PERFORATED FILM AND ITS FORMATION PROCESS Russian patent published in 1999 - IPC

FIELD: production of films. SUBSTANCE: perforated laminated films contain stretchable thermoplastic material having multitude of microholes formed by net of fiber-like elements. Films are formed by directing of liquids, primarily, water to upper surface of source film in the form of column-shaped flows to contact zone. In this case, film is positioned on supporting member. The latter is provided with local bearing zones for film and with zones having hollows which allow film deformation. Liquid is directed by distributing pipeline adjacent to source film and provided with many holes within the range from 1,1811•10³ to 3,937•10³ per running meter with diameter from 0.0762 to 0.254 mm. Perforated films obtained are porous with open flow section. They are soft, strong, pliable in treatment and pleasant by touch. They have fabric-like appearance and are adaptable to form. It is good practice to use films as covering materials for hydroscopic products. EFFECT: improved hydroscopic properties. 24 cl, 28 dwg, 2 tbl