Stratasys TangoPlus FLX930 and TangoBlackPlus FLX980 are jetted as the elastomeric primary phase, while Rigur is assigned to the rigid secondary phase in multi-material PolyJet builds. The combination is not a melt-blended compound; phase distribution is controlled by droplet-level digital material dithering. Layer thickness on current PolyJet systems is typically selected between 16 µm and 30 µm, depending on the proportion of flexible phase in a given zone. Rigur contributes latch stiffness and geometric stability, whereas the Tango pair contributes Shore A 26–28 compliance and tear-limited stretch. Parent-grade TangoPlus FLX930 datasheet values include tensile strength of 0.8–1.5 MPa under ASTM D412, elongation at break of 170–220% under ASTM D412, tear strength of 2.5–4.0 kgf/cm under ASTM D624 Die C, and compression set of 0.2–0.5% under ASTM D395-18 Method B. Published mechanical data for the exact TangoPlus/Rigur digital blend remain limited; design values below are therefore anchored to parent-grade datasheets and test-coupon validation rather than a single blended-filament specification.

Overmoulded Wearable Diagnostic Monitor Housings and Display Gaskets

Display gaskets in wearable diagnostic monitors require compression recovery across repeated battery-access and sensor-cable routing. For a housing printed with Rigur frames and a TangoPlus FLX930 gasket bead, the design envelope is defined by compression set measured according to ASTM D395-18 Method B at 70 °C for 22 h, with the bead cross-section not less than 0.8 mm in width. Rigur latch arms with nominal wall thickness of 1.2 mm and deflection of 0.35 mm to 0.50 mm retain the display without screw bosses. The soft bead is compressed to 15–25% strain against the lens or housing lip, sufficient for immersion testing under IEC 60529 IPX7 when the groove flatness across the sealing path is held to 0.05 mm. The transition between rigid and elastomeric phases is printed as a 0.5 mm digital material ramp; sharp boundaries at the gasket root are avoided because tensile tear at jetted ridges initiates at the phase interface during ejection. Support removal in narrow gasket grooves uses water-jet pressure below 3 bar and a standoff of 50 mm; higher pressure tears TangoPlus sections thinner than 0.6 mm. Prior to adhesive bonding of a protective glass, TangoPlus surfaces are plasma-treated at 80 W for 30 s to raise surface energy above 50 mN/m, with contact angle verified by ASTM D5946-17. The Rigur frame is printed at 30 µm layer thickness for throughput, while the gasket bead is printed at 16 µm to reduce stair-stepping on the sealing rib. Leakage after assembly is monitored by pressure-decay testing with a threshold of 0.05 bar/min for 30 s dwell after pressurisation to 0.2 bar.

When a Wire-Harness Boot Must Survive Installation Tear Without a Secondary Clamp

The boot body is produced from TangoBlackPlus FLX980 because the black grade masks handling marks in cabin and exterior lighting mock-ups, while the clip flange is printed in Rigur to seat into a sheet-metal slot. Datasheet tear strength for the TangoBlackPlus FLX980 parent grade under ASTM D624 Die C is in the range 2.5 kgf/cm to 4.0 kgf/cm. This limits the allowable tear energy during harness insertion: the boot opening is enlarged by 10% relative to the connector cross-section, and the transition radius is not reduced below 0.6 mm. Terminal retention clips in Rigur are evaluated for snap insertion force at 50 mm/min according to ASTM D638-14 using a Type IV specimen, with insertion force held below 20 N to avoid stressing the adjacent soft phase. The continuous service boundary is 50 °C, based on the heat deflection temperature of the Tango phase under 0.45 MPa; underhood exposure above 60 °C is outside the validated envelope. Wire insulation plasticiser compatibility is screened by immersion in insulation jacket extract according to ISO 1817 for 72 h at 23 °C. Support remnants at the inner bore create a processing bottleneck: boot bodies printed with residual support edges show tear propagation from the remnant edge under 15% strain. Visual inspection at 10× magnification after support removal is therefore mandatory before installation testing. Vibration exposure on prototype harness boards follows ISO 16750-3 profiles with 10–50 Hz swept sine and 1.0 g acceleration, but the material combination is not qualified as a production underhood elastomer.

Compression set after repeated reprocessing defines layer thickness in laparoscopic training phantoms. TangoPlus FLX930 is selected for the external abdominal simulation layer and Rigur for internal rib-cage landmarks. The elastomer is printed at 1.0 mm thickness and conditioned at 23 °C for 24 h before first use; compression set measured according to ASTM D395-18 Method B remains below 0.5% for the parent grade, but the presence of Rigur constraints raises local stiffness at the interface. The phantom is chemical-disinfected with quaternary ammonium compounds at 2% concentration and 22 °C for 10 min, followed by distilled water rinse. Alcohol soak beyond 10 min is not recommended because surface microcracking at the digital-material boundary has been observed on test coupons under 20× optical inspection. This configuration is not a body-contact certified device; cytotoxicity screening follows ISO 10993-5 only as an internal material-release gate, and the elastomer is not rated for autoclave exposure at 134 °C because that exceeds the heat deflection temperature of both phases under load. When rib-cage landmarks are printed in Rigur with 0.8 mm wall thickness, the tactile mismatch against cortical bone remains high; the phantom therefore serves instrument path planning rather than cortical stiffness simulation. Repeated instrument insertion with an 8 Fr catheter at 30 mm/min is used to establish superficial damage thresholds, and any visible tear at the access port requires reprinting before the next training session.

What Limits Pressure-Cycled Bellow Life in Soft Robotic Gripper Fingers?

In bellow-type gripper fingers, TangoPlus FLX930 forms the pressure boundary and Rigur forms the hub, bolt flange, and vacuum-channel housing. The Tango membrane is printed at 1.0–1.5 mm wall thickness and actuated between 20 kPa and 40 kPa pneumatic pressure at 0.2–0.5 Hz, with strain kept below 30% during inflation. Parent-grade elongation at break is 170–220% under ASTM D412, but cyclic fatigue in this application is governed by tear initiation at support-removal nicks, not ultimate elongation. Tear strength of the parent TangoPlus is 2.5–4.0 kgf/cm under ASTM D624 Die C. The Rigur hub is designed with a flange thickness of 2.0 mm and through-holes with a chamfer of 0.3 mm to prevent cutting the soft membrane during pressure reversal. Pneumatic fittings are bonded with a primerless cyanoacrylate; lap shear coupons are conditioned at 23 °C and 50% RH for 48 h prior to pull testing at 10 mm/min under ASTM D3163-01. Pressure-decay testing is performed at 50 kPa with a leak threshold of 0.5 kPa/min. Published data for the exact TangoPlus/Rigur digital interface under cyclic pressure are limited; benchmark testing therefore uses a minimum of 5 printed fingers per geometry and records crack location after every 1,000 cycles. The dominant failure mode observed in bench testing is not membrane burst but radial tear at the bellow root, where the digital material gradient should be no narrower than 0.5 mm and the root radius should not fall below 0.4 mm.

Footwear outsole traction-element prototyping places Rigur in a load-spreading shank and lug-mount plate, while TangoPlus FLX930 supplies discrete flexing traction nodes for quick-change design iterations. TangoPlus is not a production outsole rubber; its abrasion resistance is below vulcanised styrene-butadiene rubber and is not specified under DIN 53516. The printed midsole assembly is used for wet-coefficient-of-friction screening on ceramic tile according to ASTM F2913-17 at a normal force of 500 N, but the elastomer nodes show visible surface roughening after 50 test cycles. Rigur plate thickness of 1.5 mm is sufficient for longitudinal flex stiffness comparisons when tested in a three-point bend at 5 mm/min. The soft nodes are printed with a truncated cone geometry of 3.0 mm base diameter and 2.0 mm height, with centre-to-centre spacing of 6.0 mm; this provides node shear displacement during strike without tearing at the node base. The digital-material transition under each node is ramped over 0.5 mm; a sharp step transition induces premature crack formation after fewer than 1,000 flex cycles. For traction-pattern comparisons, the rig is run at 1 Hz for 2,000 cycles on a wet tile bed, and the acceptance criterion is the absence of full-thickness tear at more than 10% of the nodes. Soft node recovery after cyclic compression is checked by measuring node height before and after a 24 h rest period with a non-contact profilometer; height loss greater than 0.2 mm is treated as a failed geometry.

Matching Bone-to-Soft Tissue Modulus in Patient-Specific Training Phantoms

Patient-specific phantoms are prepared from computed tomography segmentations with Rigur assigned to rib and vertebral landmarks and TangoPlus FLX930 assigned to intercostal and visceral soft-tissue volumes. The phase assignment is visual, tactile, and instrument-path related; it does not replicate the elastic modulus of cortical bone. Rigur is a rigid polymer with flexural modulus closer to 1,000–1,500 MPa by ASTM D790-17, whereas human cortical bone is commonly cited at 10–20 GPa in standard anatomical references. TangoPlus has Shore A 26–28 under ASTM D2240, comparable to soft-tissue tactile response for instrument palpation only. Interface modelling between hard and soft regions is generated through a digital-material ramp of 1.0 mm to reduce stress concentration at rib root; phantom reusability is then assessed by puncture resistance with an 8 Fr catheter at 30 mm/min. Cleaning uses neutral enzymatic detergent at 40 °C for 15 min; no autoclave or hydrogen peroxide sterilant is used because the photopolymer phases are not rated for that exposure. The phantom is an anatomical instructional model; regulatory claim is limited to short-term skin contact and is not a replacement for implant-grade silicones or thermoplastics. Build orientation is assigned so that the soft tissue surface is formed against support rather than on the top surface; top-surface release films on TangoPlus can reduce tactile consistency and leave a residual gloss boundary at the digital material interface. Each phantom is measured against the segmentation file with 0.1 mm accuracy at 3 landmark positions using blue-light scanning before acceptance for teaching use.

End-of-arm tooling pads for polypropylene bottle handling are printed as a single multi-material set: Rigur locator brackets and TangoPlus FLX930 contact pads. The pad contact face is 1.5 mm thick and the rigid back plate is 3.0 mm thick, with a bridge area of digital material extending 2.0 mm beyond the pad edge. Surface scratch testing on bottle walls uses a constant normal force of 1.2 N for 100 mm travel at 50 mm/min and is evaluated by ASTM D7027-13. Contact pads in TangoPlus reduce marring on polypropylene compared with rigid clamping elements, but the soft phase is limited to momentary contact at 40 °C; continuous exposure to blow-moulding extraction temperatures above 60 °C is outside the validated service range. Mounting brackets printed in Rigur are tapped to M4 inserts with an installation torque of 0.4 N·m, while the contact face is kept free of threaded inserts to avoid stress concentration at the rigid-soft boundary. Published data for production-line cycle life of this exact pad geometry are limited; the pad set is therefore evaluated with a 10,000-cycle bench test at 0.5 Hz before deployment. After 5,000 cycles, pad thickness loss is measured by profilometry and replacement is triggered at 0.3 mm cumulative wear. The tooling is stored away from direct UV exposure because TangoPlus surfaces yellow and embrittle under prolonged ultraviolet radiation; UV screening for prototype applications is based on ASTM G154-16 cycle tests, but long-term outdoor-rated stability is not claimed.