Operation of in-line, multiple-coating equipment used in paper or card manufacture, replaces coating medium with water during start up or reinstatement

摘要

The equipment (2) produces fibrous webs (30) for paper or card manufacture. During start up, or alternatively following tearing of the web, coating from one or more coating units (8, 9, 10) is interrupted. During this interval, the web is started or reinstated using a preparation unit. This commences with an edge strip (21) which is widened-out to reach the total web width. During interruption of coating material application, a fluid, especially water, is applied to at least one side of the web. Considered in the direction of web advance, coating in the first unit (8) after the drying section (6) is interrupted. As required, water is coated in the coating units (8, 9, 10). Coating may be interrupted at all these units, initiating water coating at all of them if required. A fluid or water is supplied at the same coating units (16, 17, 18) used for the coating medium, or alternatively the fluid or water is coated using a separate coating unit. The running web is monitored. When a signal is given indicating a tear, the supply of coating medium to the coating device in the respective unit is interrupted. Simultaneously or with delay, a fluid or water is coated. This may be coated ahead of the coating assembly (16, 17, 18) for the coating medium. The quantity of water coated, corresponds with that contained in the coating medium. The water used is process water, especially from the wet section (31) or the drying section (6). Coated reject material from the preparation unit is supplied to a mixing vat (29) in another part of the equipment (2), for recycling. Fluid or water is applied by spraying or by a curtain coater. It is applied to one or both sides of the web. Ahead of the first coating unit (16), the web is pre-smoothed. At each coating unit (8, 9, 10) the web leaving is dried. An independent claim IS INCLUDED FOR corresponding equipment.