LAMINATED MATERIAL AND PROCESS FOR MANUFACTURE SAME Russian patent published in 1994 - IPC

FIELD: chemistry; polymer industry. SUBSTANCE: laminated material includes alternating interconnected polyolefin lamellas, in particular, polyolefin net and polyolefin film having perforations, each having diameter of 5 to 10 mm and numerical density of 25-100dm², and lamellas of fibrous nonwoven needle-pierceable fabric made of polypropylene fibres each 15 to 35 microns in diameter, 0,095-1,05g/cm³ in apparent density and 1.5 to 2.5 mm thick. Nonwoven fabric is sandwiched in between polyolefin net and film. All three layers are interconnected by separate threads, with numerical density of bunches ranging from 10-60dm^-2. Laminated material is prepared by stacking alternating polyolefin layers and attaching layers in stack. This material is characterized in that polyolefin net and polyolefin film having perforations, each having diameter of 5 to 10 mm and numerical density from 25-100dm^-2 are employed as polyolefin layers of laminated material and needle-pierceable material made of polypropylene fibres, each having diameter of 15 to 35 microns, apparent density of 0,095-1,05g/cm³ and thickness of 1.5 to 2.5 mm, is used as fibrous nonwoven fabric. When stacking layers, nonwoven fabric must be placed in between polyolefin net and perforated polyolefin film and layers in stack must be attached to one another by squeezing stacked layers positioned in between perforated plates at pressure of 0.01 to 0.5 MPa and finally broaching stacked layers with separate threads, with density of bunches ranging from 10-60dm^-2. EFFECT: excellent material for filtering sheets. 2 cl, 1 tbl