PolyJet rubber-like materials are flexible photopolymers that are jetted and UV-cured in the same thin layers as rigid PolyJet materials. Agilus and Tango are well-known examples of the class; newer grades resist tearing and repeated flexing better than earlier ones. On multi-material printers, the flexible material can be printed on its own, at about 30 Shore A, or mixed in fixed ratios with rigid material to create digital materials with intermediate hardness up to about 95 Shore A. Rigid and flexible regions can be combined in one part without assembly or adhesive.
Choose it when a prototype must look and feel like a rubber or overmolded part: soft-touch grips, buttons and keypads, gaskets and seals for fit and assembly tests, bellows, wearable mock-ups and anatomical models with soft tissue. It is not a production elastomer. Tensile and tear strength are far below silicone, TPU or cast polyurethane, parts tear from notches and sharp corners, and the material hardens and loses elasticity with age, UV light and heat. For parts that must flex or seal over a long service life, use a molded or cast elastomer.
Mechanical and physical properties
| Property | Typical value | Notes |
|---|---|---|
| Hardness, flexible base material | ≈ 26–35 Shore A | ASTM D2240; newer grades at the upper end. |
| Hardness, digital materials | ≈ 40–95 Shore A | Fixed mixes with rigid material; available steps depend on the printer. |
| Tensile strength | ≈ 1–3 MPa | ASTM D412, base material; silicone reaches ≈ 6–11 MPa. |
| Elongation at break | ≈ 170–270% | ASTM D412, base material; falls as hardness increases. |
| Tear strength | ≈ 2–7 kN/m | ASTM D624; low, so cuts and notches spread easily. Silicone reaches ≈ 20–50 kN/m. |
| Resistance to repeated flexing | Limited; grade-dependent | Newer grades tolerate more cycles; validate flexing features on a prototype. |
| Density | ≈ 1.12–1.15 g/cm³ | Cured base material. |
| Aging under heat and UV light | Poor | Hardens, discolors and loses elasticity over time. |
| Colors | Typically black or clear; color on full-color printers | Color and hardness options depend on the printer and are confirmed in the quote. |
| Layer thickness | ≈ 15–30 µm | Depends on printer and print mode. |
Typical datasheet values for rubber-like PolyJet base materials, measured on printed test specimens. Digital materials have their own values for each hardness step, and real parts vary with grade, wall thickness, print mode, orientation and age. Shore values are nominal: a thin flexible layer over a rigid core feels harder than a thick section of the same material.
Designing for rubber-like PolyJet
Rubber-like parts follow the general PolyJet rules: overhangs and cavities are built on a support material that is removed after printing, usually by water jet. Thin flexible features need extra care, because they tear easily during support removal and use:
- Wall thickness: plan flexible walls of at least about 1 mm, and more for parts that are handled often. Thinner membranes are possible but fragile.
- Notches and corners: generous fillets and rounded edges reduce tearing. Avoid sharp internal corners, thin flaps and holes close to edges.
- Overmold-style parts: give the soft layer a thickness of about 1 mm or more over the rigid core, and design the joint as a broad interface rather than a thin line. Rigid and flexible regions bond during printing; mechanical interlocks are optional but help in highly stressed areas.
- Hardness by region: assign each body or region its Shore value. Upload separate bodies or a 3MF file and list the target hardness for each.
- Seals and gaskets: rubber-like parts are useful for checking seal geometry and assembly, but compression and recovery differ from molded rubber. Validate sealing performance in the final material.
- Tubes, bellows and closed volumes: support fills enclosed cavities during printing. Leave openings large enough for support removal, and avoid long, narrow channels.
Digital materials and hardness
Digital materials are produced by jetting flexible and rigid material together in fixed microscopic patterns. The result behaves like a uniform material with an intermediate hardness. The steps on offer depend on the printer; typical ranges are:
| Hardness | Feel | Typical use |
|---|---|---|
| ≈ 30 Shore A (base material) | Very soft, like a rubber band | Soft-tissue models, soft-touch skins, light gaskets |
| ≈ 40–50 Shore A | Soft, like a pencil eraser | Grips, buttons, keypads, seals for fit tests |
| ≈ 60–70 Shore A | Medium, like a tire tread | Bumpers, feet, gaskets, overmold-style grips |
| ≈ 85–95 Shore A | Firm, like a shoe heel | Firm flexible covers, cable sleeves, hard-rubber look-alikes |
Tolerances and surface
Without a tolerance on the drawing, Uretyco's default for PolyJet parts is ±0.2 mm or ±0.2%; tighter values apply only when they are stated on the drawing and accepted in the quote. Flexible parts deform under handling and measuring force, so define how critical dimensions are measured, or place them on rigid regions. Surfaces show fine detail; rubber-like faces have a matte, slightly tacky feel and pick up dust more easily than rigid ones.
Finishing options
Rubber-like PolyJet parts are usually delivered as printed. Any coating or paint must stay flexible, or it cracks when the part bends.
| Finish | Effect | Notes |
|---|---|---|
| As printed | Lowest cost | Matte, slightly tacky surface; fine features need careful support removal. |
| Full-color printing | Color without paint | Colored flexible regions on full-color printers; color and hardness combinations are confirmed in the quote. |
| Flexible paint or coating | Exact color or surface feel | Must stay elastic; rigid paint cracks when the part flexes. |
| Finishing rigid regions | Smooth rigid faces next to soft areas | Sanding and polishing work on rigid regions only; soft regions cannot be sanded. |
| Inserts in rigid regions | Durable fastening | Place threads and inserts in rigid material, never in rubber-like regions. |
Rubber-like photopolymers harden, discolor and lose elasticity over time, faster under UV light and heat. Store parts dark and cool, test them soon after delivery, and do not rely on them for long-term sealing or repeated flexing.
Cost and lead-time drivers
Rubber-like parts are priced like other PolyJet parts, and multi-material builds cost more than single-material prints:
- Part volume, bounding box, orientation, support material and machine time. Soft parts with many cavities, such as bellows, use a lot of support.
- Number of materials and hardness steps in one build, and whether color is required.
- Manual work: careful support removal on thin flexible features, and flexible painting where specified.
- Lead time: small parts can be fast; large overmold-style assemblies, color and many hardness steps add time.
PolyJet rubber-like vs. other flexible options
| Material and process | Hardness range | Tear strength and aging | Rigid and soft in one part | Typical use |
|---|---|---|---|---|
| PolyJet rubber-like | ≈ 30–95 Shore A | Low; ages noticeably | Yes, in one print | Look-and-feel and overmold-style prototypes |
| Flexible SLA resin | ≈ 50–80 Shore A, grade-dependent | Low to moderate | No | Single-material flexible prototypes |
| TPU (MJF, FDM) | ≈ 85–95 Shore A | High tear and abrasion resistance | Limited; usually separate parts | Functional flexible parts and lattices |
| Cast polyurethane | ≈ 30 Shore A to 85 Shore D | Good | Yes, by overcasting inserts | Small series of overmold-style parts |
| Silicone (LSR, silicone molding) | ≈ 10–80 Shore A | Good tear strength, very good aging and heat resistance | Yes, with inserts in molding | Seals and long-life soft parts |
Use rubber-like PolyJet materials to show and test the look, feel and assembly of soft parts early in development. When the part has to work over time, move to TPU for tough printed parts, cast polyurethane for small series with production-like properties, or molded silicone and rubber for seals and long service life.
When not to choose PolyJet rubber-like
Seals and gaskets that must hold over time, under pressure or with heat: use silicone, molded rubber or cast polyurethane. Parts that flex repeatedly in service, such as living hinges, straps or clips. Thin flaps and membranes that are stretched or pulled at their edges, because tears start easily. Outdoor use or long storage in light and heat. Skin contact beyond short handling, food contact or medical use: standard rubber-like materials are not certified for it. End-use production parts.
Typical applications
- Overmold-style prototypes: rigid housings with soft grips or seals in one part.
- Soft-touch grips, buttons, keypads and switch covers.
- Gaskets, seals and bellows for fit and assembly tests.
- Wearable and ergonomic mock-ups such as straps, earpieces and handles.
- Anatomical models that combine soft tissue with rigid bone regions.
- Footwear and sole concepts with several hardness zones.
Specifying PolyJet rubber-like on Uretyco
- 1Upload 3MF or separate bodies
Model rigid and flexible regions as separate bodies; a STEP or STL file with a body list also works. Add a drawing for critical dimensions.
- 2Choose PolyJet rubber-like and the hardness
State the Shore A value for each region, for example 50 Shore A for a grip on a rigid housing.
- 3State color and cosmetic faces
State the base color or full color, and which faces are visible on the finished part.
- 4Describe the use
Tell the assistant whether the part is a look-and-feel model, a seal test or an assembly check, and how long it must last, so mismatches can be flagged.
- 5Review the quote
Feasibility, available hardness steps, colors and lead time are confirmed during quote and order review.
FAQ
Which Shore hardness can I get?
The flexible base material is about 30 Shore A. Digital materials mix it with rigid material in steps up to about 95 Shore A, and the steps on offer depend on the printer. Shore values are nominal, and printed parts can feel different from molded rubber of the same hardness, so check the feel on a sample when it matters.
Can rubber-like PolyJet parts be used as seals?
For fit, assembly and short leak tests, yes. For seals in service, no: tear strength is low, compression and recovery differ from rubber, and the material ages. Use silicone, molded rubber or cast polyurethane for functional seals.
How well do rigid and flexible regions bond?
Both materials cure together in the same print, so the interface bonds without adhesive and usually holds better than a glued assembly. Under load, failures tend to start as tears in the flexible material near sharp transitions. Broad interfaces and rounded transitions make the joint more durable.
How long do rubber-like parts last?
It depends on light, heat and handling. Parts stored dark and cool keep their properties longer, while parts in daylight or in frequent use harden and tear sooner. Treat them as prototypes for evaluation, not as spare parts.
Related resources
- PolyJet Rigid OpaqueThe rigid partner for overmold-style parts.
- TPU 95ATough flexible printed parts.
- Flexible Resin (SLA)Single-material flexible SLA parts.
- Liquid Silicone Rubber (LSR)Seals and long-life soft parts.
- Cast PolyurethaneSmall series across a wide hardness range.
- Thermoplastic Elastomers (TPE)Soft thermoplastics for printing and molding.
Related materials
Elastomers
TPU 95A
Tough, abrasion-resistant thermoplastic elastomer with a firm, rubber-like Shore 95A hardness. Printed by MJF or FDM, or injection-molded, for grips, bumpers, covers, light-duty seals and cushioning.
Elastomers
Flexible Resin
Soft, rubber-like photopolymers from about Shore 50A to 80A that bend, stretch and spring back. For soft-touch prototypes, small seals, grips and fine elastic details; less tear- and abrasion-resistant than TPU or silicone.
Elastomers
TPE
Soft, rubber-like FDM filament in the Shore 60A to 90A range, softer than TPU 95A. For grips, feet, dampers, soft covers and flexible prototypes; slow to print, and no substitute for silicone in heat or long-term sealing.
Plastics
PolyJet Rigid
Rigid, UV-cured acrylic photopolymer jetted in very thin layers. Very smooth surfaces, fine detail, color and multi-material options for visual prototypes and master patterns; not meant for load-bearing or hot parts.
Plastics
PolyJet Bio
Rigid clear or opaque PolyJet photopolymers tested for biocompatibility, used for surgical guides, dental devices and skin-contact prototypes. Compliance depends on the certified grade, the validated process and the device maker's own regulatory work.
Plastics
PolyJet Clear
Rigid, near-colorless acrylic photopolymer jetted in very thin layers. Polished, it becomes clear enough for see-through housings, light-guide mock-ups and flow models. It is brittle and softens at about 45–50 °C, so it does not suit optics or loaded parts.
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