The fastest way to choose: pick absorptive metal panels for the bulk of a traffic wall, and use transparent modules only where daylight, sightlines or landscape views are a contract requirement — both on one shared post system.
Absorptive metal panels win on acoustic performance, durability and cost for most highway and railway walls — they meet NRC ≥ 0.60 and Rw ≥ 26 dB under JT/T 646-2025. Transparent panels (PC/PMMA) win on daylight, views and urban aesthetics but cost more and need more upkeep. The right answer is usually hybrid: transparent only where it is justified, absorptive everywhere else, on the same H-section post system.
The face type should follow the acoustic requirement first.
For most highway sound barrier and railway projects, an absorptive metal panel is the default. A perforated galvanized-steel or aluminium face over a mineral-wool core both blocks sound (transmission) and swallows reflected sound (absorption), which is exactly what traffic noise demands. Standard constructions reach NRC 0.80–0.95 and STC 25–35 dB, comfortably above the JT/T 646-2025 thresholds of NRC ≥ 0.60 and Rw ≥ 26 dB.
Transparent panels — polycarbonate (PC) or PMMA acrylic — earn their place where the wall would otherwise block a valued view, daylight into a building, or a sensitive streetscape. They share the same post system as metal panels, so a hybrid wall is straightforward. Choose the face by location, not by fashion: absorptive where noise rules, transparent where the view rules.
Five dimensions that decide the spec.
| Dimension | Absorptive metal panel | Transparent panel (PC / PMMA) |
|---|---|---|
| Acoustic performance | Strong: NRC 0.80–0.95, STC 25–35 dB; meets Rw ≥ 26 dB, NRC ≥ 0.60 | Useful transmission, but lighter and lower source-side absorption |
| Daylight & views | Opaque — blocks sightlines | Preserves daylight and views where required |
| Landscape / aesthetics | Solid colour (RAL), lower visual impact concern | Preferred for urban frontages and prestige roads |
| Maintenance | Robust; periodic wash of perforated face | Frequent cleaning; sheet can scratch / yellow over time |
| Cost scenario | Cost-effective for long runs | Higher material and cleaning cost |
Both panel families mount on the same H-section steel post system at 2.0–4.0 m spacing, so a hybrid wall mixes them without changing the foundation design.
Match the face to the site condition.
Highway and railway corridors: absorptive metal throughout. The perforated face keeps reflected noise off the road and meets the acoustic threshold at the lowest lifetime cost. This is the workhorse choice for a noise barrier along transport corridors.
Urban roads, bridges and residential frontages: hybrid. Run absorptive metal along the noisiest stretches and drop in transparent modules where residents or planners require views or daylight. The shared post system keeps it one continuous wall.
Industrial boundaries: if reflected noise is acceptable, a full-metal reflective panel is the lowest-cost option; if the plant sits near homes, switch to absorptive. Transparent rarely justifies its cost here unless a sightline is contractually mandated.
See the full panel-type range and construction details on the noise barrier specifications page.
You rarely have to choose only one across the whole project.
Because transparent and absorptive modules share the same H-section post system, designers routinely stack them into one wall: transparent where the view matters, absorptive where the noise load is highest. Polycarbonate is impact-rated and UV-stabilised for outdoor service, and the modules lock into the same rails as the metal panels. That removes the either/or pressure — you optimise each segment for its own condition while keeping a single foundation and post type, which simplifies procurement and installation.
The cheaper panel per metre is not always the cheaper wall.
Absorptive metal panels are the cost-effective workhorse for long runs: lower material cost and modest upkeep. Transparent panels cost more per square metre and, because they soil and scratch more readily, need more frequent cleaning to stay effective and presentable. Over a 20-year service life, the cleaning and possible sheet replacement on a fully transparent wall can outweigh the upfront saving elsewhere.
The efficient pattern is therefore to minimise transparent area to what the project genuinely requires, and to let absorptive metal carry the acoustic load. That keeps both the capital cost and the maintenance budget under control while still hitting the acoustic target.
Bring your required height, length and panel split to the noise barrier product page for a quotation that prices each module type separately.
Polycarbonate and PMMA transparent panels can deliver useful transmission performance, but they are generally lighter than a full absorptive metal panel and do not provide the same source-side absorption. For traffic noise the absorptive face matters because it stops sound reflecting back across the road. The practical answer is to combine them: use transparent modules where sightlines are essential and absorptive metal modules elsewhere, sharing one H-section post system so the wall performs continuously.
Absorptive metal panels are robust and easy to wash down; their main upkeep is periodic cleaning of the perforated face to keep absorption effective. Transparent panels need more frequent cleaning to stay clear, and the sheet itself can scratch or yellow over time despite UV stabilisation. In high-traffic or polluted urban corridors, budget for more frequent washing of transparent sections than of metal panels.
Yes. Both panel families are designed around the same H-section steel post system with 2.0-4.0 m spacing, so a project can mix transparent and absorptive modules in one continuous wall. That is what makes hybrid designs practical — you get daylight and views where needed and full acoustic performance where the noise load is highest, without a different foundation or post type.
Under JT/T 646-2025, non-transparent panels must reach Rw of at least 26 dB and absorptive panels must reach NRC of at least 0.60. Transparent panels are assessed on their own acoustic and safety criteria within the standard. Zhaobang Metal specifies its standard panels to meet or exceed these thresholds, so whichever face type you choose, confirm the relevant figure is written into the contract with the test report reference.