Objet Digital Materials™ DM_9850/9750 Rubber-like Prototyping Polymer is a PolyJet photopolymer package supplied under two digital blend designations. The DM_9850 order code corresponds to a cured indentation hardness of 85 Shore A, and the DM_9750 order code corresponds to 75 Shore A, as specified in the manufacturer’s digital material selection guide. The material is not supplied as a single pre-compounded resin but as a paired combination of an elastomeric Tango-series acrylate oligomer and a rigid Vero-series acrylate oligomer. These two streams are jetted separately and mixed in a voxel-level digital ratio at the build plane to produce a cured network with intermediate elastomer-like behavior. Because the blend ratio is controlled by the printer’s job-parameter file rather than by a batch compounding operation, the same cartridge set can generate multiple Shore A values when the build software is reprogrammed. The designation “Rubber-like” in this context refers to the cured material’s low- to mid-durometer response, not to a thermoplastic elastomer or silicone elastomer. The cured structure is a UV-polymerized acrylate network with glassy Vero domains distributed within a soft Tango phase; the resulting morphology approximates an interpenetrating network rather than a conventional melt-processed TPE. DM_9850 requires a higher Vero fraction than DM_9750, which raises crosslink density, increases stiffness, and reduces recoverable strain. Hardness is measured under ASTM D2240-15(2021) on conditioned specimens; density is evaluated under ISO 1183-1:2019, Method A. Tensile and tear data should be taken from the current Objet/Stratasys digital-material datasheet because published data for this specific configuration is limited to grade-specific manufacturer documentation.

What Distinguishes DM_9850 from DM_9750 at the Cured Network Scale?

The primary difference between the two grades is the ratio of rigid Vero oligomer to elastomeric Tango oligomer in the printed voxel matrix. DM_9850 contains a sufficient Vero fraction to raise the cured durometer to 85 Shore A; DM_9750 produces 75 Shore A. The increase in Vero content does not produce a simple linear stiffening effect because the rigid domains constrain the soft Tango network in a non-linear manner. Tensile modulus rises as the Vero fraction increases, while elongation at break and tear resistance may decrease once the glassy domains percolate. For DM_9850, the material behaves more like a hard rubber or soft engineering plastic; it is selected when a prototype must resist fingernail indentation, maintain geometry under clamp compression, or replicate a commercial elastomer in the 80–90 Shore A window. DM_9750 is selected for lower-durometer gaskets, flexible couplings, soft-touch housings, and parts that must conform to irregular mating surfaces. Under cyclic loading, the higher crosslink density of DM_9850 reduces viscoelastic damping but increases heat buildup at high strain rates. DM_9750 exhibits higher viscous loss and greater recovery after low-rate deformation. Because the two grades share the same Tango and Vero base chemistry, their chemical resistance, moisture equilibrium, and UV stability are closer than their mechanical stiffness might suggest. The relevant test standards for comparing the grades are ISO 37:2017 for tensile strength and elongation, ASTM D412-16 Die C for elastomer tensile behavior, and ASTM D624-00(2020) Die C for tear resistance. Specimen conditioning is typically performed at 23 ± 2 °C and 50 ± 5 % relative humidity for at least 24 h before testing.

For design iterations requiring variable durometer within a single part, the two grades can be jetted in the same build sequence only if the printer supports multi-material digital blending. In this situation, DM_9850 and DM_9750 are not post-machined or glued; the material transition is generated at the voxel level by changing the droplet ratio in the job file. The boundary between 85 Shore A and 75 Shore A regions can be made sharp or graded, depending on the software assignment. However, the transition region may exhibit anisotropic mechanical behavior because the droplet-scale distribution of rigid and soft resin follows the printhead raster direction. Specimens extracted parallel to the X-axis can give different modulus values from specimens extracted along the Y-axis at the same nominal grade. This orientation effect is measurable with ISO 37:2017 Type 4 specimens and should be quantified before using DM_9850/DM_9750 for functional sealing prototypes.

When Tango and Vero Streams Are Jetted Through a Multi-Material PolyJet Head Array

The DM_9850 and DM_9750 digital packages require an Objet Connex-series or Stratasys J-series PolyJet printer with multi-material jetting capability. The two cartridge resins are heated to the standard jetting temperature window, typically 70–75 °C, to bring their viscosity into the range required for consistent drop formation. At the printhead, the droplets are deposited in a digital matrix; the Tango-rich voxels and Vero-rich voxels are interspersed according to the selected Shore A value. A UV source curing unit passes over the deposited layer to polymerize the acrylate network before the next layer is jetted. The standard layer-thickness options on Connex platforms are 16 µm in high-quality mode and 30 µm in high-speed mode; the digital material may be restricted to one of these modes depending on the printer model and material license file. Printhead condition is a critical production variable. Batch-to-batch viscosity drift, partially clogged nozzles, or insufficient printhead voltage calibration produce missing jets that appear as surface voids and local soft spots. On production-scale lines using Connex500-class systems with 8 printheads, daily head calibration and a test-print module are used to maintain droplet placement accuracy. When jetting stability is lost, the cured part may show striations parallel to the scan direction, non-uniform Shore A readings, and poor sealing behavior at gasket flanges. These failures are observed even when the digital blend ratio is correct, indicating that the printing process controls the final network morphology as much as the resin chemistry.

After the build finishes, the support material is removed with a pressurized water jet rather than a solvent bath. The uncured residue is minimal if the tray temperature and UV dose are within specification; under-cured surfaces may remain tacky because of oxygen inhibition at the air-layer interface. A post-build stabilization period of 24 h at 23 °C ± 2 °C is recommended before dimensional inspection because the material may undergo slight volume relaxation after support removal. DM_9850 and DM_9750 do not require thermal post-curing for standard prototyping use; elevated-temperature exposure above the manufacturer’s recommended limit can darken the resin, increase brittleness, and alter Shore A readings. Cleaning of printed parts should be limited to isopropyl alcohol wipes or brief immersion; ketone-based solvents can swell the network and reduce tear resistance.

Application Boundaries, Silicone Comparison Points, and Storage-Shelf-Life Data

The DM_9850/DM_9750 package is used for short-run gasket fabrication, dust seal prototyping, overmolded grip simulation, wearable device straps, cable strain-relief boots, footbed cushioning trials, and soft-touch control surfaces. In sealing applications, the printed gasket can be compressed between rigid flanges and tested under ASTM F36-15 to determine compressibility and recovery. The material is not a direct substitute for platinum-catalyzed liquid silicone rubber or compression-molded RTV silicone in high-temperature sealing applications. Silicone elastomers generally offer lower compression set, higher tear strength, and broader thermal stability than acrylate-based PolyJet digital materials. The DM grades are also not intended for repeated steam autoclave cycling, continuous hot-oil exposure, or high-velocity dynamic sealing where hysteresis heat generation may exceed the network’s thermal resistance. For these reasons, DM_9850/DM_9750 parts are best used for form, fit, and limited functional testing rather than long-term production service.

Compared with single-cartridge TangoPlus FLX930 or TangoBlackPlus FLX980, DM_9850 and DM_9750 are stiffer and exhibit lower elongation because of the Vero fraction incorporated into the digital matrix. The single-cartridge Tango materials cure to a much lower Shore A range and are used when a very soft, highly flexible prototype is required. Conversely, the Vero-series rigid photopolymers are much harder and more brittle than DM_9850/DM_9750. The digital material thus fills the intermediate durometer band between soft Tango and rigid Vero. The presence of two product codes in one package indicates that the buyer receives either both Shore A variants or a selected variant under a shared resin family, not that the two grades are identical. In a multi-material build, the two grades may be combined only if the machine configuration includes the appropriate resin cartridges and a digital material license.

Storage of unopened cartridges should follow the manufacturer’s recommended temperature band of 15–27 °C with protection from direct UV and sunlight. Cartridge shelf life is commonly 12 months from the date of manufacture when stored in the sealed original container. Once a cartridge is loaded into the printhead system, the material should be used within the printer’s recommended open-cartridge interval to avoid viscosity drift from ambient moisture absorption. Moisture uptake in the uncured acrylate can alter jetting rheology, reduce cure conversion, and produce a tacky surface on finished parts. Equipment-level experience indicates that high relative humidity above 60 % in the print environment may require more frequent printhead purges and test prints. The material is supplied in sealed PolyJet cartridges with RFID tags that allow the printer to track material type, batch, and remaining volume; this reduces the risk of using an expired cartridge or a mismatched digital pair. The RFID data also supports traceability under ISO 9001:2015 production control requirements when the printed parts are used for functional prototype validation.

In industrial practice, the DM_9850 grade is selected when a prototype must survive assembly with threaded fasteners, snap-fit engagement, or metal insert retention without excessive deformation. The DM_9750 grade is selected when a component must bend repeatedly, seal against a rough cast surface, or recover from finger deflection without cracking. The choice between the two should be based on a measured force-deflection curve from a physical test coupon rather than durometer alone, because two photopolymer blends with the same nominal Shore A value can differ in hysteresis, tear strength, and compression set. When test coupons are printed on the same tray with the same digital ratio, the mechanical response may still vary by up to several percentage points depending on tray position, UV lamp age, and support-removal waterjet pressure. These sources of variance are part of the process capability and should be considered if DM_9850/DM_9750 is used for short-run functional parts instead of display prototypes. No conclusion is reached here; the material’s suitability is determined by the specific seal geometry, environmental exposure, and cyclically applied deformation rate of the intended application.