratio. A few methods for foaming after mixing two supercritical gases are basically the same as the method for foaming a single supercritical fluid, the mixed foaming is not really realized, and the regulation and control of the cellular structure of the polymer microporous material cannot be realized.
Disclosure of Invention
In view of the problems in the prior art, it is an object of the present invention to provide a system and a method for mixing and foaming a polymer supercritical fluid.
In order to solve the technical problems, the technical scheme of the invention is as follows:
first aspect, a polymer supercritical fluid mixes foaming system, include, supercritical fluid gas source I, supercritical fluid gas source II, I pressure boost control pump of gas source, II pressure boost control pumps of gas source, first high-pressure solenoid valve, second high-pressure solenoid valve, reation kettle, the pressure release pipeline, supercritical fluid gas source I connects gradually I pressure boost control pump of gas source, first high-pressure solenoid valve, then be connected with reation kettle's air inlet, supercritical fluid gas source II connects gradually II pressure boost control pumps of gas source, second high-pressure solenoid valve, then be connected with reation kettle's air inlet, reation kettle's air inlet and pressure release pipeline are connected.
In the process of polymer supercritical fluid microcellular foaming, the cell structures and performances of the prepared polymer porous materials are different due to different types and properties of the supercritical fluids. By taking common supercritical carbon dioxide and supercritical nitrogen as examples, for most polymer materials, the supercritical carbon dioxide has high solubility and fast diffusion, and the prepared polymer porous material has high foaming ratio, low cell density and large size; the supercritical nitrogen has low solubility and slow diffusion, and the prepared polymer porous material has high cell density, small size and relatively low foaming ratio. As most of the existing polymer supercritical fluid foaming processes only use one supercritical fluid foaming agent, the essential defect is caused in the aspect of comprehensive regulation and control of the cellular structure of the polymer cellular material.
The mixed foaming system and the method can accurately control the injection partial pressure, the mixed total pressure, the saturation time and the foaming temperature of the supercritical fluid, and establish a stable and reliable polymer supercritical fluid mixed foaming process by matching with the mechanical control of a downstream reaction kettle, thereby realizing the controllability and the adjustability of the cellular structure of the polymer cellular material.
The mixed foaming system and the method establish a polymer supercritical fluid mixed foaming process, and the dissolution and diffusion characteristics of the two supercritical fluid foaming agents are cooperatively exerted through different partial pressure ratios of the two supercritical fluid foaming agents, so that the controllability and adjustability of the cellular structure of the polymer cellular material are realized. The prepared polymer microporous material has high foaming multiplying power, small internal cell size and high density.
The supercritical fluid gas source I, the gas source I pressurization control pump and the first high-pressure electromagnetic valve form an air inlet pipeline of the gas source I, and the supercritical fluid gas source II, the gas source II pressurization control pump and the second high-pressure electromagnetic valve form an air inlet pipeline of the gas source II. And the outlet of the air inlet pipeline of the air source I and the outlet of the air inlet pipeline of the air source II are respectively connected with the reaction kettle. The two air sources are respectively and independently controlled. The booster control pump is used for controlling the air pressure of the air source, and the high-pressure electromagnetic valve is used for controlling the flow of the air source. The booster control pump is preferably a high pressure syringe pump.
In some embodiments of the present invention, the present invention further comprises a gas source i stop valve and a gas source ii stop valve, wherein the gas source i stop valve is connected between the supercritical fluid gas source i and the gas source i pressure boost control pump, and the gas source ii stop valve is connected between the supercritical fluid gas source ii and the gas source ii pressure boost control pump. The stop valve controls the start and stop of the output of the air source.
In some embodiments of the invention, a third high pressure solenoid valve is provided on the pressure relief line; furthermore, a silencer is arranged on the pressure relief pipeline. The third high-voltage solenoid valve is used for controlling the discharge of gas.
In some embodiments of the invention, the reaction kettle further comprises a hydraulic machine, the hydraulic machine comprises an upper workbench and a lower workbench, and the reaction kettle is arranged between the upper workbench and the lower workbench in a matching manner. The hydraulic machine comprises a hydraulic control device, and the hydraulic machine, the reaction kettle and the hydraulic control device form a polymer supercritical fluid foaming mechanical system, wherein the reaction kettle is arranged between an upper workbench and a lower workbench of the hydraulic machine, and the hydraulic control device is connected with the hydraulic machine.
In some embodiments of the invention, the device further comprises an electric heating rod and a temperature sensor, the electric heating rod is embedded in the upper workbench and the lower workbench of the hydraulic machine, and the temperature sensor is connected with the reaction kettle. The temperature sensor is preferably a thermocouple.
In some embodiments of the present invention, the reactor further comprises a pressure sensor, and the pressure sensor is connected with the reaction kettle.
In some embodiments of the invention, the controller is further included, and the controller is respectively in electrical signal connection with the first high-pressure solenoid valve, the second high-pressure solenoid valve, the third high-pressure solenoid valve, the temperature sensor, the pressure sensor, the hydraulic machine and the electric heating rod.
In some embodiments of the present invention, the reaction kettle is preferably a disk-type reaction kettle capable of being opened and closed, the inner diameter is preferably 50-100 mm, and the height of the inner cavity is preferably 5-15 mm.
In a second aspect, a method for performing supercritical fluid mixing foaming of a polymer by using the system of the first aspect is provided, wherein the method comprises:
the controller heats the reaction kettle according to the foaming process parameters, and the temperature is accurately controlled after the foaming temperature is reached;
after the temperature reaches and enters the heat preservation, the controller outputs a signal to open the first high-pressure electromagnetic valve, the supercritical fluid gas source I is injected into the reaction kettle, and after the internal pressure of the reaction kettle is divided by the supercritical fluid gas source I, the controller outputs a signal to close the first high-pressure electromagnetic valve, so that the injection of the supercritical nitrogen foaming agent is completed;
the controller outputs a signal to open the second high-pressure electromagnetic valve, a supercritical fluid gas source II is injected into the reaction kettle, and when the internal pressure of the reaction kettle reaches the set supercritical fluid mixing total pressure, the controller outputs a signal to close the second high-pressure electromagnetic valve, so that the injection of the supercritical fluid gas source II foaming agent is completed;
and (3) starting the polymer blank in the reaction kettle to enter a mixed foaming saturation stage, and opening a pressure relief pipeline after the set saturation time is reached, so as to quickly relieve the pressure of the reaction kettle and induce the polymer blank to foam.
In some embodiments of the invention, the source of supercritical fluid gas i and the source of supercritical fluid gas ii are carbon dioxide, nitrogen or argon.
In some embodiments of the present invention, the delay is 1-5s after the internal pressure of the reaction vessel is reached after the partial pressure of the supercritical fluid gas source i is reached, and then the first high-pressure solenoid valve is closed.
In some embodiments of the present invention, the delay is 1-5s after the internal pressure of the reaction vessel is reached after the partial pressure of the supercritical fluid gas source II is reached, and then the second high-pressure solenoid valve is closed.
In some embodiments of the invention, the table pressing force of the hydraulic machine is 30-100 kN.
In some embodiments of the invention, the polymer billet is a sheet, block, strip, or other geometric profile of the polymer article.
In some embodiments of the invention, the polymer billet is polypropylene (PP), Polystyrene (PS), thermoplastic polyurethane elastomer (TPU), polybutylene terephthalate-adipate (PBAT), or the like. Furthermore, the molecular chain of the PBAT material is of a straight chain structure, so that the PBAT material is relatively small in molecular weight, low in melt strength and high in crystallization rate, the foaming of the PBAT material is difficult, the foaming ratio is low, and meanwhile, the foamed foam material has an obvious shrinkage phenomenon and is large in shrinkage rate. The foaming method effectively solves the technical problems of low foaming ratio, uneven cell size, large shrinkage rate, difficulty in regulation and control and the like of the conventional PBAT foam material, and realizes the controllable preparation of the PBAT microporous foam material with high foaming ratio and low shrinkage.
In some embodiments of the invention, the pressure of the source I and source II booster control pumps is in the range of 0 to 35 MPa.
In some embodiments of the invention, the supercritical fluid I partial pressure is preferably 4-20 MPa, and the supercritical fluid total mixing pressure is preferably 5-30 MPa; furthermore, the preferable partial pressure of the supercritical fluid I is 4-10 MPa, and the preferable total mixed pressure of the supercritical fluid is 10-20 MPa.
In some embodiments of the present invention, the foaming saturation temperature is 60-120 ℃ and the saturation time is 300-3600 s. The foaming saturation temperature is also referred to herein as the foaming temperature.
In some embodiments of the present invention, the working pressure of the first, second, and third high-pressure solenoid valves is preferably 0 to 40 MPa.
One or more technical schemes of the invention have the following beneficial effects:
(1) through the cooperative control of a computer, a PLC (programmable logic controller) and related valve pipelines, the mixed injection of two supercritical fluid foaming agents in the foaming process of the polymer supercritical fluid is realized, and the defect that only one supercritical foaming agent can be injected in the traditional polymer supercritical fluid foaming system is overcome.
(2) The supercritical fluid mixing foaming system is utilized to establish a polymer supercritical fluid mixing foaming process, and the dissolution and diffusion characteristics of the two supercritical fluid foaming agents are cooperatively exerted through different partial pressure ratios of the two supercritical fluid foaming agents, so that the controllability and adjustability of the cellular structure of the polymer cellular material are realized.
(3) The polymer supercritical fluid mixing foaming system and the process method are stable and reliable, high in automation degree and precision and good in safety.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the invention and not to limit the invention.
Fig. 1 is a schematic structural diagram of a polymer supercritical fluid mixing foaming system.
FIG. 2 is SEM image of the internal cell structure of PP cellular material prepared by using single supercritical carbon dioxide foaming agent in comparative example 1.
FIG. 3 is SEM image of the internal cell structure of PP cellular material prepared by using single supercritical nitrogen foaming agent in comparative example 2.
FIG. 4 is SEM image of the internal cell structure of PP cellular material prepared by mixing foaming agent in example 2.
FIG. 5 is SEM image of the internal cell structure of PP cellular material prepared by mixing foaming agent in example 3.
Fig. 6 is an SEM image of the internal cell structure of PBAT microporous material prepared in example 4 of the present invention.
Fig. 7 is an SEM image of the internal cell structure of the PBAT microporous material prepared in comparative example 3 of the present invention.
Fig. 8 is an SEM image of the internal cell structure of the PBAT microporous material prepared in comparative example 4 of the present invention.
Fig. 9 is a graph showing a comparison of expansion ratios of PBAT microcellular materials prepared in example 4, comparative example 3, and comparative example 4 of the present invention (initial time).
FIG. 10 is a graph showing the change of the expansion ratio of PBAT microcellular materials prepared in example 4, comparative example 3, and comparative example 4 according to the present invention with time.
In fig. 1, a supercritical fluid gas source i; 2. a stop valve of an air source I; 3. a gas source I is a pressurization control pump; 4. a first high-pressure solenoid valve; 5. a supercritical fluid gas source II; 6. a gas source II stop valve; 7. a gas source II is a pressurization control pump; 8. a second high-pressure solenoid valve; 9. a muffler; 10. a third high voltage solenoid valve; 11. a hydraulic press; 12. an electric heating rod; 13. a pressure sensor; 14. a reaction kettle; 15. a temperature sensor; 16. a computer; 17. a PLC controller; 18. a hydraulic control device.
Detailed Description
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise. The invention will be further illustrated by the following examples
Example 1
A polymeric supercritical fluid hybrid foaming system comprising: the system comprises a bottled nitrogen gas 1, a bottled nitrogen gas stop valve 2, a bottled nitrogen gas pressurization control pump 3, a first high-pressure electromagnetic valve 4, a bottled carbon dioxide 5, a bottled carbon dioxide stop valve 6, a bottled carbon dioxide pressurization control pump 7, a second high-pressure electromagnetic valve 8, a silencer 9, a third high-pressure electromagnetic valve 10, a hydraulic machine 11, an electric heating rod 12, a pressure sensor 13, a reaction kettle 14, a temperature sensor 15, a computer 16, a PLC (programmable logic controller) 17 and a hydraulic control device 18.
The system comprises a bottled nitrogen gas 1, a bottled nitrogen gas stop valve 2, a bottled nitrogen gas pressurization control pump 3 and a first high-pressure electromagnetic valve 4, wherein the bottled nitrogen gas 1, the bottled nitrogen gas stop valve 2, the bottled nitrogen gas pressurization control pump 3 and the first high-pressure electromagnetic valve 4 are sequentially connected to form a supercritical nitrogen gas pressurization pipeline, and bottled carbon dioxide 5, a bottled carbon dioxide stop valve 6, a bottled carbon dioxide pressurization control pump 7 and a second high-pressure electromagnetic valve 8 are sequentially connected to form a supercritical carbon dioxide pressurization pipeline; the outlet of the first high-pressure electromagnetic valve 4 and the outlet pipeline of the second high-pressure electromagnetic valve 8 are combined and then connected with the reaction kettle 14 to form a supercritical fluid mixed injection pipeline; and the third high-voltage solenoid valve 10, the silencer 9 and the combined supercritical fluid mixed injection pipeline are connected to form a pressure relief gas circuit.
The supercritical fluid mixed foaming control system is formed by connecting the first high-pressure electromagnetic valve 4, the second high-pressure electromagnetic valve 8, the third high-pressure electromagnetic valve 10, the pressure sensor 13, the temperature sensor 15 and the electric heating rod 12 with a PLC (programmable logic controller) 17 through cables; the PLC controller 17 is connected to and interacts with the computer 16.
The hydraulic machine 11, the reaction kettle 14 and the hydraulic control device 18 form a polymer supercritical fluid foaming mechanical system, wherein the reaction kettle 14 is arranged between an upper workbench and a lower workbench of the hydraulic machine 11, and the hydraulic control device 18 is connected with the hydraulic machine 11.
The electric heating rod 12 is embedded in the upper and lower working tables of the hydraulic press 11 and used for heating the working tables and the reaction kettle 14; the pressure sensor 13 and the temperature sensor 15 are respectively installed at both sides of the reaction kettle 14 to measure the internal pressure and temperature of the reaction kettle 14.
Example 2
(1) Preparation of polymer billets before foaming: before the polymer supercritical fluid mixing and foaming system is started, a polymer blank (polypropylene PP) is placed into the reaction kettle 14, then the reaction kettle 14 is placed on a workbench of the hydraulic machine 11, and the upper workbench and the lower workbench of the hydraulic machine 11 are operated by the hydraulic control device 18 to be closed and tightly press the reaction kettle 14.
According to the polymer supercritical fluid mixing foaming process, the output pressure of the first pressurization control pump 3 of the gas source is set to be the I partial pressure of the supercritical fluid, the output pressure of the second pressurization control pump 7 of the gas source is set to be the total mixed pressure of the supercritical fluid, and the first pressurization control pump 3 of the gas source and the second pressurization control pump 7 of the gas source are started.
(2) Supercritical fluid mixed foaming agent injection: starting the system, setting the technological parameters of the polymer supercritical fluid mixing foaming on a computer interface: the supercritical fluid I partial pressure, the supercritical fluid mixing total pressure, the foaming temperature and the saturation time are clicked to start. After receiving the foaming process parameters, the PLC 17 switches on the electric heating rod 12 to start heating until the temperature detected by the temperature sensor 15 reaches the foaming temperature, and then enters precise heat preservation.
After the temperature reaches and enters the heat preservation, the PLC 17 outputs a signal to open the first high-pressure electromagnetic valve 4, supercritical nitrogen is injected into the reaction kettle 14, when the internal pressure of the reaction kettle 14 detected by the pressure sensor 13 reaches the set supercritical fluid I partial pressure (4MPa), the delay is 2s, and the PLC 17 outputs a signal to close the first high-pressure electromagnetic valve 4, so that the injection of the supercritical nitrogen foaming agent is completed.
After the first high-pressure electromagnetic valve 4 is closed, the PLC 17 outputs a signal to open the second high-pressure electromagnetic valve 8, supercritical carbon dioxide is injected into the reaction kettle 14, when the internal pressure of the reaction kettle 14 detected by the pressure sensor 13 reaches the set supercritical fluid mixing total pressure (12MPa), the delay is 2s, and the PLC 17 outputs a signal to close the second high-pressure electromagnetic valve 8, so that the injection of the supercritical carbon dioxide foaming agent is completed.
(3) Polymer billet saturation and foaming: after the second high-pressure electromagnetic valve 8 is closed, the polymer blank in the reaction kettle 14 enters a mixing, foaming and saturation stage, and the PLC 17 enters saturation timing until the time reaches the set saturation time. After the saturation time is reached, the PCL controller 17 outputs a signal to open the third high-voltage solenoid valve 10, so as to rapidly release the pressure of the reaction kettle 14 and induce the foaming of the polymer blank.
After the pressure relief is completed, the PLC controller 17 outputs a signal to close the third high-voltage solenoid valve 14, close the heat preservation, prompt the completion of foaming, and wait for the next cycle.
(4) Taking out the polymer microporous material: the hydraulic press 11 is operated by the hydraulic control device 18 to start the upper and lower working tables, the reaction kettle 14 is taken down, the prepared polymer microporous material is opened and taken out after cooling, a new blank is put in, and the next process cycle is carried out.
Example 3
Compared with the embodiment 2, the partial pressure of the supercritical fluid I is 4MPa, and the total mixed pressure of the supercritical fluid is 12 MPa. The other process steps are the same as in example 2.
Comparative example 1
Compared with the embodiment 2, the single supercritical carbon dioxide foaming agent is injected, the supercritical fluid I is not injected, and the mixing total pressure of the supercritical fluid is 12 MPa. The other process steps are the same as in example 2. The method comprises the following specific steps:
(1) preparation of polymer billets before foaming: before the polymer supercritical fluid mixing and foaming system is started, a polymer blank is placed into the reaction kettle 14, then the reaction kettle 14 is placed on a workbench of the hydraulic machine 11, and the upper workbench and the lower workbench of the hydraulic machine 11 are operated to be closed and tightly press the reaction kettle 14 through the hydraulic control device 18.
According to the polymer supercritical fluid mixing foaming process, the output pressure of the air source II pressure boost control pump 7 is set to be the total supercritical fluid mixing pressure, and the air source II pressure boost control pump 7 is started.
(2) Supercritical fluid mixed foaming agent injection: starting the system, setting the technological parameters of the polymer supercritical fluid mixing foaming on a computer interface: supercritical fluid mixing total pressure, foaming temperature, saturation time, click "start". After receiving the foaming process parameters, the PLC 17 switches on the electric heating rod 12 to start heating until the temperature detected by the temperature sensor 15 reaches the foaming temperature, and then enters precise heat preservation.
After the temperature reaches and enters the heat preservation, the PLC 17 outputs a signal to open the second high-pressure electromagnetic valve 8, supercritical carbon dioxide is injected into the reaction kettle 14, when the internal pressure of the reaction kettle 14 detected by the pressure sensor 13 reaches the set supercritical fluid mixing total pressure (12MPa), the delay is 2s, and the PLC 17 outputs a signal to close the second high-pressure electromagnetic valve 8, so that the injection of the supercritical carbon dioxide foaming agent is completed.
(3) Polymer billet saturation and foaming: after the second high-pressure electromagnetic valve 8 is closed, the polymer blank in the reaction kettle 14 enters a mixing, foaming and saturation stage, and the PLC 17 enters saturation timing until the time reaches the set saturation time. After the saturation time is reached, the PCL controller 17 outputs a signal to open the third high-voltage solenoid valve 10, so as to rapidly release the pressure of the reaction kettle 14 and induce the foaming of the polymer blank.
After the pressure relief is completed, the PLC controller 17 outputs a signal to close the third high-voltage solenoid valve 14, close the heat preservation, prompt the completion of foaming, and wait for the next cycle.
(4) Taking out the polymer microporous material: the hydraulic press 11 is operated by the hydraulic control device 18 to start the upper and lower working tables, the reaction kettle 14 is taken down, the prepared polymer microporous material is opened and taken out after cooling, a new blank is put in, and the next process cycle is carried out.
Comparative example 2
Compared with the embodiment 2, the supercritical nitrogen foaming agent is injected singly, the carbon dioxide foaming agent is not injected, and the supercritical fluid mixing total pressure is 12 MPa. The other process steps are the same as in example 2.
Examples 2-3 and comparative examples 1-2 the main process parameters for the preparation of polymeric microporous materials are shown in table 1:
TABLE 1 Main Process parameters of examples 2-3 and comparative examples 1-2
The internal cell structure of the polymer cellular materials prepared in examples 2-3 and comparative examples 1-2 is shown in fig. 2-5, and it can be seen that: the PP microporous material prepared by the single supercritical carbon dioxide foaming agent (the supercritical fluid I partial pressure is 0MPa) has high foaming ratio, but the internal cells have large size and small density (figure 2); the PP cellular material prepared by the single supercritical nitrogen foaming agent (the supercritical fluid I partial pressure is 12MPa) has small internal cell size and high density, but has smaller foaming ratio (figure 3); the PP microporous material prepared by the supercritical fluid mixing foaming process (the supercritical fluid I partial pressure is respectively 4MPa, example 2 and examples 3 and 8MPa) has high foaming ratio, small internal cell size and high density, and the cell structure is obviously improved compared with single supercritical fluid foaming (figure 4 and figure 5, figure 4 is example 2, and figure 5 is example 3).
Example 4
A supercritical fluid mixed foaming method for polymer uses PBAT as raw material and has a density of 1.26g/cm and a trade name of Ecoflex C12003(ISO 1183) a melt flow index of 3.8g/10min (ISO 1133); the foaming agent is supercritical CO with purity of 99.9%2And supercritical N2Adding the dried PBAT granules into a double-screw extruder, and performing melt extrusion to obtain strip-shaped blanks with the diameter of 3.5mm and the length of 25 mm;
the foaming method comprises the following steps: the differences from example 2 are: the foaming saturation temperature is 110 ℃, the supercritical fluid I is nitrogen, the partial pressure of the supercritical fluid I is 8MPa, the supercritical fluid II is carbon dioxide, the total pressure is 12MPa, and the saturation time is 720 s. A PBAT microcellular foam was obtained.
Comparative example 3
To compare the foaming effect of the PBAT microcellular foam material prepared by the method of the present invention, a single supercritical CO was selected under the same conditions as in example 42PBAT foams prepared by batchwise foaming were used as comparative example 3.
Supercritical CO2A process for preparing the microporous foam PBAT material by intermittent foaming features that the PBAT, Ecoflex C1200, density of 1.26g/cm3(ISO 1183) a melt flow index of 3.8g/10min (ISO 1133); the foaming agent is supercritical CO with purity of 99.9%2Adding the dried PBAT granules into a double-screw extruder, and carrying out melt extrusion to obtain a strip-shaped blank with the diameter of 3.5mm and the length of 25 mm.
The foaming method comprises the following steps: the differences from the method of example 4 are: the supercritical fluid I is not injected, the supercritical fluid II and carbon dioxide are directly injected to reach the total pressure. The other procedure was the same as in example 4 to obtain a PBAT microcellular foam.
Comparative example 4
To compare the foaming effect of the PBAT microcellular foam prepared by the method of the present invention, a single supercritical N was selected under the same conditions as in example 12Intermittent foamingThe PBAT foam prepared was used as comparative example 2.
Supercritical N2A process for preparing the microporous foam PBAT material by intermittent foaming features that the PBAT, Ecoflex C1200, density of 1.26g/cm3(ISO 1183) a melt flow index of 3.8g/10min (ISO 1133); the foaming agent is supercritical N with the purity of 99.9 percent2Adding the dried PBAT granules into a double-screw extruder, and carrying out melt extrusion to obtain a strip-shaped blank with the diameter of 3.5mm and the length of 25 mm.
The foaming method comprises the following steps: the differences from the method of example 4 are: the supercritical fluid I, namely nitrogen, is directly injected without injecting the supercritical fluid II to reach the total pressure. The other procedure was the same as in example 4 to obtain a PBAT microcellular foam.
The densities of the PBAT stock and the PBAT foams obtained in example 4, comparative example 3, and comparative example 4 were measured by a drainage method and an analytical balance, and the expansion ratio of the PBAT foam was calculated on the basis of the measured densities, and the calculation formula was as follows:
ψ＝ρs/ρf
in the formula:
ρf-density of PBAT foam;
ρs-density of PBAT stock.
According to the above measurement and calculation method, the expansion ratios of the PBAT foams obtained in example 4, comparative example 3, and comparative example 4 were measured and calculated every 10min within 1h after the preparation of the foam, and the expansion ratios of the PBAT foams obtained in example 4, comparative example 3, and comparative example 4 were measured and calculated again after 5h, to obtain a change curve of the expansion ratio of the foam with time, that is, a shrinkage condition of the corresponding foam.
The internal cell structures of the PBAT microcellular foams prepared in example 4, comparative example 3, and comparative example 4 are shown in fig. 6 to 8, and the expansion ratios at the initial time of preparing the foams are shown in fig. 9, and it can be found that: at the initial moment, comparative example 3 uses single supercritical CO2The PBAT foam material prepared by intermittent foaming has the maximum foaming multiplying power which reaches 26.2, but the internal cell size is maximum and the density is minimum; comparison ofExample 4 use of a single supercritical N2The PBAT foam material prepared by intermittent foaming has smaller internal cell size and larger density, but the foaming multiplying power is the lowest and is only 6.3; example 4 use of supercritical CO2And supercritical N2The PBAT foam material prepared by mixing and foaming has compact and uniform internal cell size, the cell size and the density are equivalent to those of a comparative example 4, and the foaming multiplying power is obviously improved to 16.8.
Further, the change of the foaming ratios of the PBAT microcellular materials prepared in example 4, comparative example 3, and comparative example 4 with time is shown in fig. 10, and it can be seen that: the foaming ratio of the PBAT foam material prepared in the comparative example 3 is sharply reduced along with time, the shrinkage is very obvious, the shrinkage is 64.1 percent after 60min, and the shrinkage is 79.4 percent after 300 min; the foaming ratio of the PBAT foam material prepared in the comparative example 4 is not greatly reduced along with the time, the shrinkage is very small, and the shrinkage is 4.7% after 300min, but the significance of the shrinkage degree is not large because the initial foaming ratio is very small; the expansion ratio of the PBAT foam prepared in example 4 slightly decreased with time, but the degree was not so great, with shrinkage of 4.3% after 60min and 5.9% after 300 min. In conclusion, the PBAT microporous foam material prepared in example 4 has a large foaming ratio, a low shrinkage rate, and a dense cell structure, and has good development and application prospects.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A polymer supercritical fluid mixing and foaming system is characterized in that: including, supercritical fluid gas source I, supercritical fluid gas source II, I pressure boost control pump of air supply, II pressure boost control pumps of air supply, first high-pressure solenoid valve, second high-pressure solenoid valve, reation kettle, the pressure release pipeline, I pressure boost control pump of air supply is connected gradually to supercritical fluid gas source I, first high-pressure solenoid valve, then be connected with reation kettle's air inlet, II pressure boost control pumps of air supply are connected gradually to supercritical fluid gas source II, second high-pressure solenoid valve, then be connected with reation kettle's air inlet, reation kettle's air inlet and pressure release tube coupling.
2. The polymeric supercritical fluid hybrid foaming system of claim 1, wherein: still include I stop valve of air supply and II stop valves of air supply, I stop valve of air supply is connected between I and I booster control pump of supercritical fluid air supply, and II stop valves of air supply are connected between II booster control pumps of supercritical fluid air supply and air supply.
3. The polymeric supercritical fluid hybrid foaming system of claim 1, wherein: a third high-voltage solenoid valve is arranged on the pressure relief pipeline.
4. The polymeric supercritical fluid hybrid foaming system of claim 1, wherein: the reaction kettle is arranged between the upper workbench and the lower workbench in a matching way.
5. The polymeric supercritical fluid hybrid foaming system of claim 1, wherein: the electric heating rod is embedded in the upper workbench and the lower workbench of the hydraulic press, and the temperature sensor is connected with the reaction kettle;
or the reaction kettle also comprises a pressure sensor, and the pressure sensor is connected with the reaction kettle.
6. A method for performing supercritical fluid mixing and foaming of a polymer using the system of any one of claims 1 to 5, wherein: the method comprises the following steps:
the controller heats the reaction kettle according to the foaming process parameters, and the temperature is accurately controlled after the foaming temperature is reached;
after the temperature reaches and enters the heat preservation, the controller outputs a signal to open the first high-pressure electromagnetic valve, the supercritical fluid gas source I is injected into the reaction kettle, and after the internal pressure of the reaction kettle is divided by the supercritical fluid gas source I, the controller outputs a signal to close the first high-pressure electromagnetic valve, so that the injection of the supercritical nitrogen foaming agent is completed;
the controller outputs a signal to open the second high-pressure electromagnetic valve, a supercritical fluid gas source II is injected into the reaction kettle, and when the internal pressure of the reaction kettle reaches the set supercritical fluid mixing total pressure, the controller outputs a signal to close the second high-pressure electromagnetic valve, so that the injection of the supercritical fluid gas source II foaming agent is completed;
and (3) starting the polymer blank in the reaction kettle to enter a mixed foaming saturation stage, and opening a pressure relief pipeline after the set saturation time is reached, so as to quickly relieve the pressure of the reaction kettle and induce the polymer blank to foam.
7. The method of claim 6, wherein the supercritical fluid mixing foaming of the polymer is as follows: the supercritical fluid gas source I and the supercritical fluid gas source II are carbon dioxide, nitrogen or argon.
8. The method of claim 6, wherein the supercritical fluid mixing foaming of the polymer is as follows: delaying for 1-5s after the internal pressure of the reaction kettle is subjected to partial pressure of the supercritical fluid gas source I, and then closing the first high-pressure electromagnetic valve;
or delaying for 1-5s after the internal pressure of the reaction kettle is subjected to the partial pressure of the supercritical fluid gas source II, and then closing the second high-pressure electromagnetic valve;
alternatively, the polymer billet is a sheet, block, strip or other geometric configuration of the polymer article.
9. The method of claim 6, wherein the supercritical fluid mixing foaming of the polymer is as follows: the preferable partial pressure of the supercritical fluid I is 4-20 MPa, and the preferable total mixed pressure of the supercritical fluid is 5-30 MPa; furthermore, the preferable partial pressure of the supercritical fluid I is 4-10 MPa, and the preferable total mixed pressure of the supercritical fluid is 10-20 MPa.
10. The method of claim 6, wherein the supercritical fluid mixing foaming of the polymer is as follows: the foaming temperature is 60-120 ℃, and the saturation time is 300-3600 s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210157774.XA CN114311487A (en) | 2022-02-21 | 2022-02-21 | Polymer supercritical fluid mixing foaming system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210157774.XA CN114311487A (en) | 2022-02-21 | 2022-02-21 | Polymer supercritical fluid mixing foaming system and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114311487A true CN114311487A (en) | 2022-04-12 |
Family
ID=81029731
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210157774.XA Pending CN114311487A (en) | 2022-02-21 | 2022-02-21 | Polymer supercritical fluid mixing foaming system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114311487A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114851463A (en) * | 2022-05-09 | 2022-08-05 | 东莞兆阳兴业塑胶制品有限公司 | Supercritical foaming equipment for aviation foaming material |
| CN114849613A (en) * | 2022-05-12 | 2022-08-05 | 黄河三角洲京博化工研究院有限公司 | Anhydrous foaming reaction kettle and anhydrous foaming method |
| CN114953321A (en) * | 2022-05-25 | 2022-08-30 | 东莞海博斯新材料科技有限公司 | Preparation method of efficient environment-friendly supercritical die-pressing foaming elastomer |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102310516A (en) * | 2011-08-30 | 2012-01-11 | 中国科学院宁波材料技术与工程研究所 | Injection apparatus for supercritical fluid |
| CN202878585U (en) * | 2012-11-02 | 2013-04-17 | 山东大学 | Supercharging and measuring device for supercritical fluid |
| CN109016320A (en) * | 2018-09-08 | 2018-12-18 | 广东奔迪新材料科技有限公司 | A kind of thermoplastic polymer particles mould inner mold foaming and forming apparatus and its forming method |
| CN109385058A (en) * | 2018-09-06 | 2019-02-26 | 广东奔迪新材料科技有限公司 | A kind of method of the supercritical fluid preparation without mould stereochemical structure foaming product |
| CN109571847A (en) * | 2019-01-07 | 2019-04-05 | 山东大学 | A kind of multistage control pressurer system of supercritical fluid for polymer batch-foamed and method |
| CN109955423A (en) * | 2019-04-30 | 2019-07-02 | 广东奔迪新材料科技有限公司 | A kind of large-scale ultrahigh pressure thermoplastic polymer foaming and forming apparatus and its method |
| CN110480913A (en) * | 2019-09-24 | 2019-11-22 | 四川大学 | Multicomponent multi-phase complex system self-balancing supercritical foaming method and device |
| EP3720675A1 (en) * | 2017-12-04 | 2020-10-14 | Sapa S.P.A. | Method of production via injection-compression or a combination of injection-compression and injection of an object made of thermoplastic polymer admixed with at least one gas at the supercritical state |
| CN112829164A (en) * | 2021-01-13 | 2021-05-25 | 郑州大学 | Integrated ultrasonic-assisted supercritical fluid foaming reaction kettle and use method thereof |
| CN113059742A (en) * | 2021-03-31 | 2021-07-02 | 山东大学 | Mold cavity high-pressure gas control system and control method |
-
2022
- 2022-02-21 CN CN202210157774.XA patent/CN114311487A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102310516A (en) * | 2011-08-30 | 2012-01-11 | 中国科学院宁波材料技术与工程研究所 | Injection apparatus for supercritical fluid |
| CN202878585U (en) * | 2012-11-02 | 2013-04-17 | 山东大学 | Supercharging and measuring device for supercritical fluid |
| EP3720675A1 (en) * | 2017-12-04 | 2020-10-14 | Sapa S.P.A. | Method of production via injection-compression or a combination of injection-compression and injection of an object made of thermoplastic polymer admixed with at least one gas at the supercritical state |
| CN109385058A (en) * | 2018-09-06 | 2019-02-26 | 广东奔迪新材料科技有限公司 | A kind of method of the supercritical fluid preparation without mould stereochemical structure foaming product |
| CN109016320A (en) * | 2018-09-08 | 2018-12-18 | 广东奔迪新材料科技有限公司 | A kind of thermoplastic polymer particles mould inner mold foaming and forming apparatus and its forming method |
| CN109571847A (en) * | 2019-01-07 | 2019-04-05 | 山东大学 | A kind of multistage control pressurer system of supercritical fluid for polymer batch-foamed and method |
| CN109955423A (en) * | 2019-04-30 | 2019-07-02 | 广东奔迪新材料科技有限公司 | A kind of large-scale ultrahigh pressure thermoplastic polymer foaming and forming apparatus and its method |
| CN110480913A (en) * | 2019-09-24 | 2019-11-22 | 四川大学 | Multicomponent multi-phase complex system self-balancing supercritical foaming method and device |
| CN112829164A (en) * | 2021-01-13 | 2021-05-25 | 郑州大学 | Integrated ultrasonic-assisted supercritical fluid foaming reaction kettle and use method thereof |
| CN113059742A (en) * | 2021-03-31 | 2021-07-02 | 山东大学 | Mold cavity high-pressure gas control system and control method |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114851463A (en) * | 2022-05-09 | 2022-08-05 | 东莞兆阳兴业塑胶制品有限公司 | Supercritical foaming equipment for aviation foaming material |
| CN114851463B (en) * | 2022-05-09 | 2024-05-24 | 东莞兆阳兴业塑胶制品有限公司 | Supercritical foaming equipment for aviation foaming material |
| CN114849613A (en) * | 2022-05-12 | 2022-08-05 | 黄河三角洲京博化工研究院有限公司 | Anhydrous foaming reaction kettle and anhydrous foaming method |
| CN114953321A (en) * | 2022-05-25 | 2022-08-30 | 东莞海博斯新材料科技有限公司 | Preparation method of efficient environment-friendly supercritical die-pressing foaming elastomer |
| CN114953321B (en) * | 2022-05-25 | 2023-03-14 | 东莞海博斯新材料科技有限公司 | Preparation method of efficient environment-friendly supercritical die-pressing foaming elastomer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114311487A (en) | Polymer supercritical fluid mixing foaming system and method | |
| EP3643739B1 (en) | Method for preparing foamed product of moldless three-dimensional structure by means of supercritical fluid | |
| CN203282653U (en) | Polymer mould pressing foaming device assisted by supercritical fluid | |
| CN100411843C (en) | Multipurpose polymer forming machine | |
| CN104097288B (en) | A kind of supercritical fluid auxiliary polyalcohol moulded from foam device | |
| CN109571847B (en) | Supercritical fluid multi-stage pressure control system and method for intermittent foaming of polymer | |
| CN105690698B (en) | A kind of injection mold and the control system and method for controlling mold cavity pressure | |
| CN113134934B (en) | Gas-liquid two-phase self-balancing supercritical swelling foaming method | |
| CA2629315A1 (en) | Rapid non-equilibrium decompression of microorganism-containing waste streams | |
| CN102350780B (en) | Apparatus and method for preparing polymer foam material based on differential principle | |
| EP2178686A1 (en) | Press system | |
| CN100537176C (en) | Method and apparatus for producing biodegradable foam | |
| CN111978585A (en) | Preparation method and application of polymer foam material with trimodal cellular structure | |
| CN113059742B (en) | Mold cavity high-pressure gas control system and control method | |
| WO2020220382A1 (en) | Large ultra-high-pressure thermoplastic polymer foam-forming device and method therefor | |
| CN110239013B (en) | Preparation device, method and application of bimodal cell polymer foam material | |
| CN111319182A (en) | Graded pressure-control type die-opening foaming process and device and obtained foaming product | |
| CN100415820C (en) | Process for preparing teflon expanded sealing plate used for space air vehicles | |
| AU2003273976A1 (en) | Device and method for producing physically expanded structural foams during an injection molding process involving the use of dynamic mixing elements | |
| CN108467280B (en) | Heat preservation and insulation material for solar energy | |
| CN210617106U (en) | Self-balancing supercritical foaming device for multi-component multi-phase complex system | |
| CN109910254B (en) | Temperature control system for high-temperature gas circulation of injection mold cavity | |
| Sumarno et al. | Polystyrene microcellular plastic generation by quick‐heating process at high temperature | |
| JPH07178747A (en) | Method and device for imparting internal pressure to preformed polyolefin resin foam particle | |
| CN102886856A (en) | Supercritical fluid metering injection device and injection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |