A METHOD AND A PLANT FOR PRODUCING A MINERAL FIBER-INSULATED WEB, AND A MINERAL FIBER-INSULATED PLATE

摘要

A method of producing a mineral fiber-insulating web comprises the steps of firstly producing a first non-wowen mineral fiber web. The first mineral fiber web contains mineral fibers arranged generally in the longitudinal direction of the mineral fiber web. Secondly, the first mineral fiber web is moved in the longitudinal direction of the web and folded parallel with the longitudinal direction and perpendicular to the transversal direction of the first mineral fiber web, so as to produce a second mineral fiber web comprising a central body and opposite surface layers sandwiching the central body, which central body contains mineral fibers arranged generally perpendicular to the longitudinal and transversal directions of the second mineral fiber web and which surface layers contain mineral fibers arranged generally in the transversal direction of the second mineral fiber web. Thirdly, a third non-wowen mineral fiber web being a mineral fiber web of a higher compactness as compared to the second mineral fiber web is produced and adjoin in facial contact with the second mineral fiber web for producing a fourth composite mineral fiber web which is thereupon cured. The method also optionally includes longitudinally compressing and/or transversally compressing the second mineral fiber web. The composite mineral fiber web may additionally be combined with additional mineral fiber webs or coverings for producing a composite mineral fiber web product which is cured in a single curing process.