Polymaker Fiberon PA6-CF20

# Polymaker Fiberon PA6-CF20

Overview

Polymaker Fiberon PA6-CF20 is a 20 wt% carbon-fiber-reinforced PA6 (Nylon 6) filament for rigid engineering parts, tooling, fixtures, automotive components, and low-volume production. It is the Fiberon-branded continuation of Polymaker's former PolyMide PA6-CF formulation.

The material combines high stiffness, strong dry mechanical performance, and unusually high heat-deflection values for a printable nylon composite. Polymaker's current technical data sheet reports 109.3 ± 2.4 MPa XY tensile strength, 8.64 GPa XY Young's modulus, 161.0 ± 3.9 MPa XY flexural strength, and 215°C HDT at 0.45 MPa for the characterized dry material.

Those headline numbers need context. Polymaker states that its dry and wet mechanical test specimens were annealed at 100°C for 16 hours, and PA6-CF20 is highly moisture sensitive. Moisture can substantially reduce tensile strength and stiffness while increasing ductility and impact behavior, so drying and humidity control are part of the engineering workflow.

For current manufacturer information, see the official Fiberon PA6-CF20 page and official PA6-CF20 technical data sheet.

Key Strengths

• 20 wt% carbon-fiber-reinforced PA6
• 109.3 ± 2.4 MPa dry annealed XY tensile strength
• 8.64 GPa dry annealed XY Young's modulus
• 161.0 ± 3.9 MPa dry annealed XY flexural strength
• 215°C HDT at 0.45 MPa
• 173°C HDT at 1.8 MPa
• Fiber Adhesion technology
• High stiffness and dimensional stability
• Up to 300 mm/s published print speed
• Same core formula as former PolyMide PA6-CF

Best For

1. Engineering prototypes
2. Jigs and fixtures
3. Industrial tooling
4. Automotive brackets and housings
5. Rigid machine components
6. Heat-resistant functional parts
7. Low-volume production

Technical Specifications

Mechanical-data note: The current Polymaker TDS states that the dry and wet mechanical test specimens were annealed at 100°C for 16 hours. The published tensile and modulus values should therefore not be presented as guaranteed as-printed properties.

Mechanical Profile

Polymaker's dry, annealed printed-specimen data shows strong directional mechanical performance:

The high modulus and low elongation make PA6-CF20 best suited to stiff, load-bearing geometry rather than flexible parts.

The difference between XY and Z properties also matters. Carbon fiber improves stiffness and dimensional behavior, but it does not eliminate FDM anisotropy. Critical parts should still be oriented so the most important loads are carried in the strongest print direction whenever possible.

Moisture Sensitivity

PA6 is hygroscopic, and Fiberon PA6-CF20 should be treated as a moisture-sensitive engineering filament.

Polymaker's wet-condition data illustrates why this matters. After annealing and moisture conditioning to an average moisture content of approximately 5.3%, the published XY tensile strength falls to roughly 54.7 MPa and XY Young's modulus to about 2.51 GPa.

Moisture therefore changes the mechanical behavior of the nylon matrix rather than only affecting surface appearance.

For repeatable engineering results, control:

• Drying before use
• Humidity while printing
• Dry-box storage
• Time exposed to room air
• Finished-part conditioning
• Service humidity

A dry TDS value should not automatically be used as the design value for a part that will operate in a humid environment.

Drying and Storage

Polymaker recommends storing and using PA6-CF20 under dry conditions with relative humidity below approximately 20%.

When the filament has absorbed moisture, Polymaker specifies:

100°C for 10 hours

Polymaker also lists a PolyDryer Level 3 cycle of approximately 18 hours.

Typical signs of wet PA6 include popping during extrusion, rough surfaces, stringing, bubbles, inconsistent flow, and changes in finished-part behavior.

For long jobs, feeding directly from a dry box or active dryer can help maintain more consistent processing.

Printing Requirements

The manufacturer's current recommended profile is:

• Nozzle: 280–300°C
• Bed: 40–50°C
• Chamber: room temperature
• Cooling fan: off
• Speed: up to 300 mm/s

A suitable printer should have:

• All-metal hotend capable of the full temperature range
• Wear-resistant nozzle
• Heated build plate
• Reliable filament drying
• Stable extrusion path

The 300 mm/s figure is a maximum material-profile speed. Actual production speed depends on hotend flow, nozzle diameter, layer height, geometry, acceleration, and the printer's ability to melt a fiber-filled nylon consistently.

Abrasion and Nozzle Choice

PA6-CF20 is highly abrasive.

Polymaker's current technical documentation specifically warns about rapid brass-nozzle wear and recommends wear-resistant hardware such as:

• Hardened steel
• Ruby
• Equivalent abrasion-resistant nozzle materials

A worn nozzle can change extrusion width, flow calibration, dimensional accuracy, and surface quality over time.

For repeated production, nozzle condition should be included in normal process-control checks.

Enclosure and Chamber Requirements

The dedicated Fiberon PA6-CF20 product profile specifies room-temperature chamber conditions and states that a heated chamber is not required.

That makes `requiresEnclosure: false` appropriate for the structured listing.

A conventional enclosure can still reduce drafts and make the local environment more consistent for large or warp-sensitive parts, but it should not be described as a mandatory material requirement.

Among indexed printers, the Bambu Lab H2D and Creality K2 Plus are relevant high-temperature composite platforms. The Bambu Lab P2S is another compact option when its nozzle, filament handling, and profile are configured for PA-CF.

Printer compatibility should be based on the full material path, not nozzle temperature alone.

Annealing

Polymaker recommends annealing PA6-CF20 at:

100°C for 16 hours

The published dry mechanical data is based on annealed specimens.

Annealing can improve thermal and mechanical performance, but it may also cause small dimensional changes. For tolerance-critical production parts, print and anneal a representative coupon before finalizing compensation values.

A practical validation workflow is:

1. Print a representative sample.
2. Measure the as-printed dimensions.
3. Anneal using the intended production cycle.
4. Measure again.
5. Apply compensation where necessary.
6. Validate the finished production part.

Heat Resistance

Polymaker publishes:

• 215°C HDT at 0.45 MPa
• 173°C HDT at 1.8 MPa
• 219.2°C Vicat softening temperature
• 218.5°C melting temperature

HDT is a standardized deflection test under a defined load. It is not the same as a guaranteed continuous service temperature.

Long-duration use at elevated temperature also depends on load, creep, humidity, orientation, thermal cycling, and chemical exposure.

Comparison With Other Carbon-Fiber Materials

Prusament PA11 Carbon Fiber

Prusament PA11 Carbon Fiber uses a different nylon chemistry with a stronger emphasis on toughness, wear behavior, chemical resistance, and lower moisture sensitivity than PA6.

Fiberon PA6-CF20 is the stronger choice when maximizing dry stiffness, tensile performance, and HDT is the main priority.

Prusament PC Blend Carbon Fiber

Prusament PC Blend Carbon Fiber provides a polycarbonate-based alternative with strong dimensional stability and less nylon-style moisture sensitivity.

PA6-CF20 offers substantially higher published HDT, while PC Blend CF can be easier to manage when moisture conditioning is a major concern.

For printer selection, see Best 3D Printers for Carbon-Fiber Materials in 2026.

Former PolyMide PA6-CF Name

Polymaker states that Fiberon PA6-CF20 uses the same proven formula as PolyMide PA6-CF.

The newer Fiberon material may have a slightly darker black appearance, but older PolyMide PA6-CF references remain relevant when checking historical profiles and application examples.

Packaging, Price, and Availability

The dedicated Fiberon product page lists 1.75 mm filament in 500 g and 2 kg formats.

Polymaker's current US store lists pricing from US$39.99 for 500 g.

Limitations and Practical Considerations

• Highly moisture sensitive
• Abrasive and unsuitable for standard brass-nozzle use
• Published headline mechanical values are based on annealed specimens
• Wet properties differ substantially from dry properties
• Low elongation means the dry material is stiff rather than ductile
• Annealing can change dimensions
• FDM parts remain anisotropic
• HDT is not a continuous-use temperature rating
• Maximum print speed depends strongly on printer flow capability
• Current US inventory is limited

Callout Section

Recommended use: Choose Polymaker Fiberon PA6-CF20 when high dry stiffness, strong tensile performance, dimensional stability, and elevated-temperature capability justify disciplined drying, abrasive-material hardware, and post-print annealing.

Frequently Asked Questions