Steel purlin is usually made of cold-formed steel that is thin enough to put screws through. Cold-formed steel is made by rolling or pressing thin sheets of steel into the desired shape. Usually in "C" shape or "Z" shape. Purlins are most commonly used in Metal Building Systems, where Z-shapes are utilized in a manner that allows flexural continuit1
PU sandwich panel performance full as the unique properties of PU material, with high effect for water-resistance, thermal insulation, acoustic insulation and other aspects.