Stratasys Vero™ Agilus30 Black FLX985 is the black elastomeric PolyJet photopolymer supplied in sealed 3.6 kg cartridges under material code FLX985. The resin cures through ultraviolet-initiated acrylate polymerization after piezoelectric jetting and is characterized by a Shore A hardness range of 30–35 when tested according to ASTM D2240. The material is intended for multi-material PolyJet platforms, including the J750 and J850 series, where it can be jetted as a standalone elastomer or blended at the voxel level with rigid Vero resins to produce intermediate Shore A responses. The black variant shares the base Agilus30 chemistry with the clear formulation but incorporates carbon-based pigment that produces opaque, light-blocking parts and can influence UV cure depth, printhead maintenance intervals, and optical inspection contrast.

Cartridge storage uses the standard PolyJet resin handling window of 15–25 °C for sealed, unopened cartridges. Operator-adjustable parameters are limited to print mode, finish type, and digital material assignment. Once polymerized, FLX985 is a thermoset and cannot be remelted or solvent-welded.

What Distinguishes FLX985 from Rigid Vero and Clear Agilus30 Formulations?

The principal difference from rigid Vero materials is the elastomeric mechanical response. Representative datasheet values for FLX985 include tensile strength of 2.4–3.3 MPa and elongation at break of 220–240 % under ASTM D412, whereas rigid VeroBlackPlus RGD875 exhibits tensile strength of 50–65 MPa and elongation at break of 10–25 % under ASTM D638. Hardness for FLX985 is 30–35 Shore A, compared with 83–86 Shore D for VeroBlackPlus RGD875. Against clear Agilus30 FLX984, the black pigmentation is the primary distinction; mechanical property ranges are generally aligned, but the carbon black loading alters optical density and may change the energy input required for full cure at the lowest layer thickness. FLX985 is a standalone Agilus30 resin, not a digital blend, but it can be combined with Vero in printer software to produce Shore A values across the 30–95 range when the system is configured for Digital Shore A materials.

Rigid Vero materials are governed by a glassy polymer response at room temperature, with high modulus and low elongation. FLX985 operates above its glass transition temperature, which gives elastomeric recovery but also introduces time-dependent strain recovery and creep. This distinction carries through to part design: snap-fit calculations for rigid Vero use linear elastic assumptions, whereas FLX985 gaskets require hyperelastic material models such as Mooney-Rivlin or Ogden models fitted to stress-strain data from ASTM D412.

Values are representative of published PolyJet datasheets for high-quality mode. Batch-to-batch variation and printer calibration can shift these ranges; users should verify with a co-printed coupon rather than relying solely on datasheet central values.

PolyJet Jetting Constraints and Support Removal Sequence for Black Elastomer Prototypes

FLX985 is jetted through multi-nozzle piezoelectric printheads at a controlled temperature and cured by UV lamps during the deposition pass. The black pigment raises optical density; the printer firmware compensates by regulating UV exposure per voxel to prevent undercuring in thin walls and overcuring in tall, solid elastomer sections. Layer thickness is typically 14 µm in High Quality mode and 27 µm in High Speed mode, depending on the system. Build orientation alters mechanical isotropy; tensile properties measured on Z-oriented coupons may be lower than XY-oriented coupons because of interlayer photopolymer conversion differences.

The uncured FLX985 formulation exhibits a higher pigment-related viscosity than clear Agilus30 at the same temperature; the printer firmware compensates by adjusting printhead voltage and waveform. Operators should not attempt to modify jetting parameters outside the locked printer configuration because waveform changes can produce satellite droplets that degrade surface finish and dimensional accuracy. Support removal for flexible black parts is performed in two stages. Bulk support is removed with a water jet, followed by short immersion in the soluble support bath if the software-selected support chemistry requires alkaline dissolution. Flexible Agilus30 surfaces can retain support residue under compression; internal channels and bellows geometries require longer agitation than rigid Vero parts. After washing, parts are dried and conditioned at 23 °C and 50 % RH before measurement. No thermal post-cure is required; however, short-term property stabilization may occur during the first 24 h, and published FLX985-specific stabilization curves are limited.

Production-scale observations on J850 systems running black Agilus30 indicate that large monolithic sections can retain more UV-generated heat than clear Agilus30. This thermal load may produce a measurable upward shift in local Shore A hardness within the core of the section. The effect is not fully quantified in published manufacturer data; when thick sections are built, operators should co-print a hardness coupon at the same local thickness and orientation. Printhead purge cycles and wiper intervals are typically more frequent with carbon-pigmented elastomers than with clear resins because pigment settling can reduce nozzle health during long uninterrupted builds.

On continuous black Agilus30 builds, the most frequently observed failure mode is gradual nozzle dropout in the high-frequency channels. Nozzle dropout appears as surface streaks along the X axis and localized hardness changes because missing droplets alter the local soft/hard ratio in digital blends. Correction requires printhead cleaning cycles or printhead replacement after the manufacturer-specified service interval. This is a jetting maintenance concern specific to pigmented elastomers, not a bulk cure failure.

Chemical exposure data for FLX985 under ASTM D543 are not fully published. The acrylate network is expected to soften or swell in ketones, chlorinated solvents, and strong esters. Short-term isopropanol contact during support removal is generally acceptable, but prolonged immersion should be avoided because surface softening can reduce tear strength. Amine-based cleaning agents are not recommended because residual amine species can attack ester linkages in the polymer network. For functional fluid contact, a 7-day immersion test at 23 °C using the target fluid and ASTM D543 procedures should be conducted before release of production parts.

When Black Flexible Prototypes Replace Silicone Moldings in Low-Volume Functional Evaluation

The substitution is most reliable for short-term fit, feel, and sealing evaluation at room temperature and low strain rates. Under ASTM D412, FLX985 reaches 220–240 % elongation before rupture, but the response is viscoelastic and strain-rate-dependent. Cyclic loading above 50 % strain may accumulate permanent set; users should validate compression set and recovery using ASTM D395 Method B or a custom loading profile matched to the application. FLX985 is not a direct replacement for molded silicone in fatigue life, creep resistance, or high-temperature service. Its tear strength of 4–6 kg/cm under ASTM D624 is lower than many high-consistency silicone rubbers, and its UV-cured acrylate network does not exhibit the same high-temperature stability as platinum-catalyzed silicone systems.

The black opaque variant is useful when surface crack detection under white light is required, but it may conceal internal voids in computed tomography scans unless scan energy is adjusted for high carbon black attenuation. For sealing prototypes, the material can be printed with integrated rigid Vero flanges in a single build, which reduces assembly variability when evaluating gasket compression profiles.

When FLX985 is jetted alongside Vero rigid photopolymers on a J750 or J850, the system creates transitional zones at the interface by alternating jetted droplets of the two resins. The final Shore A durometer of a digital blend depends on the ratio of soft Agilus30 to rigid Vero and on the spatial frequency of the droplet exchange. This is materially different from a compounded thermoplastic elastomer; there is no melt compounding step, and the two cured networks remain as distinct voxel phases. The result is a gradient-elastomeric structure rather than a homogeneous copolymer network. Tear strength and fatigue life of a digital blend should not be assumed to match a homogeneous molded elastomer of equivalent Shore A durometer. Mechanical testing of digital blends should be performed on the exact build orientation and print mode because droplet-scale phase distribution is orientation-dependent.

Thin-walled FLX985 parts with wall stock below 2 mm can exhibit curvature after support removal because the elastomer modulus is too low to resist residual polymerization stress. The effect is more pronounced in black materials when thicker support structures retain heat. Compensation offsets in the printer software can reduce XY deviation, but Z-axis accuracy is affected by the elastomer’s compression under the wiper blade during deposition. Co-printed reference geometry is required to separate material-induced distortion from machine calibration drift. Published data for FLX985-specific shrinkage rates are limited; a first-article dimensional study on the target geometry is advised.

PolyJet photopolymers can absorb atmospheric moisture; conditioning at 23 °C and 50 % RH before measurement follows ISO 291 or ASTM D618. Moisture uptake may produce a slight reduction in tensile modulus in thin sections, but the black pigment itself does not alter water absorption compared with clear Agilus30. For wet-environment applications, users should conduct a 48-hour water immersion test under ASTM D570 and measure property retention before design freeze.

Prolonged outdoor UV exposure can degrade the acrylate network and fade or chalk the black surface. The material should not be used for long-term outdoor service without accelerated weathering per ASTM G154 or ISO 4892-2. Carbon black may provide some surface stabilization, but the surrounding matrix remains UV-sensitive. For black flexible prototypes used in ultraviolet-rich environments, a UV-blocking coating is preferred over uncoated resin.

Uncured FLX985 photopolymer is classified as a skin and eye irritant under current safety data sheets. Handling requires nitrile gloves, protective eyewear, and local exhaust ventilation during support removal and waste transfer. Cured parts should be washed and dried before prolonged skin contact. Compliance with REACH, RoHS, and regional chemical inventories must be verified by the user against the current SDS and product compliance documentation; the presence of carbon black and acrylate monomers may trigger reporting obligations in specific jurisdictions. No food-contact or medical-device certification is supplied with this material unless the user validates the finished part under applicable standards such as ISO 10993 or FDA 21 CFR 175.300 for the intended use.

Material waste and support residues are disposed of in accordance with local photopolymer waste regulations. Unused cartridge shelf life and open-cartridge pot life should be confirmed from the manufacturer’s current technical bulletin because the black pigment can accelerate settling in cartridges stored beyond the recommended orientation.