PC/PBT
PC/PBT is an alloy of amorphous polycarbonate with semicrystalline polybutylene terephthalate, classified under ASTM D5927, and stocked as natural, impact-modified, glass-filled (GF15/GF30), mineral-filled, UV, FR, high-heat and PCR-content grades.
Reference datasheet — PC/PBT is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PC/PBT grades and fills
PC/PBT is supplied in 7 conditions, soft to hard.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Impact-modified / high-impact grade | Pick when ductile failure is required down to -30/-40 °C, e.g. bumper systems and rocker panels. | 46 | 47 | 150 | 72 Shore D |
Post-consumer-recycled content grade | Use when 20–50 % PCR content is required by an OEM sustainability spec; slightly lower and more variable impact. | 49 | 50 | 80 | 75 Shore D |
Heat-stabilized grade | Antioxidant/heat-stabilizer package for prolonged service near 110–120 °C (e.g. paint-bake or lamp-adjacent parts). | 54 | 55 | 100 | 76 Shore D |
Mineral / talc filled | Choose for isotropic shrinkage and low CTE on large painted exterior panels without fiber read-through. | 56 | 57 | 25 | 80 Shore D |
Flame-retardant, UL 94 V-0 | Select for enclosures and E&E parts requiring V-0 at 1.5 mm; some loss of ductility and heat resistance. | 56 | 57 | 55 | 78 Shore D |
15 % glass-fiber reinforced | Mid stiffness/low warpage compromise for painted structural trim and brackets. | 85 | 6 | ||
30 % glass-fiber reinforced | Highest stiffness and heat resistance of the family; use for load-bearing housings and under-hood brackets. | 115 | 3.5 |
Supply forms, finishes and certifications
Ways PC/PBT is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
UV | UV-stabilized / weatherable exterior grade | Grade option |
NATDefault | Unfilled / Natural injection-molding grade | Standard supply |
What is PC/PBT?
PC/PBT is an alloy of amorphous polycarbonate with semicrystalline polybutylene terephthalate, classified under ASTM D5927, and stocked as natural, impact-modified, glass-filled (GF15/GF30), mineral-filled, UV, FR, high-heat and PCR-content grades. The unfilled blend combines 53 MPa tensile strength with about 120 % elongation, and engineers select it for large painted injection-molded exterior panels and enclosures where PC alone would be too solvent-sensitive. It is opaque and not an optical material, needs thorough drying to avoid hydrolysis, and cannot be joined with solvent cements; PC/PET is the nearest alternative when higher surface hardness is wanted. PC/PBT has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 130°C (266 °F). PC/PBT has a yield strength of 52 MPa (7.54 ksi) and a tensile strength of 53 MPa (7.69 ksi) — stronger than 56% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.2 GPa (0.312 Msi).
What is PC/PBT used for?
- automotive body panels
- bumper components
- electrical enclosures
- chemical-resistant housings
Advantages
- Good UV / weathering resistance — 55/100, better than 77% of polymer grades
PC/PBT properties
Typical room-temperature values; bars are the position among polymer grades.
Physical5
PC/PBT has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 130°C (266 °F).
Mechanical11
PC/PBT has a yield strength of 52 MPa (7.54 ksi) and a tensile strength of 53 MPa (7.69 ksi) — stronger than 56% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.2 GPa (0.312 Msi).
Thermal11
PC/PBT is rated for continuous service to 100°C (212 °F). It conducts heat at 0.21 W/m·K (0.121 BTU/hr·ft·°F), better than 55% of polymer grades. Thermal expansion is 80 µm/m·K (44.4 µin/in·°F).
Electrical7
PC/PBT is an electrical insulator with a dielectric strength of 26 kV/mm (660.4 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of polymer grades. UV resistance is good.
Sustainability4
Producing a kilogram of PC/PBT takes about 95 MJ of energy and emits 5.5 kg of CO₂ — less than 70% of polymer grades. Typical recycled content is 10%.
Manufacturability7
PC/PBT's machinability is good (62/100, better than 60% of polymer grades); weldability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PC/PBT is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PC/PBT
Is PC/PBT easy to machine?
Machines like tough PC: sharp positive-rake carbide tools, high speed / moderate feed, air or mist cooling; avoid stress-inducing dry drilling and anneal (~110 °C) before solvent contact.
Can PC/PBT be welded?
Joins well by ultrasonic, laser, hot-plate and vibration welding; adhesive bonding with polyurethane/epoxy after abrasion or flame/plasma treatment — avoid solvent cements that stress-crack the PC phase.
Can PC/PBT be formed, bent or molded?
Injection mold at 245–275 °C melt / 50–90 °C tool with pellets dried to <0.02 % moisture (2–4 h at 100–120 °C) to prevent hydrolytic splay and loss of impact; shrinkage 0.5–1.0 % unfilled.
PC/PBT 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 |
|---|---|---|
| polycarbonate (PC)bisphenol-A polycarbonate matrix phase | 45 – 75 | 60 |
| poly(butylene terephthalate) (PBT)semi-crystalline phase, provides chemical/weather resistance | 20 – 50 | 32 |
| impact modifier (MBS/core-shell acrylic low-temperature toughness | 3 – 12 | 6 |
| compatibilizer / transesterification catphosphite/epoxy stabilizers, antioxidants, mold release | 0.3 – 2 | 1 |
What surface finishes work on PC/PBT?
Excellent for painting — accepts 1K/2K automotive basecoat-clearcoat with adhesion promoter; can be laser-marked, hot-stamped, in-mold decorated or vacuum metallized, but is opaque and not suitable for optical polishing.
How much does PC/PBT cost?
PC/PBT is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PC/PBT — frequently asked
What is PC/PBT used for?
PC/PBT is typically used for automotive body panels, bumper components, electrical enclosures and chemical-resistant housings. In short: paintable exterior PC blend; better chemical resistance than PC; tough at low temperature.
What is the yield strength of PC/PBT?
PC/PBT has a typical yield strength of 52 MPa (7.54 ksi) and a tensile strength of 53 MPa (7.69 ksi) — stronger than 56% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is PC/PBT easy to machine?
Reasonably — machinability is rated good (62/100, better than 60% of polymer grades). Machines like tough PC: sharp positive-rake carbide tools, high speed / moderate feed, air or mist cooling; avoid stress-inducing dry drilling and anneal (~110 °C) before solvent contact.
Can PC/PBT be welded?
Yes — weldability is rated very good (70/100). Joins well by ultrasonic, laser, hot-plate and vibration welding; adhesive bonding with polyurethane/epoxy after abrasion or flame/plasma treatment — avoid solvent cements that stress-crack the PC phase.
What surface finishes work on PC/PBT?
Excellent for painting — accepts 1K/2K automotive basecoat-clearcoat with adhesion promoter; can be laser-marked, hot-stamped, in-mold decorated or vacuum metallized, but is opaque and not suitable for optical polishing.
Can PC/PBT be formed, bent or molded?
Injection mold at 245–275 °C melt / 50–90 °C tool with pellets dried to <0.02 % moisture (2–4 h at 100–120 °C) to prevent hydrolytic splay and loss of impact; shrinkage 0.5–1.0 % unfilled.
What is the maximum service temperature of PC/PBT?
PC/PBT is rated for continuous use to about 100°C (212 °F), and briefly to 130°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PC/PBT cost?
PC/PBT is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM D5927 — Standard Specification for Thermoplastic Polyester (TPES) Injection Molding and Extrusion Materials — ASTM International (2018)
- ISO 7391 — Polycarbonate (PC) moulding and extrusion materials — ISO (2006)
- Xenoy PC/PBT resin product datasheets and processing guide — SABIC Specialties (2023)
- Makroblend PC+PBT grade datasheets — Covestro (2023)
- CAMPUS plastics database — PC+PBT blends (ISO 10350 datasets) — CWFG / CAMPUS consortium (2024)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.