From the prepreg to the final part, the carbonfiber composite material needs to be processed by the molding process. With thedevelopment of carbon fiber technology, the molding process of carbon fibercomposite materials is also constantly improving, but the various molding processes of carbon fiber composite materials do not exist in the way of updateand elimination, and often multiple processes coexist to achieve the most underdifferent conditions and different situations.

The following is a list of the 12 most commonly used carbon fiber composite molding processes at this stage, see which ones you know.

Injection molding process

It is a type of low-pressure molding in the handlay-up process. After mixing chopped fibers and resin through a spray gun,compressed air is sprayed on the mold to reach a predetermined thickness, and then manually pressed with a rubber roller, and then cured and molded. Asemi-mechanized molding process created to improve hand lay-up molding has acertain degree of improvement in work efficiency, but it still cannot meet themass production. It is used to manufacture car bodies, hulls, bathtubs, and storage tanks crossing layer.

Winding

The continuous fiber or cloth tape impregnated with resin glue is wound onto the core mold according to a certain rule, and then cured and demolded to become a composite material product. Carbon fiber winding molding can give full play to its high specific strength, high specific modulus and low density. The product has a single structure and can be used for manufacturing cylinders, spheres and certain positive curvature rotators orcylindrical carbon fiber products.

Liquid forming

The process of synthesizingthe liquid monomer into a polymer, and then changing the polymer curingreaction into a composite material is directly completed in the mold at the same time, which not only reduces the energy consumption in the process, but also shortens the molding cycle (only It takes about 2 minutes to complete aproduct). However, the application of this process must be based on precise pipeline transportation and metering, as well as automatic control of temperature and pressure. It belongs to the cross category of polymer materialsand modern high-tech science and technology. The current application is notvery wide.

Resin transfer molding (RTM)

Resin Transfer Molding (RTM: Resin Transfer Molding)technology is a low-cost composite material manufacturing method that was initially mainly used for aircraft secondary load-bearing structural parts,such as hatches and inspection hatches. In 1996, the U.S. Defense Research and Development Agency launched a research on low-cost RTM manufacturing technology for high-strength main load-bearing components. RTM technology has the advantages of high efficiency, low cost, good part quality, high dimensional accuracy, and little environmental impact. It can be applied to the molding of composite parts with large volume, complex structure, and high strength. It has become an aerospace industry in recent years.

Molding

The carbon fiber prepreg is placed between the upper and lower molds, the mold is closed and the mold is placed on the hydroforming table, and after a certain period of high temperature and high pressure to cure the resin, the carbon fiber products are removed. This molding technology has the advantages of high efficiency, good quality of parts, high dimensional accuracy, and little impact on the environment. It is suitable for the formation of batched and high-strength composite parts. However, the early mold manufacturing is complicated and the investment is high. The size of the parts is limited by the size of the press.

Injection molding

This is a new technology. Bole CIML equipment integrates the traditional "multi-step method" process into a"one-step method", which greatly shortens the process flow and better preserves the fiber length to achieve energy-saving and efficient production.Through solving a series of key technical issues such as formulation optimization, compounding system, intelligent control system and molding process parameter optimization in material-equipment-manufacturing, it fullymeets the needs of automobile light weight for product strength, cost and efficiency A weapon that is tailored for light weight vehicles.

Hand lay-up-wet lay-up molding

Apply mold release agent and gel coat on the working surface of the mold, lay the cut carbon fiber prepreg on the working surface of the mold, brush or spray the resin system glue to reach the required thickness, and then form and solidify and release the mold. In today's highly developed preparation technology, hand lay-up technology is still widely usedin many fields such as petro chemical containers, storage tanks, and automobile shells due to its advantages of simple process, low investment, and wideapplication. The disadvantage is that the texture is loose, the density is low,the strength of the product is not high, and it mainly depends on labor, the quality is unstable, and the production efficiency is very low.

Vacuum autoclave

The single-layer prepreg is laid in a predetermined direction to place the composite material blank in a hot-pressed tank to complete the curing process at a certain temperature and pressure. The autoclave is a special pressure vessel that can withstand and regulate acertain temperature and pressure range. The blank is laid on the surface of themold with release agent, and then covered with porous anti-sticking cloth(film), suction felt, and air-felt, and sealed in a vacuum bag, and then placedin a hot-pressing tank. Before heating and curing, the bag is evacuated to remove air and volatiles, and then heated, pressurized and cured according to different resin curing systems. The formulation and implementation of the solidification system is a guarantee to prove the key to the quality of autoclave molded parts.

Vacuum introduction

Referred to as VIP, a "dry" carbon fiber composite material is placed on the mold, then a vacuum bag is placed, and the vacuum in the system is drawn to form a negative pressure in the mold cavity.The pressure generated by the vacuum is used to pass the unsaturated resin through the pre-paved pipeline. Press into the fiber layer, let the resin infiltrate the reinforcing material, and finally fill the entire mold. After the product is cured, remove the vacuum bag material to obtain the desired product from the mold. The resin impregnates the carbon fiber in a vacuum environment,and there are very few bubbles in the product. The product has higher strength and lighter quality. The product quality is relatively stable, and the resinloss is reduced. Only one side of the mold can be used to obtain smooth and flat products on both sides. , Can better control the thickness of the product.Generally used in rudder and thunder in the boat industry shields, blades in wind power, engine roomcovers, various roofs, windshields, cars in the automotive industry.

3iTech induction heating

A new type of induction heating process that integrates the sensor in the mold. Itcan process carbon fiber at a temperature of 20 °C-400 ° C and heat the surface of the mold by using the sensor integrated in the mold through thermal conduction. This is a supplementary technology launched by the emerging companyRocTool on the Cage system. The electromagnetic induction can quickly heat themold and can control the local temperature well. The advantage is that it significantly reduces cycle time and component costs. However, this technology is not yet suitable for large components, and the related output must be large enough.

Lamination

The layered prepregs are placed between the upper and lower flat molds under pressure to heat and solidify. This process can directly inherit the production method and equipment of wood plywood, and improve and perfect according to the rheological properties of the resin. The lamination molding process is mainly used to produce composite plates of various specifications and different uses. It has the characteristics of high degree of mechanization and automation, stable product quality, etc., but the equipment investment is large.

Pultrusion

Continuous carbon fiber tow, belt or cloth impregnated with resin glue is shaped and solidified by an extrusion die under the action of traction force to continuously produce profiles of unlimited length. Pultrusion is a special process in the molding process of composite materials. Its advantage is that the production process can be fully automated and the production efficiency is high. The fiber mass fraction in pultruded products can be as high as 80%, and the dipping is carried out under tension,which can fully play the role of reinforcing materials. The product has high strength. The vertical and horizontal strength of the finished product can be adjusted arbitrarily to meet the different mechanics of the product Performancer equirements. The process is suitable for the production of profiles of various cross-sectional shapes, such as I-shaped, angled, grooved, profiled cross-section tubes and combined cross-section profiles composed of the above cross-sections.