Nergeco - A specifically designed door for any activity, size, use or environment of any project. A technologically innovative new curtain provides flexibility as it's pushed down from top to fit firmly into the side guides by its interior stiffeners, resulting in a more air tight curtain with uniform wind resistance. It can be rolled up in confined interior spaces or folded up to accommodate and better insulate large exterior openings even when exposed to high winds and extreme temperature differences. It protects the thermal mattress by opening vertically within the opening without creating air turbulence: and facilitates the smooth passage by clearing the full width of the opening from the bottom up upon arrival of each load. In all instances the bottom edge remains light, flexible and soft increasing safety for personnel, loads and for the curtain itself.