CN112959594A - Injection molding system and method for thermoplastic resin articles - Google Patents
Injection molding system and method for thermoplastic resin articles Download PDFInfo
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- CN112959594A CN112959594A CN202110188767.1A CN202110188767A CN112959594A CN 112959594 A CN112959594 A CN 112959594A CN 202110188767 A CN202110188767 A CN 202110188767A CN 112959594 A CN112959594 A CN 112959594A
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- control device
- molten resin
- homogeneous solution
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- 238000001746 injection moulding Methods 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims abstract description 27
- 229920005992 thermoplastic resin Polymers 0.000 title claims abstract description 21
- 229920005989 resin Polymers 0.000 claims abstract description 75
- 239000011347 resin Substances 0.000 claims abstract description 75
- 239000012456 homogeneous solution Substances 0.000 claims abstract description 73
- 239000004088 foaming agent Substances 0.000 claims abstract description 65
- 238000002347 injection Methods 0.000 claims abstract description 45
- 239000007924 injection Substances 0.000 claims abstract description 45
- 238000005086 pumping Methods 0.000 claims abstract description 17
- 239000004604 Blowing Agent Substances 0.000 claims description 10
- 239000000243 solution Substances 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims 1
- 238000005187 foaming Methods 0.000 abstract description 6
- 230000007547 defect Effects 0.000 abstract description 5
- 239000007789 gas Substances 0.000 description 79
- 239000000047 product Substances 0.000 description 15
- 229910000831 Steel Inorganic materials 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/0025—Preventing defects on the moulded article, e.g. weld lines, shrinkage marks
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/0053—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor combined with a final operation, e.g. shaping
- B29C45/0055—Shaping
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/1701—Component parts, details or accessories; Auxiliary operations using a particular environment during moulding, e.g. moisture-free or dust-free
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/76—Measuring, controlling or regulating
- B29C45/77—Measuring, controlling or regulating of velocity or pressure of moulding material
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
The application relates to an injection molding system and method of a thermoplastic resin product, the method comprises an injection molding device, a mold which is connected with the injection molding device and is provided with a mold cavity, a gap which is arranged on the mold and is communicated with the mold cavity, a high-pressure gas injection device and a vacuum pumping device which are connected with the gap, and a control device which is respectively connected with the injection molding device, the high-pressure gas injection device and the vacuum pumping device; before injecting the homogeneous solution of the molten resin/foaming agent into the mold cavity, controlling a high-pressure gas injection device by a control device to establish prepressing of 0.5-10 Mpa in the mold cavity, so that the homogeneous solution of the molten resin/foaming agent can stably fill the mold cavity in a uniform pressure state; after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, the control device controls the vacuumizing device to vacuumize the mold cavity, so that the discharge speed of gas in the mold cavity is accelerated, the surface of the prepared product is full, and the foaming defect is avoided.
Description
Technical Field
The present application relates to the field of plastic forming processing technology, and more particularly, to a system and method for injection molding thermoplastic resin articles.
Background
In the injection molding process, before the homogeneous solution of the molten resin/the foaming agent is filled into the mold cavity, a certain pressure is established in the mold cavity by using compressed gas, and then the homogeneous solution of the molten resin/the foaming agent is injected into the mold cavity. During the injection of the homogeneous solution of molten resin/blowing agent into the mold cavity, the volume of the cavity is gradually occupied by the homogeneous solution of molten resin/blowing agent, and the compressed gas inside the cavity is passively discharged through the mold slit.
In view of the above-mentioned related technologies, the inventor believes that when the size of the slit of the mold is small, the discharge of the compressed gas in the cavity of the mold is slow, which results in incomplete filling of the homogeneous solution of the molten resin/foaming agent, incomplete molding of the product or material shortage; when the size of the mold slit is large, a homogeneous solution of the molten resin/foaming agent flows into the mold slit in the process of exhausting gas, and the next injection molding of the product is affected.
Disclosure of Invention
In order to rapidly discharge the compressed gas in the mold cavity, the present application provides a system and method for injection molding a thermoplastic resin article.
In a first aspect, the present application provides an injection molding system for thermoplastic resin products, which adopts the following technical solutions:
an injection molding system for a thermoplastic resin article, comprising:
the injection molding device is connected with the injection molding device and is provided with a mold cavity, a gap which is arranged on the mold and is communicated with the mold cavity, a high-pressure gas injection device and a vacuumizing device which are connected with the gap, and a control device which is respectively connected with the injection molding device, the high-pressure gas injection device and the vacuumizing device;
the control device is used for controlling the operation of the motor,
controlling the injection molding device to inject a homogeneous solution of molten resin/blowing agent into the mold cavity;
before injecting homogeneous solution of molten resin/foaming agent into the mold cavity, controlling the high-pressure gas injection device to inject high-pressure gas into the mold cavity, so that the pressure in the mold cavity reaches 0.5-10 Mpa;
and after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, controlling the vacuumizing device to vacuumize the mold cavity until the homogeneous solution of the molten resin/foaming agent fills the mold cavity.
By adopting the technical scheme, the control device controls the high-pressure gas injection device to establish a positive pressure of 0.5-10 Mpa in the mold cavity, so that a homogeneous solution of the molten resin/foaming agent can stably fill the mold cavity in a uniform pressure state and control the cavity filling speed; after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, the control device controls the vacuumizing device to vacuumize the mold cavity, so that the discharge speed of gas in the mold cavity is accelerated, the influence on the filling speed and the speed adjusting range of the homogeneous solution of the molten resin/foaming agent is reduced, and the surface of the prepared product is full and smooth and has no foaming defect.
Optionally, the vacuum pumping device includes a first cut-off valve, a vacuum tank set and a vacuum pump, which are sequentially connected along a direction of exhausting high-pressure gas in the mold cavity, a first pressure sensor is disposed on the vacuum tank set, and the control device is respectively connected to the first cut-off valve, the first pressure sensor and the vacuum pump;
the control device is used for controlling the operation of the motor,
after the homogeneous solution of the molten resin/foaming agent fills 80-90% of the volume of the mold cavity, controlling the first stop valve to be opened and the vacuum pump to be opened so as to vacuumize the mold cavity;
after the homogeneous solution of the molten resin/foaming agent is filled in the die cavity, controlling the first stop valve to be closed, and controlling the vacuum pump to continue vacuumizing the vacuum tank set, so that the pressure in the vacuum tank set reaches-0.05 to-0.03 MPa.
By adopting the technical scheme, the control device controls the vacuum tank group to vacuumize the mold cavity, the gas pressure of-0.05 to-0.03 Mpa in the vacuum tank group is far lower than the gas pressure in the mold cavity, and the vacuum tank group has suction to the gas in the mold cavity, so that the mold cavity can be vacuumized; the vacuum pump continues to vacuumize the vacuum tube after the first stop valve is closed, so that the pressure in the vacuum tank set reaches-0.05 to-0.03 MPa, and the vacuum tank set can vacuumize the mold cavity in time next time.
Optionally, the high-pressure gas injection device includes a high-pressure gas source, a pressure control valve set and a second stop valve, which are sequentially connected along the high-pressure gas injection direction, and the pressure control valve set and the second stop valve are both connected to the control device;
and the control device is used for controlling the second stop valve to be opened before injecting the homogeneous phase solution of the molten resin/foaming agent into the mold cavity, so that the high-pressure gas in the high-pressure gas source is injected into the mold cavity, and the pressure in the mold cavity reaches 0.5-10 Mpa.
Through adopting above-mentioned technical scheme, controlling means is through controlling the second stop valve for high pressurized air source pours into the mould die cavity into, and is provided with the pressure control valves between high pressurized air source and second stop valve, makes the gas pressure to pouring into in the mould die cavity adjustable and more stable.
Optionally, the system further includes a second pressure sensor disposed on the mold, and the second pressure sensor is connected to the control device and configured to detect the pressure in the mold cavity and feed back a pressure value to the control device.
Through adopting above-mentioned technical scheme, controlling means can receive the pressure numerical value that second pressure sensor fed back to according to from the start-up of pressure numerical value control injection moulding device and the opening and closing of second stop valve.
Optionally, the control means is arranged to obtain signals from the injection moulding means to determine the volume of the mould cavity filled with the homogeneous solution of molten resin/blowing agent.
By adopting the technical scheme, the injection molding device is used for injecting the homogeneous solution of the molten resin/foaming agent into the mold cavity, and the control device acquires a signal from the injection molding device to determine the volume of the mold cavity filled with the homogeneous solution of the molten resin/foaming agent, so that a product is stably prepared.
In a second aspect, the present application provides a method for injection molding a thermoplastic resin article, which adopts the following technical solution:
a method of injection molding a thermoplastic resin article of an injection molding system for thermoplastic resin articles, comprising:
before injecting homogeneous solution of molten resin/foaming agent into the mold cavity, controlling a high-pressure gas injection device to inject high-pressure gas into the mold cavity by a control device, so that the pressure in the mold cavity reaches 0.5-10 Mpa;
after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, the control device controls the vacuumizing device to vacuumize the mold cavity until the homogeneous solution of the molten resin/foaming agent fills the mold cavity.
By adopting the technical scheme, the control device controls the high-pressure gas injection device to establish a positive pressure of 0.5-10 Mpa in the mold cavity, so that a homogeneous solution of the molten resin/foaming agent can stably fill the mold cavity in a uniform pressure state and control the cavity filling speed; after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, the control device controls the vacuumizing device to vacuumize the mold cavity, so that the discharge speed of gas in the mold cavity is accelerated, the influence on the filling speed and the speed adjusting range of the homogeneous solution of the molten resin/foaming agent is reduced, and the surface of the prepared product is full and smooth and has no foaming defect.
Optionally, the controlling means controls the vacuum-pumping device to perform vacuum-pumping treatment on the mold cavity until the mold cavity is filled with the homogeneous solution of the molten resin/the foaming agent, and the method includes:
the control device controls the first stop valve to be opened and the vacuum pump to be opened so as to vacuumize the mold cavity;
after the homogeneous solution of the molten resin/foaming agent is filled in the die cavity, the control device controls the first stop valve to be closed, and controls the vacuum pump to continue to vacuumize the vacuum tank, so that the pressure in the vacuum tank reaches-0.05 to-0.03 MPa.
By adopting the technical scheme, the control device controls the vacuum tank to vacuumize the mold cavity, the gas pressure of-0.05 to-0.03 Mpa in the vacuum tank is far lower than the gas pressure in the mold cavity, and the vacuum tank has suction to the gas in the mold cavity, so that the mold cavity can be vacuumized; the vacuum pump continues to vacuumize the vacuum tube after the first stop valve is closed, so that the pressure in the vacuum tank reaches-0.05 to-0.03 MPa, and the vacuum tank can vacuumize the mold cavity in time next time.
Optionally, the control device controls the high-pressure gas injection device to inject high-pressure gas into the mold cavity, and the control device includes:
the control device controls the second stop valve to be opened, so that high-pressure gas in the high-pressure gas source is injected into the mold cavity.
By adopting the technical scheme, the control device can conveniently control the high-pressure air source to inject into the mold cavity by controlling the second stop valve.
Optionally, the method further includes:
the second pressure sensor detects the pressure in the mold cavity and feeds the pressure value back to the control device.
Through adopting above-mentioned technical scheme, controlling means can receive the pressure numerical value that second pressure sensor fed back to according to from the start-up of pressure numerical value control injection moulding device and the opening and closing of second stop valve.
Optionally, the method further includes:
a control device obtains the volume of the homogeneous solution of the molten resin/blowing agent filling the mold cavity from the injection device.
By adopting the technical scheme, the injection molding device is used for injecting the homogeneous solution of the molten resin/foaming agent into the mold cavity, and the control device obtains the homogeneous solution of the molten resin/foaming agent from the injection molding device to fill the volume of the mold cavity, so that the product is stably prepared.
According to the injection molding system and method for the thermoplastic resin product, the control device controls the high-pressure gas injection device to establish a positive pressure of 0.5-10 Mpa in the mold cavity, so that a homogeneous solution of the molten resin/foaming agent can stably fill the mold cavity in a uniform pressure state and control the cavity filling speed; after 80-90% of the volume of the mold cavity is filled with the homogeneous solution of the molten resin/foaming agent, the control device controls the vacuumizing device to vacuumize the mold cavity, so that the discharge speed of gas in the mold cavity is accelerated, the influence on the filling speed and the speed adjusting range of the homogeneous solution of the molten resin/foaming agent is reduced, and the surface of the prepared product is full and smooth and has no foaming defect.
Drawings
FIG. 1 is a schematic view showing the overall configuration of an injection molding system for thermoplastic resin articles according to an embodiment of the present invention.
FIG. 2 is a schematic view showing the steps of the injection molding method of the thermoplastic resin article according to the embodiment of the present application.
Description of reference numerals: 10. an injection molding device; 20. a mold; 21. a front mold; 22. a rear mold; 23. a mold cavity; 24. a gap; 30. a high-pressure gas injection device; 31. a high pressure gas source; 32. a pressure control valve group; 33. a second stop valve; 40. a vacuum pumping device; 41. a first shut-off valve; 42. a vacuum tank group; 43. a vacuum pump; 44. a one-way valve; 51. a first sensor; 52. a second sensor; 60. and a control device.
Detailed Description
The present application is described in further detail below with reference to figures 1-2.
Referring to fig. 1, an injection molding system for thermoplastic resin articles includes an injection molding device 10, a mold 20, a high-pressure gas injection device 30, a vacuum pumping device 40, and a control device 60.
Wherein the injection molding apparatus 10 is connected to a mold 20 for injecting a homogeneous solution of molten resin/blowing agent into the mold 20. The mold 20 is provided with a gap 24 communicating with the mold cavity 23, and a high-pressure gas injection device 30 is connected to the gap 24 for injecting high-pressure gas into the mold cavity 23. A vacuum-pumping device 40 is also connected to the mold 20 at the gap 24 for rapidly evacuating the high-pressure gas from the mold cavity 23. The control device 60 is connected to the injection device 10, the high-pressure gas injection device 30, and the vacuum extractor 40, respectively, and the control device 60 is configured to control the high-pressure gas injection device 30 to inject the high-pressure gas into the mold cavity 23 and control the vacuum extractor 40 to extract the high-pressure gas from the mold cavity 23.
The injection molding device 10 comprises an injection molding machine driving mechanism and an injection molding screw, wherein the injection molding machine driving mechanism is respectively connected with the injection molding screw and used for controlling the injection molding screw to inject the homogeneous solution of the molten resin/the foaming agent into the mold cavity 23, and the control device 60 can determine the volume of the homogeneous solution of the molten resin/the foaming agent injected into the mold cavity 23 according to the position of the injection molding screw by feeding back the position of the injection molding screw to the control device 60.
The mold 20 may include, for example, a front mold 21 and a rear mold 22, the front mold 21 and the rear mold 22 may form a mold cavity 23 after being closed, grooves may be formed in opposite side surfaces of the front mold 21 and the rear mold 22, respectively, and when the front mold 21 and the rear mold 22 are closed, the grooves in the front mold 21 and the grooves in the rear mold 22 may jointly form a gap 24. A gate is provided in the front mold 21, and the injection molding device 10 can communicate with the mold cavity 23 through the gate.
The material of the mold 20 may be corrosion-resistant steel including, but not limited to, P-20 steel, H-13 steel and S-7 steel, and A-2 steel, D-2 steel or M-2 steel having a higher corrosion resistance may be embedded at the gate of the mold 20.
In order to facilitate the connection between the high-pressure gas injection device 30 and the vacuum extractor 40 and the gap 24, a joint may be disposed at the gap 24, the joint is hermetically connected to the gap 24, a common pipeline is connected to the joint, the high-pressure gas injection device 30 and the vacuum extractor 40 may be connected to the common pipeline, and high-pressure gas is injected into the mold cavity 23 or high-pressure gas in the mold cavity 23 is extracted through the common pipeline.
The control device 60 may be a PLC controller, and before the injection device 10 injects the homogeneous solution of the molten resin/foaming agent into the mold cavity 23, the control device 60 controls the high-pressure gas injection device 30 to inject the high-pressure gas into the mold cavity 23, so that the pressure in the mold cavity 23 reaches 0.5-10 Mpa, and thus the homogeneous solution of the molten resin/foaming agent can be stably filled into the mold cavity 23 under a certain pressure state, and the speed of filling the homogeneous solution of the molten resin/foaming agent into the mold cavity 23 can be controlled by adjusting the pressure in the mold cavity 23.
The high-pressure gas injection device 30 may include a high-pressure gas source 31, a pressure control valve group 32, and a second stop valve 33 sequentially connected in the high-pressure gas injection direction, the second stop valve 33 is connected to the common line, both the pressure control valve group 32 and the second stop valve 33 are connected to the control device 60, the control device 60 may adjust the pressure of the high-pressure gas injected into the mold cavity 23 by controlling the pressure control valve group 32, and control the volume of the high-pressure gas injected into the mold cavity 23 by controlling the second stop valve 33, and a person skilled in the art may configure the control device 60 according to experience, so that the control device 60 controls the pressure control valve group 32 and the second stop valve 33, so that the pressure of the high-pressure gas injected into the mold cavity 23 reaches 0.5 to 10 Mpa.
A second pressure sensor can be further arranged on the mold 20 and used for detecting the pressure in the mold cavity 23, and the control device 60 is connected with the second pressure sensor, so that the pressure value feedback of the detection of the second pressure sensor can be used for controlling the pressure control valve group 32 and the second stop valve 33, and the pressure of the high-pressure gas injected into the mold cavity 23 reaches 0.5-10 Mpa.
In a specific example, before injecting the homogeneous solution of the molten resin/the foaming agent into the mold cavity 23, the control device 60 controls the second stop valve 33 to open and controls the pressure control valve set 32 to inject the nitrogen gas into the mold cavity, when the pressure value fed back by the second pressure sensor reaches 3Mpa, the control device 60 controls the second stop valve 33 to close, and then the injection molding machine driving mechanism is started, and the injection molding screw is controlled by the injection molding machine driving mechanism to act so as to inject the homogeneous solution of the molten resin/the foaming agent with a preset volume into the mold cavity 23. In the process of injecting the homogeneous solution of the molten resin/the foaming agent, when the pressure value fed back by the second pressure sensor is less than 3Mpa, the control device 60 controls the second stop valve 33 to be opened briefly to supplement high-pressure nitrogen gas into the mold cavity 23, so as to control the gas pressure in the cavity to be 3 Mpa.
When the control device 60 controls the high-pressure gas injection device 30 to inject the high-pressure gas into the mold cavity 23, the high-pressure gas injection into the mold cavity 23 may be stopped after the high-pressure gas of 0.5 to 10Mpa is directly injected into the mold cavity 23; or continuously injecting high-pressure gas into the mold cavity 23 to stabilize the gas pressure in the mold cavity 23 at 0.5-10 Mpa.
After the pressure in the mold cavity 23 reaches 0.5-10 Mpa, the injection device 10 injects the homogeneous solution of the molten resin/the foaming agent into the mold cavity 23, and it should be noted that the control device 60 can control the volume ratio of the injected homogeneous solution of the molten resin/the foaming agent in the mold cavity 23 when controlling the injection device 10 to inject the homogeneous solution of the molten resin/the foaming agent into the mold cavity 23.
For example, the volume of the mold cavity 23 can be known after the mold 20 is molded, and when the volume ratio of the homogeneous solution of the molten resin/the foaming agent in the mold cavity 23 needs to be detected, the moving distance of the injection screw is only needed to be detected, and then the volume of the homogeneous solution of the molten resin/the foaming agent injected into the mold cavity 23 can be determined through the moving distance of the injection screw.
After the volume of the mold cavity 23 filled with the homogeneous solution of the molten resin/foaming agent reaches 80-90%, the high-pressure gas in the mold cavity 23 needs to be discharged from the gap 24, the aperture of the gap 24 is usually 0.01-0.03 mm, and if the gap of the gap 24 is enlarged, the homogeneous solution of the molten resin/foaming agent enters the gap 24 in the process of exhausting, so that the appearance of the product is affected, the gap 24 is blocked, and the high-pressure gas in the mold cavity 23 cannot be discharged when the injection product is molded again. Since the gap of the gap 24 is small, the gas is exhausted slowly, which causes many disadvantages, and therefore, the vacuum apparatus 40 is required to rapidly exhaust the high-pressure gas in the mold cavity 23.
After the volume of the homogeneous solution of the molten resin/foaming agent filled in the mold cavity 23 reaches 80-90%, the control device 60 controls the vacuum-pumping device 40 to perform vacuum-pumping treatment on the mold cavity 23 until the homogeneous solution of the molten resin/foaming agent fills the mold cavity 23.
The vacuum pumping device 40 may include a first cut-off valve 41, a vacuum tank group 42, and a vacuum pump 43 connected in sequence along a direction in which the high-pressure gas in the mold cavity 23 is discharged, wherein the first cut-off valve 41 is connected to the common line, and the control device 60 controls the first cut-off valve 41 to be opened and the vacuum pump 43 to be opened during the vacuum pumping process so as to perform the vacuum pumping process on the mold cavity 23, so that the high-pressure gas in the mold cavity 23 is completely discharged.
Since there is a short delay when the vacuum pump 43 is turned on until it can pump the high-pressure gas in the mold cavity 23, in order to avoid that the high-pressure gas in the mold cavity 23 cannot be discharged in time due to the delay, the vacuum tank group 42 may be configured in a negative pressure state in advance to ensure that the high-pressure gas in the mold cavity 23 can be pumped out in time at the moment when the first shut-off valve 41 is turned on.
For example, the control device 60 may control the vacuum pump 43 to continue operating to vacuumize the vacuum tank group 42 after controlling the first shut-off valve 41 to be closed, so that the vacuum tank group 42 becomes a negative pressure state. Alternatively, the pressure within the vacuum tank bank 42 may be between-0.05 and-0.03 Mpa.
Specifically, a first pressure sensor may be disposed on the vacuum tank group 42, the first pressure sensor is used for detecting the pressure inside the vacuum tank group 42 and is connected to the control device 60, and the control device 60 may control the vacuum pump 43 to perform the vacuum pumping process on the vacuum tank group 42 according to the pressure value fed back by the first pressure sensor.
Note that, the size of the cavity differs for different molds, and the negative pressure required for evacuation treatment differs for different molds, for example, when the mold cavity 23 has a large volume, a large negative pressure is required, and in this case, the mold cavity 23 can be evacuated by using a large number of vacuum tanks in the vacuum tank group 42, whereas the mold cavity 23 can be evacuated by using a small number of vacuum tanks in the vacuum tank group 42.
A check valve 44 may be further provided between the vacuum tank group 42 and the vacuum pump 43, so that the gas in the vacuum tank group 42 can only flow in one direction to the vacuum pump 43, and cannot flow in the vacuum tank group 42 in the opposite direction.
The vacuumizing device 40 is used for vacuumizing the mold cavity 23, so that the gas discharge speed in the mold cavity 20 is accelerated after the volume of the molten resin/foaming agent homogeneous solution filled in the mold cavity 23 reaches 80-90%, the influence on the filling speed and the speed adjusting range of the molten resin/foaming agent homogeneous solution is reduced, the foaming rate of a product is high, the weight reduction effect is good, the surface of the prepared product is full and smooth, the foaming defect is avoided, the injection speed can be controlled sensitively when a plurality of products with large sizes are manufactured, and the product with stable quality is prepared.
In another aspect, the present application also provides an injection molding method of a thermoplastic resin article based on the above injection molding system of a thermoplastic resin article.
Referring to fig. 2, the method comprises the steps of:
step 210, before injecting the homogeneous solution of the molten resin/foaming agent into the mold cavity 23, the control device 60 controls the high-pressure gas injection device 30 to inject the high-pressure gas into the mold cavity 23, so that the pressure in the mold cavity 23 reaches 0.5-10 Mpa.
Step 220, after the volume of the homogeneous solution of the molten resin/foaming agent filled in the mold cavity 23 reaches 80-90%, the control device 60 controls the vacuum-pumping device 40 to perform vacuum-pumping treatment on the mold cavity 23 until the homogeneous solution of the molten resin/foaming agent fills the mold cavity 23.
In some embodiments, step 220 specifically includes the following steps:
in step 2201, the control device 60 controls the first stop valve 41 to be opened and the vacuum pump 43 to be opened, so as to perform the vacuum process on the mold cavity 23.
Step 2202, after the homogeneous solution of the molten resin/the foaming agent is filled in the mold cavity 23, the control device 60 controls the first stop valve 41 to be closed, and controls the vacuum pump 43 to continue to vacuumize the vacuum tank set 42, so that the pressure in the vacuum tank set 42 reaches-0.05 to-0.03 Mpa.
In some embodiments, step 210 specifically includes the following steps:
the control device 60 controls the second shut-off valve 33 to open so that the high-pressure gas in the high-pressure gas source 31 is injected into the mold cavity 23.
In some embodiments. The injection molding method of the thermoplastic resin article further comprises the steps of:
the second pressure sensor detects the pressure in the mold cavity 23 and feeds back the pressure value to the control device 60.
In some embodiments. The injection molding method of the thermoplastic resin article further comprises the steps of:
the control apparatus 60 obtains the volume of the homogeneous solution of molten resin/blowing agent filling the mold cavity 23 from the injection apparatus 10.
It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working process of the described method may refer to the corresponding process in the foregoing system embodiment, and is not described herein again.
The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (10)
1. An injection molding system for thermoplastic resin articles, comprising:
the injection molding device comprises an injection molding device (10), a mold (20) which is connected with the injection molding device (10) and is provided with a mold cavity (23), a gap (24) which is arranged on the mold (20) and is communicated with the mold cavity (23), a high-pressure gas injection device (30) and a vacuum device (40) which are connected with the gap (24), and a control device (60) which is respectively connected with the injection molding device, the high-pressure gas injection device (30) and the vacuum device (40);
the control device (60) is used for,
controlling the injection molding device (10) to inject a homogeneous solution of molten resin/foaming agent into the mold cavity (23);
before injecting a homogeneous solution of a molten resin/foaming agent into the mold cavity (23), controlling the high-pressure gas injection device (30) to inject high-pressure gas into the mold cavity (23) so that the pressure in the mold cavity (23) reaches 0.5-10 Mpa;
after the 80-90% volume of the mold cavity (23) is filled with the homogeneous solution of the molten resin/foaming agent, controlling the vacuumizing device (40) to vacuumize the mold cavity (23) until the homogeneous solution of the molten resin/foaming agent fills the mold cavity (23).
2. The system according to claim 1, wherein the vacuum pumping device (40) comprises a first stop valve (41), a vacuum tank set (42) and a vacuum pump (43) which are connected in sequence along the discharging direction of the high-pressure gas in the mold cavity (23), a first pressure sensor is arranged on the vacuum tank set (42), and the control device (60) is respectively connected with the first stop valve (41), the first pressure sensor and the vacuum pump (43);
the control device (60) is used for,
after the homogeneous solution of the molten resin/foaming agent fills 80-90% of the volume of the mold cavity (23), controlling the first stop valve (41) to be opened and the vacuum pump (43) to be opened so as to vacuumize the mold cavity (23);
after the homogeneous solution of the molten resin/foaming agent is filled in the mold cavity (23), the first stop valve (41) is controlled to be closed, and the vacuum pump (43) is controlled to continue vacuumizing the vacuum tank set (42), so that the pressure in the vacuum tank set (42) reaches-0.05 to-0.03 MPa.
3. The system according to claim 1, characterized in that said high-pressure gas injection means (30) comprise a high-pressure gas source (31), a pressure control valve group (32) and a second stop valve (33) connected in sequence along said high-pressure gas injection direction, said pressure control valve group (32) and said second stop valve (33) being connected to said control means (60);
the control device (60) is used for controlling the second stop valve (33) to be opened before homogeneous phase solution of molten resin/foaming agent is injected into the mold cavity (23), so that high-pressure gas in the high-pressure gas source (31) is injected into the mold cavity (23), and the pressure in the mold cavity (23) reaches 0.5-10 Mpa.
4. The system according to claim 1, characterized in that it further comprises a second pressure sensor arranged on the mould (20) and connected to the control device (60) for detecting the pressure inside the mould cavity (23) and feeding back the pressure value to the control device (60).
5. The system according to claim 1, wherein the control device (60) is adapted to obtain signals from the injection molding device (10) to determine the volume of the homogeneous solution of molten resin/blowing agent filling the mold cavity (23).
6. An injection molding method of a thermoplastic resin article based on the injection molding system of a thermoplastic resin article according to any one of claims 1 to 5, characterized by comprising:
before injecting homogeneous solution of molten resin/foaming agent into the mold cavity (23), the control device (60) controls the high-pressure gas injection device (30) to inject high-pressure gas into the mold cavity (23), so that the pressure in the mold cavity (23) reaches 0.5-10 Mpa;
after 80-90% of the volume of the mold cavity (23) is filled with the homogeneous solution of the molten resin/foaming agent, the control device (60) controls the vacuumizing device (40) to vacuumize the mold cavity (23) until the homogeneous solution of the molten resin/foaming agent fills the mold cavity (23).
7. The method of claim 6, wherein the controlling means (60) controls the evacuating means (40) to evacuate the mold cavity (23) until the homogeneous solution of molten resin/blowing agent fills the mold cavity (23), comprising:
the control device (60) controls the first stop valve (41) to be opened and the vacuum pump (43) to be opened so as to vacuumize the mold cavity (23);
after the homogeneous solution of the molten resin/the foaming agent is filled in the die cavity (23), the control device (60) controls the first stop valve (41) to be closed, and controls the vacuum pump (43) to continue to vacuumize the vacuum tank (42), so that the pressure in the vacuum tank (42) reaches-0.05 to-0.03 MPa.
8. The method according to claim 6, wherein the control device (60) controls the high-pressure gas injection device (30) to inject the high-pressure gas into the mold cavity (23), including:
the control device (60) controls the second stop valve (33) to be opened, so that the high-pressure gas in the high-pressure gas source (31) is injected into the mold cavity (23).
9. The method of claim 6, further comprising:
the second pressure sensor detects the pressure in the mold cavity (23) and feeds back the pressure value to the control device (60).
10. The method of claim 6, further comprising:
a control device (60) obtains from the injection device (10) a volume at which the homogeneous solution of molten resin/blowing agent fills the mold cavity (23).
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1383397A (en) * | 2000-06-14 | 2002-12-04 | 旭化成株式会社 | Method of injection molding of thermoplastic resin |
| CN1484576A (en) * | 2000-12-27 | 2004-03-24 | ������������ʽ���� | Foam injection molding method |
| CN101028739A (en) * | 2006-02-27 | 2007-09-05 | 北京中拓机械有限责任公司 | Air-auxiliary injection forming process of thermoplastic resin product |
| CN101495291A (en) * | 2006-06-01 | 2009-07-29 | 先进塑料技术卢森堡有限公司 | Plastic multi-piece containers and methods and systems of making same |
| CN103386729A (en) * | 2013-07-25 | 2013-11-13 | 延锋伟世通汽车饰件系统有限公司 | Method for improving appearance of injection molded foaming product |
| CN203974001U (en) * | 2014-04-30 | 2014-12-03 | 青岛海信模具有限公司 | Molding mold cavity control pressurer system |
| CN105690698A (en) * | 2016-04-27 | 2016-06-22 | 山东大学 | Injection mold and control system and method for controlling pressure of mold cavity |
| CN108189308A (en) * | 2017-12-28 | 2018-06-22 | 上汽通用五菱汽车股份有限公司 | A kind of mould embeds film decoration chemistry foam injection molding technique |
| CN108859044A (en) * | 2017-05-09 | 2018-11-23 | 临沂大学 | Negative pressure chemical blowing injection molding forming method |
| CN109849257A (en) * | 2018-12-29 | 2019-06-07 | 山东大学 | A method of it promoting injection foaming and forms plastic surface quality |
-
2021
- 2021-02-19 CN CN202110188767.1A patent/CN112959594A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1383397A (en) * | 2000-06-14 | 2002-12-04 | 旭化成株式会社 | Method of injection molding of thermoplastic resin |
| CN1484576A (en) * | 2000-12-27 | 2004-03-24 | ������������ʽ���� | Foam injection molding method |
| CN101028739A (en) * | 2006-02-27 | 2007-09-05 | 北京中拓机械有限责任公司 | Air-auxiliary injection forming process of thermoplastic resin product |
| CN101495291A (en) * | 2006-06-01 | 2009-07-29 | 先进塑料技术卢森堡有限公司 | Plastic multi-piece containers and methods and systems of making same |
| CN103386729A (en) * | 2013-07-25 | 2013-11-13 | 延锋伟世通汽车饰件系统有限公司 | Method for improving appearance of injection molded foaming product |
| CN203974001U (en) * | 2014-04-30 | 2014-12-03 | 青岛海信模具有限公司 | Molding mold cavity control pressurer system |
| CN105690698A (en) * | 2016-04-27 | 2016-06-22 | 山东大学 | Injection mold and control system and method for controlling pressure of mold cavity |
| CN108859044A (en) * | 2017-05-09 | 2018-11-23 | 临沂大学 | Negative pressure chemical blowing injection molding forming method |
| CN108189308A (en) * | 2017-12-28 | 2018-06-22 | 上汽通用五菱汽车股份有限公司 | A kind of mould embeds film decoration chemistry foam injection molding technique |
| CN109849257A (en) * | 2018-12-29 | 2019-06-07 | 山东大学 | A method of it promoting injection foaming and forms plastic surface quality |
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Application publication date: 20210615 |