Within the handheld power tool segment, the replacement of mechanically assembled TPE overmolds with a single-build VisiJet RBK-EBK-D60 structure is evaluated when pilot-test housings must match production durometer without hard tooling. The material is not handled as a two-part barrel blend; the MultiJet Printing build software generates a per-voxel distribution of VisiJet CE-BK elastomeric black and VisiJet CR-BK rigid black to yield a Shore D60-class surface. In the grip zone, the outer contour is built CE-BK-dominant while the screw bosses and snap hooks remain CR-BK-rich. The transition is graded through the shell thickness, commonly over 0.4–1.2 mm depending on curvature, so that there is no discrete adhesive line or mechanical interlock. Process control begins with printhead maintenance: missing CE-BK jets produce local rigid-rich bands that shift durometer values upward; missing CR-BK jets produce soft chip pockets near fastening points. A daily jet check and a trial patch before production builds are necessary. Support removal uses the standard MJP wax process; blind holes below 1.5 mm diameter require extended bath time and low-frequency ultrasonic agitation, otherwise wax residue compromises friction testing. Compliance screening for power tool grips is based on ASTM D1894 static coefficient of friction after dry and oil-contaminated conditioning; a common target is >0.5 dry and >0.3 after SAE 10W-30 oil exposure, with the final threshold set by the OEM. Chemical resistance is screened under ISO 175 by immersion in reference cutting fluid for 24 h at 23 °C. The terminal part is a production-intent angle grinder rear housing with integrated soft-touch overmold, printed in one build and used for a 2 m drop test onto concrete according to the OEM internal procedure. The printed D60 housing is not a substitute for electrical insulation verification, but it permits grip geometry trials before hard tooling.

What Changes When D60 Digital Material Replaces EPDM Strain Relief in Medical Cart Cable Outlets?

Medical cart cable egress points are traditionally protected by EPDM grommets with Shore A 55–70 hardness and high tear resistance. A VisiJet RBK-EBK-D60 replacement changes the failure mode from grommet tear to interphase delamination if the bellows fold is printed with abrupt CE-BK-to-CR-BK transitions. The D60 recipe is therefore generated with a 0.6 mm minimum gradient zone; the bellows valley is CE-BK-dominant, and the mounting flange is CR-BK-dominant. The part is produced on a multi-material MJP platform with paired material channels; there is no manual weighing of components. The digital-material ratio is executed by the printer's voxel mask, and the whole part is UV-cured in situ. In medical cart applications, the enclosure mechanical strength gate is IEC 60601-1:2005+A1:2012 subclause 9.4.1, which covers fixed enclosures and accessible parts; if the cable outlet is within the operator-accessible area, a 0.25 J impact from a spring-operated tool is a typical test condition, but the actual acceptance is set by the manufacturer. Material flammability may also be assessed if the outlet is part of a fire enclosure; the relevant clause is IEC 60601-1:2005+A1:2012 subclause 11.3. Surface hardness is verified by ASTM D2240 Type D; the target is Shore D60 ±5 after conditioning for 24 h at 23 °C and 50% RH. Because medical carts are disinfected daily, the composite must be aged with 70% isopropanol and a 0.5% quaternary ammonium solution. Published data for this specific configuration is limited; ISO 2810 weathering is not sufficient on its own, so chemical immersion per ISO 175 is required before release. The terminal printed component is a cable egress strain relief with integrated truck-mount clip, fitted into an IV pole cart harness. Wax removal from the thin bellows folds requires gentle support melting; over-aggressive ultrasonic treatment can fracture the CE-BK fold at the root. This is an operational boundary, not a material incompatibility.

Automotive interior harness clips and anti-rattle grommets are normally two-shot molded with a polypropylene body and an EPDM sealing lip. At prototype volumes below 200 units, a single-build VisiJet RBK-EBK-D60 component permits the rigid snap leg and the flexible damper to be printed as one continuous digital material. The CR-BK phase is assigned to the panel-engaging snap leg, the hat flange, and the cable tie slot; the CE-BK phase is assigned to the anti-rattle ring and the door panel contact surface. The D60 formulation is software-defined and not a physical compound; the printer places CE-BK-dominant voxels in areas of high compliance and CR-BK-dominant voxels in areas of high retention. In the interphase zone between the flange and the sealing lip, the transition is graded over 0.3–0.8 mm. The build orientation is selected so that the snap leg is printed in the XY plane rather than in Z as a stack of shear-prone micro-layers. For interior acceptance, OEMs normally apply VDA 270 for odor class, DIN 75201 for fogging, and ISO 3795 for horizontal burn rate. The D60 material must be tested in the as-built state; no secondary coating is assumed. Published data for this specific configuration under VDA 270 is limited, so a 24 h heat aging at 80 °C in a ventilated chamber is used as a screening gate. If the fogging result exceeds the OEM limit, the part is rejected because the material may contain unreacted UV-curable residues; a low-temperature bake may reduce condensable emissions, but this must be confirmed by the OEM before use. The terminal part is an under-dash wiring harness clip for a 6.3 mm elongated panel hole, printed with an integral EPDM-like anti-rattle washer. It is intended for mock fitment and noise-rattle validation, not for production certification.

When a Shore D60 Digital Material Is Selected for Wearable Device Band Links and Latch Housings

Wearable device band links require a living hinge that survives repeated buckling and a latch housing that retains its snap force after sweat exposure. The VisiJet RBK-EBK-D60 composite is evaluated when the industrial design team needs a one-piece strap link with soft flex zones and hard pin retainers. The CE-BK volume fraction is raised in the hinge root, while the CR-BK phase is concentrated around the steel pin bore. The build software imposes a gradient rather than a sharp interface; this is necessary because a sharp boundary becomes an orientation-sensitive cleavage plane. The hinge root is printed in the XY plane to keep the elastomer-rich layers continuous along the flex axis. For skin-contact bands, the final device manufacturer must evaluate the part under ISO 10993-12 for extractables and ISO 10993-5 for cytotoxicity if the band is worn more than 30 days; the raw material datasheet does not release the printed part as biocompatible. Skin sensitization is screened under ISO 10993-10, and abrasion under wash cycles is compared to the OEM reference band. Hardness is checked by ASTM D2240 Type D after 24 h immersion in synthetic sweat prepared according to ISO 105-E04; a shift greater than ±5 Shore D deems the latch housing unsuitable. Mechanical fatigue is evaluated on a custom 10,000-cycle bend fixture with a 90° flex angle; the pass criterion is no visible cracking at 10× magnification. The terminal product is a wrist-worn patient monitoring band link with integrated spring pin retainer, printed in one build without secondary adhesive.

On depalletizing end-effectors that operate at 0.6 bar vacuum differential, gripper jaws require a rigid load-bearing frame and a soft face seal. Replacing the three-part machined jaw, foam gasket, and vacuum port with a single printed VisiJet RBK-EBK-D60 unit compresses the bill of materials but changes the leak-prone gasket joint into a micro-scale material interphase. The D60 recipe is biased toward CE-BK in the sealing lip and toward CR-BK in the mounting flange and internal vacuum channel. The lip is printed with a CE-BK-dominant volume fraction, but the outer lip root is reinforced with a CR-BK micro-rib to limit creep under repeated vacuum cycling. Process reliability depends on the support material being fully removed from the internal vacuum channel; a residual wax film below 0.1 mm thickness reduces the effective inner diameter and can produce a false leak signature. The robot interface is machined to ISO 9409-1:2004 so the printed jaw can be mounted on a standard robot wrist flange. Load-bearing validation is carried out under the manufacturer's risk assessment per EN ISO 12100, and the seal lip is tested for 100,000 vacuum cycles at 0.6 bar differential with a soap-film leak detector. Published data for this specific configuration under 100,000 cycles is limited; pilot testing in batches of 10 jaws is used to establish a B10 life, not to generate a certified failure rate. The terminal part is an end-of-arm tool for case packing of consumer packaged goods, where the jaw must handle corrugated cardboard with a surface dust load. The hard-soft transition is inspected by cross-sectioning one sample per build lot every 20 builds to confirm that the gradient zone has not collapsed due to jetting imbalance.

Laboratory Fluid Manifold Prototypes Without Molded Silicone Gaskets

Benchtop analytical instruments often use a rigid manifold with compressed silicone gaskets. A prototype manifold printed from VisiJet RBK-EBK-D60 combines a CR-BK rigid body with CE-BK face seals, eliminating the gasket groove and the compression hardware. The D60 digital material is not specified for high-pressure LC flow paths; it is limited to non-wetted connector shrouds and low-pressure aqueous ports. The build software assigns the CE-BK phase to the sealing ribs and the CR-BK phase to the threaded boss and manifold wall. The interphase is graded over 0.4–0.8 mm; if the rib width is below 0.8 mm, the software may not resolve the gradient and the part is rejected for seal validation. For laboratory equipment, the material must be screened under RoHS Directive 2011/65/EU Annex II and REACH Regulation (EC) No 1907/2006 SVHC candidate list; the material supplier's declaration is not sufficient for finished device certification in the EU. Wetted compatibility is evaluated by soaking printed coupons in the instrument's cleaning solution, typically 10% sodium hypochlorite or 70% ethanol, for 24 h at 23 °C. Hardness and mass change are recorded; any increase in mass above 1% indicates solvent uptake. The terminal part is a PCR instrument inlet manifold prototype used for thermal block fitment trials; it is not exposed to live amplification chemistry. This application uses the D60 composite as a design surrogate for two-shot molding, not as a production wetted component.