摘要 |
A multi-layer sheet useful as a separator (10) in a lead acid battery is disclosed. The sheet comprises at least a first layer (12) and a second layer (14), and has been produced by the method consisting of the steps of: forming the first layer (12) by depositing a first, substantially binder free furnish consisting essentially of glass fibers onto the wire (36) of a paper making machine (30) and forming the second layer (14) by depositing a second, substantially binder free furnish consisting essentially of glass fibers and silica powder or another suitable silicate powder onto the first layer (12) on the wire (36) of the paper making machine (30). The silica or silicate powder has a particle size and is present in the second layer (14) in an amount such that, if the second, substantially binder free furnish was deposited directly on the wire (36) of the paper making machine (30), a significant portion of the silica or silicate powder would pass through the wire (36). |