6mm Clear Twinwall Polycarbonate Sheet is a dual-wall structured polycarbonate panel engineered for applications requiring light transmission, thermal insulation, and long-term weather resistance. The twin-wall geometry - two parallel skins connected by internal ribs - delivers meaningfully better thermal performance than solid sheet of equivalent thickness, with a heat deflection temperature of 290°F and a coefficient of linear thermal expansion of 3.6 × 10⁻⁵/°F. Light transmission ranges from 81–90% depending on thickness (ASTM D1003), and the panel carries a 10-year limited product warranty. Standard applications include greenhouses, skylights, canopies, patio covers, awnings, covered walkways, restaurant outdoor enclosures, facades, roofing, and architectural partitions. The 6mm panel installs in standard aluminum U-channel and glazing extrusion systems. Frame design must account for thermal movement - at 3.6 × 10⁻⁵/°F expansion rate, a 48" panel length requires approximately 1/4" combined expansion/contraction allowance plus edge engagement in the rabbet depth. EPDM or neoprene gaskets are recommended for dry glazing; compatible sealants with high elongation for wet glazing. Like all polycarbonate, twinwall cannot be laser cut - CNC routing and scoring are the correct methods for custom sizing. CPC stocks Weld-On 3, 4, and 16 for bonding applications. Additional twinwall thicknesses beyond 6mm are available as special order. Full sheets are stocked at 48" × 96". Custom cutting is available in-shop at CPC's Canal Street location. CPC stocks polycarbonate twinwall equivalent to Lexan and Makrolon multiwall product lines. Details · Light transmission: 81–90% thickness dependent (ASTM D1003)· Heat deflection temperature: 290°F @ 264 psi (ASTM D648)· Coefficient of linear thermal expansion: 3.6 × 10⁻⁵/°F — frame design must allow for movement· Izod impact strength: 15 ft·lbs/in notched (ASTM D256)· 6mm dual-wall construction — lightweight, rigid, thermally insulating· UV stabilized outer surface — 10-year limited product warranty· Suitable for greenhouses, skylights, canopies, awnings, patio covers, covered walkways, facades, roofing, and outdoor enclosures· Installs in standard aluminum U-channel and glazing extrusion systems· Cannot be laser cut — CNC routing and scoring only· Full sheets: 48" × 96"· Additional thicknesses available as special order· Equivalent to Lexan and Makrolon multiwall sheet· Custom cutting available in-shopLooking for a custom quote? Contact us via our custom order form.