The choice of polymer in 3D printing significantly affects the mechanical properties and print quality of the final object. Different polymers have unique characteristics that influence the strength, flexibility, durability, and appearance of the printed object. Some of the most common polymers used in 3D printing include PLA polylactic acid , ABS acrylonitrile butadiene styrene , PETG polyethylene terephthalate glycol , and TPU thermoplastic polyurethane .1. Strength: The strength of a 3D printed object depends on the polymer's tensile strength and resistance to deformation. For example, ABS is known for its high strength and toughness, making it suitable for functional parts and prototypes. PLA, on the other hand, is more brittle and less suitable for high-stress applications.2. Flexibility: Polymers with higher flexibility, such as TPU, can be used to create objects that need to bend or flex without breaking. In contrast, more rigid polymers like PLA and ABS are better suited for rigid structures and objects.3. Durability: Some polymers are more resistant to wear, chemicals, and environmental factors like UV radiation. For example, PETG has excellent chemical resistance and durability, making it suitable for outdoor applications or objects that will be exposed to chemicals.4. Print quality: The choice of polymer also affects the print quality, including surface finish, layer adhesion, and dimensional accuracy. PLA is known for its ease of printing and good surface finish, while ABS can be more challenging to print due to its tendency to warp and shrink during cooling. PETG offers a balance between ease of printing and strength, making it a popular choice for many applications.5. Print temperature and speed: Different polymers require different printing temperatures and speeds, which can affect the print quality and success rate. For example, PLA prints at a lower temperature 180-220C and can be printed at faster speeds, while ABS requires higher temperatures 230-260C and slower printing speeds to prevent warping.6. Post-processing: Some polymers, like ABS, can be easily sanded, painted, or acetone-vapor smoothed for a better surface finish. Others, like PLA, are more difficult to post-process due to their lower melting point and brittleness.In conclusion, the choice of polymer in 3D printing plays a crucial role in determining the mechanical properties and print quality of the final object. It is essential to select the appropriate polymer based on the desired characteristics and application of the printed object.