3D Systems VisiJet RBK-RWT-L30 Multi-Material Composites

3D Systems VisiJet RBK-RWT-L30 Multi-Material Composites is a paired acrylate photopolymer set comprising VisiJet CR-BK rigid black and VisiJet CR-WT 200** rigid white. The RBK-RWT designation identifies a rigid black/rigid white build mode, and the L30 suffix denotes a 30 µm layer-thickness configuration. The set enables a single monolithic MultiJet Printing build to contain discrete rigid black and rigid white regions without mechanical assembly, adhesive bonding, or secondary coloration. Typical applications include functional prototypes with embedded marking, housings, jigs, and instructional components in which both phases must remain rigid.

Compared with single-material VisiJet M2R-BK and VisiJet M2R-WT, the RBK-RWT-L30 pairing is validated for co-jetting through separate model-material channels. Single-material cartridges are not considered a direct substitute because pigment-package differences can alter interfacial wetting and cure response. The paired resins are lot-controlled to reduce mismatched shrinkage. This pairing also differs from elastomeric or wax-based VisiJet materials; it remains rigid after UV cure, and no Shore A phase or sacrificial burnout profile is present.

What Processing Window Is Implied by the L30 Suffix?

The L30 suffix denotes a 30 µm build layer mode specified for the pairing. At 30 µm layer thickness, the printer deposits nominal 30 µm layers of model material and support material. Each layer is planarized and exposed to UV-A radiation in the 365–405 nm band before the next deposition. The two model resins remain segregated in feed lines until the printhead nozzle array. The material bay and printhead temperatures are controlled within closed-loop limits. Deviations outside those limits can alter jetting viscosity, droplet formation, and cure conversion. No open-vat mixing is used; the only co-mixing zone is the droplet overlap at the black-white transition. Layer thickness also influences surface stair-stepping on angled transition walls. A 30 µm mode reduces stair-stepping relative to thicker modes but increases build time relative to faster 50 µm or 60 µm single-material settings if platform-supported modes are compared. The manufacturer’s process parameters for this composite set should be used rather than generic MultiJet Printing settings.

VisiJet CR-BK and VisiJet CR-WT 200** Pairing in MultiJet Processing

VisiJet CR-BK is a rigid black acrylate formulation; VisiJet CR-WT 200** is a rigid white counterpart with matched cure response. Matching cure kinetics is required because both phases are cured by the same UV exposure schedule. If one resin reaches gelation earlier than the other, differential shrinkage at the transition can produce curl, step-line readout, or delamination. The black phase contains dispersed pigment; the white phase contains a scattering agent. Pigment loading in the black resin influences UV penetration depth and may require exposure compensation in the build routine. The white resin scatters UV radiation, which can produce a local hardness gradient near the transition if exposure is not controlled. These effects are managed through printhead firing algorithms and layer-wise exposure control. The two materials are formulated for similar bulk shrinkage and modulus development, but the transition zone is a graded acrylate network rather than a sharp adhesive bond line.

Support removal follows the standard MultiJet Printing wax-support sequence. The support wax is liquefied in a temperature-controlled support-removal oven, typically in the 35–45 °C range for wax-based support formulations, followed by ultrasonic bath rinsing. Technical service reports indicate that transition-boundary walls below 1.0 mm wall thickness can exhibit dimensional drift after support removal at the upper oven temperature if the part is not fixtured. A two-stage support-removal protocol—low-temperature melting followed by ultrasonic bath rinsing—reduces residual wax deposition at the interface. No thermal post-cure is required after printing; the as-built acrylate network is UV-cured in the chamber. Conditioning at 23 ± 2 °C and 50 ± 10 % relative humidity for 24 h before metrology is recommended because moisture uptake can temporarily alter dimensional stability in humid environments.

Process conflicts arise when a part contains both large solid black regions and thin unsupported white tabs. The black phase absorbs more UV and may cure slower at the core of thick sections; the white phase scatters UV and may cure faster at exposed surfaces. This creates a local exposure mismatch at the transition when section thickness changes abruptly. Build orientation should place the transition interface parallel to the planarizer direction where possible. If the interface is perpendicular to the planarizer, a small lip or witness line can be transferred from the leveling blade. Parts with transition walls below 1.0 mm should be supported by adjoining black geometries or thickened to at least 1.2 mm to reduce curl. Tolerances on the transition line under standard build conditions are generally within ± 0.15 mm for well-constrained planar interfaces; the manufacturer does not publish a universal transition-line tolerance, so process capability studies are required for critical features.

When the Black–White Transition Must Carry Mechanical Load

Mechanical loads across the black–white interface require specimen-level evaluation. The as-jetted transition is not a discrete adhesive bond line but a graded diffusion zone controlled by droplet overlap and the time delay between jetting and UV cure. Tensile testing of neat VisiJet CR-BK and VisiJet CR-WT 200** bars per ASTM D638-14 establishes bulk resin properties; published data for the transition zone itself is limited. When the transition must carry load, test coupons should be printed with the interface perpendicular to the load axis and evaluated using ASTM D638-14 at a crosshead displacement rate of 5 mm/min. The measured strength is typically lower than the weaker neat resin because pigment-related cure inhibition and local stress concentration occur at the boundary. For preliminary design, a knock-down factor of 0.80 to 0.95 on the neat tensile strength may be applied until transition-zone data is generated. This range is a conservative engineering estimate and is not a manufacturer-published value, because interface strength depends on build orientation, layer thickness, and storage conditions.

Mechanical response is anisotropic. MultiJet Printing builds by layer stacking, so tensile properties measured parallel to the build plane may differ from those measured perpendicular to the build plane. The manufacturer’s published data are usually generated in the preferred build orientation. For load-bearing parts, ISO 527-2:2012 can be used to compare in-plane and through-plane behavior. The transition zone introduces an additional orientation-dependent variable; an interface printed in the XY plane often shows a wider mixed region than an interface printed in the Z axis.

Neat-resin mechanical and thermal response values published by the manufacturer are summarized in Table 1. Specimens are conditioned at 23 ± 2 °C and 50 ± 10 % relative humidity for 48 h before testing. Values represent bulk resin specimens printed in the standard orientation; they do not quantify the black-white transition zone. Confirm current datasheet values for the specific cartridge lot before design release.

Thermal performance remains rigid at moderate elevated temperatures. The heat deflection temperature values in Table 1 indicate that continuous exposure above 50 °C under load may produce creep. Chemical resistance to water and weak acids is moderate; prolonged immersion in strong organic solvents, ketones, or aromatic hydrocarbons can cause swelling, surface crazing, and reduction in hardness. Solvent compatibility should be tested to ASTM D543-21 if service conditions require chemical contact. The materials are not stabilized for long-term outdoor UV exposure; unpigmented or white sections may yellow under prolonged actinic exposure.

If a Part Requires Regulatory Documentation, What Standards Apply?

Regulatory compliance is limited to manufacturer declarations and industrial material status. The resins are typically assessed under the EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No 1907/2006. No food-contact or medical-grade designation should be assumed. Users requiring FDA 21 CFR 177.2600 or ISO 10993-1 cytotoxicity evaluation must perform application-specific testing. The materials are industrial photopolymers, not certified for implantable or mucosal contact. Disposal must follow local regulations for uncured acrylate waste.

Unopened cartridges should be stored at 15–30 °C, away from UV and sunlight. The manufacturer assigns a shelf life; expired material may exhibit viscosity drift and pigment settling. The white resin can settle faster than the black resin because of scattering-agent density; cartridges should be agitated according to equipment protocol before installation. High-humidity environments above 60 % RH increase moisture absorption at the exposed surface and may reduce interlayer adhesion or increase brittleness in thin sections. Build chamber humidity is typically maintained in the 40–60 % RH range; excursions beyond this range can produce dimensional drift in unsupported walls. Printhead channels must be purged after extended idle periods. The dual-material configuration requires both channels to be verified for jetting uniformity, because a partly occluded black channel changes the local transition-zone composition. Do not mix VisiJet CR-BK or VisiJet CR-WT 200** with other VisiJet resins in a single material channel; the two-component set is validated only as a pair.