The introduction of Composite Autoclave

There are dozens of molding processes for carbon fiber composite materials, among which the autoclave process is the most widely used and the most common molding method.

Process principle

The carbon fiber prepreg is laid on the mold according to the layup requirements, and the blank is sealed in a vacuum bag and placed in a carbon fiber autoclave. Under the vacuum state, through the procedures of heating, pressurizing, heat preservation, cooling and decompression of the autoclave equipment, the uniform temperature and uniform pressure provided in the autoclave can be used to achieve curing, so that the surface and internal quality can be formed. Carbon fiber composite parts with complex shapes and huge areas.

Process development

The autoclave process is a process developed for the production of second-generation composite materials. It was formed in the 1940s and was gradually promoted and used until the 1960s. Later, it was widely used in aerospace, composite materials, electronics, weapons, etc. High-tech fields such as transportation, sports equipment and new energy, especially in the production of various skin parts, have played a huge role and have now become a mature technology. The composite products produced by the autoclave process account for more than 50% of the total composite product output, and the proportion in the aerospace field is as high as more than 80%. At present, the autoclave process, as one of the forming methods of carbon fiber composite components, is also widely used by many carbon fiber composite parts manufacturers.

Autoclave

Autoclave is a kind of process equipment according to the characteristics of polymer matrix composite materials molding process. Using autoclave molding is the main method of manufacturing continuous fiber reinforced thermosetting composite parts. It is suitable for advanced composite material structures, honeycomb sandwich structures and metal parts. Or in the molding of composite bonded structures. Generally, it has the advantages of high temperature and pressure control accuracy, safe and reliable structure, good system stability, low energy consumption, simple operation and maintenance, etc. It can realize modularization and serialization, and can meet the needs of different fields, different processes and different specifications.

Equipment composition

As a system equipment for the curing of carbon fiber composite materials, carbon fiber autoclave can realize sequential and real-time online control of process parameters such as temperature, pressure, vacuum, cooling, and circulation. The device includes the following components:

1. Overall structure: A high-pressure and high-temperature tank is formed by the tank body, the tank door mechanism, the high-temperature motor, and the air duct board insulation layer.

2. Safety interlocking device: It is composed of pressure automatic interlocking, manual interlocking and ultra-high pressure alarm device.

3. Quick-opening device: manual and electric dual-purpose quick-opening design, can open and close the tank door normally when the power is cut off;

4. Sealing device: The tank door is sealed with silica gel inflatable, which is resistant to high pressure.

5. Pressure system: The pressure transmission and control system is composed of compressor, gas storage tank, pressure control valve, pipeline, pressure transmitter and pressure gauge. The pressure in the tank can reach 1.5-2.5MPa, and the error is not more than 0.05 MPa, with safety explosion-proof device.

6. Heating system: It is composed of stainless steel electric heating pipe, high temperature fan, air duct plate, heat insulation layer and temperature control system. The heating power meets the requirements of the highest temperature of the cavity and the requirements of the heating rate.

7. Temperature circulation system: It consists of a circulating fan, a wind deflector, and a shroud, which accelerates the conduction and circulation of heat flow and forms a uniform temperature field.

8. Vacuum system: It is composed of vacuum pump, pipeline, vacuum gauge and vacuum valve, which provides vacuum conditions for the encapsulated composite material prefabricated parts, and requires multiple vacuum pipe joints to meet the forming process requirements.

9. Automatic control system: PLC control system is adopted to realize the whole process of high-precision control and real-time recording of process parameters such as pressure, temperature and cooling.

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