Patent DE-102008042869-A1 (DE)
Title: Apparatus to process moving material web e.g. paper-, cardboard- or other fibrous material web, comprises arrangement for coating liquid/pasty coating medium on web side, first and second rollers, web outlet, and circulating endless belt
Inventor: KENDEL FRIEDRICH
IPC: D21H23/32
Filed: 2008-10-15
Abstract: The apparatus (10) for processing a moving material web (12) such as a paper-, cardboard- or other fibrous material web, comprises an arrangement (34, 36, 38) for coating a liquid or pasty coating medium on a side of the material web, first and second rollers (16, 18), which have rotating axles parallel to each other and whose surfaces are adjacent to each other, so that the surfaces define between a press gap (20), where the material web is guided or guidable through the press gap, a web outlet, which is arranged to the coating arrangement and the press gap, and a circulating endless belt. The apparatus (10) for processing a moving material web (12) such as a paper-, cardboard- or other fibrous material web, comprises an arrangement (34, 36, 38) for coating a liquid or pasty coating medium on a side of the material web, first and second rollers (16, 18), which have rotating axles parallel to each other and whose surfaces are adjacent to each other, so that the surfaces define between a press gap (20), where the material web is guided or guidable through the press gap, a web outlet, which is arranged to the coating arrangement and the press gap and is viewed in a running direction of the material web, and a circulating endless belt, which is arranged to support the material web in a supporting section between the press gap or the coating arrangement and the web outlet along a straight path. In the operation of the apparatus, the material web is supported along the supporting section only from below through the endless belt. The supporting section reaches from the press gap up to the web outlet, and horizontally runs to its total length. The endless belt is guided through the press gap. An expander roller that is viewed in the running direction of the material web is upstreamly arranged to the press gap to expand the material web. A contact area of the expander roller, in which the expander roller is contacted with the material web, lies from the press gap in a distance of 500-2500 mm, where a contact angle to the expander roller is 5-90[deg] . The material web flows into the press gap along a tangent running through the press gap to the first and second rollers below an angle (alpha ) that is 0-45[deg] . The feed dry content of the material web is 70-80% during entering into the press gap and/or passing the expander roller. The apparatus further comprises a pre-drying device, which is upstreamly arranged to the press gap in the running direction of the material web and is designed to guide the material web with a dry content of 70-80% over the expander roller, and a moistening device, which is upstreamly arranged to the press gap, is designed to reduce the dry content of the material web before flowing into the press gap and adjusts the dry content of the material web to a value of 70-80%. A moisture measuring device, with which the dry content of the material web is detectable, is upstreamly arranged to the moistening device. The moistening device operates after measuring the detection results of the moisture measuring device and is connected with the moisture measuring device for exchanging control-/regulation information. The expander roller is arranged between the moistening device and the press gap. A drying arrangement such as an air drying device is arranged between the coating arrangement and the web outlet and is viewed in the running direction of the material web, where the endless belt runs through the drying arrangement. The web outlet is designed to draw the material web from the endless belt and to guide to a material web path deviating from a further running path of the endless belt. The apparatus has a further drying arrangement, where the web outlet is designed to deliver the material web to the further drying arrangement. The web outlet has a low pressure transporting device, which is designed to suck the material web and to guide along the predetermined material web path. The coating arrangement applies the coating medium directly to the endless belt. The endless belt is directly diverted to a lower roller of the first and second rollers in a diverting area before entering into the press gap. An independent claim is included for a method for processing a moving material web such as a paper-, cardboard- or other fibrous material web.