CN-117162383-B - Injection molding method of carbon fiber/silicone resin composite material

Abstract

The patent relates to an injection molding method of a carbon fiber/silicone resin composite material, which comprises the steps of performing foam removal treatment on a sizing material for multiple times by using a vacuum pump, maintaining a vacuum environment in a mold, injecting the sizing material into the mold under the injection pressure of 0.12-0.18MPa, removing the vacuum condition when the glue injection amount reaches 40-70% of the capacity of the mold, closing corresponding valves until all the sizing material overflows when the sizing material overflows from a sizing material outlet of the mold, maintaining the glue injection pressure after closing all the sizing material outlet valves, opening one sizing material outlet valve for foam removal, closing a ball valve without foam removal, performing the same operation on adjacent sizing material outlet valves until foam removal is performed on all the sizing material outlet ball valves, and closing all the sizing material outlet valves for pressure maintaining treatment. Compared with the whole-process vacuum maintenance, the partial vacuum maintenance can more effectively reduce the occurrence of air hole glue shortage defects, obviously improve the apparent quality of the molded test piece and also obviously improve the internal quality of the test piece.

Inventors

• XIAO YONG
• Jiang Xunhui
• Chen Kunwen
• XIONG YI
• CHEN HAIYA
• ZHOU CHAO
• MA BAOHE
• XU CHUANGXIN
• LI YANG
• LI KAI
• ZHANG FEIFEI

Assignees

• 湖北航聚科技股份有限公司

Dates

Publication Date

20260512

Application Date

20230824

Claims (8)

1. 1. An injection molding method of a carbon fiber/silicone composite material, comprising the steps of: S1, performing multiple defoaming treatment on sizing materials by using a vacuum pump; s2, maintaining a vacuum environment in the mold, injecting glue into the mold, and removing the vacuum condition when the glue injection amount reaches 40-70% of the capacity of the mold, wherein a glue outlet of the mold is provided with a valve, and when the glue outlet of the mold overflows, the corresponding valve is closed until all glue outlets overflow glue; And S3, maintaining the glue injection pressure after closing all the glue outlet valves, then opening one of the glue outlet valves for discharging bubbles until no bubbles are discharged, closing the ball valve without bubble discharge, performing the same operation on the adjacent glue outlet valves until all the glue outlet ball valves are discharged, and closing all the glue outlet valves for pressure maintaining treatment.
2. 2. The injection molding method of a carbon fiber/silicone composite material according to claim 1, wherein in the step S3, the injection pressure is maintained for 10-20min after all the glue outlet valves are closed.
3. 3. The injection molding method of a carbon fiber/silicone composite material according to claim 1, wherein the pressure maintaining treatment in the step S3 is performed for a time of 10 to 20 mm.
4. 4. The injection molding method of a carbon fiber/silicone composite material according to claim 1, further comprising the step of curing at 130-170 ℃ for 2-5 hours and then demolding.
5. 5. The method for injection molding of a carbon fiber/silicone composite material according to claim 1, wherein the valve of the glue outlet is a ball valve, and the ball valve is in threaded connection with the glue outlet.
6. 6. The injection molding method of a carbon fiber/silicone composite material according to claim 1, wherein in the step S2, the vacuum degree in the mold is maintained at-0.50 to-0.90 bar.
7. 7. The method of injection molding a carbon fiber/silicone composite material according to claim 1, wherein the sizing material comprises a phenyl vinyl silicone and a platinum catalyst.
8. 8. A carbon fiber/silicone composite material, characterized by being produced by the injection molding method of claim 4.

Description

Injection molding method of carbon fiber/silicone resin composite material Technical Field The patent relates to the technical field of resin composite materials, in particular to an injection molding method of a carbon fiber/silicone resin composite material. Background In recent years, the aerospace field is developed faster and faster, the period of upgrading and updating the solid rocket engine is shorter and shorter, but the used heat insulation material is not correspondingly updated along with the upgrading and updating of the solid rocket engine. The high-temperature ablation resistance of the heat insulating material in the solid rocket engine has extremely high requirements, and is related to whether the solid rocket engine can successfully launch. The heat insulating material has large sealing head ratio, high cost and high temperature scouring resistance, and adopts a method of reinforcing the composite material to improve the ablation resistance of the sealing head. The composite material is a novel material with the characteristics of high specific strength, specific modulus, low density, customizable design and the like, and is widely applied to the fields of aerospace, automobile manufacturing, medical appliances and the like. The composite material mainly comprises a matrix material and a reinforcement body, wherein the matrix material is divided into a resin matrix, a metal matrix and a ceramic matrix. At present, the resin matrix composite is widely applied in the aerospace field. Silicon resin is used as a continuous phase, and carbon fiber is used as a composite material of a reinforcing material, which is already applied to the aerospace field and is used as a special material for high-temperature ablation resistance. However, the formation of the silicone resin/carbon fiber composite material often has defects such as glue shortage and air holes, and the mechanical property, the ablation property and the stability are obviously reduced. How to reduce the air hole and glue shortage of the silicon resin/carbon fiber composite material is still a problem to be solved. Disclosure of Invention The invention provides a method for preparing a silicon resin/carbon fiber composite material by using a partial vacuum assisted injection molding method, which reduces the generation of air holes in the composite material by partially introducing vacuum conditions in the injection process. The invention adopts the technical scheme that the injection molding method of the carbon fiber/silicone resin composite material comprises the following steps: S1, performing multiple defoaming treatment on sizing materials by using a vacuum pump; s2, maintaining a vacuum environment in the mold, injecting glue into the mold at the injection pressure of 0.12-0.18MPa, removing the vacuum condition when the glue injection amount reaches 40-70% of the capacity of the mold, and closing the corresponding valve when the glue at the glue outlet of the mold overflows until all the glue at the glue outlet overflows; And S3, maintaining the glue injection pressure after closing all the glue outlet valves, then opening one of the glue outlet valves for discharging bubbles until no bubbles are discharged, closing the ball valve without bubble discharge, performing the same operation on the adjacent glue outlet valves until all the glue outlet ball valves are discharged, and closing all the glue outlet valves for pressure maintaining treatment. Further, in the step S3, the glue injection pressure is maintained for 10-20min after all the glue outlet valves are closed. Further, the pressure maintaining treatment time in the step S3 is 10-20 mm. Further, the method also comprises a step S4 of curing for 2-5 hours at 130-170 ℃ and then demolding. Further, the glue outlet valve is characterized in that a ball valve is adopted, and the ball valve is connected to the glue outlet through threads. Further, in the step S2, the vacuum degree in the mold is maintained at-0.50 to-0.90 bar. Further, the sizing comprises phenyl vinyl silicone and a platinum catalyst. The invention also provides a carbon fiber/silicone resin composite material which is prepared by the preparation method. Compared with the prior art, the invention has the following advantages and beneficial effects: The problem of the sample glue-lacking air holes can be improved by vacuum assistance in the conventional injection molding, but the invention discovers that the problem of the glue-lacking air holes cannot be completely solved by the whole-course vacuum assistance in the process of injecting glue into a mold, and compared with the whole-course maintenance of the vacuum condition, the generation of the air hole glue-lacking defect can be effectively reduced by partially maintaining the vacuum condition, namely, the vacuum is maintained in the first half section of the injection process, the vacuum condition is removed in the second half section, the apparent quali