PC-Optical HMW
Grade
HMW = high-molecular-weight / ophthalmic lens grade
Use for eyewear and safety lenses / thick glazing where impact resistance and drill-tap durability matter more than flow length.
Values for the HMW condition
Other PC-Optical grades and fills
PC-Optical is listed in 3 conditions; see the grade overview at PC-Optical.
Compare all 3 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Light-diffusing optical grade | Use when LED sources must be hidden and light homogenized; diffusing particles trade total transmittance for near-zero hot-spot visibility. | 62 | 64 | 80 | 82 Shore D |
HMWThis page High-molecular-weight / ophthalmic lens grade | Use for eyewear and safety lenses / thick glazing where impact resistance and drill-tap durability matter more than flow length. | 63 | 68 | 130 | 83 Shore D |
High-flow optical grade (MVR ≈ 60–80), thin lenses / disc substrate | Pick for very thin or long-flow optics (optical discs, micro lens arrays) where minimum orientation birefringence outranks impact strength. | 64 | 65 | 60 | 83 Shore D |
What is PC-Optical HMW?
PC-Optical HMW is PC-Optical in the HMW grade — use for eyewear and safety lenses / thick glazing where impact resistance and drill-tap durability matter more than flow length. PC-Optical HMW has a yield strength of 63 MPa (9.14 ksi) and a tensile strength of 68 MPa (9.86 ksi) — stronger than 74% of polymer grades. Elongation at break is 130% and the elastic modulus is 2.4 GPa (0.341 Msi). PC-Optical HMW has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 57% of polymer grades. Its glass-transition temperature is 147°C (297 °F).
Advantages
- Polishes to a fine finish — 90/100, better than 96% of polymer grades
Limitations
- Needs corrosion protection — 55/100, worse than 94% of polymer grades
PC-Optical HMW properties
Typical room-temperature values for PC-Optical HMW; 28 are specific to this condition. Other listed values are PC-Optical reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PC-Optical HMW has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 57% of polymer grades. Its glass-transition temperature is 147°C (297 °F).
Mechanical17
PC-Optical HMW has a yield strength of 63 MPa (9.14 ksi) and a tensile strength of 68 MPa (9.86 ksi) — stronger than 74% of polymer grades. Elongation at break is 130% and the elastic modulus is 2.4 GPa (0.341 Msi).
Thermal11
PC-Optical HMW is rated for continuous service to 125°C (257 °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 67 µm/m·K (37.2 µin/in·°F).
Electrical7
PC-Optical HMW is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 94% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PC-Optical HMW takes about 108 MJ of energy and emits 6.5 kg of CO₂ — more than 61% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PC-Optical HMW's machinability is good (62/100, better than 60% of polymer grades); weldability very good (70/100); formability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PC-Optical HMW
Is PC-Optical easy to machine?
Machines and drills readily with sharp, high-rake carbide tools and air blast; avoid coolants containing amines or aromatics and anneal (120 °C) before and after cutting to prevent stress crazing.
Can PC-Optical be welded?
Joined by ultrasonic, hot-plate, laser transmission or solvent (methylene chloride) bonding; solvent bonding must be done on annealed parts to avoid crazing in the optical zone.
Can PC-Optical be formed, bent or molded?
Dry 4 h at 120 °C to <0.02 % moisture; inject at 280–320 °C melt with mold at 100–130 °C, slow fill and high hold pressure to minimize orientation birefringence — variotherm/rapid heat-cool tooling is standard for precision lenses.
What surface finishes work on PC-Optical?
Diamond-turned or high-polish steel tooling reproduces optical surfaces directly; parts are usually hard-coated (siloxane) or AR-coated for scratch and UV protection, and can be vacuum metallized for reflectors.
PC-Optical 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 |
|---|---|---|
| mold release / processing aidpentaerythritol tetrastearate or similar, kept low to avoid plate-out on lens tooling | 0.02 – 0.3 | 0.1 |
| heat/process stabilizer (phosphite)controls yellowness index during high-temperature molding | 0.01 – 0.1 | 0.05 |
| UV absorberonly in UV-stabilized variant | 0 – 0.5 | 0 |
| bisphenol-A polycarbonate (BPA-PC)linear aromatic polycarbonate from BPA + phosgene or melt transesterification with DPC; high-purity, low-ionic optical resin | ≥ 99.5 (balance) | — |
PC-Optical HMW — frequently asked
What is PC-Optical HMW used for?
PC-Optical HMW is typically used for eyewear lenses, optical discs, LED lenses, camera lens elements and light guides. In short: lowest-birefringence PC grade; impact-resistant optical resin; needs hard coat.
What is the yield strength of PC-Optical HMW?
PC-Optical HMW has a typical yield strength of 63 MPa (9.14 ksi) and a tensile strength of 68 MPa (9.86 ksi) — stronger than 74% of polymer grades. Strength varies by condition: see the 3 listed tempers.
Is PC-Optical HMW easy to machine?
Reasonably — machinability is rated good (62/100, better than 60% of polymer grades). Machines and drills readily with sharp, high-rake carbide tools and air blast; avoid coolants containing amines or aromatics and anneal (120 °C) before and after cutting to prevent stress crazing.
Can PC-Optical HMW be welded?
Yes — weldability is rated very good (70/100). Joined by ultrasonic, hot-plate, laser transmission or solvent (methylene chloride) bonding; solvent bonding must be done on annealed parts to avoid crazing in the optical zone.
What surface finishes work on PC-Optical HMW?
Diamond-turned or high-polish steel tooling reproduces optical surfaces directly; parts are usually hard-coated (siloxane) or AR-coated for scratch and UV protection, and can be vacuum metallized for reflectors.
Can PC-Optical HMW be formed, bent or molded?
Dry 4 h at 120 °C to <0.02 % moisture; inject at 280–320 °C melt with mold at 100–130 °C, slow fill and high hold pressure to minimize orientation birefringence — variotherm/rapid heat-cool tooling is standard for precision lenses.
What is the maximum service temperature of PC-Optical HMW?
PC-Optical HMW is rated for continuous use to about 125°C (257 °F), and briefly to 140°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D3935 — Standard Classification System for Polycarbonate (PC) Molding and Extrusion Materials — ASTM International (2017)
- ISO 7391-1/-2 — Plastics: Polycarbonate (PC) moulding and extrusion materials — ISO (2006)
- Makrolon optical and LED grades (LQ/OD/LED series) product information — Covestro (2023)
- Panlite optical polycarbonate grade data — Teijin Limited (2022)
- Iupilon optical / disc grade polycarbonate data sheets — Mitsubishi Engineering-Plastics (2022)
- CAMPUS plastics database — polycarbonate unfilled grades — CWFG/CAMPUS consortium (2023)
- Engineered Materials Handbook Vol.2: Engineering Plastics — ASM International (1988)
- GB/T 26538 — (PC) (2011)
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.