3D Systems VisiJet RCL-EBK-A90 Multi-Material Composites (VisiJet CR-CL 200** + VisiJet CE-BK) is a two-resin photopolymer set for MultiJet Printing platforms capable of co-printing rigid and elastomeric components in a single build. The designation encodes the material architecture: RCL identifies the rigid clear phase derived from VisiJet CR-CL 200**, EBK identifies the elastomeric black phase derived from VisiJet CE-BK, and A90 indicates the target bulk durometer of 90 Shore A. The trailing double asterisk on the CR-CL 200** component is retained from the supplier’s composite nomenclature and identifies the rigid clear grade as a co-processed constituent of this set rather than an independent single-material qualification for all build modes. In operation, the two photopolymers are delivered from isolated reservoirs and deposited by piezoelectric inkjet heads alongside a sacrificial wax support material, then cured by UV irradiation. The composite is therefore not a pre-compounded blend but a spatially co-deposited structure in which the CR-CL 200 phase contributes tensile modulus, dimensional rigidity, and thin-wall stability, while the CE-BK phase contributes elongation, recovery, and tear propagation resistance. The bulk hardness target is measured under ASTM D2240-15 using a stacked specimen with a 6.4 mm thickness and a 15 s dwell time. Published multi-point mechanical data for the completed composite remain limited; tensile modulus, tensile strength, elongation at break, tear resistance, and compression set should be obtained from the current manufacturer technical bulletin because values shift with build orientation, wall thickness, and support removal protocol.

The two source resins are conventionally screened under different mechanical tests because their strain-at-break regimes differ. The rigid clear component is normally evaluated under ASTM D638-14 tensile-bar conditions, whereas the elastomeric black component is evaluated under ISO 37:2017 or ASTM D412 using die-cut tensile specimens. A single test method applied to the composite requires reporting of specimen orientation, build layer count, and any post-process heat history. Without those descriptors, inter-lot comparisons become unreliable. Because the composite is produced by droplet-wise co-deposition rather than melt compounding, no screw shear, pelletization, or mold thermal history exists. Instead, the two photopolymers must exhibit compatible droplet wetting and viscosity behavior. A viscosity mismatch large enough to produce satellite droplets or head starvation appears in the finished build as interfacial porosity, especially where rigid and elastomeric zones meet at steep angles through the build direction.

Target applications are typically prototypes and short-run production aids in which a rigid transparent viewing window, clip, rib, boss, or lens surface must be combined with a black elastomeric seal, grip, compression stop, or shock-absorbing structure without secondary assembly. In such builds, the CR-CL 200** phase can form internal ribs, snap features, and threaded bosses, while the CE-BK phase can form gasket lips and impact-absorbing covers. The build preparation software assigns each voxel to one of the two resins or to support material; the resulting composite therefore has localized property gradients that are not possible in a homogeneous injection-molded resin. This also means the stated 90 Shore A target is not a guaranteed value for every point in the part; it is a bulk specimen target under standard test conditions.

What Distinguishes the Co-Deposited Composite from Single-Component VisiJet CR-CL 200 and CE-BK?

Standalone VisiJet CR-CL 200 is a rigid, transparent photopolymer whose primary function is structural clarity and high-modulus response. Standalone VisiJet CE-BK is a black elastomeric photopolymer intended for low-hardness, high-elongation components such as gaskets, soft-touch grips, and crush zones. The RCL-EBK-A90 composite occupies an intermediate mechanical position: the 90 Shore A target is higher than many sealing elastomers but lower than rigid structural grades. The principal structural difference is the absence of a discrete adhesive bond line. In conventional manufacturing, a rigid clear insert and elastomeric black overmold would be joined by two-shot molding, ultrasonic welding, or adhesive, producing a sharp interface with known surface energy. In the co-deposited composite, the printer may generate either abrupt or graded transitions between the two phases according to the build recipe. The transition length is not fixed by mold geometry but by print resolution and the selected digital mixing profile.

Compared with a filled thermoplastic elastomer system from injection molding, the composite does not require tooling and permits internal rigid zones, but the final mechanical properties are governed by photopolymer crosslink density rather than thermoplastic melt processing history. Compared with separate CR-CL 200 and CE-BK parts joined in assembly, the multi-material build reduces part count and eliminates the thickness variation introduced by adhesive bond lines, but the interface fatigue and peel strength data are not yet comprehensively published for industrial load cases. Published data for this specific configuration is limited; qualification for load-bearing applications should include ASTM or ISO test programs run on specimens built in the exact production orientation and support-removal protocol.

When Oven Support Removal Is Applied to Multi-Material Jetting Builds

Support removal is a critical process window for this two-resin composite because the sacrificial wax used in MultiJet Printing is normally removed by elevated temperature or agitated solvent. The temperature setpoint is determined by the support wax melting range and not by the build material, but the rigid and elastomeric phases exhibit different coefficients of thermal expansion. During ramp-up and dwell, the CR-CL 200 phase constrains expansion of the CE-BK phase; the resulting interfacial stress is highest in thick sections where a rigid core is surrounded by an elastomeric skin. In production-scale equipment, this failure mode appears as micro-crazing at the rigid-elastomer interface or as localized debonding in blind cavities that trap support material. Operators should not increase oven temperature to shorten cycle time unless the manufacturer’s technical bulletin specifically supplies an upper thermal limit for this composite. The recommended recipe should be treated as a maximum-dwell condition because continued heat transfer into thick parts after support wax is molten can produce dimensional relaxation in the elastomeric phase. Batch rack loading may also alter heat transfer; tight packing can extend effective thermal exposure and shift final hardness.

After support removal, residual wax film on high-elongation surfaces should be cleared with an approved non-reactive cleaning sequence. Chemical compatibility data for the completed composite are limited for ketone and chlorinated solvents; aggressive solvent exposure can reduce the CE-BK phase hardness and produce surface tack. If automated degreaser equipment is used, the wash temperature and immersion time must be validated with dimensional measurements and Shore A hardness coupons. Low-frequency ultrasonic cleaning may assist in clearing trapped wax from internal channels, but thin elastomeric membranes can undergo cavitation erosion at unsupported regions. Dimensional metrology should be delayed until the part has been conditioned in a standard laboratory atmosphere of 23 °C and 50% RH in accordance with ISO 291:2008. Support material residues in narrow channels should be detected by mass gain or micro-CT before mechanical testing, because residual wax acts as a crack-initiation site at rigid-elastomer interfaces.

In sealing applications requiring repeated compression, the 90 Shore A target places the material in the same nominal durometer range as some industrial nitrile and neoprene gaskets, but the photopolymer base differs in viscoelastic recovery and compression set. Compression set should be evaluated under ASTM D395 Method B at the application-specific temperature and time, not inferred from Shore A durometer alone. Tear strength, when required for dynamic lip seals, should be measured under ASTM D624 or ISO 34-1. Fluid compatibility should be confirmed by immersion testing under ISO 1817 for the target medium; the supplier’s printed chemical resistance data should not be extrapolated to blended fuels, brake fluid, or chlorinated process streams without verifying the composite’s specific response. For functional prototypes of two-shot molded parts, the build orientation determines the property balance: the Z-direction interlaminar boundary through the elastomeric phase typically exhibits lower elongation than the XY plane. Qualification coupons should therefore be placed in the same orientation and position on the build tray as production-like components. Published data for dynamic fatigue of this specific composite is limited, so rotating-bend or cyclic tensile screening is required before using the material in snap-fit or living-hinge geometries.

Interface Microstructure, Shrinkage Anisotropy, and Storage Life

The two photopolymers do not share identical volumetric shrinkage after UV exposure. The rigid clear phase forms a higher crosslink density network, producing greater localized shrinkage at the interface than the elastomeric black phase. In multi-material jetting, this mismatch generates residual stress that can warp thin ribs, curl unsupported edges, or shift the final bulk durometer when the rigid fraction is locally concentrated. Build preparation software can reduce these effects by adjusting the transition length and placing rigid zones away from unsupported boundaries. However, no universal area threshold applies across all platform sizes; the maximum contiguous rigid area is a function of part height, support density, and the specific build platform temperature used by the MJP system. Microstructural inspection of co-deposited sections can be performed by optical microscopy under transmitted light for the clear phase and by micro-CT for internal voids; the black elastomeric phase requires reflected-light or contrast-enhanced imaging to resolve grain boundaries and droplet coalescence.

Resin logistics also affect batch-to-batch variance. The elastomeric black component is sensitive to moisture uptake if the container is left open at relative humidity above 60%; absorbed water can alter viscosity and reduce droplet formation stability in piezoelectric heads. New resin lots should be qualified with a nozzle test pattern and a hardness coupon build before transfer to long-duration production. Containers should be sealed when not in use and stored away from direct UV/visible light. The uncured CE-BK phase should not be contacted with amine-containing additives or uncured epoxy streams in shared tooling; unintended contact can inhibit surface cure or produce a tacky interface. The composite is supplied as a manufacturing material subject to standard hazard communication under EC 1272/2008; end-use compliance under REACH EC 1907/2006 and RoHS Directive 2011/65/EU should be verified with the supplier’s certification for the specific shipment and build configuration.