PAR GF20
Reinforced grade
also Ardel, Durel
GF20 = 20 % glass-fiber reinforced
Use where higher stiffness and lower creep at 120–150 °C are needed and transparency is not required.
Values for the GF20 condition
Other PAR grades and fills
PAR is listed in 5 conditions; see the grade overview at PAR.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
PAR blended with PET/PBT | Blend used to lower cost and melt viscosity and raise chemical/solvent resistance where full PAR transparency is not needed. | 60 | 65 | 30 | 84 Shore D |
polyarylate–polycarbonate blend | Cheaper, easier-flowing compromise: better melt processability and clarity than neat PAR, with heat resistance between PC and PAR. | 62 | 66 | 80 | 82 Shore D |
FR V-0 | Use for electrical housings and connectors requiring UL 94 V-0 at thin wall together with high HDT. | 65 | 68 | 35 | 85 Shore D |
GF20This page 20 % glass-fiber reinforced | Use where higher stiffness and lower creep at 120–150 °C are needed and transparency is not required. | — | 100 | 4 | — |
30 % glass-fiber reinforced | Highest stiffness/dimensional stability PAR grade for structural and connector parts at elevated temperature. | — | 120 | 2.5 | — |
What is PAR GF20?
PAR GF20 is PAR in the GF20 grade — use where higher stiffness and lower creep at 120–150 °C are needed and transparency is not required. PAR GF20 has a yield strength of 68 MPa (9.86 ksi) and a tensile strength of 100 MPa (14.5 ksi) — stronger than 77% of polymer grades. Elongation at break is 4% and the elastic modulus is 5.8 GPa (0.841 Msi). PAR GF20 has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is 190°C (374 °F).
Advantages
- Good UV / weathering resistance — 90/100, better than 91% of polymer grades
- Stiff — 5.8 GPa (0.841 Msi), better than 89% of polymer grades
- Polishes to a fine finish — 75/100, better than 86% of polymer grades
- Low, predictable mold shrinkage — 0.4%, better than 82% of polymer grades
- High service temperature — 155°C (311 °F), better than 81% of polymer grades
Limitations
- High embodied carbon — 7.5 kg CO₂/kg, worse than 79% of polymer grades
- Limited ductility — 4%, worse than 78% of polymer grades
- Heavy — 1.35 g/cm³ (0.0488 lb/in³), worse than 75% of polymer grades
- Difficult to machine — 48/100, worse than 75% of polymer grades
PAR GF20 properties
Typical room-temperature values for PAR GF20; 13 are specific to this condition. Other listed values are PAR reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PAR GF20 has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is 190°C (374 °F).
Mechanical16
PAR GF20 has a yield strength of 68 MPa (9.86 ksi) and a tensile strength of 100 MPa (14.5 ksi) — stronger than 77% of polymer grades. Elongation at break is 4% and the elastic modulus is 5.8 GPa (0.841 Msi).
Thermal11
PAR GF20 is rated for continuous service to 155°C (311 °F). It conducts heat at 0.18 W/m·K (0.104 BTU/hr·ft·°F), worse than 73% of polymer grades. Thermal expansion is 35 µm/m·K (19.4 µin/in·°F).
Electrical7
PAR GF20 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of PAR GF20 takes about 145 MJ of energy and emits 7.5 kg of CO₂ — more than 83% of polymer grades. Typical recycled content is 0%.
Manufacturability7
PAR GF20's machinability is fair (48/100, worse than 75% of polymer grades); weldability good (60/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PAR GF20
Is PAR easy to machine?
Machines like polycarbonate — sharp positive-rake tools, high speed, low feed and air cooling; anneal near 160 °C before tight-tolerance cuts to relieve moulding stress and avoid solvent-induced cracking.
Can PAR be welded?
Joins well by ultrasonic, hot-plate and laser welding; solvent bonding with methylene chloride works but risks stress cracking, so adhesives (epoxy, urethane) are usually preferred.
Can PAR be formed, bent or molded?
High melt viscosity: dry 4–6 h at 130 °C, mould at 320–360 °C melt / 110–150 °C tool with generous gates and runners; extruded sheet thermoforms at 200–230 °C.
What surface finishes work on PAR?
Takes vacuum metallizing, hard-coat and antireflective coatings well thanks to its high heat resistance; polishes to optical clarity but is scratch-soft, so a silicone/acrylic hard coat is normal for lenses.
PAR 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 |
|---|---|---|
| bisphenol A residuediphenol component of the aromatic polyester backbone | 45 – 55 | 50 |
| terephthalic acid residuetypically ~50:50 tere/iso for amorphous, transparent behaviour | 15 – 35 | 25 |
| isophthalic acid residuesuppresses crystallinity, gives clarity | 15 – 35 | 25 |
| UV/heat stabilizers, mould releaseadditive package, grade dependent | 0.1 – 2 | 0.5 |
PAR GF20 — frequently asked
What is PAR GF20 used for?
PAR GF20 is typically used for automotive lighting lenses, electrical connectors, solar panel components, sunglass lenses and outdoor sensor housings. In short: most weatherable clear engineering plastic; higher heat than polycarbonate; high-viscosity, hot-tool moulding.
What is the yield strength of PAR GF20?
PAR GF20 has a typical yield strength of 68 MPa (9.86 ksi) and a tensile strength of 100 MPa (14.5 ksi) — stronger than 77% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is PAR GF20 easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 75% of polymer grades). Machines like polycarbonate — sharp positive-rake tools, high speed, low feed and air cooling; anneal near 160 °C before tight-tolerance cuts to relieve moulding stress and avoid solvent-induced cracking.
Can PAR GF20 be welded?
Yes — weldability is rated good (60/100). Joins well by ultrasonic, hot-plate and laser welding; solvent bonding with methylene chloride works but risks stress cracking, so adhesives (epoxy, urethane) are usually preferred.
What surface finishes work on PAR GF20?
Takes vacuum metallizing, hard-coat and antireflective coatings well thanks to its high heat resistance; polishes to optical clarity but is scratch-soft, so a silicone/acrylic hard coat is normal for lenses.
Can PAR GF20 be formed, bent or molded?
High melt viscosity: dry 4–6 h at 130 °C, mould at 320–360 °C melt / 110–150 °C tool with generous gates and runners; extruded sheet thermoforms at 200–230 °C.
What is the maximum service temperature of PAR GF20?
PAR GF20 is rated for continuous use to about 155°C (311 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- U-Polymer polyarylate resin technical data — Unitika (2020)
- Ardel polyarylate resin product data — Amoco / Solvay Advanced Polymers (2002)
- Durel polyarylate resin data sheet — Celanese (Hoechst Celanese) (1998)
- Engineered Materials Handbook Vol. 2 — Engineering Plastics — ASM International (1988)
- CAMPUS plastics datasheets — polyarylate (PAR) — CWFG / CAMPUS (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.