Covestro Addigy FPC 3D1000 is a flame-retardant polycarbonate monofilament developed for fused filament fabrication. The model designation FPC 3D1000 identifies an unreinforced, amorphous bisphenol-A polycarbonate formulated with a non-halogen flame-retardant package and converted into dimensionally controlled filament. The manufacturer lists two diameter grades, 1.75 mm and 2.85 mm, with a nominal diameter tolerance of ±0.05 mm and roundness measured at 0.03 mm. Spools are sealed in moisture-barrier packaging. This product is intended for industrial three-dimensional printers fitted with actively heated build chambers, rather than open-frame equipment.

Typical density is published as 1.19 g/cm³ under ISO 1183-1. Melt volume rate at 300 °C and 1.2 kg is 10 cm³/10 min under ISO 1133-1. The amorphous phase has a glass transition temperature near 145 °C measured by differential scanning calorimetry under ISO 11357-2. This thermal baseline requires a heated chamber because the material solidifies through a rubbery-to-glassy transition that produces significant bulk shrinkage when the part surface cools below 145 °C before the next layer is deposited.

The FPC designation denotes flame-retardant behaviour. The base resin carries a thickness-dependent UL 94 classification, with a 1.5 mm test specimen listed as V-0 in the manufacturer’s resin Yellow Card. Printed-part flammability depends on shell count, infill index, layer fusion, and air voids. The filament is therefore specified for electrical and electronics enclosures, while the final printed part must be validated under the relevant end-product standard.

What Causes Layer Delamination When Chamber Temperature Falls Below the PC Glass-Transition Envelope?

In fused filament fabrication of amorphous polycarbonate, the chamber setpoint functions as a slow-cooling environment that reduces the cooling rate of the printed skin and the interior weld zones. When the chamber temperature drops below 70 °C, the upper surface of a deposited bead can pass through the glass transition before the next bead is placed. The interface temperature at the moment of contact then falls below 145 °C, limiting chain diffusion and reducing weld strength to a value below the bulk tensile yield stress.

High-mass parts with unequal wall thicknesses develop thermal gradients across the z-axis. A build chamber setpoint of 80 °C to 90 °C is specified because the thermal expansion mismatch between the deposited skin and the already cooled core creates tensile residual stress. On aluminium build plates with a polyetherimide adhesion sheet, deviations of 5 °C from the lower setpoint have been observed to produce corner lifting at build heights above 40 mm in parts with rib-to-wall thickness ratios greater than 1.2.

Layer delamination is further amplified by moisture-induced hydrolysis. Residual moisture above 0.02 wt% lowers molecular weight during extrusion. Hydrolytic cleavage reduces entanglement density and shifts the ductile-to-brittle transition. The effect is most severe in the first 0.25 mm of the vertical sidewall, where the interlayer weld is colder than the nozzle setpoint.

Sealed filament must be dried before processing when the spool has been exposed to ambient air at relative humidity above 60% for more than 4 h. Polycarbonate absorbs moisture reversibly but hydrolyses irreversibly during melt processing. A desiccant dryer with a dew point below -20 °C is preferred. The manufacturer recommends drying at 80 °C for 4 h in a forced-air dryer. Drying above 120 °C is not recommended because oxidative discoloration and molecular weight reduction can occur. The dried filament should be fed from a sealed dry box maintained below 10% relative humidity if ambient residence time exceeds 1 h.

At the nozzle, the recommended setpoint range is 260 °C to 300 °C. The lower bound is set by melt viscosity: below 260 °C, layer fusion becomes insufficient at print speeds above 30 mm/s. The upper bound is set by thermal degradation: above 300 °C, residence times longer than 5 min produce yellowing and carbonised deposits on the nozzle bore. The build plate setpoint is 100 °C to 120 °C. Adhesion on glass or polyetherimide surfaces declines below 100 °C, while plate temperatures above 120 °C can soften polycarbonate near the first layer and produce elephant-foot deformation.

Tensile, Thermal, and Melt-Volume-Rate Benchmarks

Representative material data for the 1.75 mm filament are summarised in the table below. These values are taken from the manufacturer’s current technical datasheet and refer to printed specimens prepared under optimised processing conditions. They are not end-use part design allowables.

The mechanical values place Addigy FPC 3D1000 above typical unfilled polycarbonate filament in notched impact when printed with full interlayer fusion. Tensile modulus of 2300 MPa is appropriate for rigid fixtures, but creep resistance above 80 °C should be evaluated using dynamic mechanical analysis because the polycarbonate matrix enters the alpha-relaxation region near 145 °C.

Compared with PC/ABS filaments, the absence of a butadiene-rich rubber phase in Addigy FPC 3D1000 removes a low-temperature impact modifier but also reduces dark-brown thermal oxidation products during recycle. Compared with unfilled ABS, the polycarbonate backbone gives higher dimensional stability under load at 80 °C, with a heat distortion temperature of 118 °C at 1.8 MPa under ISO 75-2.

The key difference from third-party polycarbonate filament is resin-level specification control. The manufacturer supplies the same base resin to filament conversion lines and injection moulders, so melt-volume-rate drift across spool batches is narrower than that typical of filament producers purchasing wide-spec resin or regrind. The published datasheet also includes a non-halogen flame-retardant classification, which is not present in all unfilled polycarbonate filament.

When Addigy FPC 3D1000 Replaces Flame-Retardant PC/ABS in Enclosed Electronic Housings

Flame-retardant polycarbonate filament is selected for enclosures, fan ducts, and electrical fixtures when the final part must pass a UL 94 V-0 vertical burn test at 1.5 mm. In printed housings, the effective wall thickness must be maintained at or above the Yellow Card thickness by adjusting shell count, perimeter overlap, and infill density. A 0.2 mm layer height with 4 perimeters produces a nominal shell thickness near 0.8 mm, while a 1.5 mm element requires additional perimeters or solid fill.

Replacing PC/ABS with Addigy FPC 3D1000 eliminates the acrylonitrile-butadiene-styrene phase and its associated melt-phase odour. The material has superior stiffness and heat deflection, but lower low-temperature impact. Parts exposed to polar solvents or plasticising oils should be evaluated for environmental stress cracking. Chlorinated solvents, esters, and amine-based cleaning agents can initiate crazing. Aliphatic hydrocarbon cleaners or mild soap solutions are preferable.

Printed fan ducts in forced-air systems have been run at 80 °C continuously, but published data for this specific configuration is limited. For any continuous-load application above 80 °C, creep testing under the intended load and temperature is required before production release.

On production-scale FFF equipment with a heated chamber, a tooling plate, and a hardened steel nozzle, the filament runs at 30–60 mm/s with no cooling fan or a fan speed limited to 10%. Layer heights from 0.10 mm to 0.25 mm are permitted. Lower layer heights improve overhang and sidewall finish but increase build time and the number of reheating cycles, which can increase yellowing if the chamber is held at 90 °C for more than 12 h.

Spool-to-spool variance is controlled at the resin stage. Incoming quality checks should confirm diameter with a two-axis laser micrometer, moisture with a Karl Fischer analyser, and melt-volume rate with a melt indexer meeting ISO 1133-1. Batches that fail to meet a residual moisture criterion of 0.02 wt% or show diameter outliers beyond ±0.05 mm should be rejected before entering a heated chamber printer.