PU-PC-like STD-CLEAR
Grade · default condition
Default choice for see-through prototype housings, lenses and light pipes where PC stiffness and clarity are needed at room temperature.
Values for the STD-CLEAR condition
Other PU-PC-like grades and fills
PU-PC-like is listed in 4 conditions; see the grade overview at PU-PC-like.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Flame-retardant transparent/translucent grade | Select for electrical enclosures and lighting prototypes that must pass a V-0 style burn check; expect slight haze and lower toughness. | 45 | 52 | 7 | 84 Shore D |
Impact-modified tough transparent grade | Use for drop-test covers, clip features and thin snap-fits where standard clear PU cracks. | — | 48 | 60 | 76 Shore D |
STD-CLEARDefaultThis page standard transparent, UV-stabilized PC-like PU | Default choice for see-through prototype housings, lenses and light pipes where PC stiffness and clarity are needed at room temperature. | 50 | 60 | 12 | 82 Shore D |
Heat-resistant transparent grade | Pick when the clear part sees warm environments, LED heat or paint-bake / humid-heat testing above 80 °C. | — | 70 | 6 | 85 Shore D |
What is PU-PC-like STD-CLEAR?
PU-PC-like STD-CLEAR is PU-PC-like in the STD-CLEAR grade — default choice for see-through prototype housings, lenses and light pipes where PC stiffness and clarity are needed at room temperature. PU-PC-like STD-CLEAR has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 67% of polyurethane grades. Elongation at break is 12% and the elastic modulus is 2.2 GPa (0.319 Msi). PU-PC-like STD-CLEAR has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 55% of polyurethane grades. Its glass-transition temperature is 75°C (167 °F).
Advantages
- Good UV / weathering resistance — 65/100, better than 100% of polyurethane grades
- Polishes to a fine finish — 85/100, better than 98% of polyurethane grades
- Low, predictable mold shrinkage — 0.15%, better than 92% of polyurethane grades
PU-PC-like STD-CLEAR properties
Typical room-temperature values for PU-PC-like STD-CLEAR; 25 are specific to this condition. Other listed values are PU-PC-like reference data and may not represent this condition. Bars are the position among polyurethane grades.
Physical6
PU-PC-like STD-CLEAR has a density of 1.13 g/cm³ (0.0408 lb/in³), lighter than 55% of polyurethane grades. Its glass-transition temperature is 75°C (167 °F).
Mechanical15
PU-PC-like STD-CLEAR has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 67% of polyurethane grades. Elongation at break is 12% and the elastic modulus is 2.2 GPa (0.319 Msi).
Thermal11
PU-PC-like STD-CLEAR is rated for continuous service to 70°C (158 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 60% of polyurethane grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).
Electrical5
PU-PC-like STD-CLEAR is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 74% of polyurethane grades. UV resistance is good.
Sustainability4
Producing a kilogram of PU-PC-like STD-CLEAR takes about 105 MJ of energy and emits 5.5 kg of CO₂ — more than 64% of polyurethane grades. Typical recycled content is 0%.
Manufacturability6
PU-PC-like STD-CLEAR's machinability is good (65/100, better than 62% of polyurethane grades); weldability not recommended (0/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PU-PC-like STD-CLEAR
Is PU-PC-like easy to machine?
Trims, drills and taps easily with sharp carbide and light feeds; keep tools cool and avoid dry sanding to prevent surface haze and heat marks.
Can PU-PC-like be welded?
Thermoset — cannot be welded; join with PU or epoxy adhesives, cyanoacrylate or mechanical inserts.
Can PU-PC-like be formed, bent or molded?
Vacuum-cast into silicone moulds at 30–40 °C mix temperature, degassed to avoid bubbles, demoulded after 20–60 min and post-cured 2–8 h at 60–80 °C; resin is moisture-sensitive so keep components dry and sealed.
What surface finishes work on PU-PC-like?
Sand progressively to 2000 grit and polish or dip/spray with a clear PU lacquer for optical clarity and scratch resistance; hard coating is recommended for touched or outdoor surfaces.
PU-PC-like 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 |
|---|---|---|
| aliphatic polyisocyanate prepolymer (HDIcomponent A; aromatic MDI variants yellow faster under UV | 35 – 55 | 45 |
| UV absorber + HALS stabilizer | 0.3 – 1.5 | 0.8 |
| optical brightener / dye (optional)for water-clear or tinted appearance | 0 – 0.5 | 0.05 |
| polyol (polyester/polyether/polycarbonatcomponent B, contains chain extender and catalyst | ≥ 40 (balance) | — |
PU-PC-like STD-CLEAR — frequently asked
What is PU-PC-like STD-CLEAR used for?
PU-PC-like STD-CLEAR is typically used for light covers/lenses, transparent housings, display models and fluid sight glasses. In short: clearest PU casting resin; PC look without tooling; UV-stabilized transparency.
What is the yield strength of PU-PC-like STD-CLEAR?
PU-PC-like STD-CLEAR has a typical yield strength of 50 MPa (7.25 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 67% of polyurethane grades. Strength varies by condition: see the 4 listed tempers.
Is PU-PC-like STD-CLEAR easy to machine?
Reasonably — machinability is rated good (65/100, better than 62% of polyurethane grades). Trims, drills and taps easily with sharp carbide and light feeds; keep tools cool and avoid dry sanding to prevent surface haze and heat marks.
Can PU-PC-like STD-CLEAR be welded?
Not readily — weldability is rated not recommended (0/100). Thermoset — cannot be welded; join with PU or epoxy adhesives, cyanoacrylate or mechanical inserts.
What surface finishes work on PU-PC-like STD-CLEAR?
Sand progressively to 2000 grit and polish or dip/spray with a clear PU lacquer for optical clarity and scratch resistance; hard coating is recommended for touched or outdoor surfaces.
Can PU-PC-like STD-CLEAR be formed, bent or molded?
Vacuum-cast into silicone moulds at 30–40 °C mix temperature, degassed to avoid bubbles, demoulded after 20–60 min and post-cured 2–8 h at 60–80 °C; resin is moisture-sensitive so keep components dry and sealed.
What is the maximum service temperature of PU-PC-like STD-CLEAR?
PU-PC-like STD-CLEAR is rated for continuous use to about 70°C (158 °F), and briefly to 100°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between PU-PC-like STD-CLEAR and PU-PC-like FR-V0?
STD-CLEAR is the default condition — default choice for see-through prototype housings, lenses and light pipes where PC stiffness and clarity are needed at room temperature. FR-V0: select for electrical enclosures and lighting prototypes that must pass a V-0 style burn check; expect slight haze and lower toughness. Yield strength is 50 MPa in STD-CLEAR versus 45 MPa in FR-V0.
Sources
- PX 521 / PX 521HT transparent polyurethane casting resin TDS — Axson Technologies (Sika) (2020)
- Hei-Cast / Crystal-series clear vacuum casting PU data sheets — H&K / prototyping resin suppliers (2022)
- Polyurethanes: Science, Technology, Markets and Trends — Wiley (2014)
- ISO 527 / ISO 178 / ISO 75 plastics test methods — ISO (2019)
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.