3D Systems VisiJet RBK-EBK-A80 Multi-Material Composites is a two-resin material set for MultiJet Printing platforms configured for simultaneous rigid and elastomeric photopolymer deposition. The product identification refers to paired VisiJet CR-BK rigid black and VisiJet CE-BK elastomeric black cartridges; the A80 suffix denotes a nominal Shore A 80 intermediate durometer generated through digital material blending rather than through a separately packaged third resin. The system is processed by piezo-electric inkjet printheads that selectively jet the two build resins and a sacrificial support wax onto the build platform, followed by UV cure. Because the rigid and elastomeric components are merged at voxel scale, the final part can contain discrete rigid and elastomeric regions or a gradient between them. Mechanical response is influenced by part orientation, layer count, printhead calibration, UV dose, and support removal. The material set is not a thermoplastic compound and cannot be reground or reprocessed after cure.

How Is the Shore A 80 Intermediate Grade Generated During MultiJet Printing?

The Shore A 80 intermediate grade is generated by the printer’s digital material routine, which alternates or mixes jetted drops of VisiJet CR-BK and VisiJet CE-BK according to the build file’s material assignment. The two liquids are not reacted in the cartridge. Mixing occurs on the build plane in the liquid state prior to UV exposure, and the resulting cured network is a heterogeneous composite at the scale of the printed voxel. Therefore, the A80 value is a bulk durometer response, not a molecular copolymer property. Machine calibration directly affects the result. Printhead drop mass, jetting temperature, and UV lamp output must remain within the printer’s specified control limits; a sustained shift in either channel can alter the local rigid-to-elastomeric ratio and shift Shore A readings. Published data for the exact RBK-EBK-A80 composite are limited. 3D Systems supplies separate datasheets for CR-BK and CE-BK, while the mixed intermediate grade is typically verified by lot-specific durometer testing on printed witness plaques. Operators should not assume that tensile strength or elongation of the composite is an arithmetic average of the two feedstock values.

On production equipment, the material bay holds both cartridges and heated feed lines; the machine’s control software uses separate temperature offsets for CR-BK and CE-BK. If a cartridge is below recommended temperature at start-up, initial drop mass can be low and cause missing jets in the rigid channel; if overheated, the elastomer may exhibit reduced cure response. The MJP printhead maintenance station periodically wipes and caps the nozzle plate to prevent cross-contamination. Cross-contamination of CR-BK into CE-BK channels may result in harder-than-expected elastomer zones and brittle inclusions. Because the A80 specification is sensitive to local mixing accuracy, any build stoppage or manual intervention that interrupts the material feed path should be followed by a calibration print and durometer plaque check before production resumes.

Mechanical characterization of the two feedstock materials is governed by separate test families because CR-BK is a rigid plastic-like resin and CE-BK is an elastomeric resin. For CR-BK, tensile properties are obtained on printed specimens under ASTM D638, flexural properties under ASTM D790, and heat deflection temperature under ASTM D648. Hardness is reported on the Shore D scale under ASTM D2240. For CE-BK, tensile strength and elongation at break are evaluated under ASTM D412, tear resistance under ASTM D624, and hardness under ASTM D2240. The RBK-EBK-A80 composite is most directly specified by the Shore A 80 target, but composite tensile, tear, and elongation properties are not always bounded by the neat resin values. Numerical values for a given production lot should be taken from the current 3D Systems certificate of analysis or datasheet. The test methods listed above use specific specimen conditioning and build orientation; any deviation from those conditions invalidates comparison with published values.

A Processing Boundary Between Rigid Black Feedstock and Elastomeric Black Feedstock

The most restrictive process boundary for RBK-EBK-A80 builds occurs during support wax removal. MultiJet Printing deposits a phase-change support material to protect overhangs and internal channels; this support must be melted out or dissolved in dedicated equipment before part use. Because VisiJet CE-BK has a lower thermal tolerance than VisiJet CR-BK, the elastomeric regions control the allowable wax-removal temperature and dwell time. Heated oil baths and purpose-built wax removal ovens should be operated at the support material’s specified melting range, with temperature monitored by a calibrated thermocouple rather than by the equipment’s dial indication alone. If the bath overshoots, CE-BK regions may soften, swell, or retain oil on the surface. Incompressible or low-clearance internal channels can retain wax because capillary forces and temperature gradients limit wax flow; incomplete removal is often detected as local tack or depressed Shore A readings. For this reason, durometer verification on cleaned elastomeric surfaces is recommended before dimensional inspection or assembly.

Solvent exposure is a second boundary. Cured CE-BK and the A80 composite should not be immersed in isopropyl alcohol, acetone, toluene, or chlorinated solvents without compatibility verification. Brief solvent wipes may be tolerated on CR-BK, but the elastomeric phase can absorb solvent and exhibit temporary swell, altered surface friction, and delayed recovery. If application-specific chemical exposure is required, testing under ASTM D543 or an equivalent immersion standard should be performed on cleaned coupons that match the production build orientation. Ultrasonic cleaning after wax removal should also be time-limited for elastomeric sections. Cavitation can damage thin free-standing rubber-like walls and can generate localized heating. The support removal protocol for mixed builds should therefore treat the CE-BK phase as the limiting material, not the CR-BK phase.

In production, two failure modes are commonly reported for multi-material MJP jobs. The first is interfacial separation or cracking at the transition plane when the rigid and elastomer regions are subjected to tensile load along the build-layer direction. The second is delayed wax bleed-out from semi-porous elastomer sections after apparent cleaning. Both are managed by modifying orientation, transition length, and wash-out time rather than by changing the material blend ratio, which is locked by the printer’s software. Published peer-reviewed data on the fatigue limit of the CR-BK/CE-BK interface is limited; design safety factors should reflect that uncertainty.

Cartridges should be stored in the manufacturer’s specified temperature and light-exclusion conditions. Exposure to ambient UV or elevated room temperatures can increase viscosity and may change jetting behavior. Cartridge shelf life is stated on the label and should not be exceeded for critical builds. Before loading, cartridges should be allowed to reach printer bay temperature; inversion or gentle agitation may be required to redisperse pigments, but the manufacturer’s cartridge preparation instructions take precedence. Disposable mixing protocols are not applicable because the two resins are not combined until reaching the build plane.

Geometric transition zones between CR-BK and CE-BK are not infinitely sharp. The printer uses a discrete drop grid; therefore, the interface has a finite transition width determined by native resolution and layer thickness. When the part contains thick rigid sections adjacent to thick elastomer sections, differential polymerization shrinkage can create interfacial stress that appears as edge lift or local distortion after support removal. Support scaffolding and orientation should be arranged so that large rigid regions do not constrain the elastomer during build. Surface finish of CR-BK is typically harder and more scratch-resistant than CE-BK; the elastomer surface can retain a matte appearance and may show support-contact texture. Published data for dimensional accuracy of the RBK-EBK-A80 composite is limited; therefore, critical dimensions should be assessed on witness coupons and production-run first articles.

When CR-BK Alone Would Be Preferred Over the RBK-EBK-A80 Set

Selection between the multi-material set and a single material should be based on functional requirements and post-processing capacity. If the part does not require an elastomeric region, VisiJet CR-BK used alone avoids the additional thermal restrictions, solvent sensitivity, and support-removal complications introduced by CE-BK. If the part requires only a low-durometer elastomer, VisiJet CE-BK alone may produce the intended compliance without the stiffness of a rigid black counterpart. The RBK-EBK-A80 set is justified when the design requires a Shore A 80 intermediate stiffness, an abrupt or graded rigid-to-elastomeric transition, or the inclusion of stiff and soft regions in one build without secondary adhesive bonding. The multi-material pair increases material handling complexity because two cartridges must be loaded and recognized, and the support removal cycle may be longer than for a rigid-only build. Compared with conventional injection-molded thermoplastic elastomers, the cured MJP composite is thermoset-like and does not exhibit the same melt reprocessability or dynamic mechanical response across all frequencies and temperatures.

Compared with other 3D Systems VisiJet material families, the RBK-EBK-A80 set occupies a specific position. CR-BK is a general-purpose rigid black material with Shore D hardness, while CE-BK is a black elastomeric material with a lower Shore A durometer. Other VisiJet elastomeric or rigid grades, including translucent or natural variants, may have different photopolymer cure response, different tensile behavior, or different support removal compatibility. The A80 designation is the controlling distinction for this product: it specifies an intermediate Shore A 80 digital material rather than a neat resin. This does not make it a substitute for all thermoplastic elastomers or cast polyurethanes. For applications requiring a specific compression set, rebound resilience, or dynamic mechanical performance, the relevant test data should be obtained from 3D Systems or through independent coupon testing. Published data for the RBK-EBK-A80 configuration is limited; the safest engineering approach is to use the A80 value only as a starting point for durometer verification, not as a complete mechanical specification.

Application usage of the RBK-EBK-A80 material set is concentrated in multi-durometer prototypes and short-run manufacturing aids where rigid and elastomeric regions must coexist without adhesive assembly. Typical geometries include overmolding simulations for grips and hand tools, compression-limiting gaskets, sealing collars, vibration isolation pads, flexible housing edges, and wearable device prototypes. The digital material transition can be placed at a specified boundary or graded over a distance; however, the minimum transition length is bounded by printer resolution. Published application-specific data for cyclic fatigue, compression set, and long-term hydrolytic or UV stability of the A80 grade is limited. Designs intended for cyclical loading or outdoor exposure should be validated by end-use testing under the relevant application standard. For medical or skin-contact applications, biocompatibility is not automatically conferred by the material designation; cleaned and cured parts would require evaluation under ISO 10993 or equivalent regulatory protocols. Compliance with EU REACH, RoHS, and any food-contact or medical packaging requirements must be verified against the current 3D Systems Safety Data Sheet and lot-specific certification for the specific cartridge batch.