PC-Si
PC-Si is a polycarbonate–siloxane copolymer in which siloxane blocks raise low-temperature impact strength and give inherent halogen-free flame retardance, including V0 ratings in thin walls.
Reference datasheet — PC-Si 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-Si grades and fills
PC-Si is supplied in 9 conditions, soft to hard.
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Ultra-low-temperature impact grade | Highest PDMS block content for ductile notched failure down to about -60 to -100 °C in power tools and outdoor/EV parts. | 53 | 55 | 130 | 78 Shore D |
Post-consumer recycled content grade | Use to meet corporate recycled-content targets in consumer electronics while retaining V-0 and good impact. | 56 | 58 | 90 | 79 Shore D |
FR V-0 thin-wall grade | Pick when UL 94 V-0 or 5VA must be certified at 0.8–1.2 mm wall with low smoke and no halogen/antimony. | 57 | 58 | 100 | 80 Shore D |
High-flow thin-wall molding grade | For long-flow, thin-wall housings and complex IT/mobile parts where fill pressure limits design. | 57 | 58 | 100 | 80 Shore D |
Translucent / optical-clarity copolymer grade | Low-siloxane or compatibilized copolymer for light-diffusing lenses and translucent housings where some haze is acceptable. | 60 | 62 | 110 | 81 Shore D |
Antistatic / ESD-dissipative grade | Carbon-based or permanent antistat compound for electronics trays, sensor housings and dust-sensitive enclosures. | 60 | 62 | 20 | 82 Shore D |
10% glass-fiber reinforced PC-Si | Modest stiffness and dimensional-stability boost while keeping useful impact and V-0. | 78 | 8 | ||
20% glass-fiber reinforced PC-Si | Balanced stiffness/warpage grade for structural housings and battery brackets. | 95 | 5 | ||
30% glass-fiber reinforced PC-Si | Maximum stiffness/creep resistance grade; accept much lower notched impact and anisotropic shrinkage. | 112 | 3.5 |
Supply forms, finishes and certifications
Ways PC-Si is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
MED | Healthcare / biocompatible grade | Certification |
UV | UV-stabilized / weatherable grade | Grade option |
UnfilledDefault | Unfilled / natural PC-Si copolymer | Standard supply |
What is PC-Si?
PC-Si is a polycarbonate–siloxane copolymer in which siloxane blocks raise low-temperature impact strength and give inherent halogen-free flame retardance, including V0 ratings in thin walls. The unfilled condition provides 60 MPa tensile strength and about 120 % elongation, with FR-V0, high-flow, low-temperature, transparent, UV, GF10–GF30, PCR, medical and ESD conditions on file. It is more expensive and less widely stocked than standard FR polycarbonate, remains sensitive to solvents and stress cracking, and the siloxane-rich surface can resist paint and ink without pretreatment; halogen-free FR PC is the usual lower-cost alternative when cold impact is not critical. PC-Si has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 143°C (289 °F). PC-Si has a yield strength of 58 MPa (8.41 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 66% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.2 GPa (0.319 Msi).
What is PC-Si used for?
- electrical connectors
- thin-wall enclosures requiring V0
- consumer electronics housings
- automotive electronics
Advantages
- Polishes to a fine finish — 80/100, better than 89% of polymer grades
Limitations
- High embodied carbon — 7.8 kg CO₂/kg, worse than 81% of polymer grades
PC-Si properties
Typical room-temperature values; bars are the position among polymer grades.
Physical5
PC-Si has a density of 1.19 g/cm³ (0.043 lb/in³), heavier than 53% of polymer grades. Its glass-transition temperature is 143°C (289 °F).
Mechanical16
PC-Si has a yield strength of 58 MPa (8.41 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 66% of polymer grades. Elongation at break is 120% and the elastic modulus is 2.2 GPa (0.319 Msi).
Thermal11
PC-Si is rated for continuous service to 115°C (239 °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).
Electrical7
PC-Si is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (75/100), worse than 66% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of PC-Si takes about 112 MJ of energy and emits 7.8 kg of CO₂ — more than 67% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PC-Si's machinability is good (60/100, better than 51% of polymer grades); weldability very good (70/100); formability good (60/100).
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-Si is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PC-Si
Is PC-Si easy to machine?
Machines like PC — sharp, polished, high-rake tools, high speed and low feed with air cooling; avoid sharp internal corners and anneal 120 °C to relieve stress before solvent contact.
Can PC-Si be welded?
Ultrasonic, vibration, hot-plate and laser welding all work well; solvent bonding with methylene-chloride blends or UV/epoxy adhesives is common but raises stress-cracking risk.
Can PC-Si be formed, bent or molded?
Dry 4 h at 120 °C to <0.02 % moisture; mold at 270–305 °C melt / 70–110 °C tool with generous gates and radii; siloxane blocks give easy release but avoid excessive residence time to limit splay.
PC-Si 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 |
|---|---|---|
| polydimethylsiloxane (PDMS) blocksoft block; higher content = better low-temperature impact and FR, more haze | 4 – 20 | 6 |
| anti-drip / flame-retardant synergist (Phalogen-free FR package in V-0 grades | 0 – 1 | 0.4 |
| heat and hydrolytic stabilizers, mold rephosphite/epoxy stabilizers | 0.1 – 0.8 | 0.4 |
| bisphenol-A polycarbonate blockPC hard segment | ≥ 80 (balance) |
What surface finishes work on PC-Si?
Takes hard coats, PVD, painting and laser marking; use PC-compatible primers/adhesives only, and note that surface siloxane can require plasma or flame pretreatment before painting or printing.
How much does PC-Si cost?
PC-Si is a premium-cost polymer ($$$), cheaper than about 51% 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-Si — frequently asked
What is PC-Si used for?
PC-Si is typically used for electrical connectors, thin-wall enclosures requiring V0, consumer electronics housings and automotive electronics. In short: halogen-free V0 polycarbonate; best cold-impact PC grade; thin-wall flame retardance.
What is the yield strength of PC-Si?
PC-Si has a typical yield strength of 58 MPa (8.41 ksi) and a tensile strength of 60 MPa (8.7 ksi) — stronger than 66% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is PC-Si easy to machine?
Reasonably — machinability is rated good (60/100, better than 51% of polymer grades). Machines like PC — sharp, polished, high-rake tools, high speed and low feed with air cooling; avoid sharp internal corners and anneal 120 °C to relieve stress before solvent contact.
Can PC-Si be welded?
Yes — weldability is rated very good (70/100). Ultrasonic, vibration, hot-plate and laser welding all work well; solvent bonding with methylene-chloride blends or UV/epoxy adhesives is common but raises stress-cracking risk.
What surface finishes work on PC-Si?
Takes hard coats, PVD, painting and laser marking; use PC-compatible primers/adhesives only, and note that surface siloxane can require plasma or flame pretreatment before painting or printing.
Can PC-Si be formed, bent or molded?
Dry 4 h at 120 °C to <0.02 % moisture; mold at 270–305 °C melt / 70–110 °C tool with generous gates and radii; siloxane blocks give easy release but avoid excessive residence time to limit splay.
What is the maximum service temperature of PC-Si?
PC-Si is rated for continuous use to about 115°C (239 °F), and briefly to 145°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PC-Si cost?
PC-Si is a premium-cost polymer ($$$), cheaper than about 51% 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
- LEXAN EXL siloxane copolymer resin datasheets — SABIC (2023)
- TARFLON / siloxane-copolymer PC grade data — Idemitsu Kosan (2022)
- CAMPUS ISO 10350 single-point data for PC copolymers — CWFG / CAMPUS (2024)
- UL 94 Tests for Flammability of Plastic Materials — UL Solutions (2021)
- ISO 527 / ISO 178 / ISO 75 / ISO 306 plastics test methods — ISO (2019)
- 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.