Method and an apparatus for manufacturing a fiber web provided with a three-dimensional surface structure

A method for manufacturing a fiber web having a three-dimensional surface structure and a strength, comprising the steps of:

• introducing a fiber suspension from a headbox onto an imprinting band, said fiber suspension becoming the fiber web;
• pre-imprinting the fiber web at a dry content of less than 10% with said imprinting band using a first pressure field;
• pressing the fiber web onto said imprinting band using a second pressure field, said pressing step further dewatering and drying the fiber web fixing the three-dimensional surface structure and the strength;
• guiding a clothing together with said imprinting band, with the fiber web interposed therebetween about at least one suction roll;
• and
• forming the fiber web on said imprinting band, said introducing step, said pre-imprinting step, said pressing step, said guiding step and said forming step each involving said imprinting band without transfer of the fiber web therefrom.

A method for manufacturing a fiber web having a three-dimensional surface structure and a strength, comprising the steps of:

• introducing a fiber suspension from a headbox onto an imprinting band, said fiber suspension becoming the fiber web;
• pre-imprinting the fiber web at a dry content of less than 25% with said imprinting band using a first pressure field;
• pressing the fiber web onto said imprinting band using a second pressure field, said pressing step further dewatering and drying the fiber web fixing the three-dimensional surface structure and the strength, said method being carried out using a plurality of rolls arranged in parallel bounding a pressure space pressurized by a compressed gas for driving out water from the fiber web, the fiber web and said imprinting band guided together through said pressure space at least once;
• positioning the fiber web and said imprinting band between a fine membrane and a coarse-mesh membrane prior to said pressing step;
• and
• forming the fiber web on said imprinting band, said introducing step, said pre-imprinting step, said pressing step, said positioning step and said forming step each involving said imprinting band without transfer of the fiber web therefrom.

A method for manufacturing a fiber web having a three-dimensional surface structure and a strength, comprising the steps of:

• introducing a fiber suspension from a headbox onto an imprinting band, said fiber suspension becoming the fiber web;
• pre-imprinting the fiber web at a dry content of less than 25% with said imprinting band using a first pressure field;
• pressing the fiber web onto said imprinting band using a second pressure field, said pressing step further dewatering and drying the fiber web fixing the three-dimensional surface structure and the strength, said pressing step including the steps of:
• bounding a pressure space with at least four rolls;
• pressurizing said pressure space with a compressed gas;
• interposing the fiber web between a plurality of membranes;
• and
• guiding the fiber web, said plurality of membranes and an imprinting band through said pressure space at least once;
• positioning the fiber web and said imprinting band between a fine membrane and a coarse-mesh membrane prior to said pressing step;
• and
• forming the fiber web on said imprinting band, said introducing step, said pre-imprinting step, said pressing step, said positioning step and said forming step each involving said imprinting band without transfer of the fiber web therefrom.