PETG · grade · default condition
PETG Unfilled
Properties of the Unfilled condition, compared with the other PETG grades.
Default choice for transparent, tough, easily formed parts and general injection molding.
What is PETG Unfilled?
PETG Unfilled is PETG in the Unfilled grade — default choice for transparent, tough, easily formed parts and general injection molding. PETG Unfilled has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 52% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.1 GPa (0.305 Msi). PETG Unfilled has a density of 1.27 g/cm³ (0.0459 lb/in³), heavier than 66% of polymer grades. Its glass-transition temperature is 80°C (176 °F).
Advantages
- Low, predictable mold shrinkage — 0.35%, better than 87% of polymer grades
- Forms and bends easily — 88/100, better than 85% of polymer grades
- Polishes to a fine finish — 72/100, better than 85% of polymer grades
- Readily welded — 80/100, better than 84% of polymer grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 81% of polymer grades
Limitations
- Limited service temperature — 63°C (145 °F), worse than 85% of polymer grades
PETG Unfilled properties
Typical room-temperature values for PETG Unfilled — 7 properties are specific to this condition; the rest are grade-level values shared by every PETG grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical6
PETG Unfilled has a density of 1.27 g/cm³ (0.0459 lb/in³), heavier than 66% of polymer grades. Its glass-transition temperature is 80°C (176 °F).
Mechanical12
PETG Unfilled has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 52% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.1 GPa (0.305 Msi).
Thermal11
PETG Unfilled is rated for continuous service to 63°C (145 °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 68 µm/m·K (37.8 µin/in·°F).
Electrical6
PETG Unfilled is an electrical insulator with a dielectric strength of 16 kV/mm (406.4 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 63% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of PETG Unfilled takes about 84 MJ of energy and emits 3.2 kg of CO₂ — less than 81% of polymer grades. Typical recycled content is 0%.
Manufacturability7
PETG Unfilled's machinability is good (65/100, better than 66% of polymer grades); weldability very good (80/100); formability excellent (88/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other PETG grades and fills
PETG is also supplied in 9 other conditions. The full side-by-side table is on the PETG overview.
- UnfilledDefaultDefault choice for transparent, tough, easily formed parts and general injection molding.50 MPa tensile
- GFPick when stiffness, creep resistance and lower shrinkage matter more than transparency or toughness.65 MPa tensile
- StandardPick for stock extruded sheet used in glazing, machine guards, signage and thermoforming.50 MPa yield
- CFPick for stiffer, more dimensionally stable printed parts with matte black finish; brittle and abrasive to nozzles.48 MPa tensile
- ESDPick for electronics handling trays, guards and cleanroom fixtures needing 10^6–10^9 Ω surface resistivity.45 MPa tensile
- As PrintedUse these de-rated values for FDM-printed PETG parts; expect 40–60% of molded strength in Z.38 MPa yield
Working with PETG Unfilled
Is PETG easy to machine?
Machines and routes well with sharp, polished, high-rake tools and air blast; keep feeds high and coolant/mist on to avoid gumming and edge crazing, and avoid stress at drilled holes.
Can PETG be welded?
Excellent hot-plate, hot-gas, ultrasonic and RF/high-frequency welding; solvent bonds with cyclohexanone/MEK-based cements and glues well with cyanoacrylate or two-part urethane.
Can PETG be formed, bent or molded?
Thermoforms at 120–160 °C with little pre-drying and cold-bends without stress-whitening; inject at 230–260 °C melt / 10–40 °C mold, dry pellets 4 h at 65 °C to prevent hydrolytic splay.
What surface finishes work on PETG?
Takes screen/digital printing, hard-coating and vacuum metallizing; edges can be sanded and buffed (flame polishing is riskier than for acrylic), and paint/adhesive systems must be solvent-checked for crazing.
PETG 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 |
|---|---|---|
| terephthalate (PTA/DMT) repeat unitacid component of the copolyester backbone (mol basis) | 48 – 52 | 50 |
| 1,4-cyclohexanedimethanol (CHDM) unit~30 mol% of the glycol fraction; suppresses crystallinity (amorphous) | 12 – 20 | 16 |
| additives (stabilizers, colorants, UV/FRgrade dependent; fillers listed separately per variant | 0 – 15 | 1 |
| ethylene glycol unitglycol component balance | ≥ 30 (balance) | — |
PETG Unfilled — frequently asked
What is PETG Unfilled used for?
PETG Unfilled is typically used for transparent machine guards, retail displays and shelf fixtures, light-box and signage panels, food-contact parts and containers, bottles and medical device housings. In short: versatile tough plastic.
What is the yield strength of PETG Unfilled?
PETG Unfilled has a typical yield strength of 50 MPa (7.25 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 52% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is PETG Unfilled easy to machine?
Reasonably — machinability is rated good (65/100, better than 66% of polymer grades). Machines and routes well with sharp, polished, high-rake tools and air blast; keep feeds high and coolant/mist on to avoid gumming and edge crazing, and avoid stress at drilled holes.
Can PETG Unfilled be welded?
Yes — weldability is rated very good (80/100). Excellent hot-plate, hot-gas, ultrasonic and RF/high-frequency welding; solvent bonds with cyclohexanone/MEK-based cements and glues well with cyanoacrylate or two-part urethane.
What surface finishes work on PETG Unfilled?
Takes screen/digital printing, hard-coating and vacuum metallizing; edges can be sanded and buffed (flame polishing is riskier than for acrylic), and paint/adhesive systems must be solvent-checked for crazing.
Can PETG Unfilled be formed, bent or molded?
Thermoforms at 120–160 °C with little pre-drying and cold-bends without stress-whitening; inject at 230–260 °C melt / 10–40 °C mold, dry pellets 4 h at 65 °C to prevent hydrolytic splay.
What is the maximum service temperature of PETG Unfilled?
PETG Unfilled is rated for continuous use to about 63°C (145 °F), and briefly to 75°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in PETG Unfilled?
Yes — PETG Unfilled is available for CNC machining, sheet metal, injection molding and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Eastman Eastar / Spectar copolyester (PETG) product data — Eastman Chemical (2023)
- SKYGREEN PETG resin grades data sheets — SK Chemicals (2022)
- CAMPUS plastics database — PETG copolyester ISO data sets — CWFG / CAMPUS (2024)
- ISO 527-2 / ISO 178 / ISO 75 / ISO 306 test methods — ISO (2019)
- ASTM D256 / D638 / D648 / D785 test methods — ASTM (2022)
- Ensinger / Curbell semi-finished PETG sheet technical data — Ensinger, Curbell Plastics (2023)
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.