ETEC WIC 100 Series is a liquid methacrylate-based photopolymer supplied by ETEC (EnvisionTEC) for vat photopolymerization platforms operating in the 385–405 nm band. The resin is formulated as a water-clear impact grade, meaning that the cured polymer retains translucency while providing a higher elongation-at-break envelope than conventional rigid clear acrylates. The product is used on digital light processing (DLP), scan-spin-selectively photocure (3SP), and continuous digital light manufacturing (cDLM) systems equipped with compatible UV-A projectors. Manufacturer documentation classifies WIC 100 as a prototyping and indirect manufacturing resin, not as a burnout casting resin, biocompatible dental resin, or high-temperature tooling resin. Incoming resin is controlled by lot, and certificates of analysis report liquid density, dynamic viscosity, and photoactive solids content. Cured-property qualification is commonly performed using ASTM D638 for tensile response, ASTM D790 for flexural modulus, ASTM D2240 for Shore D hardness, ASTM D648 for heat deflection temperature, and ASTM D570 for water absorption. Optical acceptance of polished parts is expressed through ISO 13468 total luminous transmittance and ASTM E313 yellowness index.

What Distinguishes WIC 100 from Castable and Opaque Modelling Resins?

In the ETEC resin portfolio, WIC 100 occupies a different position from PIC 100-class sacrificial casting resins, E-Model Light opaque ABS-like grades, and HTM 140 high-temperature tooling resins. The principal difference is the combination of optical clarity and impact-oriented failure strain. Technical bulletins classify WIC 100 as a water-clear impact prototype material rather than a burnout material for precious-metal casting. Investment foundries generally specify PIC-series resins because those grades are formulated for clean burnout and lower residual ash; WIC 100 is not marketed with an ash content specification for direct casting. Compared with opaque ABS-like modelling resins, WIC 100 enables inspection of internal channels, fluid paths, or light-guide geometry without destructive sectioning. Compared with high-temperature mold resins, WIC 100 has a lower service ceiling and is not rated for short-run injection tooling. The distinction is also visible in post-processing: clear parts require surface polishing or clear coating to reduce layer-line haze, whereas opaque engineering grades are often tested in the as-built or lightly sanded state.

For preliminary design work, the following material-class envelope is used. Lot-specific values from the WIC 100 certificate of analysis take precedence over these broad class limits.

On 3SP and cDLM platforms, the practical processing window is controlled more by vat temperature and resin viscosity than by projector irradiance alone. Green-part quality declines when the liquid is colder than 20 °C because the material does not recoat uniformly over large solid cross-sections. The standard preparation procedure is to roll the container for 30 min and equilibrate the vat to 23 ± 2 °C before starting a build. If viscosity measured according to ASTM D7867 exceeds the upper limit in the table, the resin may be outside its intended recoat envelope for standard DLP or 3SP dynamics. The resin should not be diluted with water or isopropanol; polar contaminants disrupt free-radical polymerization and create tacky surfaces. Resin age, ambient humidity, and long exposure to low-intensity stray light alter the photoactive species, so an all-window exposure test is performed after any material change.

Equipment-Specific Processing Parameters for 3SP and cDLM Platforms

On an ETEC 3SP platform such as the Xtreme 8K with a 405 nm LED projector, WIC 100 is generally run at 50–100 µm vertical slice thickness. The exposure per layer is programmed as a dose integral, not a single time, because large-area solid sections require different irradiance compensation than isolated supports. On cDLM systems with an oxygen-permeable build interface, the dead-zone thickness changes with irradiance, resin viscosity, and part cross-section; WIC 100 typically requires lower continuous pull speed than low-viscosity dental resins to prevent delamination of large cross-sections. The build engine records projector power, exposure time, and temperature; these records are required for lot traceability and troubleshooting. Published data for this specific configuration is limited, so new installations should be qualified with a standardized build containing vertical and horizontal ASTM D638 specimens, a 50 mm diameter disk, and a sectioned hollow channel.

Mechanical performance in photopolymer parts is anisotropic because the weakest plane often lies between successive layers. In WIC 100 builds, the difference between xy-plane tensile elongation and z-axis tensile elongation can be the controlling factor for load-bearing prototypes. One practical evaluation method is to machine slabs from a 10 mm-thick build block and extract tensile bars parallel and perpendicular to the build direction, then test according to ASTM D638. If z-axis elongation falls below 70% of the xy-plane value, thin vertical walls under snap deflection may require design changes or alternative orientation. Post-curing in a 405 nm chamber at moderate temperature increases crosslink density and surface hardness but also increases brittleness; the post-cure cycle is therefore balanced against the required impact performance. Fourier-transform infrared analysis of the carbonyl or acrylate peaks is used for process control when changing post-cure lamps or layer thickness. Published data for this specific configuration is limited, so acceptance limits are generated from internal build qualifications.

Transparent fluid-flow visualization manifolds are built in WIC 100 because the cured polymer permits internal inspection without destructive sectioning. Luminous transmittance acceptance is often linked to ISO 13468, and yellowness index to ASTM E313. Polishing with 600–1200 grit abrasives followed by a clear acrylic lacquer is used to reduce layer-line scattering. For impact-loaded snap-fit or housing prototypes, design practice requires both xy-plane and z-axis test specimens because photopolymer layer interfaces produce anisotropic tensile elongation. Notched Izod impact according to ASTM D256 is measured before risk-prone features are placed near the build platform. The resin is also used for short-run transparent covers, lens prototypes, and packaging display parts in which the user evaluates form, fit, and visual appearance rather than production-grade optical performance.

Common production-line failure modes observed with water-clear impact resins include vat film clouding, part chipping during support removal, and surface crazing after excessive solvent exposure. Vat film clouding occurs when polymerized debris remains on the release surface or when ambient dust enters the vat. Parts left in solvent immersion exceeding 5 min can develop microcracks, especially around sharp corners or thick-to-thin transitions. Support removal is therefore performed before solvent immersion where possible, using sharp diagonal cutters with the part at room temperature. If chilled, the material becomes more brittle and the probability of chipping at support contact points increases. Surface crazing is evaluated under 20× magnification after solvent immersion; any visible microcrack network is recorded as a process deviation.

When Continued Exposure to Water or Elevated Temperature Becomes the Limiting Factor

Cured WIC 100 is not specified for continuous service in pressurized aqueous lines or repeated steam sterilization. Water absorption measured according to ASTM D570 gradually reduces the glass-transition-related performance, and wetted parts may show a measurable reduction in ASTM D790 flexural modulus and ASTM D648 heat deflection temperature. Chemical compatibility should be examined with the actual process fluid because aromatic hydrocarbons, ketones, and strong alkaline cleaning agents can attack the crosslinked acrylate network. Compatibility testing follows ASTM D543; the part is immersed for a defined period and then re-measured for hardness, mass change, and visual surface degradation. Outdoor exposure increases ASTM E313 yellowness index over accumulated UV-A dose, even when a UV stabilizer package is present in the formulation. Optical prototypes intended for prolonged natural light should therefore be used as short-term evaluation aids rather than as permanent glazing components.

Uncured resin handling follows standard photopolymer safety procedures. The material is classified as a skin and eye irritant; operators wear nitrile gloves and sealed eye protection during vat filling, filtering, and part removal. Spent wash solvent contains uncured monomer and should be disposed of as hazardous liquid waste. Internal channels and blind holes can retain uncured resin after bulk washing; they are flushed with ≥99% isopropanol and exposed to a 405 nm light guide before the part is considered safe for routine handling. The manufacturer’s safety data sheet and lot-specific certificate of analysis are the controlling documents for regulatory, storage, and disposal requirements. Standard resin shelf life is stated on the container label; expired material should not be blended into fresh vat stock because photoinitiator depletion produces under-cured surfaces and powder deposits on the vat film.