RCL-ENT-A70 is a multi-material jetting composite produced from VisiJet CR-CL 200** and VisiJet CE-NT in a digital material ratio that yields a nominal Shore A 70 elastomer with rigid transition zones. The feedstock blend ratio is not user-adjustable; the ProJet MJP 2500-class system reads the cartridge identities and sets the jetting ratio to the OEM-calibrated A70 composite. The rigid phase contributes tensile strength and dimensional stability, while the CE-NT phase contributes low-strain compliance and tear resistance. Layer thickness is 32 µm in HD mode, and the support material is M2R-WT wax, which is removed at 65 °C in a heated bath followed by deionized water rinse. Because both phases are UV-curable acrylates, the printed network continues to develop modulus during the first 24 h to 48 h after build; mechanical testing immediately after support removal therefore underreports Shore A hardness and overreports elongation at break. The composite is not a solvent-borne or two-part thermoset; all processing occurs inside the printer, and the downstream user controls only geometry, orientation, and post-thermal exposure.

Overmoulded Soft-Touch Zones on Handheld Industrial Metrology Housings

On handheld industrial metrology housings, the RCL-ENT-A70 composite is placed over a rigid VisiJet CR-CL 200** shell to form a soft-touch grip surface with raised ribs and finger pads. The print file assigns the composite to discrete overmould regions with a nominal thickness of 1.0 mm to 1.6 mm over a rigid substrate wall of 2.5 mm, producing a local elastomeric-to-rigid thickness ratio of 0.4:1 to 0.64:1. This ratio is fixed in the part file rather than in the cartridge; the feedstock blend ratio of CE-NT to CR-CL 200** is controlled by the MJP print system to achieve the nominal Shore A 70 hardness. The composite is jetted in 32 µm layers on a ProJet MJP 2500-class platform with M2R-WT wax support; post-processing removes support wax in a heated bath at 65 °C, followed by an aqueous rinse. Drying after rinse is required for 2 h at 25 °C to 30 °C before assembly because residual moisture lowers interfacial adhesion to pressure-sensitive adhesives. On production-scale MJP machines, partially retained wax in blind grip ribs increases apparent hardness but reduces the mechanical bond of the overmould to the rigid shell; therefore the oven hold time is extended until no wax residue remains in rib features below 0.6 mm depth. Compliance is assessed at the finished assembly level under IEC 61010-1 for electrical safety, RoHS 2011/65/EU Annex II for restricted substances, and REACH 1907/2006 for SVHC. Abrasion resistance of the overmould is characterized by ISO 4649-2017 on printed plaques; published data for this specific composite is limited, so acceptance values are generated per project. Terminal articles are handheld surface profilometers, laser distance meters, and ultrasonic thickness gauges produced in batches of 50 to 200 units where injection-moulded thermoplastic elastomer tooling is not justified.In wearable optical sensor cuffs, the CE-NT phase of RCL-ENT-A70 provides a compliant skin-contact band that is printed in a three-dimensional lattice rather than a solid cross-section to reduce sweat trapping. The lattice design uses a gyroid unit cell of 3.0 mm edge length with strut diameter of 0.7 mm, giving a material volume fraction of approximately 18% to 22%; this ratio is selected to keep the contact pressure below 1.2 N/cm² when the cuff is closed over the forearm. The rigid CR-CL 200** component forms the optode mounting plate and strap anchors, creating a single build with a soft-to-rigid transition zone. Because the part is intended for skin contact, the finished device is cleaned to remove residual M2R-WT wax using a two-stage process: 65 °C wax melt-out, then 40 kHz ultrasonic rinse in deionized water for 15 min. Residual wax concentration is not directly specified by the supplier; surface cleanliness is verified by ISO 11737-1 bioburden testing on the cleaned article. Cytotoxicity and skin irritation are evaluated on the finished cleaned device according to ISO 10993-5 and ISO 10993-23; raw resin certification does not replace this evaluation. The printed cuff is assembled with a PPG sensor and flexible battery, then subjected to a 72 h wear trial using ISO 10993-1 guidance for transient skin contact. Published data for this specific configuration is limited; the supplier has not classified the composite as a long-term implantable or long-term skin-contact material. Terminal products are short-run wearable heart-rate and SpO₂ monitoring bands produced in quantities under 200 units for clinical feasibility studies.

What Controls Compression Set in Short-Run Enclosure Gaskets Printed from CE-NT/RCL-ENT-A70?

Sealing applications place the composite under sustained compressive strain, making compression set the governing metric rather than instantaneous hardness. For a field instrument enclosure rated to IEC 60529 IP67, the gasket is printed as a continuous D-shaped cross-section with a 1.8 mm nominal width and 1.2 mm height, seated in a rigid CR-CL 200** channel of 1.0 mm depth. The applied closure compression is 25% to 32% of the uncompressed height, a ratio selected to remain within the linear stress relaxation range of the CE-NT phase. Compression set is measured on printed buttons according to ASTM D395-18 Method B after 22 h at 70 °C; if the resulting compression set exceeds 35%, the closure depth is reduced rather than increasing the elastomer thickness. The gasket is oriented in the XY plane during printing so that the compression axis coincides with the build Z-direction, where photopolymer crosslink density may be lower; post-print aging at 25 °C for 24 h before installation stabilizes the low-strain modulus. Support removal uses 65 °C wax melt-out without solvent immersion because short-chain ester carriers in the CE-NT phase can swell in isopropanol and shift the gasket height by 0.1 mm to 0.2 mm. Terminal products are portable environmental data loggers, field spectrometers, and submersible inspection cameras sealed with printed gaskets in low-volume assemblies.

Compliance matrix for finished RCL-ENT-A70 composite applications

Application	Standard designation	Measured property	Acceptance basis
Overmoulded grip zones	ISO 4649-2017	Abrasive volume loss	Project-specific plaque benchmark, no visible substrate exposure at 2000 cycles
Wearable sensor cuff	ISO 10993-23:2021	Skin irritation	No erythema or oedema at 72 h
Enclosure gasket	ASTM D395-18	Compression set after 22 h at 70 °C	≤ 35%
Vibration mount	IEC 60068-2-64	Random vibration response	No resonance amplification exceeding factor 2

For portable diagnostic equipment that uses sensitive optical alignment, vibration transmitted through rigid feet induces baseline noise in absorbance measurements. The RCL-ENT-A70 composite is printed as a cylindrical vibration isolation mount with a 12 mm diameter, 8 mm height, and a central 4 mm bore for a steel insert; the height-to-diameter ratio is 0.67:1, which places the mount in a shear-dominated mode when the instrument mass is 1.2 kg to 2.0 kg per isolator. The rigid contact surfaces are printed from CR-CL 200** and bonded to the elastomeric core through the digital material transition zone. Hardness is verified at Shore A 70 using ISO 7619-1; tensile strength and elongation at break of the elastomeric phase are measured on printed dumbbells according to ISO 37, with build orientation parallel to the long axis. Random vibration exposure is assessed using IEC 60068-2-64 at 0.02 g²/Hz from 20 Hz to 500 Hz for 1 h per axis; the acceptance criterion is no resonance amplification exceeding factor 2 at the mount natural frequency. The M2R-WT wax is removed at 65 °C, and the mounts are post-cured under ambient laboratory lighting for 24 h to stabilize the UV-initiated acrylate network. Published data for this specific composite under random vibration is limited; prototypes are therefore tuned by iterating strut thickness and infill volume rather than by relying on datasheet values. Terminal products are portable blood chemistry analyzers, compact polymerase chain reaction instruments, and field microplate readers with elastomer isolation feet.

When CE-NT/RCL-ENT-A70 Replaces Molded PVC Strain Relief on Circular Connectors

When the design requirement is a cable bend radius of no less than 6× the outer jacket diameter, the CE-NT phase of RCL-ENT-A70 is printed as a tapered strain relief boot with a wall thickness that transitions from 1.5 mm at the connector face to 3.0 mm at the cable exit. This thickness gradient is set in the build file to distribute bending strain evenly along the 25 mm length of the boot. The rigid CR-CL 200** collar snaps onto the connector backshell and provides a positive stop for the elastomer section. The printed boot is oriented with the longitudinal axis in the XY plane, because layer interfaces lying perpendicular to the bend axis act as crack initiation sites when flexed. Flexural durability is assessed on completed assemblies by ISO 527-2 or ASTM D638 tensile data on the rigid phase and by ISO 34-1 tear resistance on the elastomer phase; however, published data for the A70 composite under cyclic flex is limited, so acceptance is based on a 10,000-cycle flex test at ±90° at 0.5 Hz. The support wax is removed at 65 °C, and residual wax is rinsed with deionized water rather than solvent to avoid elastomer swelling. Compliance is assessed under IEC 61984 for connector mechanical integrity and RoHS 2011/65/EU for material restrictions. Terminal products are field-installable M12 and circular industrial connectors with overmoulded strain relief used in robotics and automated test systems.

Use of A70 Composite in Repetitive Loading Pads Requires Precompression Below 25%

Repeated loading of CE-NT/CR-CL 200** composite pads in industrial workstation fixtures requires precompression below 25% to avoid accelerated compression set. The pads are printed as hexagonal tiles with a 60 mm width, 6 mm thickness, and a 20% rectilinear infill within the elastomeric core; a 0.5 mm rigid CR-CL 200** top sheet is fused to the core to resist cutting from dropped tool edges. The thickness-to-width ratio is 0.1:1, which keeps bending stresses negligible relative to compressive stresses. Hardness is checked after post-processing with ISO 7619-1; compression set is measured on slab specimens with ASTM D395-18 Method B after 24 h at 70 °C. The tiles are exposed to cleaning agents used in production environments; chemical compatibility is screened with ISO 1817:2015 immersion tests against 3% hydrogen peroxide and 70% ethanol for 2 h at 25 °C. OEM material compatibility guidance indicates that ketone-based cleaners reduce hardness of CE-NT; acetone must not be used. Support wax is removed at 65 °C, and tiles are aged for 24 h before installation to stabilize moisture uptake. Terminal products are antifatigue tiles for standing workstations and tool bench liners produced in batches of 20 to 50 units.