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PP-Like · grade

PP-Like Clear

Properties of the Clear condition, compared with the other PP-Like grades.

Use for light pipes, fluidic mock-ups and see-through housings where PP-like toughness is still needed.

Urethane castingBudget cost $

What is PP-Like Clear?

PP-Like Clear is PP-Like in the Clear grade — use for light pipes, fluidic mock-ups and see-through housings where PP-like toughness is still needed. PP-Like Clear has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 90% of polyurethane grades. Elongation at break is 28% and the elastic modulus is 1.4 GPa (0.203 Msi). PP-Like Clear has a density of 1.15 g/cm³ (0.0415 lb/in³), heavier than 63% of polyurethane grades. Its glass-transition temperature is 55°C (131 °F). STD is the default condition FabDigit quotes; Clear is available on request or by drawing note.

Limitations

  • Limited service temperature — 50°C (122 °F), worse than 100% of polyurethane grades
  • High embodied carbon — 6 kg CO₂/kg, worse than 96% of polyurethane grades
  • Low strength — 30 MPa (4.35 ksi), worse than 90% of polyurethane grades

PP-Like Clear properties

Typical room-temperature values for PP-Like Clear — 8 properties are specific to this condition; the rest are grade-level values shared by every PP-Like grade. Each bar shows where the value sits among the polyurethane grades in FabDigit's library — further right is higher.

Physical5

PP-Like Clear has a density of 1.15 g/cm³ (0.0415 lb/in³), heavier than 63% of polyurethane grades. Its glass-transition temperature is 55°C (131 °F).

Density1.15 g/cm³0.04 lb/in³
Glass Transition (Tg)55°C131 °F
Water Absorption (24 h)0.6%
Water Absorption (Saturation)1.8%
Refractive Index1.51

Mechanical17

PP-Like Clear has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 90% of polyurethane grades. Elongation at break is 28% and the elastic modulus is 1.4 GPa (0.203 Msi).

Elastic (Young's) Modulus1.4 GPa0.2 Msi
Shear Modulus0.46 GPa0.07 Msi
Bulk Modulus2 GPa0.35 Msi
Poisson's Ratio0.4
Tensile Strength (Ultimate)38 MPa5.5 ksi
Yield Strength (0.2% offset)30 MPa4.4 ksi
Elongation at Break28%
Compressive Strength60 MPa8.7 ksi
Compressive Modulus1.2 GPa0.17 Msi
Flexural Strength52 MPa7.5 ksi
Flexural Modulus1.4 GPa0.2 Msi
Shear Strength30 MPa4.4 ksi
Fracture Toughness (K_IC)1.8 MPa·√m1.6 ksi·√in
Izod Impact, Notched40 J/m0.75 ft·lbf/in
Hardness, Shore D80 Shore D
Hardness, Rockwell M55 HRM
Hardness, Rockwell R100 HRR

Thermal10

PP-Like Clear is rated for continuous service to 50°C (122 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 57% of polyurethane grades. Thermal expansion is 120 µm/m·K (66.7 µin/in·°F).

Thermal Conductivity0.2 W/m·K0.12 BTU/hr·ft·°F
Specific Heat Capacity1,500 J/kg·K0.36 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)120 µm/m·K66.7 µin/in·°F
Max Service Temperature (continuous)50°C122 °F
Min Service Temperature-20°C-4 °F
Heat Deflection Temp. @ 0.45 MPa55°C131 °F
Heat Deflection Temp. @ 1.8 MPa45°C113 °F
Flammability (UL 94)HB (typical, not rated on most consumer PP-like resins)
Limiting Oxygen Index19%
Max Service Temperature (short-term)70°C158 °F

Electrical7

PP-Like Clear is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 1×10¹² Ω·m.

Electrical Resistivity1×10¹² Ω·m3.94×10¹⁹ µΩ·in
Dielectric Strength17 kV/mm432 V/mil
Dielectric Constant (1 MHz)3.6
Dissipation Factor (1 MHz)0.03
Volume Resistivity1×10¹⁴ Ω·cm
Surface Resistivity1×10¹⁵ Ω
Comparative Tracking Index (CTI)500 V

Chemical & Environmental3

Corrosion resistance is very good (78/100), better than 73% of polyurethane grades. UV resistance is poor.

Corrosion ResistanceVery good78/100
UV / Weathering ResistancePoor18/100
Chemical Resistance SummaryGood against water, dilute acids/alkalis, oils and aliphatic fuels; attacked or softened by ketones, esters, chlorinated solvents and hot IPA soaks; post-cured parts continue to embrittle under sunlight and prolonged humid heat.

Sustainability4

Producing a kilogram of PP-Like Clear takes about 120 MJ of energy and emits 6 kg of CO₂ — more than 98% of polyurethane grades. Typical recycled content is 0%.

Embodied Energy (primary production)120 MJ/kg51,591 BTU/lb
Embodied Carbon (primary production)6 kg CO₂/kg
Embodied Water220 L/kg26.4 gal/lb
Typical Recycled Content0%

Manufacturability4

PP-Like Clear's machinability is good (55/100, worse than 67% of polyurethane grades); weldability not recommended (5/100); formability not recommended (8/100).

MachinabilityGood55/100
WeldabilityNot recommended5/100
Formability (cold)Not recommended8/100
PolishabilityGood60/100

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other PP-Like grades and fills

PP-Like is also supplied in 7 other conditions. The full side-by-side table is on the PP-Like overview.

Working with PP-Like Clear

Is PP-Like easy to machine?

Drills and mills cleanly with sharp, high-rake tools and light cuts; avoid heat build-up above ~50 °C which softens and smears the part.

Can PP-Like be welded?

Thermoset — cannot be heat welded; join with cyanoacrylate, epoxy or fresh resin cured under a 405 nm lamp.

Can PP-Like be formed, bent or molded?

Printed only by vat photopolymerization; keep exposure and layer settings tuned, then wash briefly in IPA and post-cure warm (50–60 °C) to reach rated toughness without over-embrittling.

What surface finishes work on PP-Like?

Sands and primes well; use filler primer plus 2K clear or paint, and always add a UV-blocking topcoat because bare parts yellow and embrittle in sunlight.

PP-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.

ElementSpec limit (wt %)Nominal
aliphatic urethane acrylate oligomerbackbone giving PP-like toughness35 – 6048
monofunctional acrylate monomer (IBOA/EOviscosity control, flexibility15 – 3525
difunctional acrylate crosslinker (HDDA/crosslink density / stiffness8 – 2515
photoinitiator (TPO / TPO-L / BAPO)405 nm or 355 nm sensitized1 – 42.5
TiO2 pigment / opacifierwhite PP-look grades0 – 41.5
additives (dispersant, defoamer, UV blocbalance to 100 %balance

PP-Like Clear — frequently asked

What is PP-Like Clear used for?

PP-Like Clear is typically used for snap-fit parts, hinged enclosures, living-hinge test parts, thin-wall containers and caps, cable clips and retainers and fit-and-function assembly checks. In short: semi-flexible; survives living hinges like molded PP.

What is the yield strength of PP-Like Clear?

PP-Like Clear has a typical yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 90% of polyurethane grades. Strength varies by condition: see the 8 listed tempers.

Is PP-Like Clear easy to machine?

Reasonably — machinability is rated good (55/100, worse than 67% of polyurethane grades). Drills and mills cleanly with sharp, high-rake tools and light cuts; avoid heat build-up above ~50 °C which softens and smears the part.

Can PP-Like Clear be welded?

Not readily — weldability is rated not recommended (5/100). Thermoset — cannot be heat welded; join with cyanoacrylate, epoxy or fresh resin cured under a 405 nm lamp.

What surface finishes work on PP-Like Clear?

Sands and primes well; use filler primer plus 2K clear or paint, and always add a UV-blocking topcoat because bare parts yellow and embrittle in sunlight.

Can PP-Like Clear be formed, bent or molded?

Printed only by vat photopolymerization; keep exposure and layer settings tuned, then wash briefly in IPA and post-cure warm (50–60 °C) to reach rated toughness without over-embrittling.

What is the maximum service temperature of PP-Like Clear?

PP-Like Clear is rated for continuous use to about 50°C (122 °F), and briefly to 70°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Can FabDigit make parts in PP-Like Clear?

Yes — PP-Like Clear is available for urethane casting with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. Durable / Tough photopolymer resin technical data sheetsFormlabs (2024)
  2. Somos polypropylene-like SLA resin data sheets (9120 / Evolve class)Covestro (DSM Somos) (2023)
  3. Accura SLA resin family data sheets3D Systems (2023)
  4. eSUN / Siraya Tech PP-like 405 nm resin TDSeSUN, Siraya Tech (2024)
  5. ASTM D638 / D790 / D256 / D648 test methods for plasticsASTM International (2022)

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.