Flexible 3D freeform techniques

A process for making a three-dimensional article comprising a curved 3D surface, the process includes:

• dispensing a solidifiable material in a fluid state from a dispensing head onto a target area on a base member at predetermined ambient conditions to form band-shaped materials and sequentially build up multiple band-shaped materials into said curved 3D surface;
• simultaneously with the dispensing of said solidifiable material, changing curvature of the dispensed band-shaped material in its longitudinal direction by applying a differential molding member in physical contact with selected positions on surfaces of the material dispensed at said target area and by varying geometric shape of the physical contact between the differential molding member and the material dispensed;
• simultaneously with the dispensing of said material and the changing of band-shaped material curvature in the longitudinal direction, generating relative movements between said base member and a combination of said dispensing head and said differential molding member in free space, said relative movements creating curvatures along latitudinal directions of the dispensed band-shaped materials;
• the dispensed band-shaped materials in combination forming said curved 3D surface with smooth curvature along directions of said relative movements as well as in directions perpendicular to the directions of said relative movements;
• said differential molding member comprises a curved member having different curvatures on different portions and said varying geometric shape of the physical contact is conducted by rotating said curved member to bring different curvatures corresponding to said predesigned shapes into contact with the solidifying material.