Polymers: The Future of Polymers for Additive Manufacturing

Additive manufacturing (AM), popularly known as 3D printing, is revolutionizing how products are designed and produced. But what materials are making this revolution possible? Polymers play a crucial enabling role as feedstocks for most AM processes. Let us explore how polymers are shaping the future of additive manufacturing.

Introduction to Polymers for AM
Polymers, or plastics, are the most commonly used materials for 3D printing. Polymers for Additive Manufacturing come with advantages like low cost, ease of processing, variety of properties and colors. Some key polymers used in additive manufacturing include Acrylonitrile Butadiene Styrene (ABS), Polylactic Acid (PLA), Polyethylene Terephthalate Glycol-modified (PETG), Nylon and Photopolymers. Each polymer comes with its own strengths that help produce functional parts using AM. Their versatility has made polymers the workhorse materials for the 3D printing industry.

Properties and Applications of Major Polymer Feedstocks
ABS: A soft, durable plastic known for its strength and impact resistance. Commonly used for prototyping, consumer goods and durable parts. Popular for Fused Deposition Modeling (FDM) 3D printers.

PLA: Derived from renewable resources like corn starch or sugarcane, PLA is a great alternative to oil-based plastics. It is biodegradable and compostable. Used in AM to produce functional parts, medical implants and disposable goods.

PETG: Offers high strength, flexibility and transparency. Used to print clear components, electronic enclosures and designs requiring impact resistance. Popular for Multi Jet Fusion (MJF) systems.

Nylon: Thermoplastics like Nylon 11 and Nylon 12 have high strength, flexibility and heat resistance. Used to 3D print durable parts for applications in manufacturing, engineering, consumer appliances and more.

Photopolymers: Cured using UV light, photocurable resins enable high resolution prototyping using stereolithography. Mainly used in medicine, dentistry and jewelry to produce detailed, small parts with smooth finish.

New Developments in Polymer Formulations
Continuous advancements are expanding material options for 3D printing. Some notable new polymer formulations include:

- TPU or Thermoplastic Polyurethane: Provides elasticity and flexibility and is ideal for producing springs, damping components and flexible designs.

- PC-ABS or Polycarbonate ABS: Stronger than regular ABS with heat resistance up to 120°C. Used for parts exposed to high heat like enclosures, automotive interiors etc.

- PVA or Polyvinyl Alcohol: Water-soluble support material for Multi Jet Fusion which dissolves away easily without leaving residue.

- PEEK or Polyether Ether Ketone: Engineering-grade thermoplastic with heat deflection temperature up to 260°C. Used for aerospace, medical and automotive applications demanding high heat resistance.

- Innovative composites: New filaments reinforced with materials like carbon fiber, wood or metal particles enhance strength, conductivity and aesthetics of 3D printed parts.

Sustainability and Recyclability Aspects
Many researchers are working on methodologies to close the polymer lifecycle using additive manufacturing. Some noteworthy initiatives include:

- Development of 100% recyclable and biodegradable polymers derived from agricultural or food waste for 3D printing. Examples include PHA, polylactic acid and polyhydroxybutyrate.

- Design of 3D printed parts with uniform wall thicknesses and optimized geometry to reduce material usage without sacrificing functionality.

- Techniques like selective dissolving and separation processes to recycle support materials and failed prints back into virgin polymer pellets for reprocessing.

- Depolymerization processes to break polymers back down into their basic monomers for repolymerization into new 3D printing feedstock on an industrial scale.

Polymers will continue powering the additive manufacturing revolution with endless possibilities of new material formulations, properties and applications. Governments and industries are increasingly adopting 3D printed polymers for sustainability goals like reduced waste and localized production. With ongoing material developments and recycling initiatives, polymers truly offer the future of environmentally responsible additive manufacturing.