Improving the mechanical properties of 3D printed polymer parts while maintaining their shape and dimensional accuracy can be achieved through several approaches:1. Material selection: Choose a polymer material with better mechanical properties, such as higher strength, toughness, and durability. Some examples include polycarbonate PC , polyetherimide PEI , and polyphenylene sulfide PPS . These materials generally have better mechanical properties than the commonly used PLA and ABS.2. Optimize print settings: Adjusting print settings such as layer height, infill density, and print speed can significantly affect the mechanical properties of the printed part. For example, using a lower layer height can increase the bonding between layers, resulting in better strength. Increasing the infill density can improve the overall strength and stiffness of the part.3. Print orientation: The orientation of the part during printing can affect its mechanical properties. Printing the part in an orientation that aligns the layers with the primary load direction can improve its strength and durability.4. Use of composite materials: Incorporating reinforcing fibers or particles, such as carbon fibers or glass fibers, into the polymer matrix can significantly improve the mechanical properties of the printed part. These composite materials can be used as filaments for 3D printing.5. Post-processing: Various post-processing techniques can be employed to improve the mechanical properties of 3D printed polymer parts. These include annealing heat treatment to reduce residual stresses and improve layer adhesion, chemical vapor smoothing to improve surface finish and strength, and UV curing for photopolymers to enhance their mechanical properties.6. Design optimization: Implementing design techniques such as topology optimization, lattice structures, and generative design can help create parts with improved mechanical properties while maintaining their shape and dimensional accuracy.7. Hybrid printing: Combining different materials or printing techniques, such as using continuous fiber reinforcement with thermoplastic materials, can result in parts with improved mechanical properties.By considering these approaches, it is possible to improve the mechanical properties of 3D printed polymer parts while maintaining their shape and dimensional accuracy.