What is Polycarbonate?
Polycarbonate (often abbreviated as PC) is a high-performance engineering thermoplastic with exceptional strength and thermal resistance. When we talk about 3D printing materials, polycarbonate stands out as one of the strongest options available for desktop fabrication. At the molecular level, polycarbonate contains carbonate groups (-O-(C=O)-O-) in its polymer chains, giving it its unique properties.
Think of polycarbonate as the heavyweight champion in the world of printable plastics. While materials like PLA might be the friendly neighborhood plastic that's easy to work with, polycarbonate is more like industrial-grade material that has found its way into consumer-level technologies.
History of Polycarbonate
The story of polycarbonate begins back in 1898 when German chemist Alfred Einhorn first discovered the material, though he wasn't initially successful in finding practical applications. The real breakthrough came in the 1950s when two companies, Bayer in Germany and General Electric in the United States, independently developed commercially viable processes for manufacturing polycarbonate. Bayer marketed their polycarbonate as Makrolon, while GE called theirs Lexan.
For decades, polycarbonate was used primarily in industrial applications—bulletproof glass, eyeglasses lenses, CDs and DVDs, and automotive components. Its journey into 3D printing is relatively recent, becoming more accessible to hobbyists and professionals around the mid-2010s when high-temperature 3D printers started to become more affordable.
Initially, working with polycarbonate in 3D printing was considered an advanced technique reserved for industrial machines. As printer technology evolved and more all-metal hotends capable of reaching higher temperatures became available, PC filament gradually became a viable option for enthusiasts with properly equipped printers.
Advantages of Polycarbonate for 3D Printing
Polycarbonate offers several compelling advantages that make it worth the extra effort required to print with it:
Exceptional Strength and Durability: Imagine needing to print a part that will be subjected to significant mechanical stress—perhaps a drone component or a mounting bracket. Polycarbonate provides tensile strength that far exceeds common materials like PLA or even ABS. This means your printed parts can withstand forces that would cause other materials to snap or break.
Outstanding Impact Resistance: If you've ever dropped your smartphone with a polycarbonate case and watched it bounce rather than shatter, you've witnessed this property firsthand. PC can absorb and dissipate energy from impacts remarkably well. This makes it ideal for protective cases, shields, and parts that might experience sudden forces.
High Heat Resistance: With a glass transition temperature of approximately 147°C (compared to PLA's 60°C), polycarbonate parts maintain their structural integrity in hot environments. Think about an automotive part near an engine or a component for a hot appliance—polycarbonate can handle these situations where PLA would simply deform.
Optical Clarity: Unlike many 3D printing materials that produce opaque parts, polycarbonate can be printed with a degree of transparency when processed correctly. This enables applications like light diffusers, protective covers for displays, or even custom lenses.
Dimensional Stability: Once cooled, polycarbonate maintains its shape exceptionally well, even under load. This property is crucial for precision parts or components that must maintain exact dimensions over time.
Chemical Resistance: Polycarbonate resists many chemicals and solvents that might damage other plastics, making it suitable for laboratory equipment or parts exposed to potentially corrosive substances.
Flame Retardant Properties: Polycarbonate naturally tends to self-extinguish rather than propagate flames, an important safety feature for electrical enclosures or components where fire safety is a concern.
UV Resistance: For outdoor applications where parts will be exposed to sunlight, polycarbonate offers good resistance to degradation from UV radiation.
Disadvantages of Polycarbonate
Despite its impressive properties, polycarbonate does present several challenges that anyone considering this material should understand:
High Printing Temperature Requirements: Polycarbonate needs nozzle temperatures of 260-310°C to properly extrude. This is significantly higher than the 180-220°C range used for materials like PLA or PETG. This requirement eliminates many entry-level printers from being able to work with PC.
Warping Tendencies: Due to its high printing temperature and the significant thermal contraction that occurs as it cools, polycarbonate has a strong tendency to warp. Imagine trying to keep a hot, flowing plastic perfectly in place as it cools and contracts—this is the challenge with PC. The first layers often curl up from the print bed, and larger flat surfaces may develop internal stresses that cause deformation.
Moisture Sensitivity: Polycarbonate is highly hygroscopic, meaning it readily absorbs moisture from the air. Even exposure to humid air for a few hours can cause the filament to degrade. When moisture-laden PC is heated in the printer, the water turns to steam, causing popping sounds, bubbles, and significantly weakened parts.
Bed Adhesion Difficulties: Getting that crucial first layer to stick properly to the print bed can be challenging with polycarbonate. It often requires specialized build surfaces or adhesion solutions.
Cost Considerations: Compared to more common materials like PLA (typically $20-30 per kilogram), polycarbonate filament often costs $40-80 per kilogram. This price premium reflects both the material's superior properties and the more complex manufacturing process.
Energy Consumption: The high temperatures required for printing polycarbonate translate to increased electricity usage. Your printer's heaters will need to work harder and longer, which may be a consideration for those mindful of energy costs.
Potential for Harmful Emissions: When heated to printing temperatures, polycarbonate can release ultrafine particles and volatile organic compounds that may pose health risks if not properly ventilated.
3D Printer Requirements for Polycarbonate
Not all 3D printers are created equal when it comes to handling polycarbonate. Here's what your machine needs to successfully print with this demanding material:
High-Temperature Hotend: The heart of your printer must be capable of safely reaching and maintaining temperatures of at least 300°C. This typically means an all-metal hotend, as hotends with PTFE liners (common in budget printers) begin to degrade around 250°C and can release toxic fumes at higher temperatures.
Powerful Heated Bed: Your print bed needs to reach and maintain temperatures of 100-135°C. Many standard heated beds top out at 80-100°C, which is insufficient for larger PC prints. The bed must also heat evenly to prevent differential cooling that can exacerbate warping.
Enclosed Build Chamber: Think of this as creating a specialized environment for your print. An enclosed chamber helps maintain a consistent ambient temperature around your print, reducing the temperature differential that causes warping. For polycarbonate, an enclosed chamber isn't just helpful—it's nearly essential for prints of any significant size.
Controlled Cooling: Unlike materials that benefit from rapid cooling, polycarbonate prints better with minimal cooling, particularly for the first several layers. Your printer should allow you to reduce or disable cooling fans and control cooling rates precisely.
Suitable Build Surface: Standard build surfaces often don't provide adequate adhesion for polycarbonate. Specialized surfaces like PEI (Polyetherimide), polycarbonate sheets, or glass treated with appropriate adhesives (like Magigoo PC or specialized glue solutions) are typically necessary.
Robust Frame and Motion System: The high temperatures used with PC put additional stress on your printer's mechanical components. A rigid frame and reliable motion system help maintain precision under these demanding conditions.
Filament Drying System: Due to PC's hygroscopic nature, a filament dryer is practically essential. These specialized devices remove moisture from the filament before printing, significantly improving print quality and strength.
Material Properties of Polycarbonate
Bed Temp | 80-120°C |
Density | 1.2 g/cm3 |
Heated Bed | Required |
Coefficient of Thermal Expansion | 69 µm/m-°C |
Ultimate Strength | 72 MPa |
Extruder Temp | 260-310°C |
Printability | Medium |
Max Service Temp | 121°C |
Stiffness | Medium |
Durability | Very High |
How to Print with Polycarbonate - Tips and Tricks
Think of these as the lessons learned by those who've already walked the challenging path of mastering polycarbonate printing:
Prepare Your Filament: Always dry your polycarbonate filament before printing, typically at 70-80°C for 4-8 hours in a filament dryer or modified food dehydrator. Even new, factory-sealed filament often benefits from drying.
Build Chamber Management: If your printer doesn't have an enclosed chamber, consider creating a temporary enclosure using a cardboard box or build a permanent one using heat-resistant materials. Some users even place their entire printer in a small tent to maintain ambient temperature.
Adhesion Solutions: Experiment with different bed surfaces and adhesion methods. Some users find success with a layer of glue stick on glass, while others prefer specialized PC adhesives on PEI surfaces.
Start Small: Begin with smaller prints to dial in your settings before attempting large pieces that will take many hours to complete.
Post-Processing Possibilities: Polycarbonate can be sanded, drilled, and tapped effectively. It responds well to various finishing techniques, including vapor smoothing with dichloromethane (though this requires extreme caution due to the chemical's hazards).
Ventilation Matters: Always ensure adequate ventilation when printing with polycarbonate to minimize exposure to potential harmful emissions.
Applications of Polycarbonate
The exceptional properties of polycarbonate make it ideal for specific applications where standard materials fall short:
Engineering Prototypes and Functional Parts: When your prototype needs to function like the final product or undergo real-world testing, PC provides the strength and durability to withstand actual use conditions.
Automotive Components: Parts that need to withstand engine heat or mechanical stress, such as custom intake components, mounting brackets, or interior fixtures.
Drone and RC Vehicle Parts: Frames, mounts, and protective components that need to be lightweight yet incredibly strong and impact-resistant.
Protective Cases and Enclosures: Custom cases for electronic devices or equipment that need to withstand rough handling.
Outdoor Use Components: Parts exposed to weather elements benefit from PC's UV resistance and durability.
Medical and Laboratory Equipment: Custom fixtures, holders, or tools that need to withstand sterilization processes.
Optical Components: Custom light diffusers, lenses, or protective covers for lighting systems.
What is Polycarbonate Carbon Fiber?
Polycarbonate Carbon Fiber (PC-CF) is a composite 3D printing filament made by combining Polycarbonate (PC) with carbon fiber. This blend combines the high-strength properties of polycarbonate with the lightweight reinforcement of carbon fiber, resulting in a material that is both strong, durable, and stiff, while also being lighter and offering improved thermal resistance.
Exceptional Strength and Durability: Polycarbonate is already known for its high strength, impact resistance, and toughness, and when reinforced with carbon fiber, PC-CF becomes even stiffer and stronger. It offers high tensile strength and resilience under mechanical stress, making it ideal for parts that need to withstand heavy use.
Lightweight: Despite its increased strength, the addition of carbon fiber makes PC-CF significantly lighter than pure Polycarbonate while maintaining high performance, which is ideal for applications requiring both strength and low weight.
High Heat Resistance: Polycarbonate has one of the highest heat resistance values among thermoplastics. PC-CF can withstand temperatures of up to 110-120°C before softening or deforming, making it suitable for applications that experience high temperatures.
Improved Surface Finish: The carbon fiber reinforcement gives PC-CF a matte, textured finish, which not only improves its aesthetic appearance but also reduces the visibility of layer lines in the final print. It can also enhance the material's wear resistance.
Enhanced Rigidity and Stiffness: PC-CF is much stiffer than both regular Polycarbonate and other carbon fiber composites, making it ideal for creating parts that need to maintain their form under stress.
Abrasion Resistance: The carbon fiber in PC-CF increases its abrasion resistance, making it more durable in environments where parts may be subjected to friction or wear, such as moving components, gears, and industrial applications.
Reduced Warping: Like Polycarbonate, PC-CF tends to be more prone to warping due to its high thermal contraction. However, the addition of carbon fiber helps reduce warping to some extent, though a heated bed (around 100-120°C) is still necessary.
Not right for you? Learn about other materials here.
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