In medical anatomical modelling workflows where the rigid phase must demonstrate fluid-tract transparency and the soft phase must recover after repeated compression, the A60 digital material from the VisiJet RCL-EBK-A60 Multi-Material Composites range is typically assigned to clear rigid structures from VisiJet CR-CL 200 and black elastomeric structures from VisiJet CE-BK. The 60 Shore A designation is associated with durometer measurements on the elastomer-dominant phase under ASTM D2240-15, while the clear phase retains sufficient light transmittance for vessel and sinus boundary visualization after support removal. The A60 setting does not correspond to a bulk mixing ratio; instead, the relative voxel population of CE-BK and CR-CL 200 is fixed in printer software and triggered by the digital-material selection. For clinical skills centres and teaching hospitals, documentation of cytotoxicity under ISO 10993-5:2009 and skin sensitization under ISO 10993-10:2021 is requested before models are introduced into wet-training spaces; this composite is not intended for permanent implantation, so release is often limited to surface-contact or short-term skin-contact assessment. The build is executed on MultiJet Printing platforms with a 32 µm layer height in high-resolution mode, with wax support jetted in the same pass to preserve hollow vessel lumens and thin cortical shells. Support wax is removed in a dedicated oven or mineral-oil bath maintained below 65 °C to reduce compressive set in the CE-BK regions and avoid thermal haze in the CR-CL 200 windows. Terminal models include renal collecting-system replicas in which the calyceal walls are printed in rigid clear and the ureteral segments are patterned as black elastomer, allowing trainees to practise guidewire advancement through a compliant, visually distinct duct. A known limitation is repeated disinfection: common aldehyde-based hospital sterilants can attack the crosslinked acrylic network, and no published compatibility dataset exists for more than intermittent exposure, so each clinical disinfection protocol must be tested before implementation.

When a Shore A 60 Digital Material Replaces Two-Shot Injection Tooling for Keypad Seals

Prototyping of consumer keypad seals with multi-material jetting uses CR-CL 200 and CE-BK to produce one-piece shells that carry both a rigid transparent display window and an integral black elastomeric keypad diaphragm, eliminating the need for a two-shot mold during beta-iteration builds. The A60 composition ratio is not a simple mass percentage; it is a digital voxel proportion selected in printer software to reach the Shore A 60 durometer target on the elastomer phase. The rigid phase is designed to withstand snap-fit assembly loads, and the elastomeric phase is assigned to the button perimeter where the material must flex repeatedly between 0.05 mm and 0.2 mm travel. Because the A60 composite is graded by printer software at the voxel level, designers can create a transition band rather than a discrete bond line, which reduces the risk of local delamination at the rigid-elastomer interface. For compliance, the manufacturer’s safety documentation is reviewed against RoHS Directive 2011/65/EU Annex II restricted substances, and electrical enclosure prototypes are separately checked for creepage and clearance against IEC 62368-1:2018 because the clear phase does not carry a published comparative tracking index for production use. The build is oriented with the elastomeric diaphragm facing the printhead side to minimize trapped support wax and to keep the critical sealing face free of witness marks. After the build, the part is cooled to below 25 °C before wax removal; isopropyl alcohol is then used to clear residual support from the keypad channels, and a final UV flood post-cure follows manufacturer settings to avoid yellowing the clear regions. Terminal prototypes include mobile-phone enclosure mules with integrated volume rocker seals, industrial keypads with transparent switch covers, and handheld instrument cases where the black elastomer provides dust sealing around the display perimeter. Compression set and button-return force should be verified with ASTM D395-18 Method B and a force-displacement fixture; published material-specific values for CE-BK after repeated actuation are limited, so acceptance criteria must be generated from first-article prototypes.

Directly after the build plate is cleared of residual wax, wearable-device prototypes combining CR-CL 200 sensor housings with CE-BK strap anchors are conditioned at 23±2 °C and 50±10 % RH for 24 h in accordance with ASTM D618-21 before tensile or flexural testing. This conditioning step stabilizes the absorbed moisture gradient between the two material phases and prevents premature interfacial failure when the strap is cycled. The transparent sensor window is printed in the rigid phase to allow optical interrogation during fit trials, while the black elastomeric anchor loops and skin-facing pads are digitally composed at the Shore A 60 target. In a typical wearable optical heart-rate monitor mock-up, the CR-CL 200 window is kept at a thickness of 1.2 mm to 1.5 mm to reduce flexural cracking at the charge dock, and the CE-BK strap attachment is graded into the rigid frame over a 3 mm transition instead of a butt joint. For skin-contact documentation, short-term irritation testing follows ISO 10993-23:2021 where required by the receiving laboratory; the largest uncertainty is the absence of long-wear sweat-exposure data for CE-BK, and this must be addressed with in-house cycling in pH-adjusted artificial sweat before user trials. Print orientation places the rigid window flat to the build tray with the strap loop vertical, because this reduces visible layer lines across the optical path and aligns the elastomer recovery axis with the expected loading direction. Terminal outputs include wrist-worn clinical trial enclosures, ECG chest-strip electrode carriers with clear fibre-optic inspection windows, and ear-wear hearing-device bodies that require a compliant black canal seal. Build-to-build variability in the elastomer phase is monitored by durometer measurement on a printed 6 mm plaque in every batch; deviations greater than ±3 Shore A units trigger recalibration of the printhead before production of trial units.

Fluid-Contact Prototype Performance Under ASTM D471 and ISO 34-1 Tear Screening

Automotive quick-connector and grommet development uses the A60 digital material to replicate the geometric interplay between a rigid transparent connector body and a black elastomeric sealing lip without cutting steel tooling for each port revision. The CR-CL 200 phase is assigned to the clear housing so flow visualization remains possible during bench rig tests, while the CE-BK phase is assigned to the sealing collar and anti-vibration grommet where compression recovery is critical. Before any fuel-vapour or oil-contact evaluation, elastomer-only prints are immersed in the relevant reference fluids under ASTM D471-16a for 72 h at 70 °C to measure volume swell and hardness shift; published data for CE-BK in aggressive automotive fuels is limited, so pre-testing on the actual fluid is mandatory rather than inferred from generic elastomer families. The sealing lip is also screened for tear resistance under ISO 34-1:2015 die C after fluid exposure, because stiffness loss may mask degradation of cut-growth resistance at the grommet groove. For under-hood air-management systems, a separate endurance check is performed with dry heat aging at 100 °C for 168 h using ASTM D573-04, after which the seal is compressed to 25 % deflection and inspected for surface tack or permanent set. The build strategy places the sealing lip on the top-facing surface and leaves 0.3 mm of sacrificial support clearance around the grommet groove so wax can drain without tearing thin sections. The elastomer-to-rigid interface is staggered through the wall thickness by modifying the bitmap mask over three to five layers; this creates an interlocking transition that resists peel when the connector is pulled from a mating port. Terminal prototypes include fuel rail test adapters, EV cooling-line quick connectors with transparent sight windows, and brake-booster vacuum grommets used only for fit and flow trials, not for on-vehicle durability release. For production-level validation under the automotive quality system, PPAP documentation of the photopolymer material is not directly transportable to injection-molded EPDM or FKM parts, and measured values are used solely as design inputs for tooling specification.

Because the CR-CL 200 phase supplies a transparent rigid frame and the CE-BK phase supplies a Shore A 60 frictional contact surface, multi-material prints are used in assembly robotics for end-effector fingers that must locate small parts and grip them without marring polished surfaces. The black elastomer is deposited as a cap over the rigid finger core, with the digital transition extended 2 mm rearward from the contact face to avoid a sharp material boundary under shear loading. Compressive load capacity is not published for this exact digital-material configuration; therefore, first-article grippers are tested on a universal testing machine in compression at 1 mm/min until 20 % strain or visible interfacial cracking, whichever occurs first. For abrasive service, Taber wear screening under ASTM D4060-19 using CS-17 wheels at 500 g load provides a comparative ranking against production polyurethane pads, but the test is not intended to establish field life. The build is oriented with the grip face pointing downward to reduce the amount of support wax locked into the elastomer surface, which otherwise becomes tacky after cleaning. Low-temperature performance is checked in a cold chamber at -10 °C for 4 h before repeating the compression cycle, because the CE-BK phase loses compliance at lower temperatures and the rigid CR-CL 200 fingers become more brittle. Terminal assemblies include pick-and-place fixtures for optical lenses, battery-cell handling jaws with transparent inspection windows, and clamping nests for PCB edge connectors where the black elastomer prevents short circuits and distributes contact pressure. Because the printed interface is a photopolymer network rather than a molded chemical bond, sustained shear stress above 0.5 MPa should be avoided unless fatigue testing demonstrates adequate retention in the target environment.

Does Multi-Material Jet Printing Preserve Clear Phase Transmission After CE-BK Co-Patterning?

For optical and camera-module prototyping, the A60 composite is used to produce rigid clear lens barrels or light-pipe windows with black elastomeric light-shielding gaskets and bezel seals in a single print operation. The primary yield concern is not mechanical delamination but optical contamination: waxy support material or black oligomer migration can deposit a haze layer on the CR-CL 200 window, especially when the window is built adjacent to a large CE-BK volume. Transmission is measured according to ASTM D1003-13 and total haze is checked with a hazemeter after the specified post-surface polishing procedure; a clear CR-CL 200 control plaque processed through the same support-removal oven is required to separate material haze from process haze. If the support wax is removed above 65 °C, or if oil-bath removal is followed by insufficient solvent clearing, the elastomer surface can retain a waxy film that migrates onto the clear phase over the following 48 h. Build strategy places the clear optical face on the downward side of the tray and locates the black elastomer gasket at least 1 mm outside the clear aperture to limit the contact zone. A final surface treatment with a manufacturer-approved sealant may be applied to the gasket interface, but the effect on transmission and adhesion must be qualified under ISO 2409:2013 cross-cut adhesion testing before deployment. Terminal prototypes include automotive camera gaskets where the rigid barrel is clear for lens-positioning checks, AR/VR headset frames with black elastomer light seals, and scientific instrument cuvette holders that combine transparent fluid cells with compliant black retainer lips. This configuration is not suitable for high-energy blue-violet laser beam paths because the CR-CL 200 matrix absorbs and scatters at high fluence; designers should use fused silica or glass optics for any path exceeding indirect illumination levels.