A two-ply screen for the sheet forming zone of a papermaking machine comprises weft filaments arranged in pairs one over the other and warp filaments with all the warp filaments being woven into the top layer of the screen. Only part of the warp filaments are woven also into the bottom layer of the screen....http://www.google.com.au/patents/US4499927?utm_source=gb-gplus-sharePatent US4499927 - Two-ply screen for the sheet forming zone of a papermaking machine
