Polycarbonate Prismatic Lighting Panel

A prismatic lighting panel is not a diffuser. The moulded prisms refract light as it leaves the panel, redirecting it out of the high-angle directions that cause glare and into the useful downward cone, while hiding the lamp image. That is why a prismatic lens controls glare while keeping much more light than a frosted diffuser would. It is used for troffer and recessed luminaire lenses, lay-in ceiling panels, and retrofit lenses in commercial and institutional lighting.

On patterns: the conical-prism pattern most commonly stocked is a 3/16 inch square-based FEMALE conical prism set on a 45 degree axis, published as giving maximum efficiency together with excellent direct glare control. It is catalogued as pattern 12 and also sold as K12 - the two codes are used interchangeably in the trade for the same lens, so if you have been quoted both, they are the same thing. Other patterns in the family use male cones for high-angle brightness control, larger female cones for large areas, and a shallow truss-shaped prism where sag resistance matters.

Two things we will not claim. No manufacturer publishes a light transmission figure for any prismatic pattern - the published data is luminance and efficiency curves instead - so there is no transmission number on this listing. And most prismatic lighting panel stock in the trade is acrylic rather than polycarbonate; these are listed as polycarbonate on the strength of the supplier description, so if your specification requires a polycarbonate substrate tell us and we will confirm it on the lot before shipping.

Polycarbonate substrate properties: tensile 9,500 psi ultimate, flexural 13,500 psi, Rockwell M70 and R118, heat deflection 270F at 264 psi, specific gravity 1.20, with far higher impact strength and a far wider temperature range than acrylic - which is the usual reason to choose a polycarbonate lens over an acrylic one.

Chemical compatibility and cleaning, which is where most polycarbonate failures start. Clean it with mild diluted dish soap and a soft microfibre cloth, or an ammonia-free glass cleaner. Do NOT use ammoniated glass cleaner - the common blue kind - because ammonia attacks polycarbonate, and the resin maker's own testing shows 0.1% ammonia is enough to do damage in the presence of water. Also avoid abrasive or high-alkaline cleaners, scrapers and squeegees, dry rubbing, and solvent in direct sun. Isopropyl alcohol diluted 50/50 with water handles oil and tar. Acetone, MEK, methylene chloride, chloroform, toluene, xylene and aromatic fuels all attack it, and so do amines and the plasticisers that migrate out of flexible PVC - which is why PVC gasket, tape and cable tie contact is a real failure mode. The important subtlety is that chemical resistance is not a fixed property: stress cracking only develops where the part is in tension, so a cold-bent, over-torqued or tightly framed part will fail with chemicals a compatibility chart calls safe.