The 3D Systems VisiJet RWT-EBK-A40 Multi-Material Composite is supplied as a two-cartridge photopolymer build set for MultiJet Printing (MJP) platforms that support multi-material jetting. The set comprises VisiJet CR-WT 200, a rigid white UV-curable resin, and VisiJet CE-BK, a black elastomeric UV-curable resin. The product code segments into rigid white (RWT), elastomeric black (EBK), and the A40 Shore hardness classification linked to the elastomer-bearing build configuration. The two feedstocks are not pre-blended before jetting. Each material is delivered through independent printhead channels and polymerised in place, so rigid and elastomeric zones can be generated within a single build sequence. The material set is used in functional prototyping, short-run production aids, and components that require integral elastomeric sealing, damping, or flexure features combined with rigid structural segments. Compatible hardware includes 3D Systems MultiJet Printing systems listed in the manufacturer’s qualification documentation, with the ProJet MJP 2500 Plus commonly referenced in product literature for multi-material operation.

Why Is RWT-EBK-A40 Classified as a Multi-Material Composite Rather Than a Single Resin Blend?

The two constituent feedstocks remain separate during jetting and cure as adjacent or interpenetrating domains, not as a single homogenised bulk. Final parts therefore contain discrete rigid white regions fused to elastomeric black regions without a secondary adhesive interface. The mechanical transition is produced by controlling regional deposition in the layer data, not by post-build overmoulding or mechanical joining. On compatible MJP platforms, piezoelectric printhead channels deposit CR-WT 200 and CE-BK in the same layer, allowing a digital material gradient or a defined boundary between the two photopolymers. This process differs from bonding or insert moulding because the transition zone is composed of cured resin rather than a foreign adhesive system. The absence of a bond line reduces assembly variance in small-lot production, but it introduces process considerations at the interface, including residual stress from differential polymerisation shrinkage and the need for support removal strategies that do not damage the low-tear elastomer phase.

On production-scale MultiJet Printing equipment, the material set is loaded as sealed cartridges with separate waste and purge paths for the rigid and elastomer resins. Printheads maintain reservoir temperatures specific to jetting viscosity, and support material is loaded independently. The build layer thickness and planar resolution are machine-controlled and are not user-selectable for this material set. Failure to follow the printer’s material preparation routine can produce jetting defects such as missing nozzles, satellite droplets, or non-uniform elastomer thickness. Batch-to-batch variation in the black elastomer can be observed after improper storage or expiration, so the printer should be purged and the printhead recalibrated after cartridge changes.

The mechanical property contrast between the two feedstocks is the primary design input. The following table summarises typical manufacturer-published values for the individual constituents. Test methods are the standard designations listed in the corresponding 3D Systems material datasheets. Values for the multi-material interface or for spatially graded zones are not supplied here because composite properties vary with local deposition ratio, build orientation, and post-processing.

CR-WT 200 exhibits tensile strength greater than CE-BK by a factor of approximately 29 and tensile modulus above 1,000 MPa. The elastomeric phase provides elongation at break approximately 30 times that of the rigid phase. These differences allow design of parts in which the rigid material carries structural loads and the elastomeric material accommodates strain, compression set, or flexure. The Shore A hardness of 27 for CE-BK supports conforming seal surfaces under low closure force; the Shore D hardness of 82 for CR-WT 200 provides a hard surface in mounting bosses and snap-fit latches. Composite zone values are not the arithmetic mean of the two constituents. The interface stiffness and ultimate tensile strength depend on the digital material ratio, the orientation of the tensile axis relative to the rigid-elastomer transition, and the cure state of the interface. Published data for this specific configuration is limited; lot-specific mechanical verification is recommended when design allowables are required.

Uncured resins for this build set are photopolymer liquids engineered for MultiJet Printing. Cartridge storage within the sealed container is recommended at the temperature range stated in the Safety Data Sheet; typical photopolymer storage temperatures of 15–30 °C and relative humidity below 40% are common guidance. Exposure to ambient light should be avoided because the resins contain photoinitiators. Before starting a build, cartridges should be agitated or prewarmed according to the printer maintenance cycle to avoid pigment settling in CE-BK and viscosity stratification. These preparation steps are more critical for the black elastomer because pigment loading can influence cure depth and jetting reliability.

When Elastomeric Sealing Walls and Rigid Retention Features Must Appear in the Same Build

Applications for this composite tend to concentrate in geometries where a single component must contain both screw bosses and compression seals, or both rigid housing walls and soft-grip surfaces. In these designs, CE-BK zones are specified for sealing lips, gaskets, and flexure elements because of the material’s Shore A hardness of 27 and tear strength of 3.7 kN/m under ASTM D624. CR-WT 200 zones are specified for threaded inserts, snap hooks, and rigid frames because of its tensile modulus of 1,138 MPa and flexural modulus of 1,250 MPa under ASTM D790. The build set allows these features to be produced without secondary assembly, but the low tear resistance of CE-BK imposes design constraints. Sharp transitions, fillet radii below 1 mm, and unsupported elastomeric sections thinner than 2 mm are process-sensitive because local stress concentration during support removal or service loading can initiate tearing. The processing guidance for CE-BK should be reviewed for minimum wall thickness and support geometry recommendations.

Compared with single-feedstock CR-WT 200 builds, RWT-EBK-A40 adds elastomeric function but sacrifices uniform mechanical response and may require longer post-processing because support material must be removed from confined elastomeric cavities without delaminating the interface. Compared with single-feedstock CE-BK builds, RWT-EBK-A40 adds rigid load-bearing capability but introduces interfacial zones where differential thermal expansion and polymerisation shrinkage can build residual stress. These interfacial zones are not present in pure rigid or pure elastomer parts. The composite set is therefore primarily specified when the design requires a spatial hardness contrast that cannot be achieved by changing wall thickness, infill density, or build orientation in a single material.

Handling conditions and chemical exposure limits for the composite are governed by the Safety Data Sheets for the two photopolymers. Compliance statements for REACH Regulation 1907/2006 and RoHS Directive 2011/65/EU are supplied through the manufacturer’s Safety Data Sheet; no independent food-contact or implantable-material certification is provided in standard product literature. Continuous exposure to process fluids, lubricants, or cleaning agents should be evaluated against the elastomeric phase under ASTM D471, because the rigid and elastomeric resins do not share the same solvent resistance profile. The product is not represented as a replacement for cast polyurethane or injection-moulded thermoplastic elastomer in applications requiring high tear propagation resistance or cyclic fatigue data. Published multi-axial fatigue data for this exact composite configuration is limited, and component-level validation remains necessary when the application includes repeated elastomer flexure or sustained clamping loads.