A composite material preparation method based on convergent die induced fiber orientation in DCCM process

Abstract Direct compounded compression molded (DCCM) is widely used in the automotive industry due to its efficiency and cost‐effectiveness. However, the main challenge of this process is to achieve fiber orientation in the final molded composite materials. In order to solve the problems of poor mechanical properties and disordered fiber orientation of carbon fiber/nylon 6 (CF/PA6) composites prepared by DCCM technology a new convergent die was proposed, which can realize fiber orientation through melt flow. The effects of fiber mass fraction, fiber length, and extrusion width on fiber orientation distribution were quantitatively analyzed using second‐order fiber tensor. Compared with other influencing factors, the extrusion width is crucial to the fiber orientation in the composite. When the extrusion width of the filament increases by 1.6 times, the fiber orientation tensor along the extrusion direction decreases by 47.06%. Compared to composites with random orientation, the tensile strength of composites obtained by the new mold with a certain fiber orientation was improved by 22.47%. This method lays a foundation for the orientation and molding of composites; it has important application potential in the production of lightweight parts such as automobiles and aerospace. Highlights A new convergent flow channel was proposed to realize the fiber orientation. Fiber orientation was improved by controlling the extrusion width. Quantitative characterization for fiber orientation was presented during DCCM. The method improved the tensile property of the material by 22.47%.