A double-layer fabric for the sheetforming section of a papermaking machine which is referred to as a sheet forming fabric or a dewatering fabric consists of an upper layer (1) of transverse threads (3) and a lower layer (2) of transverse threads (4) and (8) which are interwoven with a single system...http://www.google.de/patents/US5016678?utm_source=gb-gplus-sharePatent US5016678 - Double-layer papermaking fabric having a single system of non-symmetrically extending longitudinal threads
