Metso Paper Inc.

Mari Taipale

Juha S Kinnunen

Pasi Ahonen

Jyrki Huovila

Ari Puurtinen

Hannu Korhonen

Pekka Pakarinen

Pentti Rautiainen

Pirkko-Leena Aarnikoivu

Johan Gr&ouml;n

A method for manufacturing a paper or board web in which stock is fed from a headbox ( ) to a wire section ( ), in which water is removed from the web (W) and from which the web (W) is passed to a press section ( ), in which water is pressed out of the web (W) and after which the web (W) is dried in a dryer section ( ) and reeled by means of a reel-up ( ). According to the invention, additives, fillers and/or fines are fed into the stock of the surface layers of the web (W) in order to reduce the pore size distribution of the web in the surface layers so as to substantially correspond to a precoated web. The invention also relates to a paper or board machine which is characterized in that it is structured for enabling the feeding of additives, fillers and/or fines into a fiber stock such that an uncoated web substantially corresponds in its properties to a precoated web.

Method for manufacturing a paper or board web and a paper or board machine

The invention concerns a method for optimizing the degree of flocculation in a headbox. The degree of flocculation is measured continuously from a stock flow (M )/stock flows by means of a detector (R ) of flocculation, and the detector (R ) transmits a signal to a regulator (H ), which regulates the metering of retention agent ( ) and/or fillers ( ) and/or auxiliary chemicals ( ) into the stock flow (M )/stock flows continuously on the basis of the signal to an optimal level, which stock flow/flows is/are passed into the headbox (P ).

Method for optimizing the degree of flocculation

The invention concerns a method for manufacture of paper, most appropriately for porous paper for color powder printing. In the method paper is manufactured by means of a paper machine. In the method the paper stock is fed out of the headbox ( ) into the wire part ( ), in which wire part ( ) water is drained out of the paper web in both directions. In the method the paper web (W) is passed from the wire part ( ) into the press section ( ) in order to press water out of the paper web (W), and after the press section ( ), the paper web (W) is dried in the dryer section ( ) and coated/pigmented in the coating section ( ), dried in an after-dryer section ( ) and calendered in a calender ( ), and reeled in a reel-up ( ). The paper web (W) is made of layers in the Z-direction so that the desired distributions of additives and fillers are obtained in the different layers in the Z-direction of the paper web (W), and the paper web (W) is calendered in at least one calendering nip, which maintains or at least substantially retains the porosity of the web preceding the calendering. The invention also concerns a paper machine, most appropriately for manufacture of glossy and porous paper for color powder based printing. The paper machine comprises a headbox ( ), a wire part ( ), a press section ( ), a dryer section ( ), a coating section ( ), an after-dryer section ( ), a calender ( ), and a reel-up ( ). The headbox ( ) and the wire part ( ) have been formed so that the desired layers with different compositions in the Z-direction are provided in the paper, and the calender ( ) is a calender device that maintains or at least substantially retains the porosity of the paper web (W) preceding the calendering.

Method for manufacture of paper and a paper machine

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Jyväskylä, Finland

Mari Taipale