METHOD FOR SIZING A MULTI-PLY FIBER WEB AND A FORMING SECTION FOR A MULTI-PLY FIBER WEB

摘要

The invention relates to a method for forming a multi-ply fiber web, in which at least part of the forming is done in a twin-wire forming part formed between a wire (10) for the bottom layer of the multi-ply fiber web and a wire (20) for the top layer of the multi-ply fiber web, in which the layers for the multi-ply fiber web are joined and treated layers combined in the twin-wire part. At least part of sizing of the multi-ply fiber web is provided by applying sizing agent in form of foam by a curtain type application device (C10; C20) in between at least two layers of the multi-ply fiber web in forming section of a multi-ply fiber web production line. The invention also relates to a forming section for a multi-ply fiber web comprising at least one twin-wire forming part formed between a wire (10) for the bottom layer of the multi-ply fiber web and a wire (20) for the top layer of the multi-ply fiber web, in which twin-wire part in the layers for the multi-ply fiber web are joined and treated layers combined. The forming section comprises at least a curtain type application device (C10; C20) for applying sizing agent in form of foam by in between at least two layers of the multi-ply fiber web in forming section of a multi-ply fiber web production line.