Filter media including out-of-plane solid elements are generally described. Inventive methods of forming them and uses thereof are also described.

Filter media including out-of-plane solid elements are generally described. Inventive methods of forming them and uses thereof are also described.

A filter for filtering a liquid metal and to be received in a mold housing defined by internal side and face walls. The filter has a top wall and side walls extending downwardly from the top wall, the side walls being joined together at respective corners. The side walls extend downwardly towards distal end portions. The corners of the filter have a stiffness or rigidity that is higher that the remainder of the filter for increasing the strength of the overall filter and for helping the filter to maintain its shape and integrity throughout casting. The shape of the side walls allows an easy and consistent placement of the filter in the mold housing and ensures that the filter is maintained in place.

Filter media, filter arrangements and filters, such as air filters and pulse filters, are provided. A filter medium comprises a base web of cellulose fibers. The base web comprises a first and a second layer of cellulose fibers and a transition region between the first and the second layers. The cellulose fibers of the first layer and the cellulose fibers of the second layer are intertwined in the transition region. The the base web has a specific volume of from 4 m.sup.3/g to 9 m.sup.3/g. The first layer may comprise more cellulose fibers, expressed as mass of cellulose fibers per unit area, than the second layer.