Process parameters are so important! Let’s take a look at what factors are related to the surface quality of carbon fiber products

High-performance composite materials are characterized by light weight and high strength, and have extremely high potential for lightweighting. However, if this material is to be used on a large scale, it must solve the problems of long production cycle and high cost. The advent of prepreg avoids the problems of complicated operations and unstable processes of the traditional wet hand lay-up process. However, due to the use of autoclave, the cost is high and the production time is relatively long. Therefore, the out-of-autoclave (OOA=out of autoclave) process, which can not only speed up production and save costs, but also maintain the same quality of products as the autoclave process, has become a new favorite in the composite materials industry.

Most prepregs, if cured under the high pressure of an autoclave, can produce a very nice, smooth, pinhole-free product. However, the OOA process often uses an oven to cure the prepreg. The same prepreg will leave pinholes on the surface of the product, affecting the appearance.

Picture from: Testing Center of Yifa Bonding and Composite Materials Research Institute

In order to study what factors are related to the surface quality of carbon fiber products produced by the OOA process, Yifa Bonding and Composites Research Institute conducted a series of process verification work and listed the following plans:

Picture from: Testing Center of Yifa Bonding and Composite Materials Research Institute

After comparative experiments, it was found that during the OOA process, the surface quality of carbon fiber products is related to many factors:

1. The selection of release wax is crucial to the release process. It is necessary to avoid using release wax that is not resistant to high temperatures (above 120°C).

2. The type of prepreg also has a great impact on the surface of the final product. Choosing the appropriate fiber fineness, resin content, weaving form, and additive content can greatly improve the surface quality of the product.

3. If a sandwich structure is made, the pore size and pressure and temperature resistance of the foam will also affect the surface quality.

4. During the OOA process, if aluminum molds are used for mold closing, sufficient pressure and sealing must be ensured, as well as smooth exhaust and surface quality at complex structural locations.

5. Teflon release cloth can help improve the surface quality of carbon fiber when the pressure is insufficient.

6. In addition to the above experimental factors, heating and cooling rates, pressure control, resin viscosity, etc. all have a certain impact on the final product.

To sum up, the influencing factors of the surface quality of carbon fiber products are very complex. If we want to strive for excellence in making products, we cannot do without engineers having a macroscopic grasp of all aspects involved in composite materials, and having the skills in design, process, production, A series of knowledge such as detection.

Based on this, Yifa New Materials Research Institute, a subsidiary of Yifa Bonding and Composite Materials Training Center, has introduced the research and development results of Fraunhofer IFAM into China, and carried out fiber-reinforced composite material manufacturing Composite_M, maintenance Composite_R, and technician Composite_S training courses to provide enterprises with composite materials related Professional project support, special training, composite material simulation calculation and load-bearing capacity verification, process evaluation and experimental plan design and other services.

The series of composite materials courses are jointly taught by well-known German composite materials doctors and engineers and senior training instructors from Yifa New Materials Research Institute. The content covers the entire process from fibers, resins, textile semi-finished products, prepregs, textile preforms to final products. The processes involved include hand lay-up, vacuum bag, vacuum infusion, RTM resin transfer injection molding, autoclave, pultrusion, and molding. Technology, etc., and provide special training for problems that arise in the product design process. Analytical calculations and numerical analysis are combined to facilitate students to systematically master composite material design methods. At the same time, this series of courses also provides a unique series of composite material maintenance courses, learning the maintenance of composite materials from the aspects of defect sources, identification and detection, and writing maintenance operation instructions. The course combines theory with practice, and half the time is spent on practical operations, allowing students to intuitively grasp various process details. German engineers answered questions throughout the process and helped students solve problems encountered during the production process. After passing the exam at the end of the course, you will be awarded an authoritative certification from Fraunhofer IFAM.

The company's affiliated Yifa New Materials Research Institute Testing Center has CNAS qualifications and has many senior and experienced testing engineers. It can perform performance testing on bonded products in accordance with DIN6701&DIN2304 and other relevant international standards, national standards, enterprise standards, etc. The testing services that can be provided include tensile testing, shear testing, dancer roller peeling, roller peeling and other mechanical tests of bonded products and composite materials, as well as fatigue testing, aging testing, relaxation and creep performance testing, and impact load of samples. Testing etc. At the same time, it can also assist glue-using companies and composite material manufacturers to plan process assessment plans and conduct auxiliary design verification.

All rights reserved by Yifa Bonding and Composites Training Center, welcome to refer! Please indicate the source when forwarding