BASF 3D Ultrafuse PAHT CF15 is a carbon-fiber-reinforced high-temperature polyamide feedstock for fused filament fabrication. The product designation Dry identifies spools that have been pre-dried before sealing and packaged with desiccant to maintain residual moisture below 0.10 wt% at sealing. The formulated matrix is a heat-stabilized polyamide containing 15 wt% chopped carbon fiber. Available diameters are 1.75 mm and 2.85 mm depending on regional spool configuration. Compounded density is typically 1.17–1.19 g/cm³ under ISO 1183-1. The grade is specified for stiff tooling, assembly fixtures, robotic end-effector components, drill guides, inspection nests, brackets, and short-run functional parts requiring higher thermal dimensional stability than unfilled polyamide 6/66. The carbon fiber reduces warping relative to unfilled polyamide but introduces anisotropic mechanical behavior because fiber orientation follows the raster plane. Feedstock moisture, nozzle material and temperature, and build-chamber thermal uniformity are the three variables that most strongly control printed-part performance.

What separates a 15 wt% carbon-fiber high-temperature polyamide from unfilled PA6/66 in extrusion processing?

The reinforced grade primarily raises stiffness and lowers ductility. Manufacturer-published dry-condition XY properties place tensile modulus at 6,200 MPa to 6,500 MPa using ISO 527-2, tensile strength at 115 MPa to 125 MPa, flexural modulus at 5,800 MPa to 6,000 MPa using ISO 178, and elongation at break below 3%. Equivalent unfilled PA6/66 filament typically shows tensile modulus of 2,600 MPa to 3,000 MPa and elongation above 20%. Heat deflection temperature at 1.8 MPa for PAHT CF15 is generally reported between 150°C and 180°C under ISO 75-1/-2; unfilled PA6/66 is generally below 100°C. The coefficient of linear thermal expansion is reduced by the carbon fiber, which lowers in-plane warpage relative to neat polyamide but creates stronger directional variation because fiber orientation is concentrated in the deposited layer plane.

The carbon fiber also modifies melt rheology. Melt viscosity is higher than unfilled PA6/66 at equivalent shear rates, which reduces the practical printing speed and increases the risk of nozzle clogging when fiber-rich melt is retracted into cold zones. Interlayer adhesion is more sensitive to chamber temperature than in unfilled polyamide because the fiber phase disrupts polymer chain diffusion across the build surface. These effects make the processing window narrower than neat PA6/66, even though the dried feedstock produces stiffer parts.

When drying, nozzle temperature, and chamber heat become the primary process gates

The Dry designation is a packaging condition, not a permanent material property. After the sealed spool is opened, the polyamide matrix begins moisture uptake. In a production hall at 50% relative humidity, moisture regain on an open spool can reach levels that cause hydrolysis at melt temperature within 24 h. Symptoms of wet feedstock include rough extrudate surfaces, audible popping at the nozzle, reduced interlayer peel strength, and voiding on part surfaces. Spools exposed above 30% RH for more than 24 h should be re-dried at 80°C for 4–8 h in a forced-air desiccant dryer with a dew point of −20°C or lower. Vacuum drying is acceptable if the spool reaches 80°C uniformly; microwave or static-oven drying without forced air circulation is not recommended because local overheating can oxidatively degrade the polyamide matrix.

Extrusion is specified at 280–300°C nozzle temperature, with build plate temperature between 100°C and 120°C and chamber temperature between 60°C and 80°C when available. The feedstock is abrasive; nozzle orifices should be hardened steel or tungsten carbide, and 0.4 mm is the practical minimum diameter for continuous production. Layer heights of 0.15–0.25 mm with a 0.4 mm nozzle or 0.20–0.30 mm with a 0.6 mm nozzle help reduce fiber jamming. Retraction distance should be limited below 2 mm on direct-drive systems to avoid pulling fiber-rich melt into cold zones. Build surfaces are typically PEI or nylon-specific adhesive at the stated bed temperature. The material is printed with a closed chamber whenever possible; chamber temperatures below 60°C promote z-direction splitting on thick sections and sharp corners. The process window is narrower than unfilled PA6/66 because the fiber increases melt viscosity and reduces interlayer autohesion when cooling is too rapid.

In industrial practice, the material is used in assembly fixtures, robotic gripper fingers, drill guides, inspection nests, brackets subjected to moderate heat, and replacement covers on machine tools. A representative production configuration is a direct-drive FFF system with 0.6 mm hardened steel nozzle, actively heated chamber at 70°C, build plate at 110°C, and nozzle temperature held at 290°C. Raster angles of ±45° or 0°/90° are selected to distribute fiber orientation; parts loaded primarily in one plane are often printed with the dominant load direction parallel to the raster. In such configurations, published processing bulletins for carbon-fiber polyamides describe reduced warping versus neat PA, but an increase in surface roughness and the need for post-process edge breaking because cut carbon fibers produce sharp edges. Holes should be reamed rather than printed to final size when dimensional stability below 0.1 mm is required, because fiber-filled FFF hole roundness is lower than that of unfilled materials.

When replacing metal in low-mass handling equipment, PAHT CF15 parts can reduce end-of-arm tooling mass, but the design must account for orientation-dependent modulus and lower z-direction strength. Printed z-tensile and interlaminar shear values are lower than XY properties. Published data for this specific configuration is limited, but fiber-filled FFF parts often show z-direction strength reductions of 30% to 50% relative to XY tensile strength depending on chamber temperature and raster overlap. Load-bearing threaded inserts should be heat-staked or adhesively bonded rather than press-fit into undersized holes to avoid delamination at the hole wall.

Comparative selection across polyamide, glass-filled, and metal-replacement material classes

Compared with unfilled PA6/66, PAHT CF15 provides roughly 2× to 2.5× tensile modulus and higher thermal distortion resistance at the expense of elongation and notched impact. The unfilled polyamide remains preferable for snap-fit designs or cases requiring high elongation and lower feedstock cost. Compared with glass-filled polyamide filament, PAHT CF15 has lower density and higher specific stiffness, but glass-filled grades are generally lower in cost and electrically insulating; the carbon-fiber grade may exhibit surface conductivity and should be evaluated for electronic isolation. Compared with PA12 CF, PAHT CF15 tends to have higher upper-temperature capability and higher short-term stiffness, while PA12 CF has lower moisture uptake and better resistance to some automotive fluids. Compared with PEEK or PEI, PAHT CF15 processes at lower extrusion temperatures and places less demand on high-temperature build plates, but continuous-use temperature is lower; PEEK remains appropriate where service conditions exceed 180°C.

For regulatory documentation, the supplier should be asked for the current REACH and RoHS declaration for the specific spool lot. The product is not a food-contact grade, and any use in medical or pharmaceutical contact requires separate validation under applicable device or food-contact regulations. These comparisons are selection heuristics; final material substitution requires printed coupons, heat treatment, dimensional checks, and mechanical testing of conditioned parts according to project-specific standards.

Published data for creep, fatigue, UV aging, and moisture-conditioned performance in FFF PAHT CF15 are more limited than for injection-molded 15% carbon-fiber PA66. Design calculations should not use dry-room XY tensile data as isotropic. Moisture exposure at 50% RH and 23°C can reduce stiffness and increase toughness relative to dry values; the magnitude depends on wall thickness and conditioning time. Continuous contact with strong acids, strong bases, or aggressive hydraulic fluids should be avoided unless component-specific immersion testing demonstrates compatibility. Storage after opening should be in a desiccated cabinet at 20–30% RH or in a re-sealed bag with fresh desiccant; ambient bench storage in humid production halls is not recommended for more than 24 h without re-drying.