高速新聞抄紙機のウエットパート

Abstract

MHI High Speed Newsprint Machines have been developed to produce paper of the highest quality using 'state of the art' technology verified by the data from our field operations. Focussing on the 'Wet End' of the machine, the main features and resulting performance are hereby outlined.The “Concept IV-MH” Headbox has been developed and designed to deliver a uniform and stable jet at high speed. It has achieved an excellent dry basis weight profile (2 sigma= 0.13 g/m2) and uniform fiber orientation profile (less than +-2 degrees) by combining the latest technology such as “Dual Temperature Controlled Water Re-circulation”, “Edge Flow Control” and “Consistency Profile Control (CP)” system.The “MH Former +CB” can produce paper of superior quality in comparison with the “Roll Blade” type former due to the following unique features it offers.(1) Small diameter of the Forming & Breast roll makes for easy jet impingement adjustment.(2) The large radius Forming Board and alternative drainage equipment's arrangement in both wires perfects symmetrical sheet structure.(3) Location adjustable “Serrated Shoe” together with “Counter Blades” enables optimum dewatering conditions over a wide range of operational speeds.Results to date have realized and confirmed our goal of the “MH Former +CB” which produces paper of even sided sheet with excellent formation. In addition to the Head Box and Former developments, our latest Newsprint Machines are further equipped with new technology such as.-Enclosed type Shoe Press (ENP-C) -Anti-blowing boxes in the Dryer section-Center Wind Assisted Reel (TNT-C) All the above features are operating with great success in our latest High Speed Newsprint Machines, both in “Oji Paper Tomakomai mill N-6 M/C” and Iwaki-Daio Paper # 2 machine.