CN101612773A - Discontinuous foaming agent control lead-in system and method - Google Patents
Discontinuous foaming agent control lead-in system and method Download PDFInfo
- Publication number
- CN101612773A CN101612773A CN200910089569A CN200910089569A CN101612773A CN 101612773 A CN101612773 A CN 101612773A CN 200910089569 A CN200910089569 A CN 200910089569A CN 200910089569 A CN200910089569 A CN 200910089569A CN 101612773 A CN101612773 A CN 101612773A
- Authority
- CN
- China
- Prior art keywords
- air collector
- blowing agent
- valve
- injection
- gas
- 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.)
- Granted
Links
Images
Abstract
The present invention is discontinuous foaming agent control lead-in system and method, is used in the processing of macromolecule foamed plastics blowing agent is introduced in the macromolecular material.This system comprises: source of the gas, blowing agent inlet, with the pipe-line system that source of the gas is connected with blowing agent inlet fluid, the on-off valve that a gas booster, an air collector is installed in this pipe-line system and is installed in air collector entrance and exit place respectively.Between air collector outlet on-off valve and blowing agent inlet, at least one current limiter is installed.Also comprise a control system in addition, this control system is accepted the signal from processing of high molecular material equipment, and calculate pressure in the air collector, control the action of gas booster simultaneously, adapt with the processing of high molecular material process, output signal control opens or closes the on-off valve of air collector entrance and exit, thereby realizes the discontinuous injection of blowing agent.The present invention is simple in structure, easy to operate, cost is lower, is convenient to realize suitability for industrialized production.
Description
Technical field:
The present invention relates to macromolecule foamed plastics processing, more particularly, relate to and be used in the system and method for in the processing of macromolecule foamed plastics blowing agent being introduced macromolecular material.
Background technology:
At present, can use multiple technologies that macromolecular material is processed, comprise extrude, injection moulding, blowing, calendering etc., wherein extrude and be injected into two kinds of the most frequently used processing of high molecular material technology.Injection mo(u)lding is meant at the machine barrel inner macromolecule material that seals under the spiro rod plasticizing effect that heat is conducted or can be rotated in machine barrel, melt polymer material, high speed and high pressure is injected into plastic melt in the closed mold cavity under plunger or screw acting then, obtains forming method with the corresponding to plastic part of die cavity through cooling and shaping.Nearly all thermoplastic macromolecule material can injection mo(u)lding, and 80% above high performance engineering plastics is by injection mo(u)lding.Injection mo(u)lding is a kind of production process of noncontinuity.In an injection cycle, comprise that screw rod rotates the macromolecular material of plasticating, and will plastify good macromolecular material and be transported in the storage cavity of screw front end, and screw rod stops the rotation, and the macromolecular material that plasticizing is good in the storage cavity is injected into technical process such as mold cavity.In order further to reduce the weight of high molecular products, save cost, reduce the shrinkage factor of injection-molded item and improve buckling deformation, physical blowing agent can be introduced the macromolecule melt in the injection screw, mixing effect by screw rod forms macromolecule melt/blowing agent homogeneous phase solution, homogeneous phase solution is injected mold cavity, preparation macromolecular material foaming product behind the cooling and shaping.Particularly for the high crystalline macromolecular material, or expensive engineering plastics, adopt frothing injection technology to reduce cost and to improve product properties especially suitable.In the frothing injection technical process, since screw rod rotation and be discontinuous operating process to the plasticizing of macromolecular material, therefore, in order to obtain uniform foaming product, require the introducing speed of blowing agent to need to be complementary, and be discontinuous introducing process with rotatablely moving of injection screw.Many traditional blowing agent drawing-in systems are introduced macromolecular material in the machine barrel continuously to blowing agent, this continuous introduction system may lack control on the percentage of the blowing agent that injects macromolecular material, and may cause the uneven distribution of blowing agent in macromolecular material.The uneven distribution of blowing agent may cause the viscosity of the macromolecular material in injection machine to change, and this guarantees to bring problem to production stability and quality of item.
The patent No. of Trexel company in February, 2000 application is US6602063B1, name is called in the patent of " discontinuous blowing agent diliversy system and method " and discloses a kind of plunger case and piston that can limit the blowing agent fixed dosage that comprise, connect source of the gas and the pipe-line system of injection and the discontinuous blowing agent drawing-in system of some stop valves, utilize the break-make of this system by stop valve can realize that blowing agent is discontinuous and be injected into (as injection moulding and blowing) in the processing of high molecular material process, the adding speed of blowing agent is according to the temperature and pressure value of the plunger gas in the jar of measuring, thereby controls the charge velocity of blowing agent through the movement rate that the back control piston is calculated in control system analysis.(the N particularly because physical blowing agent
2, CO
2, supercritical fluid) molecular weight less, flow rate of gas is very fast, open at stop valve instantaneous because pressure reduction, the blowing agent of plunger case inner sealing can be introduced in the macromolecule melt very soon, adopts the introducing speed of the extremely difficult accurate control gas of this technical process.The patent No. of the said firm's application in February calendar year 2001 is US6926507B2, name is called in the patent of " blowing agent dilivery system " and discloses a kind of blowing agent drawing-in system that comprises bypath system, realize the discontinuous injection of blowing agent by the break-make bypass valve, but can not realize injecting the accurate metering and the charge velocity control of blowing agent.Trexel company applied for that the patent No. was US7144532B2 in 2002 10, name is called " blowing agentintroduction system and method ", and the patent No. of in August, 2000 application is US6616434B1, name is called in the patent of " blowing agent introduction system " and discloses a kind of air collector that comprises, a pressure-regulating valve, a device for pressure measurement and the control system that can pass through input and output signal controlled pressure control valve adjusting air collector internal pressure greater than the injection machine internal pressure, and utilize this control system blowing agent to be introduced the blowing agent drawing-in system and the method for processing of high molecular material process.The blowing agent drawing-in system and the method for this patent disclosure, by the pressure in the adjusting air collector, and the air collector volume of determining, realize introducing the accurate control of foaming dosage.In this blowing agent drawing-in system and method, the on-off valve of air collector outlet and/or inlet is closed and/or opened once is a gas injection cycle, can only be in a gas injection cycle once with the macromolecule melt in the blowing agent injection injection machine that is collected in the air collector, if the blowing agent that will be collected at once in the air collector in a fusion cycle of injection machine is incorporated in the macromolecule melt, because the diffusion velocity of gas is very fast, as for N
2, when air collector internal pressure and macromolecule melt pressure ratio are 2, with 11.5g N
2Introduce the time of macromolecule melt and have only 1.0 * 10
-6Ms, and for discontinuous processing technologys such as injection mouldings, the time of a fusion cycle is generally 1～10s, so just can not guarantee that gas is evenly introduced in whole fusion cycle, cause local gas concentration height, after initial mixing was finished by screw rod shearing, the melt of follow-up plasticizing can only rely on the diffusion of gas in storage cavity, reach macromolecule melt/blowing agent homogeneous phase solution, this will need long time.Will cause the uneven distribution of storing indoor gas and melt like this, local gas concentration height, can't be dissolved in fully in the melt, and the part does not contain blowing agent, thereby influence the uniformity of goods and stablizing of production technology, so this technical scheme only is applicable on the little injection machine, screw diameter is on 40mm or following injection machine; This gas drawing-in system and method also disclose a kind of technical scheme in addition, promptly in an injection cycle, carry out twice or twice above gas collection and gas injection process, attempt to solve above-mentioned deficiency, so just need in a fusion cycle, repeatedly start and stop booster, and cooperation is simultaneously repeatedly opened and/or the on-off valve of closure set gas tank inlet and/or outlet, but because the fusion cycle of common injection machine was less than 30 seconds, even less than 10 seconds, if in a fusion cycle, will realize repeatedly gas boosting, steps such as introducing are just to the pressure degree of regulation of the dynamic response process of the booster of blowing agent drawing-in system, the control accuracy of on-off valve operation precision and control system etc. has proposed very high requirement, increased the machining accuracy of booster in this gas drawing-in system so undoubtedly, automatically controlled precision, the requirement of on-off valve action response precision and control system, thereby the complexity and the production cost of a whole set of gas drawing-in system have been increased, and usually gas boosting reaches the stable time needs 10～20 seconds, so this technical scheme implements to exist sizable difficulty.
Summary of the invention
The object of the present invention is to provide a kind of discontinuous blowing agent drawing-in system and method, particularly this blowing agent drawing-in system and method can be complementary with the discontinuous process of macromolecular material, will with the quality of item quantitative really blowing agent that adapts, in a fusion cycle discontinuously repeatedly control introduce in the macromolecular material melt in the injection machine machine barrel.
Discontinuous blowing agent drawing-in system of the present invention comprises: source of the gas, blowing agent inlet, the pipe-line system that is connected with source of the gas and blowing agent inlet are equipped with a gas booster, air collector, are installed in the on-off valve in air collector porch and exit respectively in this pipe-line system.Pressure measuring element is installed on air collector.On the pipeline between air collector outlet on-off valve and the blowing agent inlet, at least one current limiter is installed.Also comprise a control system in addition, booster, two on-off valves, pressure measuring element on the air collector all is connected with control system, this control system can also be accepted the signal from processing of high molecular material equipment, and according to the volume of processing needs (a blowing agent quality that the production cycle domestic demand adds) and air collector, calculate the pressure in the air collector, control the action of gas booster simultaneously, adapt with the processing of high molecular material process, output signal control opens or closes the on-off valve in air collector inlet or exit, thereby the accurate control of realization blowing agent injection rate and an injection cycle inner control determine that the blowing agent of quality repeatedly at the uniform velocity injects.
The present invention has the following advantages: the present invention goes into macromolecule melt quality in the die cavity according to per injection in the injection cycle, and the interpolation of the blowing agent in required introducing injection moulding machine barrel percentage, calculate the blowing agent quality that in an injection cycle, needs to introduce injection machine inner macromolecule melt.According to predetermined air collector volume, the macromolecule melt back pressure that processing needs, and the blowing agent quality and the equation of gas state that need introducing, calculate the pressure that gas should reach in the air collector, control system is according to The real time measure air collector internal pressure, to booster and air collector porch on-off valve output signal, control will determine that the blowing agent of quality is collected in the air collector.
On the other hand, the present invention is by installing at least one current limiter between air collector exit on-off valve and blowing agent inlet, blowing agent is introduced the speed of macromolecule melt in the restriction set gas tank, export opening or closing of on-off valve by air collector like this, the blowing agent that control has definite quality is repeatedly introduced the macromolecular material melt in the injection machine in an injection cycle, retreat while plastifying with injection screw so well, fusion time reduces to be complementary gradually, and can be according to the relative displacement of injection screw in machine barrel, opening the time of control system control air collector outlet on-off valve, the introducing amount of blowing agent and the plastics capacity of screw rod are complementary, thereby form uniform macromolecule melt/blowing agent homogeneous system, obtain the uniform high-quality foaming product of abscess.
In addition,, can change the volume of air collector, the pressure in the air collector easily, make blowing agent drawing-in system of the present invention can adapt to the injection machine of different size by changing the position of two on-off valves.
The present invention be advantageous in that in an injection cycle gas collection process for once, like this to the corresponding reduction that requires of response time of the dynamic response index control accuracy of booster, on-off valve, thereby the manufacturing cost of blowing agent drawing-in system of the present invention is reduced, be convenient to suitability for industrialized production.
The present invention is simple in structure, easy to operate, cost is lower, is convenient to realize suitability for industrialized production, is fit to the discontinuous foaming agent control lead-in system of all size injection machine.
Description of drawings
Fig. 1 is the schematic diagram of a technical scheme of blowing agent control drawing-in system of the present invention;
Fig. 2 is the result of the test figure of blowing agent control introducing method embodiment 2 of the present invention.
The specific embodiment
With reference to accompanying drawing 1, describe discontinuous foaming agent control lead-in system of the present invention and method in detail.
Discontinuous foaming agent control lead-in system 20 of the present invention comprises that the source of the gas 1 that contains blowing agent, one are positioned at the gas injection port 2 on injection machine 34 machine barrels 31, the outlet that connects source of the gas 1 and the pipeline 3 of gas injection port 2.On pipeline 3, booster 6 with entrance and exit is installed, one has inlet 11 and outlet 12, and air collector 7 with definite volume, the inlet 11 of air collector 7 is connected with the outlet of booster 6, on the pipeline of the inlet of the outlet of booster 6 and air collector 7, an on-off valve 8 is installed, current limiter 9 with entrance and exit, the inlet of current limiter 9 is connected with air collector 7, the outlet of current limiter 9 is connected with blowing agent inlet 2, on the pipeline of air collector outlet and current limiter 9 inlets, an on-off valve 10 is installed, with blowing agent flowing in the control air collector to blowing agent inlet 2.
Contain physical blowing agent in the source of the gas 1, as normally used nitrogen, carbon dioxide etc., usually source of the gas 1 has larger volume and is used to store a large amount of blowing agents and uses for the foam production process.Between source of the gas 1 outlet and booster 6 inlets, pressure regulatory element 4 and pressure measuring element 5 (accompanying drawing 1 is not shown) are installed optionally on the pipeline 3, according to needs of production, manual adjustments pressure regulatory element 4, make the pipeline inner pressure of booster inlet upstream be stabilized in certain force value, thereby guarantee that the booster inlet pressure is stable, improve the booster job stability, make things convenient for the stable normal operation of closed-loop control booster.In some technical schemes, also pressure regulatory element 4 and pressure measuring element 5 can be installed on the pipeline 3.
In a fusion cycle, the choice relation of gas injection rate and blowing agent pressure of storage tank, volume:
Gaseous mass
P: air collector actual pressure loss in the gas injection process is pressure reduction, gas pressure P in the air collector
1With melt pressure P in the injection machine
2Poor, G is the melt quality of injection cycle inner screw plasticizing
V: air collector volume
M: the molal weight of gas
R: ideal gas constant
T: absolute temperature K
For little foaming injection process, T can be considered as constant, after gas and injected articles are determined, R then, G, M is fixed value, thus variable be P and V
Gas injection rate w=KPV
Wherein:
Can pass through to change gas pressure in the storage tank, thereby change the gas flow that injects to a certain extent.
For the injector of a definite model, the pairing gas flow of minimum and maximum value of gas reservoir internal pressure should be able to satisfy the gas injection rate requirement under the minimum and maximum injection volume condition.
For injection, the 25%-80% plastics capacity is an optimum range.
For example, for 160 tons of injector moulding PP goods, the maximum injection amount is 280g, then the injection volume scope is between 58-230, adopt nitrogen as blowing agent, gas injection rate is usually from 1%-5%, and then gas flow should be between 0.58-11.5g, for nitrogen, its density with the Changing Pattern of pressure is:
If the maximum pressure that system pressure-nitrogen storage tank can bear is 50Mpa, then basis
11.5g required flask volume is 20 milliliters under the gas 50Mpa condition.
And adopt this storage tank, when injection 0.58g gas, the pressure that the interior gas pressure of storage tank only need be higher than the about 2.6Mpa of melt pressure gets final product.
Inlet on-off valve 8 and outlet on-off valve 10 all can receive the output signal from control system 21, under a kind of state (when being communicated with) allow fluid, comprise that pressurization gas, liquid gas or supercritical fluid flow through therefrom, and (when disconnecting) stops these fluids any device by the there under another kind of state.Suitably the valve of type comprises pneumatic operated valve, magnetic valve, hydraulic valve, guiding valve or other equivalent valve.In some cases, valve 8 and 10 can be a same type, and can be dissimilar in other cases.
On the pipeline between air collector 7 outlet on-off valves 10 and the gas injection port 2 current limiter 9 being installed in the present invention, can be the current limiting element that circular throttle orifice is formed for flow control valve, by porous material or cross section.When current limiter was flow control valve, its flow adjustment range was adapted between 0.1～0.5kg/h between 0.1～1kg/h.Allow in the current limiter that uses in the present invention net sectional area that fluid passes through should less than for other pipeline sections in the pipeline 3 long-pending 1/200～1/10, suitable 1/100～1/10.
Discontinuous foaming agent control lead-in system of the present invention also comprises a control system 21, control system 21 can be accepted the signal 40 from adapted to injection system, comprise pressure signal, screw position and motor message etc. near the gas injection port 2, also can accept the signal of artificial input.After control system 21 can be calculated according to input signal simultaneously, respectively to booster 6, on-off valve 8, on-off valve 10 output signals, control motion and on-off valve 8, on-off valve 10 or connection or the cut-out of booster 6 respectively, thereby (comprise and introduce dosage and introducing Position Control) introduced in the repeatedly control that realizes blowing agent.
In the blowing agent drawing-in system of the present invention, after gathering the blowing agent of determining quality in the air collector 7, on-off valve 8 is closed.The blowing agent of determining quality is meant the pressure differential according to gas pressure in the air collector and injection moulding machine barrel interpolymer melt, can introduce the quality of the blowing agent in the extrusion barrel, and it be according to the foaming dosage of processing needs required introducing in an injection cycle.
Adapted to injection system 34 can be technical known any suitable type, in the illustrative technique scheme, adapted to injection system includes extruding machine 30 and injection mold system 35, extruding machine 30 comprises machine barrel 31 and is installed in the interior screw rod 32 of machine barrel, screw rod 32 can rotate with downstream and move axially, the material that plasticizing is good is collected at storage cavity 33, and the melt that plasticizing in the storage cavity 33 is good is injected in the die cavity 35.
Discontinuous blowing agent control introducing method of the present invention comprises:
1) on-off valve 10 at closure set gas tank outlet place is opened the on-off valve 8 of air collector import department, and control system 21 makes booster to carrying out pneumatic compression in the air collector to booster 6 output signals;
2) when the pressure in the air collector reaches setting value, this setting value should be fit to 5～30MPa, the most suitable 10～20MPa, closure set gas tank porch on-off valve greater than injection machine inner macromolecule melt back pressure 1～50MPa;
3) screw in injection molding machine 32 begins the rotation plasticizing, plasticizing edge, screw rod 32 limits axially moves backward, and will plastify the storage cavity 33 of good mass transport to screw front end, control system 21 is according to the displacement of screw rod in machine barrel, the on-off valve 10 that can repeatedly control the air collector exit in whole spiro rod plasticizing stroke opens and closes, when opening, blowing agent in the air collector is introduced in the macromolecular material melt in the injection machine 30 by current limiter 9 and blowing agent inlet 2, does not then introduce blowing agent when closing; The duration that the on-off valve 10 in control system 21 control air collector exits is opened is 0.1s～2s.As required, the on-off valve in air collector exit can repeatedly be opened at a fusion cycle, be no less than 10 times, more suitable being no less than 5 times, optimumly be no less than 2 times and open, in a fusion cycle, repeatedly blowing agent is introduced like this in the macromolecular material melt in the injection machine machine barrel, generally be no less than 10 times, be fit to be no less than the most suitable being no less than 2 times 5 times;
4) when the pressure of the pressure in the air collector and blowing agent gas injection port place melt was identical, the control system output signal was closed the on-off valve in air collector exit, finishes and repeatedly introduce blowing agent in the macromolecule melt in machine barrel in whole fusion cycle.
In the discontinuous blowing agent control of the present invention introducing method, blowing agent can be N
2, CO
2, low molecule alkane, physical blowing agents such as HFC, chloro-fluorocarbon compound.
In the discontinuous blowing agent control of the present invention introducing method, pass through the action of booster 6 from the blowing agent of source of the gas 1, make the blowing agent pressure (being measured by the pressure measuring element that is connected with the air collector pipeline) that is collected in the air collector 7 when reaching a certain setting value, control system 21 makes it stop action to booster 6 output signals.The force value that reaches in the air collector should if force value is too low, be not enough to the air injection opening 22 that is installed on the gas injection port 2 is opened greater than 1～50MPa of injection machine inner macromolecule material melt back pressure usually, and blowing agent can not be introduced in the injection machine fused mass.This force value should be associated with the foaming dosage of needs introducing, the volume of air collector 7, and the back is determined as calculated.This force value can manual input control system, and control system also can be calculated automatically according to other parameter of input and determine.
When current limiter is flow control valve, at first need the specific gas flow rate of the flow control valve of flowing through is demarcated, scaling method is: by gas booster the air collector internal pressure is increased to certain force value, the aperture of setting flow control valve is a certain value, measures the specific gas flow rate of this moment; Relation between replication air collector internal pressure, the Flow-rate adjustment valve opening flow rate, and be depicted as table or curve.
Illustrate further technical scheme of the present invention by following examples and comparative example, but the scope of the invention is not limited to following examples.
Embodiment 1:
Injection machine T120, screw diameter 36mm, draw ratio is 23.6, offers the blowing agent inlet on the injection machine machine barrel, and discontinuous foaming agent control lead-in system is connected with injection machine by pipeline at gas injection port, and the blowing agent drawing-in system comprises: N
2Air accumulator is with N
2The pipe-line system that air accumulator is connected with blowing agent inlet fluid, a gas booster is installed in this pipe-line system, an air collector, two on-off valves that are connected with air collector entrance and exit fluid respectively, surrounding the volume that forms confined space between the air collector entrance and exit is 20ml, pressure sensor is installed on the air collector, on the pipeline between air collector outlet on-off valve and the blowing agent inlet flow control valve is installed, the flow adjustment range of control valve is 0.1～0.5kg/h.Also comprise a control system in addition, this control system can be accepted the signal from injection machine, displacement as screw rod, melt pressure etc., and according to the volume of processing needs (a blowing agent quality that the production cycle domestic demand adds) and air collector, calculate the pressure in the air collector, simultaneously to the gas booster output signal, the action of control booster, adapt with the Shooting Technique process, output signal control is opened and/or the closure set gas tank enters the mouth and/or the stop valve of outlet, thereby accurate control and an injection cycle inner control of realizing the blowing agent injection rate determine that the blowing agent of quality repeatedly injects.
Processing materials is an acrylic resin, Yanshan Petrochemical company produces, K8308, MI=2.0g/10min, mould is 150mm * 150mm * 2mm sheet die, each section of injection machine temperature is set at 160 ℃ respectively from the charge door to the nozzle, and 180 ℃, 200 ℃, 210 ℃, 210 ℃, the melt back pressure set is 20MPa, and rotating speed is 80rpm during spiro rod plasticizing; Each technological parameter of injection moulding process is as shown in table 1, and gas injection rate represents to inject in the fusion cycle ratio of blowing agent quality and the melt quality of plasticizing.The N of Zhu Ruing as required
2The pressure set points that quality, control system calculate in the air accumulator is 25MPa, and the air accumulator outlet valve cuts out, and gas booster is increased to 25MPa with the pressure in the air accumulator, and the porch stop valve is closed, and the blowing agent of certain mass is collected in the air collector.The Flow-rate adjustment valve opening is full-scale 15%.
In a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, at this moment monitor near the pressure of gas injection port, when pressure reaches when stablizing, open the stop valve in air collector exit, blowing agent enters behind flow control valve in the injection machine inner macromolecule material melt in the air collector, and stop valve is closed behind the lasting 2s; When the injection screw displacement reach total displacement 50% the time, open for the second time the stop valve in air collector exit, for the second time blowing agent is introduced in the injection machine machine barrel, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
The screw rod rotation is even with blowing agent and the macromolecular material melt mixed of injecting, form homogeneous phase solution, and homogeneous phase solution carried in the storage cavity of screw head, in storage cavity, store polymer/blowing agent homogeneous phase solution and reach the injection moulding requirement, screw rod stops the rotation, and, obtain the injection foaming goods with in the injection of the homogeneous phase solution in the storage cavity die cavity.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
Embodiment 2
With embodiment 1, the Flow-rate adjustment valve opening is full-scale 20% with macromolecular material for used injection machine, blowing agent control drawing-in system, test, and gas injection rate is 0.5%, and the control booster is increased to 30MPa with the air collector internal pressure.In addition, embodiment 1 is identical for the blowing agent method for implanting, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, at this moment monitor near the pressure of gas injection port, when pressure reaches when stablizing, open the stop valve in air collector exit, blowing agent enters behind flow control valve in the injection machine inner macromolecule material melt in the air collector, continue 1s after stop valve close, when the injection screw displacement reach total displacement 30% the time, open for the second time the air collector outlet shutoff valve, for the second time blowing agent is introduced in the macromolecular material melt of injection machine machine barrel, is continued the 1s stop valve and close, when the injection screw displacement reach total displacement 60% the time, open air collector exit stop valve for the third time, for the third time blowing agent is introduced in the macromolecular material melt in the injection machine machine barrel, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.Accompanying drawing 2 is in this embodiment blowing agent introducing process, and air collector internal pressure change curve can be known from figure in a fusion cycle, in the macromolecular material melt in controlled three the introducing injection machine machine barrels of gas.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
With embodiment 1, the Flow-rate adjustment valve opening is full-scale 5% with macromolecular material for used injection machine, blowing agent control drawing-in system, test, and gas injection rate is 0.8%, and the control booster is increased to 40MPa with the air collector internal pressure.In addition, the blowing agent method for implanting is identical with embodiment 1, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, at this moment monitor near the pressure of gas injection port, when pressure reaches when stablizing, the interior blowing agent of stop valve air collector of opening the air collector exit enters behind flow control valve in the injection machine inner macromolecule material melt, stop valve is closed after continuing 0.3s, when the injection screw displacement reach total displacement 20% the time, open for the second time air collector exit stop valve, for the second time blowing agent is introduced in the macromolecular material melt of injection machine machine barrel, continue to close behind the 0.5s, when the injection screw displacement reach total displacement 40% the time, opening the exit stop valve for the third time introduces blowing agent in the macromolecular material melt in the injection machine machine barrel for the third time, continue to close behind the 0.3s, when the injection screw displacement reach total displacement 60% the time, open the exit stop valve the 4th time, the 4th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed after continuing 0.2s, when the injection screw displacement reach total displacement 80% the time, opening air collector exit stop valve the 5th time for the 5th time introduces blowing agent in the macromolecular material melt in the injection machine machine barrel, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
Embodiment 4
With embodiment 1, the Flow-rate adjustment valve opening is full-scale 5% with macromolecular material for used injection machine, blowing agent control drawing-in system, test, and gas injection rate is 1.2%, and the control booster is increased to 50MPa with the air collector internal pressure.In addition, the blowing agent method for implanting is identical with embodiment 1, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, at this moment monitor near the pressure of gas injection port, when pressure reaches when stablizing, open the stop valve in air collector exit, blowing agent enters behind flow control valve in the injection machine inner macromolecule material melt in the air collector, stop valve is closed after continuing 0.5s, when the injection screw displacement reach total displacement 20% the time, open for the second time the air collector outlet shutoff valve, for the second time blowing agent is introduced in the macromolecular material melt of injection machine machine barrel, stop valve is closed after continuing 0.4s, when the injection screw displacement reach total displacement 40% the time, open the air collector outlet shutoff valve for the third time, for the third time blowing agent is introduced in the macromolecular material melt in the injection machine machine barrel, continue to close behind the 0.3s, when the injection screw displacement reach total displacement 60% the time, open the air collector outlet shutoff valve the 4th time, the 4th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed after continuing 0.2s, when the injection screw displacement reach total displacement 80% the time, open the air collector outlet shutoff valve the 5th time, the 5th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
Embodiment 5
With embodiment 1, except that current limiter adopted the current limiting element of being made up of porous material, other parts of blowing agent drawing-in system were identical with embodiment 1 with macromolecular material for used injection machine, test.The effective cross-section that allows gas to pass through in the porous material is 1/200 of other cross-section of pipeline, and other pipe diameters are 4mm, and gas injection rate is 1.2%, and the control booster is increased to 50MPa with the air collector internal pressure.In addition, the blowing agent method for implanting is identical with embodiment 1, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, open the stop valve in air collector exit, blowing agent enters behind flow control valve in the injection machine inner macromolecule material melt in the air collector, stop valve is closed after continuing 0.1s, when the injection screw displacement reach total displacement 10% the time, open the air collector outlet shutoff valve, for the second time blowing agent is introduced in the macromolecular material melt of injection machine machine barrel, stop valve is closed after continuing 0.1s, when the injection screw displacement reach total displacement 20% the time, open the air collector outlet shutoff valve for the third time, for the third time blowing agent is introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed after continuing 0.1s, when the injection screw displacement reach total displacement 30% the time, open the air collector outlet shutoff valve the 4th time, the 4th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, continue to close behind the 0.1s, when the injection screw displacement reach total displacement 40% the time, open the air collector outlet shutoff valve the 5th time, the 5th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed Using such method, the 6th time after continuing 0.1s, the 7th time .... the tenth time blowing agent introduced in the injection machine inner macromolecule material melt, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
Used injection machine, test with embodiment 1, are that the throttle orifice of circle blowing agent drawing-in system other parts with embodiment 1 identical except that current limiter adopts the cross section with macromolecular material.The effective cross-section that allows gas to pass through in the throttle orifice is 1/100 of other cross-section of pipeline, and other pipe diameters are 4mm, and gas injection rate is 1.2%, and the control booster is increased to 50MPa with the air collector internal pressure.In addition, the blowing agent method for implanting is identical with embodiment 1, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, open the stop valve in air collector exit, blowing agent enters behind flow control valve in the injection machine inner macromolecule material melt in the air collector, stop valve is closed after continuing 0.3s, when the injection screw displacement reach total displacement 20% the time, open for the second time the air collector outlet shutoff valve, for the second time blowing agent is introduced in the macromolecular material melt of injection machine machine barrel, stop valve is closed after continuing 0.3s, when the injection screw displacement reach total displacement 40% the time, open the air collector outlet shutoff valve for the third time, for the third time blowing agent is introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed after continuing 0.2s, when the injection screw displacement reach total displacement 60% the time, open the air collector outlet shutoff valve the 4th time, the 4th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, stop valve is closed after continuing 0.1s, when the injection screw displacement reach total displacement 80% the time, open the air collector outlet shutoff valve the 5th time, the 5th time blowing agent introduced in the macromolecular material melt in the injection machine machine barrel, when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
Repeat above frothing injection process 20～50 times, all can obtain the uniform PP injection foaming of abscess goods.
Comparative example
Used injection machine, test, are not installed in pipe-line system the current limiter with embodiment 1 with macromolecular material, and other parts of blowing agent drawing-in system are identical with embodiment 1.Gas injection rate is 1.2%, and the control booster is increased to 50MPa with the air collector internal pressure.Except that following difference, the blowing agent method for implanting is identical with embodiment 1, difference is, in a fusion cycle, screw rod begins rotation, and will plastify of the storage cavity conveying of good material to screw front end, control system detects the melt pressure that is positioned at the blowing agent inlet, Deng reach stable after, open the stop valve in air collector exit, blowing agent is introduced in the injection machine inner macromolecule material melt in the air collector, and when the air collector internal pressure equated with injection machine inner macromolecule material melt pressure, the exit stop valve was closed.
Repeat above frothing injection process 20～50 times, obtain having in the PP injection foaming goods tangible bulla to exist, and foam structure is inhomogeneous, goods runner front end has air pocket.
| Embodiment | Melt back pressure (MPa) | Air collector pressure (MPa) | Gas injection rate (%) | A fusion cycle gas injects number of times |
| Embodiment 1 | ??20 | ??25 | ??0.2 | ??2 |
| Embodiment 2 | ??15 | ??25.8 | ??0.5 | ??3 |
| |
??20 | ??40 | ??0.8 | ??5 |
| Embodiment 4 | ??20 | ??50 | ??1.2 | ??5 |
| Embodiment 5 | ??20 | ??50 | ??1.2 | ??10 |
| |
??20 | ??50 | ??1.2 | ??5 |
| Comparative example | ??20 | ??50 | ??1.2 | ??1 |
Claims (10)
1, discontinuous foaming agent control lead-in system comprises that one contains the source of the gas of blowing agent, a pipe-line system that is arranged on the blowing agent inlet on the injection machine machine barrel and connects source of the gas and blowing agent inlet; A gas booster and an air collector are installed in this pipe-line system, pressure measuring element is installed on air collector, this pressure measuring element is connected with control system; The inlet of gas booster is connected with source of the gas, and outlet is connected with the inlet of air collector, and the outlet of air collector is connected with the blowing agent inlet; Entrance and exit at air collector is separately installed with on-off valve, booster, two on-off valves all are connected with control system with pressure measuring element on the air collector, it is characterized in that: on the pipeline between air collector outlet on-off valve and the blowing agent inlet current limiter is installed at least.
2, discontinuous foaming agent control lead-in system according to claim 1 is characterized in that: described current limiter is a flow control valve, and flow adjustment range is at 0.1～1kg/h, and the volume of air collector is not less than 10ml.
3, discontinuous foaming agent control lead-in system according to claim 2 is characterized in that: the flow adjustment range of flow control valve is at 0.1～0.5kg/h.
4, according to discontinuous foaming agent control lead-in system according to claim 1, it is characterized in that: described current limiter is that circular throttle orifice is formed by porous material or cross section.
5 according to claim 2 or 4 described discontinuous foaming agent control lead-in systems, it is characterized in that: the net sectional area that allows gas to pass through in the current limiter be in the pipeline other pipeline sections long-pending 1/200～1/10.
6, use the described discontinuous foaming agent control lead-in system of claim 1 with the method in the discontinuous introducing injection machine of the blowing agent inner macromolecule melt, it is characterized in that this method may further comprise the steps:
1) on-off valve at closure set gas tank outlet place is opened the on-off valve of air collector import department, and control system makes booster to carrying out pneumatic compression in the air collector to the booster output signal;
2) when the pressure setup pressure value in the air collector, control system control closure set gas tank porch on-off valve, setup pressure value should be higher than melt back pressure 1～50Mpa in the injection machine;
3) screw in injection molding machine begins the rotation plasticizing, plasticizing edge, screw rod limit axially moves backward, and will plastify the storage cavity of good mass transport to screw front end, control system is according to the displacement of screw rod in machine barrel, in whole spiro rod plasticizing stroke, the on-off valve in control system control air collector exit opens or closes, when opening, blowing agent in the air collector is introduced in the macromolecular material melt in the injection machine by current limiter and blowing agent inlet, does not then introduce blowing agent when closing; The duration that the on-off valve in control system control air collector exit is opened is 0.1s～2s; As required, the least number of times opened in a fusion cycle of the on-off valve in air collector exit is 10 times;
4) when the pressure of the pressure in the air collector and blowing agent gas injection port place melt was identical, the control system output signal was closed the on-off valve in air collector exit, finishes and repeatedly introduce blowing agent in the macromolecule melt in machine barrel in whole fusion cycle.
7, described with the method in the discontinuous introducing injection machine of the blowing agent inner macromolecule melt according to claim 6, it is characterized in that: the least number of times that the described on-off valve 10 of step 3) is opened in a fusion cycle is 5 times.
8, described with the method in the discontinuous introducing injection machine of the blowing agent inner macromolecule melt according to claim 6, it is characterized in that: the least number of times that the described on-off valve 10 of step 3) is opened in a fusion cycle is 2 times.
9, described with the method in the discontinuous introducing injection machine of the blowing agent inner macromolecule melt according to claim 6, it is characterized in that: open before the on-off valve of air collector exit, the pressure in the air collector is higher than melt back pressure 5～30Mpa in the injection machine.
10, described with the method in the discontinuous introducing injection machine of the blowing agent inner macromolecule melt according to claim 6, it is characterized in that: open before the on-off valve of air collector exit, the pressure in the air collector is higher than injection machine fused mass back pressure 10～20Mpa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100895699A CN101612773B (en) | 2009-07-24 | 2009-07-24 | Discontinuous foaming agent control lead-in system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100895699A CN101612773B (en) | 2009-07-24 | 2009-07-24 | Discontinuous foaming agent control lead-in system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101612773A true CN101612773A (en) | 2009-12-30 |
| CN101612773B CN101612773B (en) | 2011-04-20 |
Family
ID=41492741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100895699A Expired - Fee Related CN101612773B (en) | 2009-07-24 | 2009-07-24 | Discontinuous foaming agent control lead-in system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101612773B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102059767A (en) * | 2010-10-29 | 2011-05-18 | 北京化工大学 | System and method for introducing discontinuous foaming agent multiple times |
| CN103057061A (en) * | 2012-12-20 | 2013-04-24 | 华南理工大学 | Device and method for efficient mixed microcellular foaming plastic precise injection molding |
| CN104441385A (en) * | 2014-11-18 | 2015-03-25 | 中天日立射频电缆有限公司 | Dual-path gas injection system for physical foaming process and gas injection method thereof |
| CN105252696A (en) * | 2015-11-20 | 2016-01-20 | 武汉理工大学 | Supercritical micro foaming and injection molding method for polymer |
| TWI786631B (en) * | 2021-05-13 | 2022-12-11 | 天崗精機科技股份有限公司 | A system for controlling an injection of a foaming agent |
-
2009
- 2009-07-24 CN CN2009100895699A patent/CN101612773B/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102059767A (en) * | 2010-10-29 | 2011-05-18 | 北京化工大学 | System and method for introducing discontinuous foaming agent multiple times |
| CN103057061A (en) * | 2012-12-20 | 2013-04-24 | 华南理工大学 | Device and method for efficient mixed microcellular foaming plastic precise injection molding |
| CN103057061B (en) * | 2012-12-20 | 2015-10-28 | 华南理工大学 | Efficient mixing microcellular plastics precise injection molding apparatus and method |
| CN104441385A (en) * | 2014-11-18 | 2015-03-25 | 中天日立射频电缆有限公司 | Dual-path gas injection system for physical foaming process and gas injection method thereof |
| CN105252696A (en) * | 2015-11-20 | 2016-01-20 | 武汉理工大学 | Supercritical micro foaming and injection molding method for polymer |
| CN105252696B (en) * | 2015-11-20 | 2016-12-21 | 武汉理工大学 | A kind of polymer supercritical micro foaming injection moulding method |
| TWI786631B (en) * | 2021-05-13 | 2022-12-11 | 天崗精機科技股份有限公司 | A system for controlling an injection of a foaming agent |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101612773B (en) | 2011-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101612773B (en) | Discontinuous foaming agent control lead-in system and method | |
| CN101612774A (en) | Blowing agent introduction method | |
| CN100493885C (en) | Supercritical fluid assistant high molecular material extrusion forming machine | |
| CN101758599B (en) | Apparatus for and method of processing polymers containing a foaming agent | |
| CN101480831A (en) | Supercritical fluid aerating powder conveying device and control method | |
| CN103895146B (en) | A kind of polymer micro foaming product progressive forming apparatus and method | |
| CN102896729B (en) | Supercritical fluid pressure boost metering device | |
| CN201124559Y (en) | Foaming plastic emission forming device | |
| CN103057061A (en) | Device and method for efficient mixed microcellular foaming plastic precise injection molding | |
| CN103391836B (en) | The manufacture method and manufacture device of duct member | |
| EP3700730A1 (en) | Blowing agent introduction in polymer foam processing | |
| CN202114883U (en) | Injection mechanism with ultra-large injection volume | |
| CN101554771B (en) | Device for preparing polymer | |
| CN201279881Y (en) | Micropore injection mould apparatus | |
| CN202895561U (en) | Gas adding device | |
| CN102059767A (en) | System and method for introducing discontinuous foaming agent multiple times | |
| CN101428462B (en) | Expanded plastic injection molding method and apparatus | |
| CN200981323Y (en) | Gas foaming agent flow quantity controlling system | |
| CN200939682Y (en) | Super-critical fluid auxilary micro-porous injection apparatus | |
| CN201471668U (en) | Supercritical fluid foaming agent dosage control device | |
| CN203077566U (en) | Injection moulding device for on-line mixing preparation of high-performance microcellular foaming plastic | |
| CN212602950U (en) | Microcellular foaming injection molding plasticizing device | |
| CN201338361Y (en) | Supercritical fluid foaming agent conveying device | |
| CN202123615U (en) | Device for continuously conveying and metering liquid carbon dioxide | |
| CN100546805C (en) | Water aided injection forming device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110420 Termination date: 20150724 |
|
| EXPY | Termination of patent right or utility model |