3D Systems VisiJet FTX Green Plastic for SLA Systems is a green-tinted, photoreactive resin formulated for vat photopolymerization in the 355 nm UV-A region. The model designation VisiJet FTX Green identifies a semi-rigid, polypropylene-like material with published mechanical data generated according to ASTM and ISO methods. The liquid resin is supplied in sealed, light-opaque cartridges for use with compatible 3D Systems SLA machines; cartridge capacities and lot-specific viscosity are listed on the certificate of analysis. Unlike clear stereolithography resins, the green pigment reduces optical penetration at the cure wavelength and therefore changes the exposure window for a given layer thickness. This property difference is exploited for sidewall resolution but must be compensated through the system material file. The product is intended for functional prototyping, form-fit validation, low-volume fixture production, and assembly testing where moderate impact-related behaviour and visual contrast are required. It is not classified as a high-temperature photopolymer or a castable resin for investment burnout.

Representative manufacturer-published properties for post-cured material are listed below. Values are not specification limits and vary with build orientation, layer thickness, and post-curing dose. Current batch certificates govern.

The tabulated values are generated on specimens printed and post-cured according to the manufacturer’s standard protocol. The data are not directly transferable to arbitrary part geometries because photopolymerization in SLA systems is anisotropic. Thin-walled sections may exhibit lower effective elongation due to residual surface stress and interlayer boundary energy. When designing ribs or bosses, wall thickness should be kept above 0.80 mm to avoid brittle fracture during ejection or assembly; sections below this threshold require a radius at the root to distribute stress.

What distinguishes the green-tinted FTX formulation from clear SLA resins during recoating?

The green-tinted chemistry affects recoating because the pigment particles are dispersed in the oligomer matrix, not dissolved. During blade traversal at typical SLA recoater speeds of 80 mm/s to 150 mm/s, a stable film of 0.050 mm to 0.150 mm is required before each exposure. The manufacturer controls viscosity in a narrow band; a shift greater than ±10 % from the batch mean is normally sufficient to produce lamination on horizontal surfaces or starved areas on the trailing edge of the platform. In clear resins, minor viscosity drift is often compensated by an increased recoater gap, but the FTX Green pigment accelerates settling if the cartridge sits unmixed for more than 72 hours. Cartridges must therefore be rolled or shaken according to the material handling procedure before installation. At 355 nm, the green pigment reduces the depth of cure per unit exposure, which narrows the process latitude relative to transparent resins. Operators typically observe that an exposure setting optimized for a clear resin leaves FTX Green undercured at the same layer thickness, leading to weak interlayer peel strength and occasional delamination on large flat up-facing surfaces.

Recoating defects observed on the first layers are frequently traced to cartridge temperature rather than laser calibration. If the resin temperature is below 18 °C, the recoater blade may pull a partial film and leave uncoated areas near the platform edges. The material file for the target SLA system assumes a resin temperature near 25 °C; deviations beyond ±3 °C may require a temporary reduction in recoater speed. Production builds should log resin temperature and batch number to provide traceability when mechanical results fall outside the expected range. Viscosity measurements on a cone-and-plate rheometer can be used as an incoming quality check, but the test must be performed at the same shear rate as the recoater system to be meaningful. A single-point viscosity at 25 °C without shear-rate control is insufficient for predicting recoating behaviour.

For functional prototyping, VisiJet FTX Green is applied where polypropylene-like flexibility and visual contrast are needed. Snap-fit features, thin living hinges, and resilient clips are common part classes. The published elongation at break of approximately 100 % under ASTM D638-14 is often used as a design upper bound, but the effective elongation in a printed feature is orientation-dependent and can fall by more than 30 % when the tensile axis crosses multiple build layers. Hinge thicknesses between 0.30 mm and 0.50 mm are feasible when the hinge line lies parallel to the recoater direction and the part is fully post-cured before flexing. Cyclic endurance data for living hinges with this specific formulation is limited; production applications require lot-specific validation with the exact build orientation and post-cure schedule.

When 0.10 mm layer thickness is selected for snap-fit prototypes

At 0.10 mm layer thickness, the exposure window is narrower than at 0.050 mm because the polymerization front must travel through a pigmented film with higher optical attenuation. Slight undercure produces horizontal lamination, while slight overcure increases the Z-axis growth and may close small clearances. Measurements from build calibration coupons indicate that the exposure window can narrow to less than ±5 % for this material at 0.10 mm on some equipment, although platform-specific beam uniformity and laser spot size shift the actual range. The recommended approach is to run a nine-point calibration grid on the target machine and to derive scale factors from measured part deviations rather than transferring values from clear resins. Down-facing surfaces near supports often show a thin layer of incompletely cured material because the pigment limits light penetration; these surfaces require adequate support density and a reduced peel angle to prevent chipping during part removal.

The build orientation for snap-fit prototypes should place the principal bending axis in the build plane to avoid interlayer tensile failure. When the tensile axis is perpendicular to the layers, elongation at break is reduced from the XY value. Post-curing in a 405 nm UV chamber for the manufacturer-specified duration raises crosslink density and stabilizes creep. Parts tested immediately after alcohol drying often exhibit inflated compliance because residual solvent plasticizes the matrix; test specimens should be conditioned at 23 °C and 50 % RH for at least 24 hours before mechanical testing.

Snap-fit clips and cantilever latches can be produced with a printed-in deflection and then released after post-cure. The design should limit bending strain to the elastic region of the stress-strain curve; because the published elongation at break is not a design allowable, a safety factor of at least 2 is typically applied to account for lot-to-lot and orientation effects. For a cantilever latch, the maximum deflection during engagement should not exceed 50 % of the printed beam thickness. Assembly trials on production-scale equipment have shown that installing parts immediately after alcohol drying can lead to stress cracking at the gate because residual solvent reduces the tensile strength of the surface layer. Conditioning at 23 °C and 50 % RH for 24 hours after post-cure reduces this failure mode.

VisiJet FTX Green is stored between 15 °C and 27 °C in a dry, UV-shielded environment. Resin removed from cold storage must be conditioned at 23 °C for a minimum of 4 hours before loading because viscosity increases at lower temperatures and recoating defects are most common in the first layers of a build. Moisture uptake above 0.1 % by mass is generally associated with reduced crosslink density, lower tensile modulus, and an increase in surface tack after post-cure. The vat should be protected from ambient light during long idle periods; exposure to sunlight or fluorescent UV can initiate premature polymerization in the liquid and create gels that contaminate the recoater blade. When gels are observed, the vat must be drained and filtered according to the equipment maintenance schedule. Batch-to-batch shifts in pigmentation are controlled by the manufacturer, but visual color density is not a reliable indicator of cure behaviour; the material file and exposure verification remain the controlling process inputs.

Surface finish, solvent retention, and dimensional stability after IPA post-processing

Parts are washed in isopropyl alcohol or a manufacturer-approved solvent to remove uncured surface resin. Alcohol immersion times beyond the manufacturer-specified maximum cause solvent absorption, edge whitening, and temporary dimensional expansion, particularly in thin walls below 0.60 mm. Centrifugal or vacuum-assisted drying is preferred for blind holes and snap-fit recesses; residual solvent trapped in recesses leads to post-cure porosity and local softening. After drying, the green parts are post-cured in a calibrated flood UV chamber. Incomplete post-cure leaves residual acrylate groups that can cause slow dimensional drift and surface tack over several days. Overt post-cure can raise brittleness and shift the part from flexible behaviour toward brittle fracture, especially in unsupported sharp corners. Dimensional stability after post-cure is sensitive to the initial green-state geometry; measurements of 0.100 mm holes and 0.200 mm slots should be used to correct CAD scale factors for the target machine.

Cleaning solvent selection should follow the current safety data sheet and equipment manual. Isopropyl alcohol with a purity below 99 % introduces water that can slow drying and increase surface haze. Two-stage washing is preferred: a bulk rinse to remove the majority of uncured resin, followed by a clean solvent bath. If a single dirty bath is used, dissolved resin accumulates and can deposit a sticky film on the part surface during drying. This film is occasionally mistaken for undercure; a tacky surface after drying is more often a cleaning failure than a post-cure failure. Operators should change solvent according to the consumption log and use filtration to remove pigment particles that settle from saturated baths.

Relative to rigid clear SLA resins, VisiJet FTX Green trades tensile modulus and heat deflection temperature for higher elongation and improved impact-related behaviour. The published heat deflection temperature near 50 °C at 0.455 MPa limits sustained load-bearing use above that threshold. The material is not designed for thermal testing above 55 °C, nor is it suitable for outdoor UV exposure without a protective coating because unpainted green surfaces yellow and embrittle over time. Relative to castable SLA resins, the ash content after burnout is not controlled and investment casting is not a recommended application. Relative to flexible SLA elastomers, FTX Green is semi-rigid and cannot replace rubber-like parts below Shore A 70. Compliance documentation should be checked against REACH and RoHS requirements for the specific production region. No food-contact status is claimed under FDA 21 CFR, and no biocompatibility assessment is provided under ISO 10993-1. If the part is intended for skin contact, a material-specific toxicological assessment is required. Operators should avoid contact between uncured resin and amine-containing coatings or additives because residual amines can inhibit free-radical polymerization and produce a tacky, incompletely cured surface.

Compared with a rigid SLA resin having a flexural modulus above 2500 MPa, FTX Green has lower stiffness and is less suitable for load-bearing brackets that rely on screw preload. For threaded inserts, the lower heat deflection temperature limits thermal insert staking; ultrasonic insertion is preferred with low amplitude and short duration. Compared with an ABS-like SLA resin, FTX Green offers improved snap-fit recovery but may require an additional clear coat when surface scratch resistance is necessary. The green pigment can mask stress whitening that is visible in clear materials, so visual inspection for overload damage is less straightforward. Dye penetrant inspection is not recommended because the dark green color can hide crack indications.

In low-volume fixture production, the material is used for soft jaws, locating pads, and assembly aids. The maximum fixture load should be derived from the flexural modulus and part cross-section, not from the tensile strength alone. Because SLA parts are not fully isotropic, shear failure can occur along layer boundaries at loads below the XY-plane tensile strength. When a fixture must hold a metal pin or bushing, the printed hole should be undersized by 0.10 mm to 0.15 mm and reamed after post-cure to a final tolerance. Reaming removes the resin-rich surface layer and produces a more stable interference fit than printing directly to size. When dimensional acceptance criteria are tighter than ±0.10 mm, the build must be corrected for shrinkage using a target-machine calibration grid. The largest deviations are typically measured along the Z-axis on tall, thin walls where accumulated layer growth and post-cure shrinkage interact. VisiJet FTX Green is not recommended for parts requiring optical clarity, continuous service above 55 °C, or chemical resistance to strong acids and aromatic solvents; solvent-specific immersion testing is required for any sealing or fluid-contact application.