Polycarbonate Sheet, Abrasion Resistant One Side (AR1)

Abrasion-resistant polycarbonate sheet coated on one face, for panels where only one side is exposed to handling, cleaning or weather - machine guards, instrument covers, inward-facing glazing. The hard coat fixes polycarbonate's one real weakness, which is a soft surface that marks easily, and coating one side rather than two keeps the cost down where the second face is protected by the assembly.

The one thing to get right is orientation. The coated face has to go outward, toward whatever is doing the scratching, and the uncoated face keeps bare polycarbonate's surface softness and chemical sensitivity. The maker publishes no separate property table for one-side against two-side product, so the figures below are the same for both - the difference is which faces are protected. Published properties: light transmission 86% clear at 0.118 inch, tensile 9,500 psi ultimate on a 340,000 psi modulus, flexural 13,500 psi on 345,000, compressive 12,500 psi, Rockwell M70 and R118, heat deflection 270F at 264 psi, water absorption 0.15%, specific gravity 1.20. Taber abrasion by ASTM D1044 over 100 cycles with CS-10F wheels under a 500 gram load gives a 2% change in haze. The coating also brings real chemical resistance: over 24 hours by ASTM D1308 against acetone, methylene chloride, toluene, xylene, gasoline, diesel, alcohols, 10% ammonia, 10% sodium and potassium hydroxide, 20% hydrochloric, nitric and sulfuric acid, bleach and turpentine.

Three honest caveats. The hard coat costs you flammability rating and a little impact: coated sheet is UL 94 HB at both 0.060 and 0.236 inch, where plain sheet reaches V-0 around 0.394 inch, and notched Izod is 16 ft-lb/in against 18 for uncoated. The chemical-resistance list is a 24-hour spot test on the coated face, not a service-life compatibility claim - and it does not apply to the cut edges or to any uncoated face, which keep bare polycarbonate's sensitivity, so keep solvents away from them. Worth holding those two facts together: the coating resists 10% ammonia for 24 hours while the bare resin does not resist 0.1% - which is exactly why the edges matter. And do not use buffing or polishing compound on coated product; the maker's fabrication guide says buffing is not recommended and the coating cannot be repaired.

One thing to check before you order, and this is distributor practice rather than anything a manufacturer prints. Polycarbonate sheet sold as "1/4 inch" is commonly 0.220 inch, which is the 5.6 mm North American extruded gauge, or 0.236 inch, which is the metric 6 mm gauge - not 0.250 inch. Those are 7% apart in thickness and in weight, and the difference matters wherever the sheet has to fit a frame, a channel or a glazing pocket. The thickness on each listing here is the actual decimal, not the nominal label.

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.