Thermoplastic polymers are the most common materials used for 3D printing as they are able to solidify or “set” quickly once deposited. Some of the most popular 3D printing polymers include acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), nylon, and polycarbonate. ABS is a durable thermoplastic that prints easily and produces strong parts well-suited for functional prototypes. PLA is made from renewable resources like corn starch or sugar cane and is biodegradable, making it a more eco-friendly option. Nylon has high strength and stiffness properties but requires specialized 3D printers. Polycarbonate offers impact resistance and transparency. Each polymer has its advantages depending on the specific application and needs of the end-use part.

Advantages of Using Thermoplastic Polymers for Additive Manufacturing

Thermoplastic polymers offer several benefits that have made them the predominant material category used in 3D printing:

• Melt Processability — Thermoplastics can be softened or melted by increasing their temperature, allowing them to be deposited, molded, or extruded into various shapes. Additive Manufacturing melt processability enables the fused filament fabrication (FFF) technique used in fused deposition modeling (FDM) printers.

• Rapid Solidification — Once the molten or softened thermoplastic cools back down, it solidifies into a fixed shape with good structural integrity. This rapid solidification occurs almost immediately after extrusion or deposition, allowing quick 3D print build times without lengthy cooling cycles.

• Post-Processing Capability — The ability to reheat thermoplastic polymers above their glass transition temperature allows for post-processing techniques like annealing to improve mechanical properties or vapor smoothing to enhance surface finish.

• Reusability — Excess or scrap thermoplastic materials can be melted back down and reextruded for reuse as 3D printer filament, reducing material waste.

• Material Variety — A wide selection of thermoplastic polymers have been developed for different material requirements, from PLA for its sustainability to nylon for its strength.

Specialized Applications Using Engineering-Grade Thermoplastics

While commodity plastics like ABS and PLA remain workhorse materials, engineering-grade thermoplastics enable high-performance applications:

• Polyetherimide (PEI) — Used for applications requiring heat resistance up to 302°F, like engine components or medical devices. PEI offers high durability.

• Polyetheretherketone (PEEK) — A semi-crystalline thermoplastic approved for medical implants due to its biocompatibility and strength at high temperatures up to 392°F.

• Polyphenylene Sulfide (PPS) — Provides resistance to chemicals, solvents, and heat up to 302°F. Used in corrosive environments like automotive fluid systems.

• Polycarbonate (PC) — In addition to providing impact resistance and transparency, PC resin grades offer flame retardance for aviation/aerospace parts.

• Polyetherketoneketone (PEKK) — Comparable to PEEK but more chemically resistant, PEKK excels in oil/gas and semiconductor applications exposed to harsh chemicals.

While engineering plastics are more expensive than commodity plastics, their advanced material properties unlock new applications in industries with complex performance needs. As 3D printing systems continue to evolve in capabilities like multi-material printing, the industry is making more advanced thermoplastics viable for additive applications.

Opportunities for Bio-Based and Specialty Polymers

Beyond traditional thermoplastics, additive manufacturing also enables new opportunities for bio-based and specialty polymers:

• Polylactic Acid (PLA) — PLA is a promising sustainable option made from renewable resources like corn. Continuous research aims to improve PLA’s heat tolerance for more structural applications.

• Polyhydroxyalkanoates (PHAs) — Produced from bacteria or algae, PHAs can fully biodegrade and are more ductile than PLA. Optimization work focuses on making PHAs affordable for commercial 3D printing use cases.

• Polyamide 11 (PA11) — A fully bio-based polyamide made from castor oil with mechanical properties competitive with oil-based nylon. PA11 stands to replace nylon in some applications.

• Specialty Elastomers — Thermoplastic polyurethanes and other elastic polymers allow multimaterial printing of flexible parts and high-resolution soft robotics components.

As material innovation advances to develop renewable, recyclable, and customized specialty polymers, additive manufacturing enables these new materials to realize applications previously not possible through traditional means. Sustainable options will continue expanding the role of polymers in 3D printing.

Trends Shaping the Future of Polymer 3D Printing

Cutting-edge research aims to push the possibilities of polymers for additive manufacturing applications:

• Multimaterial Printing — Combining multiple polymer inputs within a single part enables new design freedoms and functional gradients not achievable before.

• Continuous Fiber Reinforcement — Infusing short or continuous carbon, glass, and other fibers directly into printed thermoplastics improves impact resistance and stiffness.

• Advanced Material Formulations — Tailoring polymer compositions with nanoclay or carbon fiber reinforcements enhances material properties like heat deflection.

• Extrusion Deposition Modeling — Larger scale polymer 3D printers using conveyor-based extrusion allow high-speed manufacturing of functional end-use parts at production scales.

• 4D Printing — Stimuli-responsive “smart” polymers can be programmed to change shape or properties when exposed to water, heat, or other triggers to enable self-assembly applications.

As polymeric materials, hardware, and software in additive manufacturing continue progressing in tandem, exciting possibilities are taking shape to revolutionize how functional parts are designed and produced across industries. The future of 3D printing seems bright thanks to polymers.

Get More Insights On Metal Additive Manufacturing

About Author:
Ravina Pandya, Content Writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemical and materials, etc. (https://www.linkedin.com/in/ravina-pandya-1a3984191)