Drying screen, drying section of a paper machine equipped with the same, and use of the paper machine in the drying section

摘要

Drying screen, suitable for use in the drying section of a paper machine, having the following characteristics: (1) the dryer fabric has a fabric composed of fabric yarns (2 to 5; 7 to 10 ; 12 to 15; 22 to 25; 27 to 30; 32 to 39); (2) the paper machine has a paper side for supporting a paper web; (3) The paper machine has a machine side opposite the paper side; (4) the paper side and machine side have in each case contact points formed by the fabric yarns (2 to 5; 7 to 10; 12 to 15; 22 to 25; 27 to 30 ; 32 to 39); (5) contact points each have a contact surface (16, 17; 40, 41); (6) the contact surfaces (16, 17; 40, 41) of the contact points on the paper side and the machine side respectively are added to form a full surface contact with a percentage of surface portion contact over the entire surface of the paper side or machine side; (7) drying the sieve has a thickness of fabric; (8) a rate of fineness of tissue for the machine side (FFI-MS) and a fineness index of tissue paper side (FFI-PS) can be calculated from the portion of contact surface, the number of contact points and the thickness of tissue according to the following formula: formula ** ** wherein the following feature: (9) the ratio of FFI-MS regarding FFI-PS is at least 1.25 : 1, preferably at least 1.5: 1.