GB775898A - Improvements in couch mechanisms for paper-making machines - Google Patents

Abstract

775,898. Couching in paper-making machines. MILLSPAUGH, Ltd. Sept. 29, 1955 [Oct. 18, 1954], No. 29871/54. Class 96. In the production of soft tissue paper &c. the web 2 on the wire-cloth 1 is subjected to light suction from suction boxes 4, and to pressure and suction at a couch press, the upper roll 7 of which is a plain roll with a felt jacket 9 to aid in picking up the web 2 which passes to a lower wet press felt 10; and the lower couch press roll has a high-speed air suction zone 12 for extracting expressed water which has passed through the wire-cloth 1. In modifications, a dense pick-up felt passes through the couch press; and the plain roll 7 is substituted by a suction roll, the suction zone of which extends from the exit side of the nip ; or the lower roll 6 may have a blowing compartment, adjacent to the suction compartment, to facilitate web transfer to the felt 10; or there may be a return roll beyond the couch press, and a suction pickup roll and pick-up felt may coact with the wire-cloth at the stretch between the couch press and the return roll. The couch roll 6 may have a plain perforated surface, or its perforations may be in a helical groove &c in the roll surface, to give more effective lifting action on the web by air blown through the perforations, or if heavier webs are being made the blowing compartment may be changed to a (second) suction compartment. The sealing-strip 13 may be adjustable.