LED panel lights have hot spots when the light from LED chips is not diffused evenly before reaching the visible surface. This problem often appears as bright dots, bright edges or uneven light patches. For lighting projects, hot spots can affect product appearance, visual comfort and customer acceptance after installation.
One common reason is the wrong distance between LED chips and diffuser sheet. When the panel depth is too shallow or the LED spacing is too wide, the diffuser sheet does not have enough space to blend the light. Another reason is poor diffuser material selection. Clear PMMA can reach about 92% light transmission under ASTM D1003 testing, but LED lighting usually needs a controlled balance between transmission and haze, not maximum clarity alone.
| Cause | Project Impact |
|---|---|
| Low haze diffuser sheet | LED dots become visible |
| Incorrect LED spacing | Uneven brightness across the panel |
| Poor Light Guide Plate design | Bright edges or dark corners |
| Thin fixture structure | Not enough mixing distance |
| Unstable material batch | Different visual effect between orders |
A trader may only provide standard diffuser sheets from stock, but hot spot control often needs material matching based on lamp structure. A manufacturer can adjust haze, light transmission, surface texture, thickness and cutting size according to LED layout.
KUNXIN manufactures Optical Plastic materials for lighting applications, including acrylic diffuser sheet, PC diffuser sheet, anti-glare diffuser sheet, Prismatic Diffuser Sheet and light guide plate. Our team can review LED pitch, panel depth, wattage and target brightness before sample testing.
A practical OEM / ODM process should begin with fixture structure review. Buyers need to confirm LED spacing, panel thickness, diffuser distance, light guide plate type and target lumen output. Sample testing should check brightness uniformity, visible LED dots, glare level and color consistency.
For bulk supply, the project sourcing checklist should include haze range, transmission range, thickness tolerance, sheet flatness, surface defects, packaging protection and batch inspection. These checkpoints help reduce visual complaints in repeated lighting orders.
During production, KUNXIN controls raw material selection, formula mixing, extrusion stability, surface texture, thickness measurement, optical testing and final inspection. ASTM D1003 is commonly used to test haze and luminous transmittance of transparent plastic materials.
For export market compliance, stable material documentation, batch labeling, safe packaging and consistent inspection records support smoother delivery to Europe, North America and other overseas markets.
Hot spots are rarely caused by one single part. They usually come from the mismatch between LED layout, panel depth, diffuser sheet and light guide plate. For stable LED panel light projects, choosing an optical plastic manufacturer with material development, OEM / ODM support and bulk supply control can help improve light uniformity from sample stage to mass production.
