Abstract: A paper machine for the manufacture of LWC printing paper which is coated once has a headbox (100), a gap former (200), a press section (300) having at least one extended nip press, a pre-dryer section (400) in which a web (W) is dried applying at least cylinder drying (R1-R7), a precalender (500) in which the web (W) is pre-calendered, at least one portion which is formed of a coating station (600) and an after-dryer section (700) and in which the web (W) is coated on both sides applying a film coating method or a non-contact coating method and dried applying at least contact-free drying (710), an end calender (800) in which the web (W) is calendered, and a reel-up (900) in which the web (W) is reeled. The pre-calender (500) is a calender which is provided with at least one nip (NE1, NE2) and in which both surfaces of the web are in contact with a calendering backup surface having a surface temperature of at least 200° C., advantageously at least 250° C.

Abstract: An arrangement in a pulp grinder comprising a grindstone (1), a feed chute (2), and a piston to feed wood (3) against the grindstone (1). The arrangement comprises separate pushing members (6), which are arranged to push the wood (3) against the grindstone (1) at essentially the entire width of the feed chute when the percussion piston is moved back to the stroke position to allow the feed of a new batch of wood.

Abstract: An arrangement for providing continuous grinding in a pulp grinder comprising a feed chute and a piston in the feed chute moving lengthwise of the feed chute for pressing the wood in the feed chute against a grindstone. The arrangement comprises rotary feed members between the piston and the grindstone on the sides of the feed chute for pushing the compressed wood further against the grindstone. Also, the arrangement comprises a closing member that can be pushed between the compressed wood and the piston to prevent the wood from moving backward with the piston as the piston is moved to the initial position, ready for the stroke, to allow the feed of a new batch of wood.

Abstract: An arrangement in a pulp grinder comprising a grindstone, a feed chute extending to the grindstone, a piston moving in the feed chute, an auxiliary piston and closing members. In the arrangement, there are recesses on the front of the piston and apertures in the auxiliary piston so that the closing members can be pushed from both sides of the feed chute through the auxiliary piston to the recesses of the piston so that they settle behind the wood pressed by the piston.

Abstract: The invention relates to an apparatus and method for measuring the properties of fiber pulp. The apparatus used in the method comprises a batching vessel (1) for measuring the volume and temperature of the sample; a filtering chamber (3, 5) by means of which the sample is filtered on a wire (4) by means of a pressure difference, and an air flow is produced through the pulp cake formed during the filtration. The apparatus has, next to the filtering chamber (3, 5), a raisable vertical central shaft (8), which can be rotated in steps, and holders for transferring the wire (4) together with the pulp cake to positions around the central shaft (8) for the functions, and for returning the wire (4) into the filtering chamber.

Abstract: A method of determining the properties of fiber pulp by separating a batch of a predetermined volume, by measuring its temperature, and by filtering water from it by means of a pressure difference. In accordance with the present invention, substantially all the water is filtered off from the pulp mixture, an air flow is produced through the filtered pulp cake by means of a pressure difference, the resisting effect of the pulp cake on the flow of air is measured, and the pulp cake is weighed, whereafter the properties of the pulp are calculated on the basis of the measurements, from mathematical models developed for this purpose.

Abstract: A method of controlling a grinding process in a pocket grinder in which a batch of wood in at least one pocket is pressed against a rotating grindstone by a pressure shoe displaceable in the pocket. At predetermined intervals an apparently produced amount of pulp is calculated at separate measuring points of the grinding stroke of the pressure shoe and the specific energy consumption calculated on the basis of this amount of pulp is compared to a target figure for the specific energy consumption. The batch grinding is adjusted depending on a deviation of the specific energy consumption from the target figure.