Polycarbonate (PC)

Polycarbonate is a high-performance thermoplastic for demanding 3D printed parts requiring toughness, heat resistance, and dimensional precision in industrial environments.

Introduction to Polycarbonate (PC) for 3D Printing

Polycarbonate (PC) is a high-performance thermoplastic known for its outstanding impact resistance, high heat deflection temperature, and dimensional stability. It is ideal for demanding functional parts such as mechanical housings, load-bearing brackets, and enclosures exposed to high temperatures or impact loads.

Fused Deposition Modeling (FDM) is the most common method for 3D printing PC, offering dimensional accuracy of ±0.2 mm and structural integrity suitable for both prototyping and low-volume end-use production.

International Equivalent Grades of Polycarbonate

Standard	Grade Code	Common Names
ISO	ISO 7391	Polycarbonate (PC) Resin
ASTM	D3935	PC Engineering Plastic
China	GB/T 12670	聚碳酸酯 (Polycarbonate)
Trade	—	Lexan®, Makrolon®, etc.

Comprehensive Properties of Polycarbonate (PC)

Property Category	Property	Value
Physical	Density	1.20 g/cm³
	Glass Transition Temperature	~147°C
	Heat Deflection Temperature	130–140°C
Mechanical	Tensile Strength	55–70 MPa
	Flexural Modulus	2,200–2,500 MPa
	Elongation at Break	60–120%
	Impact Resistance (Notched)	>700 J/m

Suitable 3D Printing Processes for Polycarbonate

Process	Typical Density Achieved	Surface Roughness (Ra)	Dimensional Accuracy	Application Highlights
FDM	≥95%	12–18 µm	±0.2 mm	Ideal for impact-resistant prototypes, enclosures, jigs, fixtures, and functional assemblies

Selection Criteria for PC 3D Printing Processes

High Heat Resistance: PC maintains shape and functionality under continuous loads at temperatures exceeding 130°C—suitable for automotive and industrial environments.
Exceptional Impact Strength: PC resists breakage under repeated or sudden loading, making it ideal for mechanical housings, lenses, and snap-fit mechanisms.
Dimensional Precision: When printed with a 260–300°C nozzle and heated bed (110–120°C), PC offers strong interlayer adhesion and low warpage.
Post-Processing Capability: PC supports sanding, machining, painting, and bonding for aesthetic and functional enhancement of printed parts.

Essential Post-Processing Methods for Polycarbonate (PC) 3D Printed Parts

CNC Machining: Provides ±0.02 mm precision for tight fits, holes, and surfaces requiring high flatness or sealing capability.
Annealing/Heat Treatment: Reduces internal stress and improves thermal resistance by annealing parts at ~110°C for 1–2 hours post-print.
Surface Sanding & Polishing: Improves optical clarity and mechanical finish, particularly for transparent PC parts or surfaces in contact applications.
Solvent Bonding & Assembly: Industrial adhesives or solvent bonding ensure structural joins in multi-part assemblies or enclosure systems.

Challenges and Solutions in PC 3D Printing

Warping and Layer Delamination: Use enclosed, heated chambers to maintain build temperature; consistent thermal control is key for warp-free PC prints.
Moisture Sensitivity: Dry filament at 80–90°C for 6–8 hours before printing. PC absorbs water quickly, causing bubbling or poor adhesion if wet.
High Print Temperature Requirements: PC prints best at 260–300°C. Ensure your printer's hotend and enclosure can support these temperatures safely and reliably.

Applications and Industry Case Studies

Polycarbonate is widely used in:

Automotive: Under-hood components, light covers, and functional brackets exposed to high mechanical and thermal stress.
Aerospace: Impact-resistant fairings, housings, and thermal enclosures with excellent dimensional control.
Tooling & Manufacturing: Jigs, inspection gauges, press-fit tools, and safety guards.
Consumer Products: Lens prototypes, protective casings, electrical housings, and durable display parts.

Case Study: A tooling supplier replaced machined polycarbonate jigs with 3D printed equivalents. The jigs maintained dimensional accuracy (±0.15 mm) and impact resistance after 500 use cycles, reducing lead time by 70%.