In precious-metal casting shops running centrifugal or vacuum induction casting units, the ETEC (EnvisionTEC) WIC 100 Series light curing resin functions as a direct lost-wax pattern material. The resin is a single-component photopolymer; no catalyst addition, solvent dilution, or filler adjustment is required before printing. Viscosity control is performed at 25 °C using a cone-plate viscometer according to ISO 2884-1:2006; when the certificate of analysis value falls outside the printer recoat envelope, build-to-build variation in green strength appears as fine-feature curl and support detachment. Patterns are built on DLP equipment operating at 405 nm, typically at layer thicknesses of 25 μm or 50 μm, with exposure energy adjusted for blackback or high-resolution print modes. Uncured resin removal uses water at 20–30 °C in an agitated bath or ultrasonic cleaning unit equipped with frequency settings from 35 kHz to 45 kHz; isopropanol is not required. Wash water must be replaced before turbidity exceeds the process-defined limit because dissolved monomer reduces wash efficiency; published data for the monomer saturation point of this resin in water is limited. After rinsing, components are air-dried and inspected for occlusion of fine filigree recesses. Spruing geometry follows investment casting practice: larger patterns require a reservoir or expansion bulb, and distal thin sections below 0.3 mm are reinforced because green photopolymer strength is anisotropic and may distort during rinsing. The printed pattern is mounted on a metal sprue base and vacuum-mixed with a gypsum-bonded investment; a typical powder-to-water ratio for jewelry flask investment is 100:28 to 100:32, but the exact ratio must be taken from the investment manufacturer’s datasheet. Vacuum mixing at 0.1 bar absolute and bench setting for 2 h reduce bubble entrapment on the pattern surface. Burnout is staged: a first ramp at 1–2 °C/min to 150 °C, a 60–90 min hold to drive off water, a second ramp at 1–1.5 °C/min to 730 °C, and a 3 h hold to mineralize carbon residues. The furnace must have oxygen ingress during resin decomposition; sealed or nitrogen-blanketed burnout profiles produce carbon-rich residues. After burnout, gold, platinum, or sterling silver alloys are cast at temperatures between 980 °C and 1020 °C for gold and approximately 1020–1100 °C for silver alloys, depending on alloy liquidus plus superheat. Final precious-metal articles—rings, pendants, bracelet links, and filigree settings—are inspected for gas porosity by radiography or ASTM E562 image analysis. Compliance of the resin itself is limited to occupational handling under REACH (EC 1907/2006) and disposal according to local photopolymer waste codes; EU nickel release compliance under EN 1811:2011+A1:2015 is an alloy property and not a resin property. Published data for WIC 100-specific ash residue after burnout is limited; foundries should verify residue below 0.05 wt% using a muffle furnace ashing test adapted from ISO 1172:1996 before committing to production.

What Does a Pressable Glass-Ceramic Workflow Demand from a Burnout Pattern Resin?

Dental laboratories using lithium disilicate and leucite-reinforced glass-ceramic ingots evaluate WIC 100 Series resin as a substitute for hand-waxed or milled polymer patterns in the pressable ceramic process. The pattern resin is not used as a final intraoral material; it must disappear completely during the press furnace burnout cycle before the ceramic ingot is pressed into the void. Mixing ratio for the press investment is specified by the investment manufacturer, commonly near 100 g powder to 22–24 mL liquid for high-expansion formulations, but no additional ratio modifier is added to compensate for polymer degradation. Patterns are printed at 50 μm or 25 μm layer thickness, washed in water at 20–28 °C, dried under filtered air, and sprued with resin or wax sprues of sufficient length to create a press channel. In the pressing furnace, wax/resin elimination is performed at a final burnout temperature of 850 °C for 45–60 min for many pressable ceramic systems; lithium disilicate ingots are then pressed at 920–950 °C under vacuum. The risk is carbon retention if the burnout dwell is shortened because carbon at the marginal interface inhibits ceramic wetting and produces edge chipping. Press furnace loading is limited by the ingot mass for the restoration; for a molar crown, a 1.0 g ingot is common, while veneers and inlays may use 0.5 g ingots. Final restorations—pressable lithium disilicate crowns, inlays, onlays, and veneers—are finished with ceramic stains and glazed. Compliance of the fired ceramic is evaluated under ISO 6872:2015 and ISO 9693:2019 for metal-ceramic bond strength where applicable. The resin itself has no direct role in final biocompatibility, but a dental laboratory must document that no uncured monomer remains in the pore structure; this is checked by gas chromatography-mass spectrometry on sintered investment debris if full clearance is unknown. Published data for WIC 100-specific press furnace compatibility with pressable ceramic cycles is limited; a single-flask trial is used before full production.

Removable partial denture frameworks cast from cobalt-chromium alloys subject the pattern material to an environment that combines high pouring temperatures with phosphate-bonded investment chemistry. WIC 100 Series resin patterns are produced on DLP equipment and washed in water at 20–30 °C; residual moisture is removed in a convection dryer at 40–50 °C for at least 15 min because trapped water inside thin clasps can disrupt phosphate investment setting. Resin patterns are then attached to a refractory cast or castable pattern base using sticky wax or resin. The phosphate-bonded investment is mixed according to manufacturer ratio, typically 100 g powder to 20–24 mL colloidal silica liquid; the expansion properties depend on the liquid dilution. Mixing under vacuum at 450 rpm for 60 s and pouring under vibration prevent bubbles on occlusal rest seats and clasp tips. Burnout follows a staged cycle: drying at 150 °C, a controlled ramp of 1 °C/min between 150 °C and 600 °C, a hold at 900 °C for 2–3 h, and casting at 1450–1480 °C for cobalt-chromium alloys. The slow ramp through the polymer decomposition band reduces carbon residue and minimizes chromium carbide formation. Cast framework terminal products include lingual bars, circumferential clasps, rest seats, and mesh retention structures. Final alloy compliance is assessed under ISO 22674:2016 for metallic dental restorations and ISO 10993-5:2009 for cytotoxicity where the framework is placed in prolonged tissue contact. The pattern resin must be completely eliminated; if carbon residue exceeds 0.1 wt% as measured by combustion analysis of residual investment, the framework lot is rejected for visible porosity and possible carbide inclusions. Published data for WIC 100-specific behavior in phosphate-bonded investments is limited; each flask configuration requires one destructive qualification casting.

When the Same Resin Replaces Wax in Small-Scale Stainless Steel Investment Castings

Small-lot precision foundries producing austenitic and precipitation-hardening stainless steel components use WIC 100 Series resin where pattern complexity exceeds wax tooling economics or where water-washable cleanup reduces solvent consumption. The resin is printed as a single-component pattern; no liquid-to-powder ratio exists at the pattern stage. Ceramic shell construction follows the same sequence used for wax patterns: a prime coat of zircon flour in colloidal silica, fused silica backup coats, and final seal coat. Each shell layer is dried at 23–25 °C and 45–60% RH; the pattern and shell remain compatible only if the first coat is applied within 2 h after water washing and drying. Burnout is performed in an air-ventilated furnace with a ramp from ambient to 180 °C at 1 °C/min, a 1 h dwell, then a ramp to 1050 °C at 2–3 °C/min, and a 2 h hold before casting. Austenitic 316L and martensitic 17-4 PH stainless steel alloys are poured at 1550–1600 °C and 1560–1620 °C respectively, depending on superheat and shell temperature. Terminal parts include micro-valve bodies, orthopaedic trial instrument handles, watch case components, and fluid connector parts. Final mechanical properties are defined by ASTM A240/A240M or ASTM A564/A564M depending on alloy, and passivation compliance is evaluated under ASTM A967/A967M. Resin removal is not a final-material compliance statement; if patient-contacting status applies, the finished metal must meet ISO 10993-1:2018 biocompatibility requirements. Published data for WIC 100-specific ceramic shell interaction in stainless steel investment casting is limited; a prime-coat wetting test and trial casting are required for each new shell slurry batch.

Water-Washable Pattern Resin in Micro-Scale Orthodontic Appliance Production

Orthodontic laboratories that cast custom clasps, band-and-loop space maintainers, and transpalatal arch frameworks use WIC 100 Series resin to replace wax hand-forming where repeatable wire-to-cast junction geometry is required. Printed patterns are generated at 25 μm layer thickness to capture bolt hole details and wire insertion slots. Water washing at 20–28 °C with a fine brush removes trapped uncured resin in socket areas; isopropanol is not required, which simplifies waste handling in a dental facility. Sprues are attached at right angles to the largest cross-section; for band loops, two 0.5–0.8 mm round sprues feed the loop to avoid cold shuts. Investment mixing ratios for orthodontic casting are the same as for removable partial denture frameworks—phosphate-bonded investment mixed at 100 g powder to 20–24 mL liquid—but flask size is smaller, and burnout time may be shortened after thermal profiling. A typical small-flask burnout uses a 150 °C drying hold, 1 °C/min ramp to 900 °C, and 2 h hold, followed by casting of nickel-free chromium-cobalt or commercially pure titanium alloys. Final devices—space maintainers, distal extensions, and transpalatal arches—are polished and passivated before intraoral delivery. Compliance is controlled under ISO 22674:2016 for the cast alloy and ISO 10271:2020 for corrosion resistance of metallic intraoral devices. The resin is a processing aid and is not present in the appliance; residual carbon in the cast surface is checked by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Published data for WIC 100-specific performance with commercially pure titanium casting is limited; titanium’s high reactivity with carbon and oxygen requires a dedicated argon-arc casting unit and a resin burnout qualification coupon.