Johns Manville DuraCore® insulation is a lightweight, highly resilient product made from borosilicate glass fibers. The insulation blanket is fiberglass bonded with a thermosetting phenolic resin and is designed to provide excellent core strength. DuraCore is ideal for HVAC equipment due to its high acoustical values in the high and low frequency ranges normally encountered in these applications. DuraCore is manufactured with consistent fiber and binder distribution to produce a stronger insulation with enhanced core strength that makes it stiffer and less susceptible to delamination.DuraCore meets typical industry standards for tensile and core strength, which makes the product more resistant to damage during lamination and installation. Because of its resiliency and flexibility, DuraCore resists settling, breakdown, sagging from vibration, and damage from impact. The blanket conforms easily around corners and curved surfaces and is readily cut in die presses or with a knife.