Water-Washable Resin Flex
Grade
Flex = flexible / elastic water-washable
Choose for gaskets, grips, shoe soles and living-hinge models needing rubber-like recovery; low tear and creep resistance.
Values for the Flex condition
Other Water-Washable Resin grades and fills
Water-Washable Resin is listed in 4 conditions; see the grade overview at Water-Washable Resin.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
FlexThis page Flexible / elastic water-washable | Choose for gaskets, grips, shoe soles and living-hinge models needing rubber-like recovery; low tear and creep resistance. | — | 8 | 110 | 30 Shore D |
Plant-based / low-odour water-washable | For schools, home offices and skin-contact-averse users: soy/plant-derived acrylate content, minimal smell, mechanicals close to standard grade. | 34 | 38 | 10 | 78 Shore D |
Tough / ABS-like water-washable | Pick when thin walls, snap features or drop resistance are needed and some stiffness can be traded away. | 38 | 48 | 22 | 77 Shore D |
High-temperature / high-stiffness water-washable | Use for jigs, lamp housings or parts that must hold shape near 90–120 °C, accepting brittle behaviour. | — | 62 | 3 | 86 Shore D |
What is Water-Washable Resin Flex?
Water-Washable Resin Flex is Water-Washable Resin in the Flex grade — choose for gaskets, grips, shoe soles and living-hinge models needing rubber-like recovery; low tear and creep resistance. Water-Washable Resin Flex has a tensile strength of 8 MPa (1.16 ksi), weaker than 81% of polymer grades. Elongation at break is 110% and the elastic modulus is 0.02 GPa (0.0029 Msi). Water-Washable Resin Flex has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 62% of polymer grades. Its glass-transition temperature is 60°C (140 °F).
Limitations
- Absorbs moisture — dry before molding — 2.2%, worse than 98% of polymer grades
- Needs corrosion protection — 50/100, worse than 97% of polymer grades
- Difficult to machine — 25/100, worse than 93% of polymer grades
- Limited service temperature — 55°C (131 °F), worse than 91% of polymer grades
- Degrades in UV without stabilisers — 25/100, worse than 76% of polymer grades
Water-Washable Resin Flex properties
Typical room-temperature values for Water-Washable Resin Flex; 17 are specific to this condition. Other listed values are Water-Washable Resin reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
Water-Washable Resin Flex has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 62% of polymer grades. Its glass-transition temperature is 60°C (140 °F).
Mechanical9
Water-Washable Resin Flex has a tensile strength of 8 MPa (1.16 ksi), weaker than 81% of polymer grades. Elongation at break is 110% and the elastic modulus is 0.02 GPa (0.0029 Msi).
Thermal10
Water-Washable Resin Flex is rated for continuous service to 55°C (131 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 100 µm/m·K (55.6 µin/in·°F).
Electrical5
Water-Washable Resin Flex is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 97% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Water-Washable Resin Flex takes about 115 MJ of energy and emits 5.2 kg of CO₂ — more than 70% of polymer grades. Typical recycled content is 0%.
Manufacturability3
Water-Washable Resin Flex's machinability is poor (25/100, worse than 93% of polymer grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Water-Washable Resin Flex
Is Water-Washable Resin easy to machine?
Post-cured parts drill, sand and file easily but chip at edges — use sharp tools, low feed, and support thin sections; wet-sand to avoid dust.
Can Water-Washable Resin be welded?
Thermoset, not weldable; join with cyanoacrylate or UV-cure resin fillets and post-cure the joint.
Can Water-Washable Resin be formed, bent or molded?
Printed on 405 nm LCD/DLP/SLA at 0.02–0.05 mm layers, 2–4 s exposure typical; wash 3–5 min in clean water only (long soaks swell and craze parts), then dry fully before 2–6 min UV post-cure.
What surface finishes work on Water-Washable Resin?
Primer/filler plus acrylic or 2K clear coat is strongly recommended — the coating both hides layer lines and seals the hydrophilic surface against humidity.
Water-Washable Resin chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| urethane/epoxy acrylate oligomernetwork backbone; determines stiffness and toughness | 25 – 55 | 40 |
| hydrophilic acrylate monomer (PEG-DA / gprovides water rinsability of uncured resin | 15 – 45 | 30 |
| reactive diluent monomer (mono-/di-functviscosity control and cure speed | 10 – 35 | 22 |
| photoinitiator (TPO / BAPO type, 405 nm) | 0.5 – 3 | 1.5 |
| pigment / dye + additives (defoamer, staopaque grades; omitted in CLEAR | 0.2 – 5 | 2 |
| acrylate resin systembalance of formulation | balance | — |
Water-Washable Resin Flex — frequently asked
What is Water-Washable Resin Flex used for?
Water-Washable Resin Flex is typically used for hobbyist/desktop printing, low-VOC workshop use and general prototypes. In short: water wash, no IPA; low-VOC post-processing; reduced moisture resistance.
What is the tensile strength of Water-Washable Resin Flex?
Water-Washable Resin Flex has a typical tensile strength of 8 MPa (1.16 ksi) — weaker than 81% of polymer grades. Strength varies by condition: see the 4 listed tempers.
Is Water-Washable Resin Flex easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of polymer grades). Post-cured parts drill, sand and file easily but chip at edges — use sharp tools, low feed, and support thin sections; wet-sand to avoid dust.
Can Water-Washable Resin Flex be welded?
Thermoset, not weldable; join with cyanoacrylate or UV-cure resin fillets and post-cure the joint.
What surface finishes work on Water-Washable Resin Flex?
Primer/filler plus acrylic or 2K clear coat is strongly recommended — the coating both hides layer lines and seals the hydrophilic surface against humidity.
Can Water-Washable Resin Flex be formed, bent or molded?
Printed on 405 nm LCD/DLP/SLA at 0.02–0.05 mm layers, 2–4 s exposure typical; wash 3–5 min in clean water only (long soaks swell and craze parts), then dry fully before 2–6 min UV post-cure.
What is the maximum service temperature of Water-Washable Resin Flex?
Water-Washable Resin Flex is rated for continuous use to about 55°C (131 °F), and briefly to 70°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Water-Washable Photopolymer Resin technical data sheets — Elegoo / Anycubic / eSUN / Phrozen (2024)
- ASTM D638 / D790 / D256 / D648 test methods for plastics — ASTM International (2022)
- Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints — SITA Technology (2010)
- Photopolymer property comparison data — FabDigit internal compilation (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.