What Material Is Used for 3D Printing? A Guide to Polymer FDM Filaments

3D printing, also known as additive manufacturing, has revolutionized how individuals and industries design, develop, and manufacture products. Perhaps more than any other production process, 3D printing allows for new and complex designs to be realized in short timeframes, as well as for custom, on-demand production. Fused deposition modeling (FDM) 3D printing in particular—which works by melting a thermoplastic filament and extruding it layer by layer onto a build platform, gradually forming a solid object based on a digital design—offers an accessible production process that can make parts out of a variety of materials, from standard thermoplastics, to high-performance polymers, to robust composites.

As we’ll see in this article, each type of plastic filament offers distinct characteristics, which make them suitable for different applications. This article explores the various categories of 3D printing filaments, from standard polymers like PLA and ABS, to more specialized materials like PEEK and fiber-filled filaments, as well as support materials.

Standard Polymers

Standard filaments are commonly used for general-purpose 3D printing. They are relatively easy to use, affordable, and offer a wide range of applications in prototypes, hobbyist projects, and educational models. While definitions can vary, when people talk about standard thermoplastic polymer filaments they are usually referring to PLA, ABS, and PETG, three of the most commonly used plastics in FDM 3D printing. 

PLA

PLA (Polylactic Acid) is one of the most popular and low cost filaments in 3D printing, especially for beginners. It is made from renewable resources like corn starch or sugarcane, making it biodegradable and more environmentally friendly than thermoplastics derived from petroleum-based products.[1] PLA offers several key benefits:

• Ease of Use: PLA has a low melting point (180-220°C), making it easy to print on most 3D printers, even without a heated bed.

• Appearance: It produces a glossy, smooth finish, ideal for aesthetic applications.

• Low Warping: PLA experiences minimal warping during printing, reducing the likelihood of print failures.

• Strength and Rigidity: While PLA is relatively brittle and not ideal for high-stress applications, it is suitable for creating aesthetically pleasing prototypes and decorative items.

However, PLA is not as heat-resistant or durable as other filaments, and it can degrade over time when exposed to moisture and high temperatures. The material is also very rigid and even brittle, which can limit functional applications.

ABS 

ABS (Acrylonitrile Butadiene Styrene) is a widely used filament known for its strength, flexibility, and heat resistance. It is commonly used for creating functional prototypes and parts that require durability. Key characteristics of ABS include:

• Strength and Durability: ABS is more robust and resistant to impact than PLA, making it suitable for mechanical parts like gears and housings.

• Heat Resistance: It can withstand higher temperatures than PLA, making it useful for applications in automotive and industrial sectors.

• Post-Processing: ABS can be easily finished using acetone vapor, which creates a smooth surface and helps reduce layer lines.

However, ABS can be more challenging to print with, as it requires higher extrusion temperatures (220-250°C) than PLA and can benefit from a heated bed to prevent warping.[2] Additionally, it emits fumes that should be ventilated properly. 

PETG 

PETG (Polyethylene Terephthalate Glycol) is a popular filament due to its balance of strength, flexibility, and ease of printing. It is commonly used in both functional and aesthetic 3D printing applications. PETG is chemically resistant, durable, and has high impact strength, making it suitable for parts that need to endure mechanical stress. Key features include:

• Strength and Flexibility: PETG combines the best aspects of PLA and ABS, offering a strong, durable material with a degree of flexibility.

• Ease of Printing: It has a low tendency to warp, making it easier to print than ABS, and requires a heated bed.

• Chemical Resistance: PETG is resistant to a wide range of chemicals and UV light, making it suitable for outdoor applications.

It also has a smooth, glossy finish and is less brittle than PLA, making it ideal for creating durable functional prototypes and everyday items like bottles and containers.

Recommended reading: PLA vs ABS vs PETG: A Comparison of 3D Printing Filaments

Engineering Polymers

Engineering polymers are designed to withstand harsher environments and more demanding mechanical conditions. These filaments are typically used for functional prototypes or parts that must maintain performance under stress.

Nylon (PA)

Nylon is a highly versatile and durable filament known for its strength, flexibility, and resistance to wear. It is often used in mechanical parts such as gears, bearings, and hinges. While its properties are advantageous, Nylon is not known for its easy printability due to its hygroscopic properties.

• Strength and Flexibility: Nylon offers superior impact strength and is highly flexible, making it ideal for parts that need to bend without breaking.

• Wear Resistance: Nylon has excellent abrasion resistance, making it suitable for moving parts.

• Moisture Sensitivity: Nylon absorbs moisture from the air, which can affect print quality. Drying the filament before use is often necessary.

• Warping: Nylon has a high thermal expansion coefficient, which means it expands when heated and shrinks when cooled. Using a heated print bed and/or enclosed 3D printer can help to mitigate this effect and minimize the risk of warping. 

Certain filaments, like Nylon and PC, require an enclosed 3D printer for the best results.

Polycarbonate (PC)

Polycarbonate is a high-performance polymer known for its excellent impact resistance and transparency. It is used in demanding applications where strength, impact resistance, temperature resistance, and clear aesthetics are important.

• Strength and Impact Resistance: Polycarbonate is one of the strongest thermoplastics, with excellent resistance to both impact and heat. This is due to its 

• Heat Resistance: It can withstand higher temperatures (up to 150°C) than most standard filaments.

• Transparency: Polycarbonate is transparent, making it suitable for applications like protective covers, light lenses, and optical devices.

• Warping: However, polycarbonate can be challenging to print due to its tendency to warp, requiring a heated bed and an enclosed print chamber. The filament should also be stored in a drybox to keep it safe from moisture.

ASA 

ASA (Acrylonitrile Styrene Acrylate) is an engineering-grade thermoplastic similar to ABS but with superior outdoor durability. It is known for its excellent resistance to UV light, weathering, and temperature fluctuations, making it a preferred choice for parts exposed to harsh environmental conditions. ASA is commonly used in automotive, outdoor, and industrial applications where parts need to withstand exposure to sunlight, moisture, and extreme temperatures.

• UV Resistance: One of ASA's standout features is its excellent UV resistance, which makes it ideal for outdoor applications where exposure to sunlight could degrade other materials. 

• Strength and Durability: ASA offers high mechanical strength, toughness, and impact resistance, making it suitable for functional parts that need to endure physical stress.

• Ease of Printing: ASA can be more challenging to print due to its tendency to warp, so a heated bed (around 90-110°C) is essential. Using an enclosed print chamber helps reduce warping and cracking, and storing ASA in a dry environment is recommended as it is hygroscopic.

• Chemical Resistance: ASA has good chemical resistance to oils, fats, and many acids, which enhances its durability in industrial environments.

ASA is a popular choice for outdoor applications, such as automotive exterior parts, electrical housings, and outdoor furniture, due to its outstanding UV resistance and durability under harsh environmental conditions. Its properties make it an excellent alternative to ABS, particularly for projects that will be exposed to sunlight.

Recommended reading: ASA vs ABS: Finding the right 3D printing filament

Flexible Filaments

Flexible filaments are designed for parts that need to bend or stretch, such as seals, gaskets, protective cases, and wearable items. These materials are more rubber-like than rigid filaments and come in different flexibility levels, ranging from soft to semi-rigid.

TPU 

TPU (Thermoplastic Polyurethane) is the most popular flexible filament, known for its rubber-like properties and high durability. It is used for applications like phone cases, wearables, and functional gaskets.

• Flexibility: TPU is highly flexible, allowing it to be stretched and compressed without losing shape. For comparison, while PLA has an elongation at break of 1-6%, TPU has a dramatically higher elongation at break of 300–700%.

• Durability: TPU is highly resistant to wear, abrasion, and impacts.

• Ease of Printing: TPU requires slower print speeds and precise extrusion to avoid issues like stringing, but with the right settings, it can be printed relatively easily. 

• Print settings: When printing TPU filament, a nozzle temperature of 220-235°C is typically required, as well as an unheated or moderately heated print bed (up to 70°C) and cooling.[3]

The flexibility and strength of TPU make it suitable for products that need to deform under pressure, like protective bumpers or shock-absorbing materials.

Flexible filaments such as TPU can be used for applications like footwear.

Polypropylene (PP)

Polypropylene is another flexible filament that stands out for its unique combination of flexibility, low density, and excellent chemical resistance. It is used in applications that require flexibility, impact resistance, and resilience, such as living hinges, storage containers, and automotive parts.

• Flexibility: Polypropylene is less flexible than TPU but still offers significant flexibility, especially when compared to more rigid materials like PLA. It has a low flexural modulus, which allows it to bend and flex without breaking.

• Durability: Polypropylene is highly resistant to fatigue, meaning it can bend repeatedly without losing its shape or structural integrity. It also performs well in harsh chemical environments, resisting solvents, acids, and bases.

• Ease of Printing: PP can be tricky to print due to its tendency to warp and its requirement for a heated bed and proper adhesion techniques. A heated bed (around 100°C) is typically necessary, and a raft or brim is often used to improve bed adhesion.

Polypropylene is ideal for creating flexible, long-lasting parts, particularly in applications where high impact resistance or chemical exposure is a concern. However, its relatively high print difficulty may require a bit more experience with tuning printer settings.

TPE

TPE (Thermoplastic Elastomer) is a highly flexible material with properties similar to rubber, but with the added advantage of being easier to process. TPE is commonly used for applications that require extreme flexibility and soft touch, such as grips, seals, and wearable devices.

• Flexibility: TPE offers a high degree of flexibility. It has a very soft, rubber-like feel, and can stretch and compress easily. With an elongation at break of around 500–600%, TPE parts can bend or stretch to a much greater degree without tearing.

• Durability: TPE is highly durable and resistant to wear, abrasion, and extreme temperatures, similar to TPU. However, it is especially effective in applications where softness and flexibility are crucial. It's also resistant to UV degradation, making it ideal for outdoor or high-usage applications.

• Ease of Printing: TPE is challenging to print than because of its softness and tendency to stretch. Printing with TPE requires a slow print speed and precise control over extrusion to avoid issues like filament slipping or uneven layer bonding. A direct-drive extruder is often recommended for better control.

TPE is widely used for products where softness, flexibility, and high deformation resistance are required, such as vibration dampeners, flexible seals, and ergonomic grips. However, due to its high flexibility and low rigidity, it can be harder to print successfully on some 3D printers.

Recommended reading: Flexible 3D printer filaments: is PLA flexible?

High-Performance Filaments

High-performance filaments are designed for extreme conditions and can withstand high temperatures, chemical exposure, and mechanical stress. These materials are commonly used in aerospace, automotive, and industrial applications since they can withstand tough environments and heavy loads. 

PEEK 

PEEK (Polyether Ether Ketone) is one of the highest-performing filaments, offering exceptional strength, chemical resistance, and heat resistance.

• High Temperature Resistance: PEEK can withstand continuous temperatures up to 260°C, making it suitable for high-performance applications in aerospace and automotive industries.

• Mechanical Properties: It has high tensile strength and can endure mechanical stress without deforming.

• Chemical Resistance: PEEK is highly resistant to most chemicals, including solvents, oils, and acids.

Due to its high extrusion temperature (around 360°C) and specific printing requirements, PEEK is challenging to print with but is invaluable for demanding applications. In order to 3D print PEEK and other high-performance filaments, a fairly sophisticated 3D printer is required. Specifically, a 3D printer must have a high-temperature capability, high-quality nozzle, a heated built plate that can reach at least 120°C and an enclosed print chamber.

PEI

PEI (Polyetherimide), commonly known by the brand name Ultem, is another type of high-performance thermoplastic known for its excellent mechanical and thermal properties.

• Strength and Durability: PEI offers high strength and resistance to impact and wear.

• Heat Resistance: It can handle high temperatures (up to 180°C) without losing structural integrity.

• Chemical Resistance: PEI is resistant to various chemicals, making it suitable for industrial uses. It is also recognized as a flame retardant material.

PEI is commonly used for functional parts like brackets, connectors, and medical devices.

PPSU 

PPSU (Polyphenylsulfone) is a high-performance polymer that combines excellent chemical resistance with high strength and heat resistance. It is used in industries like aerospace and medical for critical components.

• High Strength: PPSU exhibits excellent mechanical properties and can withstand high mechanical stress.

• Heat Resistance: It can perform in environments up to 260°C.

• Chemical Resistance: PPSU is resistant to a wide range of harsh chemicals and solvents.

Composite Filaments

Composites are fiber-filled filaments combine standard or engineering-grade polymers with reinforcing fibers, such as carbon fiber or glass fiber. These reinforced filaments offer enhanced strength, stiffness, and durability and are popular for industrial applications like mold making and metal replacement applications, since composite parts are both strong and lightweight.

Carbon Fiber-filled Filaments

Carbon fiber filaments are composite materials that are infused with fine strands of carbon fiber, which adds stiffness and strength without adding significant weight.[4] These filaments are typically based on PLA, ABS, or nylon, with the carbon fiber serving as a reinforcing agent.

• Strength and Stiffness: Carbon fiber-filled filaments are known for their high strength-to-weight ratio. They can significantly enhance the structural rigidity of prints while keeping the overall weight low. Parts printed with carbon fiber filaments are often used in high-performance engineering, automotive, and aerospace applications where both strength and low weight are critical.

• Durability: The carbon fibers help improve the durability of printed parts, making them more resistant to impact, wear, and thermal stress. They also tend to have lower thermal expansion than non-reinforced filaments, which reduces warping and dimensional changes during printing.

• Ease of Printing: Printing with carbon fiber filaments can be more challenging than with standard filaments. The abrasive nature of the carbon fibers can quickly wear out the nozzles of your 3D printer. It’s recommended to use hardened steel or carbide nozzles to avoid excessive wear. The material also requires precise temperature control (typically between 230°C and 250°C), and a heated bed is recommended to help with adhesion.

Carbon fiber filaments are commonly used for parts that need to be lightweight, stiff, and strong, such as drone frames, automotive parts, and structural components.

The addition of carbon fibers in a thermoplastic matrix can improve stiffness and strength without adding significant weight.

Glass Fiber-filled Filaments

Glass fiber-filled filaments are composite materials reinforced with tiny glass fibers, which increase the filament's strength, stiffness, and dimensional stability. Like carbon fiber filaments, glass fiber filaments are often based on PLA, ABS, or nylon.

• Strength and Stiffness: Glass fibers are known for providing high stiffness and strength to parts. While not as lightweight as carbon fiber, glass fiber-filled filaments can create parts that are significantly stronger and stiffer than standard filaments. This makes them ideal for parts that need to resist deformation under load, such as brackets, support structures, and mechanical parts.

• Durability: Glass fibers make the filament more resistant to wear and fatigue, making it suitable for applications where high mechanical stress is expected. These filaments also have improved thermal stability, allowing them to maintain their properties in higher temperature environments.

• Ease of Printing: Like carbon fiber filaments, glass fiber-filled filaments are abrasive, and will wear down regular brass nozzles. To prevent nozzle damage, it’s advisable to use a hardened steel or similar durable nozzle. Glass fiber filaments also require higher extrusion temperatures (typically between 220°C and 260°C) and a heated bed (80°C–100°C). 

Glass fiber-filled filaments are ideal for producing parts that require high strength and rigidity while remaining resistant to heat and wear. They are commonly used in engineering and industrial applications, such as machine components, automotive parts, and tooling.

Wood-Filled Filaments

Wood-filled filaments are composite materials that blend fine wood particles with a thermoplastic base, such as PLA or ABS. These filaments offer the aesthetic and tactile qualities of wood while being suitable for 3D printing. They are ideal for projects that aim to replicate wood-like textures, appearances, and even scents, such as artistic sculptures, furniture parts, and decorative objects.

• Appearance and Texture: Wood-filled filaments have a distinctive, wood-like finish. The material’s surface can be sanded or polished to achieve a smooth, realistic wood texture. It’s also possible to stain or paint wood-filled prints in a similar way to natural wood. Some wood-filled filaments even have a slight wood smell when printed.

• Printing Characteristics: Wood-filled filaments are typically based on PLA and may contain up to 70% wood fiber. While they are relatively easy to print, wood-filled filaments can be abrasive and may wear down standard brass nozzles. A hardened steel or no-clog nozzle is recommended for prolonged use.

•  Print Temperature: Wood-filled filaments are typically printed at temperatures between 190°C and 220°C and can benefit from slower printing speeds (20-50 mm/s) to prevent clogs and ensure good layer bonding.

• Post-processing: After printing, wood-filled parts can be sanded, stained, and even polished like natural wood, making them ideal for artistic and ornamental objects. You can also use a finishing technique such as a wax or polyurethane coating for an even smoother finish.

Wood-filled filaments are perfect for creating objects that look and feel like wood, but they do not have the mechanical strength of pure plastic or composite filaments. They are often used for artistic projects, prototypes, and custom designs where aesthetics and texture are required.

Support Materials

Support materials are used to create temporary structures that hold up overhangs or complex geometries during printing. After the print is completed, the support material can be removed using different types of manual or chemical processes.

PVA (Polyvinyl Alcohol)

PVA is a water-soluble filament commonly used in dual-extrusion 3D printing. It is ideal for supporting complex geometries and is easy to remove by dissolving in water.

• Water Solubility: PVA can be completely dissolved in water, leaving behind a clean print with no residual support material.

• Compatibility: It is commonly used alongside PLA, PETG, or ABS in dual-extrusion printers.

HIPS (High Impact Polystyrene)

HIPS is a another filament that can be used as a support material, particularly when paired with ABS in dual-extrusion 3D printing. Unlike PVA, HIPS is not water-soluble but can be dissolved using a limonene-based solvent, which makes it easy to remove without damaging the print.

• Dissolution: HIPS can be removed by soaking the printed part in limonene (a citrus-based solvent), which breaks down the HIPS material while leaving the primary print intact. This makes it a good support material for larger prints or parts with complex geometries that require solid support.

• Strength and Impact Resistance: HIPS is tough, durable, and impact-resistant, making it a good support material for larger, more complex prints that require robust support structures. 

• Compatibility: HIPS is commonly used with ABS or ASA due to its similar thermal properties. This compatibility ensures that both the print and the support material contract at similar rates, minimizing warping or stress between the printed object and the support.

HIPS is ideal for use in dual-extrusion setups where ABS is the primary material, offering an efficient and effective solution for creating complex and detailed models with minimal cleanup. It is also more cost-effective than PVA for certain applications, especially when working with larger support structures that don't require water solubility.

Conclusion

The variety of 3D printing filaments available today allows users to select materials that are best suited for specific applications, from basic prototypes to high-performance industrial parts. Standard filaments like PLA, ABS, and PETG offer ease of use and versatility, while engineering and high-performance materials such as PEEK and PEI are designed for challenging, demanding environments. Flexible, fiber-filled, and support filaments further expand the possibilities for creating specialized parts, whether it's for components that require flexibility, enhanced strength, or temporary support structures during the printing process. Ultimately, the choice of filament depends on the specific requirements of the project—whether that's strength, flexibility, UV resistance, or ease of use. As 3D printing technology continues to evolve, new materials and innovations are likely to open up even more possibilities for manufacturing, prototyping, and creative applications. By understanding the properties and advantages of different filaments, users can make informed decisions to achieve optimal results, whether for a hobbyist's 3D print or a high-performance, industrial-grade end-use part.

References

[1] Taib NA, Rahman MR, Huda D, Kuok KK, Hamdan S, Bakri MK, Julaihi MR, Khan A. A review on poly lactic acid (PLA) as a biodegradable polymer. Polymer Bulletin. 2023 Feb;80(2):1179-213.

[2] Lelinski M. How to Succeed with ABS Filaments When 3D Printing [Internet]. Zortrax. 2018 [cited 2024 Dec 12]. Available from: https://zortrax.com/blog/how-to-succeed-with-abs-filaments-when-3d-printing 

[3] What are flexible filaments and which one should you choose? [Internet]. UltiMaker. 2024 [cited 2024 Dec 12]. Available from: https://ultimaker.com/learn/what-are-flexible-filaments-and-which-one-should-you-choose/ 

[4] Sanei SH, Popescu D. 3D-printed carbon fiber reinforced polymer composites: a systematic review. Journal of Composites Science. 2020 Jul 24;4(3):98.