Technical Insight
Laser Marking Transparent PC Without Excessive Haze or Damage
For transparent PC, qualify additive haze, base tint and laser-induced scattering before optimizing contrast; a readable mark is not acceptable if the unmarked optical area leaves specification.
Author: Aurexene Materials Engineering Team · Last updated: 2026-08-28
Quick Answer
For transparent PC, qualify additive haze, base tint and laser-induced scattering before optimizing contrast; a readable mark is not acceptable if the unmarked optical area leaves specification.
Evidence scope: This page provides method-conditioned engineering guidance. It does not claim that one commercial grade is a drop-in replacement, universally superior, or qualified for a finished part without matched evidence.
Problem
For transparent PC, qualify additive haze, base tint and laser-induced scattering before optimizing contrast; a readable mark is not acceptable if the unmarked optical area leaves specification.
The decision boundary includes the complete host formulation, colour package, supplied additive form, compounding and moulding history, part geometry, delivered laser state and the measurement method. A result is not transferable when one of those conditions changes without review.
Mechanism
Particle refractive-index mismatch, agglomeration and laser-created microstructure scatter light, while absorber strength controls the energy needed for the mark.
Laser marking is a coupled material-and-process response. Absorption and scattering determine where energy is deposited; pulse state, focus, overlap and path determine the local history; the polymer, pigments, fillers and geometry determine whether that history creates controlled contrast or a defect.
Tradeoff
Lower loading can preserve transparency but require more energy; finer dispersion can reduce visible defects while increasing compounding demand.
The useful condition is a feasible region with margin, not the single darkest coupon. Contrast, edge, surface integrity, unmarked colour, processing, mechanical function, durability and cycle time must be evaluated together.
Material Strategy
Use Black Titania as application-specific screening candidates. The list is not a performance ranking and does not establish equivalence between chemistry families.
- Freeze the host grade, colour, thickness, geometry and acceptance criteria.
- Normalize active-content and supplied-form differences or explain why another comparison basis is used.
- Screen loading and laser variables in a bounded matrix and preserve failed runs.
- Confirm the selected window across relevant lots, parts, tools and exposures.
Recommended Architectures
| Architecture | Use when | First validation gate |
|---|---|---|
| Matched baseline | The current material, colour and laser recipe require a reproducible reference. | Optical transmission and mark quality |
| Bounded screening ladder | Loading, supplied form, colour or delivered laser variables must be separated. | unmarked haze and transmission; particle distribution; base tint; mark contrast; surface and internal damage |
| Production confirmation | A candidate window must transfer across lots, geometry, tools or lifecycle exposures. | Margin, repeatability, failures and requalification triggers |
Controls That Must Stay Visible
| Order | Control | Review rule |
|---|---|---|
| 1 | unmarked haze and transmission | Hold the other declared formulation, process, geometry and measurement conditions constant before attributing an effect. |
| 2 | particle distribution | Hold the other declared formulation, process, geometry and measurement conditions constant before attributing an effect. |
| 3 | base tint | Hold the other declared formulation, process, geometry and measurement conditions constant before attributing an effect. |
| 4 | mark contrast | Hold the other declared formulation, process, geometry and measurement conditions constant before attributing an effect. |
| 5 | surface and internal damage | Hold the other declared formulation, process, geometry and measurement conditions constant before attributing an effect. |
Measurement & Validation
Primary response: Optical transmission and mark quality.
Method: Measure haze or transmission and colour before marking, then map contrast, feature, relief and damage using the final thickness and viewing geometry.
Report the unit or grade together with instrument or verifier geometry, specimen state, conditioning, repeats, distribution or uncertainty, failures and the acceptance limit. A scanner pass, photograph or supplier representative value is not a substitute for the declared method.
Qualification Boundary
- Record exact material and lot identities, active-content basis, carrier and colour package.
- Record compounding, drying, moulding, thickness, surface and geometry.
- Record source wavelength, pulse state, spot or focus, speed, hatch, passes, field and calibration.
- Measure marked and unmarked controls using the declared method.
- Confirm production and lifecycle variation, then define requalification triggers.
Primary Sources and Standards Boundary
- ISO/CIE 11664-4:2019 — CIE 1976 L*a*b* colour space — Defines CIELAB calculation; instrument geometry, illuminant, observer, aperture and specimen state must accompany results.
Related Products
Related Applications
Related Comparisons
No reviewed comparison page is required for this decision. Keep candidate comparisons inside a matched test matrix.
Downloads & Engineering Support
Need to apply this boundary to a grade, formulation, test method, or production route? Discuss it with the Aurexene Materials Engineering Team.