As such the 3D printing process does not have to spend time to print the intricate parts, and the process can be faster. The requirement for 4D printing is that materials with special characteristics that are responsive to an activating agent need to be used.
4D printing of composites utilizes the same concept of 4D printing, except that the materials used are long fiber composite materials. 4D printing of composites utilizes the shrinkage of the matrix resin, and the difference in coefficients of thermal contraction of layers with different fiber orientations to activate the change in shape upon curing and cooling.
This behavior can be used to make parts with curved geometries without the need for a complex mold. As such manufacturing of pieces of curved shapes can be fast and economical. However, the degree of shape changing depends on the material properties, the fiber orientation, the lay up sequence and the manufacturing process. This paper presents the results obtained from a study on the effects of these aspects on the shape of the curved parts.
Suong Van Hoa, Department of Mechanical and Industrial Engineering, Concordia Center for Composites (CONCOM), Center for Research on Polymers and Composites (CREPEC), Concordia University, Montreal, Canada