Abstract:
A wet part of a paper making machine includes a distributor to which a main stream of a stock suspension is fed and which has a number of connections. The connections are connected by means of split stream lines to a machine-wide flow box which has a machine-wide slice nozzle (headbox). The split stream lines are connected (directly or indirectly) to the flow box. The slice nozzle is connected to at least one continuous web-forming screen. At least one collection trough is connected to the screen, as well as, optionally, to a backwater tank to accept the backwater trapped by the collection trough. Dilution water lines are provided to introduce backwater into the split stream lines to adjust the stock density of the split streams. The dilution water lines are connected directly to the collection trough.
Abstract:
Process and apparatus for improving a consistency cross-direction profile of a fiber web in the wet section. The process includes distributing a fiber suspension across a machine width from a headbox to one of on a wire and between two wires, adjusting a cross-sectional basis weight by sectionally mixing, across the machine width, a first suspension having a first solid content and a first percentage composition and a second suspension having second solid content that is one of lower and higher than the first solid content, and a second percentage composition of the solids content of the second suspension differs from the first percentage composition, and sectionally admixing at least a third suspension across the machine width, the third suspension having a solids content that is one of lower and higher than the solids content of at least one of the first and second solids content, and having a third percentage composition that differs from at least one of the first and second percentage compositions. The apparatus includes one of a first machine-wide feed and a first set of individual feeds for the first suspension, a second set of individual feeds for the second suspension, control devices coupled to the second set of individual feeds for regulating a flow of the second suspension, a turbulence generator, a headbox nozzle. At least a third set of individual feeds for a third suspension is positioned at least one of upstream from the turbulence generator and to act equally on each section across the machine width. The third suspension has a solids content that differs from the solids contents of the first and second suspensions, and additional control devices coupled to the third set of individual feeds for regulating a flow of the third suspension.
Abstract:
The invention relates, inter alia, to a paper machine for producing paper that can be gravure printed from a fibrous stock suspension, which can be supplied successively to a wire section, a pressing section, a drying section, a film press having a film roll for applying a coating color, a calender arranged downstream of the film press, and can be wound up on a paper roll.
Abstract:
In a method for the production and converting of paper, paper-specific information determined during paper production is transmitted to and considered during the respective converting process to thereby optimize at least one converting process.
Abstract:
Process and a device for detecting a change in the fiber orientation cross-direction profile of a paper or cardboard web in the manufacturing process on a paper or cardboard machine. It is recognized that a change in the fiber orientation cross-direction profile in the web is inferred or determined by way of a characteristic change in the basis weight cross-direction profile or at least one measurement quantity that correlates to it, and/or by way of a characteristic change in the basis weight in the travel direction of the web or at least one measurement quantity that correlates to it. The device includes an arrangement for detecting a change in the basis weight cross-direction profile and/or a characteristic chronological course of the change in the basis weight, which is characteristic for a change in the fiber orientation.
Abstract:
Process for setting a uniform characteristic cross-direction profile for a paper web with regard to at least formation, basis weight, and fiber orientation in a paper machine. The paper machine can include a headbox with an adjustable die exit opening and within which the consistency is sectionally adjustable. The process includes measuring and setting a desired basis weight cross-direction profile by adjusting the sectional consistency in the headbox, adjusting the formation cross-direction profile by adjusting a sectional, specific pulp slurry flow rate at the die exit opening, and one of enlarging the die exit opening at positions along a width of the paper machine in which a pulp slurry flow rate is higher than in other positions along the width of the paper machine and increasing the pulp slurry flow rate for positions along the width at which the die exit opening is larger than at other positions along the width. In this manner, a desired fiber orientation cross-direction profile is attained.
Abstract:
The invention concerns the wire section of a papermaking machine and a method of removing water from a fiber web in that section. A fiber suspension is discharged from a headbox on at least one and usually between two wires in the forming section. The fiber suspension is dewatered until it eventually reaches the point of immobility at which the fiber orientation is fixed. The rate of removal of water transverse to the direction of travel of the web is controlled at regions across the web. In particular, the rate of water removal is decreased at the edge regions of the wire and the web, as compared with the center region, to improve the transverse formation profile of the web. Various techniques for controlling the rate of water removal are disclosed including using different mesh of the wire at the edge regions and at the center region, a suction forming roll applying different levels of suction at different zones across the wire and the web, and adjustable ledges engaging one of the two wires and being adapted or adjusted to apply different pressure levels to the wire across the web.
Abstract:
The invention concerns a method of controlling the relative flow speed of the layers in a multi-layer headbox with laminae mounted torque-free between upper and lower lips which are stationary when in operation. The invention is characterized in that a difference in speed is produced between the individual layers by causing the static pressure to change differently in the different layers.
Abstract:
A throttle device for stock suspensions in a paper machine including a feed line, a drain line and a spatially variable cavity connecting the feed line and drain line with each other. The cavities provided with a plurality of nestable walls in which the nesting effects a lengthening of the flow path.
Abstract:
A paper machine headbox having divided sections for feeding pulp suspensions with different properties therethrough includes a single inlet line and a plurality of feed lines connected thereto. In at least one of the feed lines, there is a separation device which separates certain pulp suspension components from the pulp suspension flowing therethrough. A discharge line connected to the separation device conveys separated pulp suspension components therefrom. A continuing feed line connected to the separation device conveys the remaining pulp suspension to the headbox.