Within the VisiJet RCL-EBK-D70 multi-material composite build sequence, the rigid clear VisiJet CR-CL 200 matrix and black VisiJet CE-BK grip zones are deposited on a ProJet MJP 2500 Plus platform using independent piezoelectric inkjet channels and 32 µm layer thickness. The RCL-EBK-D70 designation carries a target digital hardness of Shore D 70; actual surface hardness is verified on co-printed plaques with ISO 868:2003 after 48 h at 23 °C ± 2 °C. The build envelope of 294 × 211 × 144 mm constrains batch orientation of multi-handle housings; the elastomeric grip plane is orientated away from the planarizer contact face to reduce wax entrapment at the rigid-to-elastomer transition. After build completion, sacrificial wax support is removed in a convection oven below 65 °C, followed by ambient stabilization at 50 % ± 5 % RH for 24 h. The modulus mismatch between the two phases is documented from co-printed tensile coupons conforming to ISO 527-2:2012; interfacial fracture must not occur before bulk elastomer tear, otherwise the mechanical interlock channel width is increased from 0.8 mm to 1.2 mm. Production inspection of similar dual-material hand tools repeatedly shows edge whitening in the clear phase after contact with ester-based cleaners; chemical immersion testing is therefore conducted according to ASTM D543-20 before release. The final handheld assembly retains a rigid transparent optical alignment housing and a black elastomeric grip formed without adhesive or post-mould overmoulding.

Fluidic Manifold with Integral Black Compression Seal

Leak-tightness in reagent delivery manifolds with clear fluid paths and black elastomeric sealing rings depends on the compression set of CE-BK after Luer engagement and on the dimensional stability of the CR-CL 200 channel after wax removal. Seal grooves are printed with a nominal elastomer height of 1.2 mm and assembled with axial compression of 12 % ± 2 %; compression below 10 % produces weeping at the Luer taper, while compression above 15 % can split the seal along the z-plane lamination boundary. Pressure-decay testing uses a transducer resolution of ±0.5 kPa and a hold pressure of 100 kPa for 30 min; records are maintained under ISO 13485:2016 clause 7.5.1. The clear phase requires visual verification of entrapped air or dye migration, with haze measured according to ASTM D1003-21 on polished coupons. Because the black elastomer contains pigment fillers, the manifold is flushed after post-cure with deionised water having resistivity not less than 18 MΩ·cm prior to installation in analytical instruments. The simultaneous jetting of both feedstocks eliminates adhesive bonding but introduces the requirement for a post-cure at 40 °C for 4 h to reduce surface tack before assembly.

During surgical phantom construction from CT-derived geometry, high-density cancellous structures are printed in clear CR-CL 200 while ligamentous and meniscal analogues are co-jetted in black CE-BK at the insertion zones. The rigid clear phase must remain free of wax residue above 5 µg/cm² because residues scatter light under fibre-optic endoscopic illumination. Large anatomical sections are divided across multiple builds within the 294 × 211 × 144 mm envelope, and a two-phase calibration coupon is embedded in each tray. Coupons are inspected at 10× magnification for voids and then sectioned with a diamond wire saw for bond-line width measurement. Secondary UV curing is performed at 40 °C for 4 h to minimize residual acrylate migration from the elastomer phase into the clear phase. Surface disinfection with 70 % isopropanol is validated under ISO 17664-1:2021 before reuse; repeated disinfection can etch the clear phase if contact time exceeds 30 min, so the phantom is limited to short wipe cycles. The final phantom combines transparent osseous structures and soft black tissue analogues in a single build without assembly adhesives.

What limits the service temperature of an automotive interior latch housing with black elastomer return springs?

Thermal soak in vehicle cabins causes dark interior surfaces to exceed 70 °C; the clear rigid phase of the composite is challenged when the latch housing must maintain spring-return function after long parking exposure. Supplier data for CR-CL 200 lists heat deflection temperature at 52 °C under 0.45 MPa according to ASTM D648-16, which places the clear phase close to its thermal limit in a dark cockpit. The black CE-BK return spring element is designed with a beam length of 8 mm, a width of 2 mm, and a flexural stroke of 2 mm; cyclic validation is performed for 10,000 cycles at 23 °C and then repeated after 72 h heat ageing at 80 °C under 50 % RH. Force decay is measured with a constant-rate tensile tester following ASTM D412-16 on die-cut co-printed slabs. Prototype failures occur when the transition radius between the clear housing and the black spring measures below 0.5 mm; increasing the radius to 1.0 mm and adding a 10° draft on the vertical sidewall reduces notch-induced tearing. Amine-containing plasticizers and PVC-insulated harness clips should not contact the black phase because they increase surface tack and can soften the elastomer; compatibility extraction follows ASTM D471-16a for 70 h at 60 °C.

When a black elastomeric isolator is printed around a clear inspection window for industrial vibration fixtures

When machine-vision inspection cells require a clear optical window surrounded by a black elastomeric isolator, the co-printed part eliminates the need for mechanical fastening and second-stage overmoulding. The clear window must maintain optical flatness within 3 fringes per 25 mm after elastomer cure shrinkage; flatness is measured against a fused silica reference flat under 589 nm sodium light before and after post-cure. The CE-BK isolator performs as a low-modulus damping rim; durometer measurement according to ISO 7619-1:2022 typically falls in the low Shore A range, although published data specific to the two-phase blend is limited. Perimeter bead width is set at 3 mm and clear window thickness at 0.8 mm to balance vibration isolation with impact resistance. Elastomer swell in cutting-fluid environments is a critical boundary; immersion in a reference water-soluble cutting fluid at 60 °C for 70 h under ASTM D471-16a produces measurable dimensional change, so fluorosilicone isolators are specified where glycol ether exposure is unavoidable. Post-build UV cure is extended to 6 h at 40 °C in a nitrogen-purged chamber to reduce surface tack. Acceptance testing includes ISO 527-2:2012 tensile pull of the clear-to-black boundary and ISO 868:2003 durometer measurements on the elastomeric rim.

Within wearable exoskeleton research builds, a transparent CR-CL 200 dorsal pad is co-printed with black CE-BK contact wings that flex during treadmill walking tests at 1.5 m/s. Build orientation places the clear pad face-up to prevent wax pooling and the black wings at 20° from the X-Y plane to preserve near-isotropic elastomer properties. Support removal below 45 °C and UV post-cure at 40 °C for 3 h are followed by skin-contact testing under ISO 10993-10:2021 for sensitization and ISO 10993-5:2009 for cytotoxicity; the black pigmentation in CE-BK does not remove the need for full extractables assessment. Cyclic flexion of the co-printed interface is run on a servo-hydraulic tensile machine at 1 Hz for 50,000 cycles with strain amplitude of 20 %; delamination at the transition occurred in pre-production samples only when the interface footprint was reduced below 2.5 mm². Chemical compatibility with perspiration simulant is evaluated according to ISO 105-E04:2013 for colour fastness to perspiration, and staining of the clear dorsal pad must remain below grade 4 on the grey scale. The final prototype merges flexible black contact elements with a transparent structural shell without solvent bonding or stitching.

Autoclave Cycling Exceeds the Heat Deflection Ceiling of the Clear Rigid Phase

Laboratory-scale single-use bioreactor adapters use CR-CL 200 as the clear probe window and CE-BK as the black sealing gasket around the sensor port. The gasket is printed with a thickness of 1.0 mm and compressed to 20 % ± 3 % against a polycarbonate vessel flange; over-compression above 25 % creates radial tear cracks at the z-layer fusion lines. Sterilization by gamma irradiation is not automatically transferable to the clear phase because rigid acrylate photopolymers can undergo discolouration and embrittlement; electron-beam sterilisation at 25 kGy is evaluated by exposing co-printed samples and then measuring tensile properties under ISO 527-2:2012. The black elastomer phase is restricted to indirect contact with cell culture media under ISO 10993-4:2017 haemocompatibility and ISO 10993-5:2009 cytotoxicity testing. Autoclave cycles at 121 °C for 15 min exceed the heat deflection temperature of the clear phase and are not recommended; alkaline detergent cleaning at 45 °C for 20 min is preferred. The terminal bioreactor adapter combines transparent probe ports and an integral black gasket, eliminating separate silicone O-rings and mechanical retainers.

Across consumer-grade controller prototype builds, co-printed faceplates use CR-CL 200 as a transparent display window and CE-BK as dark tactile button returns beneath a 1.2 mm clear cover. The black domes are printed with a diameter of 4 mm and a nominal wall of 0.6 mm; actuation force is measured with a force gauge at 1 mm/min and acceptance is set at 0.8 N ± 0.2 N for initial build runs. Because the clear cover must transmit LED outputs without haze, transmission haze is measured according to ASTM D1003-21 after support removal and post-cure at 40 °C for 3 h. Key cycle durability is evaluated with a pneumatic actuator at 3 Hz for 300,000 cycles; surface cracking near the dome base occurs if the draft angle is below 5° or if the CE-BK dome wall is reduced below 0.5 mm. The material pair is restricted to proof-of-concept and short-run human-machine interface parts due to limited UV stability of the clear phase under direct sunlight; UV exposure testing follows ASTM G154-23 for 200 h UVA-340 and records yellowness index increase above 5 as a transition criterion. The final prototype merges a transparent display window and dark tactile domes in one build without adhesive film lamination.