BASF 3D Ultrafuse ABS Fused Filament

BASF 3D Ultrafuse ABS Fused Filament is an unfilled acrylonitrile-butadiene-styrene monofilament produced for material extrusion and fused filament fabrication. The product is supplied on vacuum-sealed spools, not as pellets or powder, and is intended for functional prototypes, assembly jigs, short-run manufacturing aids, and non-load-bearing end-use parts where standard ABS heat and impact resistance are acceptable. Manufacturer-published processing notes are starting setpoints rather than validated production parameters. Batch-specific certificates supersede general web-page values.

Material Designation, Dimensional Grades, and Vacuum-Sealed Spooling

The filament is available in nominal diameter grades of 1.75 mm and 2.85 mm. The 1.75 mm grade is specified for direct-drive and Bowden feed systems using nozzle diameters of 0.4 mm or larger. The 2.85 mm grade is specified for legacy industrial feed systems and certain automated print heads. Industry-standard ovality tolerance is ±0.05 mm for 1.75 mm filament and ±0.10 mm for 2.85 mm filament; the spool label remains the controlling dimensional record.

Unopened spools should be stored at 20–25 °C and below 50 % relative humidity. The vacuum-sealed moisture barrier protects the ABS monofilament from ambient water uptake. Once the barrier is opened, the spool should be transferred to a dry box or active filament dryer if consumption is not completed within a single production shift.

The unfilled ABS formulation has a density near 1.03–1.07 g/cm³ when evaluated according to ISO 1183-1. The melt-flow rate typical of an ABS with this viscosity profile is 5–15 cm³/10 min at 220 °C and 10 kg load per ISO 1133-1. Exact product-specific values appear in the manufacturer technical data sheet.

What Extrusion and Bed Temperature Window Reduces Warp-Induced Peel?

The manufacturer-specified hot-end setpoint is 220–250 °C, with a heated bed at 90–110 °C. At nozzle temperatures below 220 °C, melt viscosity rises into the 1,000 Pa·s range at shear rates below 100 s⁻¹, which can stall extruder motors in direct-drive systems. At temperatures above 250 °C, the butadiene-rich phase begins thermal aging, generating yellowing and acidic volatiles without improving extrusion properties.

Bed temperature is the dominant variable for first-layer adhesion because ABS has a glass transition range near 100 °C. If the bed remains below 90 °C, the first layer cools below its glass transition before the next layer deposits. Residual tensile stress can then exceed the static friction limit at the PEI or polyimide interface. Print-farm observations on open-frame gantry machines show edge lift initiating at part radii below 5 mm when bed temperature drops below 90 °C and ambient air temperature falls below 20 °C. An enclosed build chamber or passive enclosure is therefore required for parts with a build footprint above approximately 100 mm in the long axis.

A build chamber held at 45–60 °C reduces vertical thermal gradients and improves interlayer fusion. First-layer speed should not exceed 30 mm/s on glass beds coated with polyimide tape or PEI. A layer height of 0.15–0.25 mm with a 0.4 mm nozzle provides adequate bond without excessive back pressure. Warp-induced peel commonly initiates in geometries thicker than 5 mm in Z when total build height exceeds 50 mm; support structures and sharp corners should be filleted to a minimum radius of 2 mm.

Spools exposed to ambient air for more than 48 h or at relative humidity above 60 % require pre-drying before printing. A vented oven at 60–80 °C for 4 h is a conservative drying profile for unfilled ABS. Inadequate drying produces surface bubbles and audible steam pops at the nozzle, especially above 240 °C. Published data for Ultrafuse ABS-specific moisture uptake at 23 °C and 50 % RH are limited; the manufacturer spool guidance should be followed. Drying temperatures above 80 °C can soften the monofilament and cause spool deformation.

When Solvent Vapor Smoothing Intersects FDM Part Certification

Acetone vapor smoothing can be applied to ABS parts to reduce layer lines, but the treatment changes dimensional stability and fracture behavior. The solvent plasticizes the butadiene-rich phase, which lowers surface roughness but can reduce tensile elongation and promote microcracking at stress concentrators after repeated thermal cycling. Published data for this specific configuration are limited; dimensional loss after smoothing depends on infill geometry and part wall thickness. If smoothing is used, parts should be conditioned at 23 ± 2 °C and 50 ± 10 % RH for at least 24 h before mechanical testing.

Solvent vapor smoothing must be performed in spark-proof, exhaust-ventilated equipment. Ketone, ester, and chlorinated solvent exposure can absorb into printed ABS and remain trapped in closed infill cells. Subsequent heating above 100 °C can evolve solvent vapor and delaminate the part. Smoothed parts should not be used in sealed enclosures or in contact with polycarbonate components without extraction. The filament is not classified as a food-contact article; any post-processing with industrial solvents invalidates standard food-contact assumptions.

Comparative Performance Data Against Standard ABS and Polycarbonate Blends

The primary difference between BASF 3D Ultrafuse ABS Fused Filament and generic ABS filament is not the underlying monomer composition but the control of melt-flow consistency, dimensional ovality, and spool dryness. In contrast to glass-filled ABS, this unfilled grade does not contain abrasive fiber reinforcement, so nozzle wear remains predominantly from brass and hardened steel flow-path abrasion rather than fiber contact. In contrast to PC/ABS blends, the heat deflection temperature and toughness of unfilled ABS are lower, but warpage potential and required bed temperature are also lower. The following table summarizes typical unfilled ABS class values, not batch-specific certificates.

Regulatory status of the final printed component depends on the filament lot, colorants, and post-processing. Under REACH (EC) 1907/2006, the monomer substances are registered and the safety data sheet lists applicable exposure limits. Under RoHS 2011/65/EU Annex II, unfilled natural ABS typically contains lead, mercury, cadmium, hexavalent chromium, PBB, and PBDE below the maximum concentration values; XRF screening of the raw pellet is required for certification of a printed part. For food-contact use, FDA 21 CFR 177.1020 applies to acrylonitrile/butadiene/styrene copolymers subject to migration limits, but the filament-grade technical data sheet does not provide a food-contact compliance letter. Do not use printed ABS parts in contact with strong ketones, esters, or chlorinated solvents at elevated temperature.