Vacuum infusion forming method for carbon fiber composite structure member

Abstract

The invention discloses a vacuum infusion forming method for a carbon fiber composite structure member. The method comprises the steps as follows: making a large-size carbon fiber composite wind power blade structure member by a vacuum infusion forming technology; bonding and fixing a guide net to a mould by a transparent double-sided tape for preventing deformation of carbon fiber fabrics due to deformation of the guide net to guarantee that carbon fiber sheet is consistent in orientation so as to obtain a composite structure member with higher mechanical performance; preheating a resin mixing solution with a carbon fiber preforming body at first to guarantee the resin mixing solution to be quickly infused in a low-viscosity state; and sealing the upper surface of the carbon fiber preforming body with a unidirectional breathable film to form a surface breathable channel, and enabling the resin mixing solution to permeate from surface and to fill fully under vacuum, thus completing the vacuum infusion forming process. The method is suitable for the carbon fiber fabrics which are shaped by hot melting lines and have different surface densities; and compared with the carbon fiber prepreg forming process, the method has the advantages of long material availability period, high process stability and low product cost, and is favorable for popularization and application.

Description

technical field [0001] The invention relates to a vacuum infusion molding method for a composite material structural part, in particular to a vacuum infusion molding method for a carbon fiber composite material structural part of a large-scale thick product; it belongs to the technical field of composite material molding. Background technique [0002] Carbon fiber reinforced epoxy resin-based composites have the advantages of high specific strength, high specific modulus, low density, stable structure size, corrosion resistance, fatigue resistance, heat resistance, low temperature resistance, and material properties can be designed. They can be used as structural materials to carry heavy loads. It can also play a role as a functional material and has been widely used in aerospace, transportation, wind turbine blade manufacturing, chemical anticorrosion, construction engineering and sports equipment and other fields. [0003] In recent years, with the development trend of lar...

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Problems solved by technology

[0005] The existing mature vacuum infusion molding process usually uses glass fiber as a reinforcing material, which is combined with a resin-based material to prepare a composite material structural part; when the structural part is used to manufacture larger wind power blades, the blade tip will easily deform and hit the tower , Rotational frequency and natural frequency are close to resonance, the direction of shimmy is prone to fatigue, and the self-weight of the blade is too large, which affects the normal use of large wind power blades and fully exposes the defects of glass fiber such as heavy mass, low modulus, and poor fatigue performance.

[0006] For this reason, in recent years, carbon fiber has been used instead of glass fiber to prepare composite structural parts of wind power blades. Among them, the method mainly used is prepreg molding method; with this method, the service life of the resin system is short, and the storage and transportation of materials are slow. A low temperature environment is required and special refrigeration equipment is required, which increases the storage and transportation costs of carbon fiber raw materials

In addition, compared with the vacuum infusion molding process of glass fiber composite materials, the vacuum infusion molding process of carbon fiber composite materials puts forward higher requirements on the reliability and stability of the resin, carbon fiber fabric and process used. The fiber is thinner, the diameter of carbon fiber monofilament is about 1 / 3 of the diameter of glass fiber monofilament, and its surface area is larger. After vacuum compaction, the gap in the carbon fiber preform is much smaller than that of the glass fiber body, and the surface of carbon fiber is chemically inert. It is difficult to be effectively impregnated, and it takes longer infusion time to impregnate completely, and the performance of carbon fiber composite materials is more sensitive to the process; for the same carbon fiber raw yarn, the mechanical properties of the material obtained by prepreg molding are usually higher than those obtained by vacuum infusion Molding, this is because the fibers in the prepreg are pre-drawn and have high fiber orientation consistency, while carbon fiber fabrics are usually loose in structure and easy to deform, which will lead to more raw materials required for vacuum infusion molding of parts with the same rigidity, Therefore, the application of low-cost carbon fiber composite material vacuum infusion molding technology in the manufacture of large wind power blades is limited.

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