CN114074438A - Method for improving injection molding defects of thermosetting composite material - Google Patents
Method for improving injection molding defects of thermosetting composite material Download PDFInfo
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- CN114074438A CN114074438A CN202110297460.5A CN202110297460A CN114074438A CN 114074438 A CN114074438 A CN 114074438A CN 202110297460 A CN202110297460 A CN 202110297460A CN 114074438 A CN114074438 A CN 114074438A
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- resin
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- injection molding
- thermosetting composite
- composite material
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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
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/40—Shaping or impregnating by compression not applied
- B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
- B29C70/46—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
- B29C70/48—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM], e.g. by vacuum
Abstract
The invention discloses a method for improving the injection molding defects of a thermosetting composite material. According to the method for improving the injection molding defects of the thermosetting composite material, the required total resin amount is injected into the molding die at intervals in batches, so that the shrinkage defects of the surface of a product in a reserved hole area caused by the solidification of the resin in an injection hole can be effectively prevented, the apparent quality of a thermosetting composite material product is effectively improved, and the molding quality of the product is improved.
Description
Technical Field
The invention relates to the technical field of injection molding, in particular to a method for improving injection molding defects of a thermosetting composite material.
Background
The HP-RTM (high pressure resin transfer molding) process is an RTM process technology that has been introduced in recent years for the production of high performance thermoset composite parts. The resin impregnation and curing process is completed under high pressure by adopting the process methods of preforming, steel molding, vacuum-assisted exhaust, high-pressure injection and the like, and low-cost, short-period (large-batch) and high-quality production is realized.
In the prior art, for a thermosetting composite material part produced by adopting an HP-RTM process, a reserved hole is usually designed in the middle of a used high-pressure RTM mold for placing an injection head, and a heating runner inside the mold cannot completely penetrate through the reserved hole area, so that the temperature of the area is lower than that of other areas, and the mold has a temperature gradient difference, as shown in fig. 1. The temperature of the reserved hole area of the mold is low, and the flowing principle of high-pressure injection resin is added, so that the curing direction of the resin in the mold spreads from the periphery to the injection port, as shown in fig. 2, the resin in the injection port is the fresest, the last cured resin, and the curing of the part of resin can absorb the resin in the part of the product area, so that the surface of the product in the peripheral area of the reserved hole generates shrinkage defects, as shown in fig. 3, and the appearance quality of the product is influenced.
Disclosure of Invention
The invention mainly solves the technical problem of providing a method for improving the injection molding defects of thermosetting composite materials, which can solve the defects in the prior art and improve the apparent quality of injection molded products.
In order to solve the technical problems, the invention adopts a technical scheme that: the method for improving the injection molding defects of the thermosetting composite material is characterized by calculating the total amount of required resin according to the size of the thermosetting composite material to be molded, injecting the required resin into a molding die at intervals for multiple times, and curing to obtain the finished thermosetting composite material.
In a preferred embodiment of the invention, the number of resin injections is two.
In a preferred embodiment of the invention, the resin is injected twice, one injection and two injections respectively.
In a preferred embodiment of the present invention, the injection amount of one injection is 90-98% of the total amount of the required resin.
In a preferred embodiment of the present invention, the injection amount of one injection is 94.2 to 97.5% of the total amount of the required resin.
Through the selection design of the primary injection amount and the secondary injection amount, on one hand, the effective curing molding of the thermosetting composite material is ensured, and on the other hand, the shrinkage of the thermosetting composite material in the reserved hole area caused by the curing of the resin in the injection hole can be effectively counteracted by the fresh resin amount of the secondary injection, so that the defect that the injection molding part generates surface shrinkage is avoided.
In a preferred embodiment of the invention, the time interval between the first injection and the second injection is the gel time of the resin at the curing temperature. The setting of this gel time, on the one hand guarantee the normal gel solidification of other regional resin in the mould, on the other hand makes the resin of reservation hole department not totally gel, can solidify with the fresh resin of secondary injection together, forms unified whole.
In a preferred embodiment of the present invention, the flow rate of the resin for the first injection and the flow rate of the resin for the second injection are both 50 to 70 g/s.
In a preferred embodiment of the present invention, the total amount of the resin is a product of a resin density and 0.4 to 0.5 times a volume of the molding die. The design of the resin amount ensures that the resin can be completely filled, and prevents resource waste caused by excessive resin.
The invention has the beneficial effects that: according to the method for improving the injection molding defects of the thermosetting composite material, the required total resin amount is injected into the molding die at intervals in batches, so that the shrinkage defects of the surface of a product in a reserved hole area caused by the solidification of the resin in an injection hole can be effectively prevented, the apparent quality of a thermosetting composite material product is effectively improved, and the molding quality of the product is improved.
Drawings
FIG. 1 is a schematic diagram of temperature gradient variation of an upper mold of a high pressure RTM mold;
FIG. 2 is a schematic view of the resin curing direction of the inside of the mold progressing from the periphery toward the injection port and shrinking areas;
FIG. 3 is a schematic illustration of the resin curing inside the injection port causing shrinkage of the product surface;
FIG. 4 is a partial view of an ultrasonic inspection type A of a thermosetting carbon fiber door jamb according to a preferred embodiment of the invention 4;
fig. 5 is a partial view of a B-shaped ultrasonic inspection of a thermosetting carbon fiber door edge rail of an aircraft prepared according to a preferred embodiment 4 of the invention.
Detailed Description
The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the invention.
Referring to fig. 1-5, an embodiment of the present invention includes:
example 1
A method for improving injection molding defects of a thermosetting carbon fiber aircraft door edge beam includes calculating a 3D model to obtain a required molding die with a volume of 6010cm3。
Adopting the epoxy resin with the brand number of Araldite LY 3585 as the A component, adopting the epoxy resin with the brand number of Aradur 3475 as the B component, mixing the A component and the B component according to the proportion to form the mixture with the density of 1.1g/cm3The mixed resin of (3) as an injection resin.
The total amount of the epoxy resin required by debugging is calculated to be 2975g according to the product of the resin density and 0.45 time of the volume of the forming die, then injection is carried out, 2975g of mixed resin is completely injected into the forming die which is preheated to the forming temperature of 110 ℃ at the flow rate of 50g/s, constant-temperature curing is carried out for 270s, die opening is carried out, and the obtained thermosetting carbon fiber airplane door edge beam surface has obvious shrinkage defects.
Example 2
The difference from the embodiment 1 is that 2800g of mixed resin (94.2 percent of the total mass of the resin) is injected into a forming die which is preheated to the forming temperature of 110 ℃ at the flow rate of 50g/s, the temperature is kept for 60s, then secondary injection is carried out, namely 175g of mixed resin is continuously injected into the forming die at the flow rate of 50g/s, the curing is continuously carried out for 270s, the die is opened after the curing and forming, and the shrinkage defect of the injection port area of the thermosetting carbon fiber airplane door side beam is improved compared with that of the primary injection forming.
Example 3
The difference from the example 1 is that 2850g of mixed resin (accounting for 95.8 percent of the total mass of the resin) is injected into a forming die which is preheated to the forming temperature of 110 ℃ at the flow rate of 50g/s, the temperature is kept constant for 60s, then secondary injection is carried out, namely 125g of mixed resin is continuously injected into the forming die at the flow rate of 50g/s, the curing is continued for 270s, the die is opened after the curing and forming, and the shrinkage defect of the injection port area of the obtained thermosetting carbon fiber airplane door side beam still exists, but the defect is improved compared with the example 2.
Example 4
The difference from example 3 is that the injection amount of the one-shot injection was 2900g of the mixed resin, accounting for 97.5% of the total mass of the desired resin, and the amount of the two-shot injection was 75g of the mixed resin.
The thermosetting carbon fiber airplane door edge beam prepared by the embodiment has the advantages of flat and smooth surface, no shrinkage defect at the glue injection port and good appearance quality.
The aircraft door jamb prepared in example 4 was subjected to ultrasonic non-destructive testing according to the standard GJB 1038.1 a.
The detection method is a direct incidence contact type pulse reflection method;
the information of the detection equipment used is: the device model is OMNI SCAN X3; the probe model is 5L 64-64X 7-NW 1-P-2.5-OM;
the coupling agent is water;
and (3) sensitivity adjustment: the bottom surface echo of the optimal region reaches 80 percent;
the scanning sensitivity was 18 dB.
And (3) displaying a detection result: and (3) carrying out ultrasonic nondestructive detection on the scannable region of the workpiece (except for the R angle, the resin-rich outer surface, the poor glue and the uneven region), and not finding the defects of layering, inclusion, dense pores and the like. The test patterns are shown in fig. 3 and 4.
The method for improving the injection molding defects of the thermosetting composite material has the following advantages:
the required total resin is injected into the forming die at intervals of more than two times, so that enough fresh resin can be supplemented to the reserved hole area, the shrinkage defect of the surface of a product in the reserved hole area caused by the solidification of the resin in the injection hole is prevented, the apparent quality of a thermosetting composite material product is effectively improved, and the product forming quality is improved.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.
Claims (8)
1. A method for improving the defect of injection molding of a thermosetting composite material is characterized in that the total amount of required resin is calculated according to the size of the thermosetting composite material to be molded, then the required resin is injected into a molding die at intervals for multiple times, and the finished thermosetting composite material is obtained after curing.
2. The method of improving injection molding defects in thermoset composite materials of claim 1, wherein the number of resin injections is two or more.
3. A method of ameliorating injection molding defects in thermoset composite materials as claimed in claim 3 wherein the resin is injected twice, one shot and two shots respectively.
4. The method for improving injection molding defects of thermosetting composite materials according to claim 3, wherein the injection amount of one injection is 90-98% of the total amount of the required resin.
5. The method for improving injection molding defects of thermosetting composite materials according to claim 4, wherein the injection amount of one injection is 94.2-97.5% of the total amount of the required resin.
6. A method of ameliorating injection molding defects in thermoset composite materials as claimed in claim 3 wherein the time interval between the primary and secondary injections is the gel time of the resin at the curing temperature.
7. The method for improving injection molding defects of thermosetting composite materials according to claim 3, wherein the resin flow rate of the primary injection and the resin flow rate of the secondary injection are both 50-70 g/s.
8. The method for improving injection molding defects of thermosetting composite materials according to claim 1, wherein the total amount of resin is the product of the resin density and 0.4-0.5 times the volume of the molding die.
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| CN202110297460.5A CN114074438A (en) | 2021-03-19 | 2021-03-19 | Method for improving injection molding defects of thermosetting composite material |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116176003A (en) * | 2023-02-23 | 2023-05-30 | 宁波丽成复合材料制品有限公司 | Fast forming and mass production manufacturing process for CFRP three-dimensional component |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1150560A (en) * | 1995-06-19 | 1997-05-28 | 艾因工程技术股份有限公司 | Reprocessed resin formed of thermoset resin foamed material, method for reprocessing thermoset resin foamed material and method for molding molded article formed of reprocessed resin |
| CN104175575A (en) * | 2014-08-18 | 2014-12-03 | 北京航空航天大学 | Whole-stepping (Resin Transfer Molding) RTM technology for large-sized composite material workpiece |
| CN104690876A (en) * | 2013-12-03 | 2015-06-10 | 康廷南拓结构塑料有限公司 | Resin transfer molding with rapid cycle time |
| CN105415711A (en) * | 2015-11-24 | 2016-03-23 | 南昌航空大学 | Method for manufacturing resin transfer molding (RTM) carbon fiber composite test blocks |
| CN105690697A (en) * | 2016-03-05 | 2016-06-22 | 苏州立创精密模具科技有限公司 | Injection molding method of battery shell grid baffle |
| CN109732866A (en) * | 2018-12-28 | 2019-05-10 | 太仓意欣智能科技有限公司 | A kind of more Shooting Technique one-step moulding methods for high tenacity home appliance panel |
| CN110239017A (en) * | 2019-05-31 | 2019-09-17 | 太仓市天丝利塑化有限公司 | A kind of high-performance electric appliance panel assembly and its production Shooting Technique |
| CN110240793A (en) * | 2019-05-31 | 2019-09-17 | 太仓市天丝利塑化有限公司 | A kind of environment-friendly type IMD operation panel and its in-mould injection moulding integrated process |
| CN111958933A (en) * | 2020-06-01 | 2020-11-20 | 海天塑机集团有限公司 | Injection molding self-adaptive compensation method based on melt viscosity fluctuation |
-
2021
- 2021-03-19 CN CN202110297460.5A patent/CN114074438A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1150560A (en) * | 1995-06-19 | 1997-05-28 | 艾因工程技术股份有限公司 | Reprocessed resin formed of thermoset resin foamed material, method for reprocessing thermoset resin foamed material and method for molding molded article formed of reprocessed resin |
| CN104690876A (en) * | 2013-12-03 | 2015-06-10 | 康廷南拓结构塑料有限公司 | Resin transfer molding with rapid cycle time |
| CN111571914A (en) * | 2013-12-03 | 2020-08-25 | 康廷南拓结构塑料有限公司 | Resin transfer molding with fast cycle time |
| CN104175575A (en) * | 2014-08-18 | 2014-12-03 | 北京航空航天大学 | Whole-stepping (Resin Transfer Molding) RTM technology for large-sized composite material workpiece |
| CN105415711A (en) * | 2015-11-24 | 2016-03-23 | 南昌航空大学 | Method for manufacturing resin transfer molding (RTM) carbon fiber composite test blocks |
| CN105690697A (en) * | 2016-03-05 | 2016-06-22 | 苏州立创精密模具科技有限公司 | Injection molding method of battery shell grid baffle |
| CN109732866A (en) * | 2018-12-28 | 2019-05-10 | 太仓意欣智能科技有限公司 | A kind of more Shooting Technique one-step moulding methods for high tenacity home appliance panel |
| CN110239017A (en) * | 2019-05-31 | 2019-09-17 | 太仓市天丝利塑化有限公司 | A kind of high-performance electric appliance panel assembly and its production Shooting Technique |
| CN110240793A (en) * | 2019-05-31 | 2019-09-17 | 太仓市天丝利塑化有限公司 | A kind of environment-friendly type IMD operation panel and its in-mould injection moulding integrated process |
| CN111958933A (en) * | 2020-06-01 | 2020-11-20 | 海天塑机集团有限公司 | Injection molding self-adaptive compensation method based on melt viscosity fluctuation |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116176003A (en) * | 2023-02-23 | 2023-05-30 | 宁波丽成复合材料制品有限公司 | Fast forming and mass production manufacturing process for CFRP three-dimensional component |
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