3D Systems VisiJet RWT-ENT-A60 is a multi-material composite build configuration based on VisiJet CR-WT 200 and VisiJet CE-NT. The designation RWT-ENT-A60 identifies a rigid white tough phase and an elastomeric natural-touch phase, with the suffix A60 indicating nominal Shore A 60 hardness in the soft phase. In manufacturer literature the product may appear as VisiJet CR-WT 200** + VisiJet CE-NT; the asterisked form is retained here as a cartridge or build-mode qualifier. The composite is not a homogeneous resin blend. It is a jetted co-deposition of two UV-curable photopolymers in one build, in which the CR-WT 200 component forms the load-bearing shell and the CE-NT component forms the compressible, flexible, or tactile regions. The two materials are cured in the same printing pass, which creates a graded boundary rather than a discrete adhesive joint. The primary manufacturing distinction is the elimination of secondary assembly in short-run functional prototypes where rigid and elastomeric zones must be integrated.

Material Partitioning and the Shore A 60 Designation

CR-WT 200 is a rigid white photopolymer. The WT in the material code denotes the white color state; the CR prefix associates the material with the engineering composite family. CE-NT denotes an elastomeric natural-touch photopolymer. The NT descriptor is consistent with a natural or translucent elastomer grade, but the printed CE-NT surface is influenced by layer orientation, support removal, and post-cure temperature. The nominal Shore A 60 value in the product designation is a reference point for soft-phase hardness; measurement under ASTM D2240-15 may yield different values depending on specimen thickness, dwell time, and build orientation. The interface between the two phases is not assigned an independent material code; its mechanical performance depends on jetting waveform calibration, UV irradiance, and the physical contact time between the two resins before full crosslinking.

Because the rigid and elastomeric phases have different crosslink density and shrinkage, the transition zone can exhibit anisotropic properties. A tensile bar printed with the long axis parallel to the phase boundary may have a higher apparent elongation than a bar printed perpendicular to the boundary. This is a build-orientation variable that must be controlled when reporting mechanical properties. Standards such as ISO 527-2:2012 and ASTM D638-14 define specimen geometry and conditioning at 23 ± 2 °C and 50 ± 5 % RH, but they do not define how to sample a multi-material gradient. Published data for this specific configuration is limited, so the following table lists the test methods typically applied to the homogeneous phases rather than a manufacturer-published property set.

Process-induced failure modes are concentrated at the phase boundary. When CR-WT 200 is deposited first and CE-NT is dispensed onto partially cured rigid resin, the degree of interpenetration between the two networks remains a function of the delay between drops and UV cure. If the CE-NT drop coalesces with an already hardened CR-WT 200 surface, the interface is thinner and may fail cohesively under repeated flexure. If the two drops remain liquid for too long before cure, the elastomer may bleed into the rigid region and reduce short-term stiffness. Production-scale equipment has shown that boundary quality is sensitive to lamp irradiance drift; a degraded UV lamp may produce parts that pass visual inspection but delaminate during shipping vibration or thermal cycling.

How Co-Deposition Changes Post-Processing Requirements Compared with Single-Resin VisiJet Builds

Single-resin VisiJet builds are post-processed by removing support material, washing, drying, and optional UV post-cure. The RWT-ENT-A60 composite is more strongly affected by the wash step because CE-NT is a lower-modulus, higher-absorption phase. Support removal media that is acceptable for CR-WT 200 may plasticize the elastomer if the exposure time exceeds the qualified window. Manufacturers of jetted elastomer photopolymers typically restrict solvent contact to the shortest duration necessary to remove support material; this is not a rigid-phase requirement but an elastomer-phase chemical resistance ceiling. The wash process therefore becomes the rate-limiting step in mixed-phase builds, and blind pockets where support wax or oil can remain are a common root cause of delayed tack and Shore A drift.

The second post-processing risk is post-cure. Post-cure may be required to stabilize CR-WT 200 dimensions or to complete the elastomer crosslinking. However, a single post-cure cycle that is too long for CE-NT can cause embrittlement and surface yellowing, while a cycle that is too short for CR-WT 200 can leave residual monomer in the rigid shell. The composite therefore has a narrower post-cure window than either material alone. Process engineering staff should qualify the post-cure chamber using calibrated UV irradiance measurement, and build logs should record the CE-NT surface temperature during cure. The manufacturer’s recommended maximum cumulative UV dose for CE-NT is the controlling upper boundary; CR-WT 200’s minimum dose is the controlling lower boundary. If the two ranges do not overlap within the available equipment, the build must be redesigned to separate the phases into two sequential post-cure schedules, which is not always possible.

Printhead maintenance is elevated from a routine task to a process variable. Because the two resins have different wetting behavior on the printhead orifice plate, cross-contamination or migrated droplets can produce a thin elastomer film on a rigid-layer surface or vice versa. This contamination layer may not be visible but can reduce local adhesion. Production lines frequently detect such defects only after the part reaches the wash station, when the contaminated interface swells and lifts. The relevant control is to inspect the orifice plate and wiper after each mixed-phase build batch. Some service bureaus add a purge interval between rigid and elastomer passes, but this interval consumes build time and may not be available on all machine configurations. Published data for this specific configuration is limited, so purge strategy is machine-specific and must be developed from first-part qualification data rather than generic guidelines.

Differential polymerization shrinkage is the main source of residual stress at the boundary. CR-WT 200 and CE-NT cure to different network densities; the rigid phase restrains shrinkage of freshly deposited CE-NT, producing tensile stress in the elastomer phase. If the boundary is placed at a sharp internal corner, the stress concentrates and may cause cohesive failure during support removal. The design mitigation is to use fillets or taper transitions at the rigid-to-soft boundary and to avoid terminating the elastomer phase at a stress-raising edge. The manufacturer’s design guidelines for multi-material builds should be followed for minimum fillet radius; generic mechanical design practice does not account for cure-induced stress.

When Multi-Material Jetting Replaces Bonded or Overmolded Assemblies

The RWT-ENT-A60 configuration is considered when a design specifies low-speed flexing, soft-touch grips, sealing ridges, or vibration isolation that must be attached to a rigid housing. In a conventional workflow, the rigid housing and elastomer gasket are produced separately; the elastomer is then inserted, overmolded, or bonded with a pressure-sensitive adhesive. The main difference with RWT-ENT-A60 is that the soft phase is generated directly on the rigid phase during printing. This allows elastomeric features to follow compound surfaces and internal channels that cannot be reached by adhesives. However, the CE-NT phase is not a high-consistency silicone rubber. Its recovery behavior and tear strength are those of a UV-curable photopolymer, and the available published data for this specific configuration is limited. Direct substitution for injection-molded thermoplastic elastomers requires tensile, hardness, and compression-set testing under ASTM D412-16 and ASTM D2240-15 at minimum.

Compared with a single-material VisiJet CR-WT 200 build, the RWT-ENT-A60 option adds an elastomeric phase that reduces the effective stiffness of the rigid shell when soft regions are large. Compared with bonding a separately printed CE-NT part to a rigid part, the co-deposited interface eliminates bond-line thickness variation and adhesive compatibility concerns, but it introduces build-orientation limits and can complicate recycling because the two resins are not easily separated after cure. Thermal stability of the whole part is also governed by the CE-NT phase, which may soften at a lower temperature than the rigid CR-WT 200 phase. A thermal test on the composite is therefore required if the part will be shipped or used near heat sources.

Handheld diagnostic enclosures, wearable device prototypes, laboratory instrument covers, and benchtop equipment control panels are typical application contexts. In these layouts, the CR-WT 200 shell is specified at the printer’s minimum recommended wall thickness and CE-NT is placed at grip pads, button diaphragms, or seal ridges. The soft phase should not be designed as an unsupported thin membrane unless the manufacturer’s design guide permits it; unsupported CE-NT spans can distort during support removal or show lower durometer readings than the nominal Shore A 60 because of incomplete polymer network development. Thick rigid bosses adjacent to thin elastomer regions should be staggered to reduce stress concentration at the phase boundary.

Regulatory and storage limits set the outer processing boundary

Compliance for this multi-material configuration is a system property, not a single-resin statement. The manufacturer’s safety data sheet and regulatory information for VisiJet CR-WT 200 and VisiJet CE-NT must be retained in the production record. Cured properties may be evaluated for RoHS-restricted substances under the relevant test methods if electronics enclosure use is claimed, but the uncured resins are photopolymer preparations with handling restrictions. No claim is made here that RWT-ENT-A60 is certified to FDA 21 CFR 177 unless the manufacturer’s grade-specific statement explicitly provides that listing. End users must not rely on generic VisiJet platform statements for food-contact or medical-device applications.

Operators should use nitrile gloves and protect cartridges from direct UV and sunlight. Cartridge storage is bounded by the label shelf life and temperature range; exceeding the maximum storage temperature can increase viscosity, while sub-ambient storage can induce condensation when cartridges are returned to ambient. Both effects can shift drop placement and reduce boundary adhesion. Uncured photopolymers are not dried in the same sense as thermoplastic pellets, but the build chamber must remain free of condensed water because water droplets can create pores and inhibit interlayer adhesion. Build platform preparation is critical for adhesion; a contaminated platform can release the first CR-WT 200 layers during printing, producing a layer shift that is misdiagnosed as a material problem.

Incompatibility boundaries include exposure to amine-based cleaning agents, strong alkalis, or solvent mixtures not listed in the manufacturer’s compatibility matrix. Residual amine contamination on the build platform or wash basket can react with uncured photopolymer films, causing tacky surfaces and incomplete cure. The CE-NT phase is particularly sensitive to solvent-induced swelling; a cleaning solvent that does not visibly attack CR-WT 200 can still degrade the soft phase’s dimensional stability. Therefore, any change to the post-processing chemistry requires controlled validation under production conditions. The build must be dried to constant mass before mechanical testing, because absorbed wash fluid reduces Shore A hardness by plasticization. The most useful process control is to weigh a fixed-size CE-NT validation coupon before and after washing; a sustained mass increase after solvent evaporation indicates incompatibility.