At nominal diameter 1.75 mm or 2.85 mm, the Clariant Black Polycarbonate 3D Printer Filament is supplied as an unfilled, carbon black-pigmented polycarbonate monofilament intended for fused filament fabrication. A grade-specific model number is not consistently used across distribution channels; the incoming lot certificate therefore functions as the primary product identifier and should record polymer family, diameter, colorant class, melt volume-flow rate, residual moisture, and winding tractive force. Published test data for this specific Clariant product configuration are limited, so batch-specific verification against the certificate of analysis is required before production use. The nominal density falls between 1.19 g/cm³ and 1.21 g/cm³ when measured by ISO 1183-1:2019. Diameter tolerance is typically controlled within ±0.05 mm for the 1.75 mm offering and ±0.10 mm for the 2.85 mm offering when sampled with an optical micrometer at 20 °C to 23 °C.

Production-scale extrusion of pigmented polycarbonate on a twin-screw line with an L/D ratio near 40:1 uses vacuum venting at approximately -0.08 MPa to hold residual moisture below 0.02 % before pelletizing and filament winding. The black coloration is achieved with a carbon black masterbatch dispersed in bisphenol-A polycarbonate; the additive package does not convert the resin into a flame-retardant compound unless the lot certificate states a UL 94 classification. The product is not a low-temperature material. It is specified for builds where the part may see short-term thermal soak or where the design requires heat deflection temperature above that of ABS or PETG. The base resin and colorant are typically supplied with declarations referencing RoHS 2011/65/EU and the REACH candidate list in force at the time of supply, but the signed lot certificate must be requested for each batch.

What processing boundaries prevent delamination and warp in this filament?

Pre-drying is required. Residual moisture above 0.02 % by weight causes hydrolysis, splay, and molecular weight loss during extrusion. A forced-air desiccant dryer held at 80 °C for 4 h to 6 h is sufficient for filament stored below 35 % relative humidity. If the spool has been exposed at 60 % relative humidity or higher for more than 72 h, drying at 120 °C for 3 h to 4 h may be required, but the spool material and label must be removed or verified to withstand that temperature. Hot-air ovens without desiccant can retard moisture removal because the air dew point remains elevated; a desiccant bed with supply dew point below -20 °C is preferred.

The extrusion temperature window is bounded by melt viscosity on the cold side and chain scission on the hot side. Melt volume-flow rate for unfilled polycarbonate filament typically falls between 5 cm³/10 min and 10 cm³/10 min under 300 °C and 1.2 kg load according to ISO 1133-1:2022. The recommended nozzle set point is 270 °C to 310 °C, with direct-drive extruders usually run at the lower end. Below 260 °C, layer fusion declines and interlayer tensile strength is reduced. Above 320 °C, residence time must be limited to avoid thermal degradation and black speck formation. A heated bed at 100 °C to 120 °C, combined with an enclosed chamber stabilized at 55 °C to 80 °C, reduces asymmetric shrinkage. Open-frame printers can build small parts but may show corner lifting for flat dimensions greater than 80 mm unless raft, brim, or polyimide tape adhesion is used.

Layer deposition should use a hardened steel or stainless steel nozzle if carbon black pigmentation creates a mildly abrasive melt stream, although unfilled polycarbonate is less abrasive than carbon fiber-reinforced grades. A 0.4 mm brass nozzle is adequate for short production runs; a 0.6 mm nozzle lowers pressure drop in high-speed tool paths. Print speeds from 30 mm/s to 60 mm/s are typical. Retraction distance for direct-drive heads is 0.5 mm to 1.5 mm; Bowden systems may require 3 mm to 6 mm but introduce greater stringing risk. The part cooling fan should remain off for the first 10 to 20 layers; subsequent cooling is limited to 20 % to 40 % to prevent layer separation and edge curl.

Comparative Mechanical Properties Against Lower-Heat Filaments

When the filament is substituted for ABS or PETG in functional prototypes, the mechanical advantage is usually expressed through tensile yield stress, flexural modulus, and heat deflection temperature rather than ultimate elongation. Table 1 summarizes comparative property ranges from standardized test methods. The values are representative for unfilled black polycarbonate filament and for widely distributed unfilled ABS, PETG, and PC-ABS blend filaments; batch-specific values should be taken from the lot certificate. Unfilled polycarbonate exhibits a yield stress near 60 MPa to 70 MPa when tested at 50 mm/min according to ISO 527-2:2012. Flexural modulus is approximately 2,200 MPa to 2,400 MPa under ISO 178:2019. Heat deflection temperature typically ranges from 130 °C to 140 °C at 1.8 MPa using ISO 75-2/A. These characteristics make the material suitable for dimensionally stable jigs and fixtures that contact hot air or are located near heat sources, but published case data for this specific filament configuration is limited.

The high modulus carries a processing penalty. Unfilled polycarbonate exhibits higher volumetric shrinkage than PLA and requires a higher chamber temperature for flat parts. Mold shrinkage for unfilled polycarbonate is typically reported between 0.5 % and 0.7 %, but fused filament fabrication part shrinkage depends on build path, raster angle, and chamber temperature. Published data for this specific product configuration is limited. Interlayer tensile strength is not covered by a globally harmonized test method; internal qualification should use a Type V tensile specimen oriented in the z-axis and report the failure mode. Fracture at the layer interface, rather than through printed roads, indicates that extrusion temperature, chamber temperature, or layer time must be adjusted.

If the printed part is exposed to fuels, cleaning solvents, or alkaline process water, where do the chemical limits lie?

Polycarbonate is sensitive to environmental stress cracking in the presence of aromatic hydrocarbons, ketones, esters, and some amines. The black pigmentation does not alter the base chemical resistance, but stress concentrations from layer grooves and build orientation accelerate crack initiation. Acetone, methyl ethyl ketone, toluene, and xylene should be avoided for cleaning and for service contact because surface crazing can occur below the short-term yield stress when the part is under continuous load. Isopropanol and ethanol at room temperature are generally acceptable for wipe cleaning, provided the part is unstressed and the solvent is allowed to evaporate before mechanical loading. Alkaline solutions at pH 10 or higher can hydrolyze the polymer surface over repeated exposure. Sustained immersion in hot water above 60 °C reduces molecular weight by hydrolysis and should be qualified with a tensile test before production use.

Hydrocarbon-based lubricants and greases with high aromatic content can plasticize and reduce modulus. Silicone-based release agents are generally compatible but may interfere with painting or adhesive bonding. Flame-retardant additives are not claimed unless specifically stated in the lot certificate; therefore, the unfilled black grade should not be used as a substitute for UL-recognized flame-retardant polycarbonate compounds without independent testing. For electronic enclosures, the applicable standard is IEC 60695-11-10 or UL 94 at the final wall thickness. Unfilled polycarbonate often exhibits a V-2 rating at 1.5 mm, but performance depends on thickness and pigment loading. Published data for this specific black product is limited. Amine-based purge compounds and certain amine-containing flame retardant masterbatches should not be combined with polycarbonate because they can promote degradation and surface haze.

In contrast to carbon fiber-reinforced polycarbonate filament, the unfilled black grade has lower tensile modulus and lower brittleness, but it also avoids galvanic wear of brass nozzles and reduces the need for hardened tooling. Compared with PETG, the unfilled polycarbonate offers higher heat deflection temperature and higher tensile yield stress, but it requires a higher nozzle temperature and a closed chamber for flat parts. Compared with ABS, the polycarbonate filament does not evolve styrene monomer during printing, which reduces odor complaints in enclosed workspaces, but local exhaust ventilation is still required for any polymer melt processing. Compared with PC-ABS blends, the unfilled polycarbonate has higher heat deflection temperature but lower low-temperature impact toughness because no elastomeric phase is present. The operational boundary of the product is therefore defined by moisture control, chamber temperature, solvent exposure, and mechanical load. The material is used in fused filament fabrication for tooling and fixture components where dimensional stability under warm air or direct contact with heated surfaces is required. The product is not recommended for continuous immersion in water at temperatures above 60 °C unless hydrolysis is accounted for in the design safety factor.