AZL Aachen GmbH (Aachen, Germany) recently announced a continuous production process for biocomposites. It is understood that the project is in charge of the Textile Research Institute (Institutfür Textiltechnik) of the Aachen University of Technology and also involves three partners: Sofila, Em-Systeme (Germany), and Safilin (France).
According to AZL, 100% bio-based thermoplastic tape can be processed on lay-up machinery or braided machinery like glass or carbon fiber tape. In this study, non-twisted flax fibers are arranged in parallel, taking full advantage of the characteristics of the fibers, and the high-quality composite materials prepared can be used in automotive parts or wind turbine blades.
Sofila, a partner, crimped the PA11 fibers and processed them into staple fibers, processed the flax fibers and PA11 fibers into mixed fiber strips, then stretched them and consolidated them into strips using ultrasonic welding. The ultrasonic module used was developed specifically for mixed slivers and was developed by project partner Em-Systeme. It can convert the energy of the mechanical vibration of the ultrasonic generator into internal friction and interfacial friction, so as to achieve heating and melting of the thermoplastic PA11 fiber; then the stretched and parallel-laid flax fibers are immersed in the molten thermoplastic.
Next, the produced tape is processed into a UD layer, which is then consolidated in a heating press. The consolidated composite material is tested to obtain its mechanical properties, especially its tensile and bending properties. According to AZL, the tensile strength of these strips is up to 233MPa, Young's modulus is up to 13GPa, bending strength is up to 280MPa, and bending modulus is up to 30GPa. Compared with commercially available linen/PP tapes and experimental comparisons, ultrasonic biocomposites have better bending strength and bending stiffness.