Within the manufacturer’s casting-pattern portfolio, 3D Systems VisiJet FTX Cast Plastic for SLA Systems is described for selected stereolithography configurations where the build engine has been qualified for the material’s laser wavelength, recoater configuration, and temperature-control envelope. The product is a castable polymer/wax pattern resin rather than a structural SLA material; its primary function is to generate sacrificial patterns for investment casting of precious and ferrous alloys. The commercial identifier should be checked against the current 3D Systems material selection guide, because SDS revisions and printer qualification matrices may separate resin families across platform generations. Unless otherwise noted, the quantitative values in this description are typical supplier-reported values from current technical literature, not independent lot-release specifications.

Because the phrase “for SLA Systems” in the ordering description is not a substitution for printer qualification, users should confirm that the exact build engine, not merely the resin family, appears on the manufacturer’s current compatibility matrix. The material’s process window is narrow in comparison with unfilled SLA resins because the thermoplastic wax fraction can separate if the reservoir temperature is held above the recommended upper limit for extended periods. The resin is supplied in light-proof containers; cartridge size and packaging differ by platform generation.

What Property Set Characterises VisiJet FTX Cast Plastic in the As-Built Condition?

The data below are reported as representative values for specimens built on a qualified platform and conditioned at 23 ± 2 °C and 50 ± 5 % relative humidity. The material exhibits a low elastic modulus, moderate elongation, and a softening range that is compatible with low-stress burnout in ceramic shells. Published data for this specific configuration is limited for some SLA platforms; where the supplier lists a range, process qualification should use the lower bound as the acceptance limit.

Because the material contains a dispersed wax phase, the measured tensile and flexural values are sensitive to build orientation. Upright specimens may show lower elongation than flat specimens due to layer-boundary localisation. The ash content, measured by thermogravimetric analysis under ASTM E1131, is the critical specification for investment casters; a value above 0.02 wt% typically indicates incomplete burnout, mould residue, or contamination from support material residues. If the current revision of the supplier datasheet differs from the values above, the supplier datasheet governs.

For SLA-based production cells, build parameter qualification begins with the derivation of a working curve from a multi-exposure test coupon. The critical exposure and penetration depth are lot-dependent because filler settling and wax crystallisation alter the photosensitive response over storage. The recoater gap, blade speed, and build chamber temperature interact with the low melt viscosity of the unpolymerised wax fraction; resin-level defects and edge curl are observed when the chamber temperature falls below the softening range. Patterns grown at a layer thickness of 0.050 mm usually display lower stair-stepping and improved edge retention, but the build time increases relative to a 0.100 mm layer. On production-scale SLA cells with a recoater blade, filled resins of this class can increase recoater blade wear compared with unfilled resins; users should monitor blade edge condition and resin-level consistency.

Support structures should be sparse and have slightly rounded contact tips to reduce surface pitting during removal. After the build, the pattern is rinsed in the manufacturer-designated solvent. Solvent immersion longer than 60 s is not recommended because the wax fraction is partially soluble in the cleaning medium, which can create microporosity and shift pattern weight. Final handling hardness develops after cooling or a brief post-cure; over-cure is not desirable because it raises crosslink density in the non-wax fraction and can interfere with the initial melt-flow stage of burnout.

Burnout Residue and Thermal Decomposition Behaviour in Ceramic Shells

In investment-casting practice, VisiJet FTX Cast Plastic is formulated for standard lost-wax processing. The pattern softens before decomposition, which limits ceramic-shell stress during the early flask ramp. This behaviour is particularly important for thin sections below 0.4 mm that would otherwise crack the shell if the pattern expanded as a rigid solid. The following table gives a representative burnout window for wax-containing castable pattern resins in phosphate-bonded investments. The values are not universal and must be adjusted for flask diameter, pack density, and alloy pouring temperature.

Residual ash below 0.02 wt% is achievable only when the furnace atmosphere remains oxidising and the load is not packed too tightly. Carbon flake formation, sticking of the cast metal surface, and black specks in the mould cavity are typically caused by insufficient oxygen exchange rather than the resin alone. For continuous production, a furnace with a calibrated air inlet and a temperature recorder trace is used to demonstrate repeatability of the final hold segment. Pattern weight loss during burnout can be monitored by thermogravimetric analysis; the exact onset temperature of rapid mass loss is formulation-specific.

When Dimensional Tolerance Below ±0.3 % Is Required, Resin Lot Qualification Is Mandatory

Compared with unfilled SLA casting resins such as 3D Systems Accura CastPro Free, VisiJet FTX Cast Plastic trades higher stiffness for a softer and more ductile response. The lower flexural modulus of approximately 1,240 MPa reduces shell cracking risk during initial heating, but it also makes large flat sections more prone to sag if the build platform is unloaded while the part is still above the softening range. Unfilled casting SLA resins typically exhibit higher tensile modulus and lower elongation; they may retain sharper edges but can show brittle failure during support removal for fine filigree. Standard engineering SLA resins with higher crosslink density are generally unsuitable as sacrificial patterns because clean burnout is not designed into their formulation and residual ash can exceed acceptable foundry limits.

Compared with injection-moulded foundry wax, the additively produced FTX pattern eliminates tooling lead time but may retain layer striations that require smoothing before high-gloss jewellery casting. For fine filigree jewellery patterns, the low elastic modulus is an advantage because it permits the pattern to relax slightly during shell drying without cracking. For larger industrial castings, the same compliance becomes a disadvantage because unsupported horizontal surfaces can creep. The geometry-dependent trade-off must be evaluated with bridge specimens and overhang coupons before production.

For dimensional tolerances tighter than ±0.3 %, a single global scale factor is insufficient. The resin lot’s working curve, build chamber temperature drift, and post-rinse solvent retention shift part dimensions independently. Flat plates longer than 50 mm are particularly sensitive to temperature drift greater than ±2 °C. Where the foundry cannot accept this tolerance, an empirical shrinkage model derived from batch-specific test coupons is used instead of the supplier’s nominal offset.

Because the material is supplied as a sacrificial casting pattern resin, it is not intended for load-bearing or functional end-use parts. Pattern storage at temperatures above 40 °C may cause dimensional relaxation. Exposure to ketone-based solvents, amine-containing cleaners, or long-chain glycol ethers may attack the wax fraction and must be avoided. Eu REACH, RoHS, and other restricted-substance compliance must be verified with the current safety data sheet and supplier declaration; this description does not assert global conformity. Biocompatibility, food-contact suitability, and USP Class VI status are not part of the standard product bulletin, and published data for these applications is limited. Foundries casting reactive metals must validate shell permeability and decomposition residues separately, because residue species that are acceptable for gold or stainless steel may be incompatible with titanium, magnesium, or aluminium-lithium alloys.