A sheet manufacturing apparatus includes: a defibration unit that defibrates a raw material containing fibers in a gas atmosphere; and a sheet former that forms a sheet by using at least a part of defibrated substances obtained through a defibrating process performed by the defibration unit. The defibration unit and the sheet former are thermally blocked from each other.

A method of making paper is described. The method includes providing a calcium bicarbonate solution an providing a cellulosic fibrous material, the cellulosic fibrous material comprising a plurality of elongated fibers having a fiber wall surrounding a hollow interior, the fibrous material having a moisture content. The method also includes adding the calcium bicarbonate solution to the cellulosic fibrous material to form a pulp mixture, the calcium bicarbonate solution containing from 0.5% to about 16% solids of calcium bicarbonate by weight. Further, the method includes dewatering the pulp slurry using a wet press device such that the solids of the calcium bicarbonate by weight is pulsed above and below 16% solids by weight, finally ending above 16% calcium bicarbonate by weight and refining the pulp mixture such that at least some of the calcium ions become associated with the reactive sites in the fiber walls. Further still, the method includes forming a web from the pulp mixture and wet pressing the web.

A method of making paper is described. The method includes providing a cellulosic fibrous material, the cellulosic fibrous material comprising a plurality of elongated fibers having a fiber wall surrounding a hollow interior, the fibrous material having moisture content. The method also includes adding calcium bicarbonate solution to the cellulosic fibrous material to form a pulp mixture, the calcium bicarbonate solution containing up to the saturation level of about 16% solids of calcium bicarbonate, the resulting pulp mixture having between 0.1% to 65% total solids by weight. Further, the method includes refining the pulp mixture such that at least some of the calcium ions become associated with the reactive sites in the fiber walls. Further still, the method includes forming a web from the pulp mixture and wet pressing the web.

The present disclosure relates to a vacuum dewatering apparatus comprising a vacuum box disposed opposite of a steam box where the steam box comprises a bottom plate having a substantially linear portion and a curvilinear portion. A plurality of apertures are disposed along at least a portion of the curvilinear portion to permit the transmission of steam. In a preferred embodiment, the curvilinear portion is adjacent to the trailing edge and the linear portion is adjacent to the leading edge of the apertured bottom plate. Further, at least a portion of the apertures are aligned opposite the vacuum box which acts to remove the steam. The vacuum dewatering apparatus of the present invention enables the use of high levels of steam improving vacuum dewatering and improving drying efficiency.

A press section which includes first and second press nips and at least one separate continuously revolving press belt which is routed around each press element of each press nip over a plurality of guide rollers. An upper press belt is led away from the fibrous web after the first press nip. Thereafter the fibrous web is transferred from a lower press belt of the first press nip to an upper press belt of the second press nip. The upper press belt of the second press nip wraps around a vacuum assisted guide roller. Thereafter the lower press belt of the second press nip is brought into contact with the fibrous web via a guide roller, after which the fibrous web travels to the second press nip via a guided path jointly with the two opposite upper and lower press belts of the second press nip.

A system comprising: (a) housing; (b) support arm; and (c) rotary actuator that rotates a steam box between a working position and a rotated position.

A method of making paper is described. The method includes providing a cellulosic fibrous material, the cellulosic fibrous material comprising a plurality of elongated fibers having a fiber wall surrounding a hollow interior, the fibrous material having moisture content. The method also includes adding calcium bicarbonate solution to the cellulosic fibrous material to form a pulp mixture, the calcium bicarbonate solution containing up to the saturation level of about 16% solids of calcium bicarbonate, the resulting pulp mixture having between 0.1% to 65% total solids by weight. Further, the method includes refining the pulp mixture such that at least some of the calcium ions become associated with the reactive sites in the fiber walls. Further still, the method includes forming a web from the pulp mixture and wet pressing the web.

The problem of inconsistent steam penetration of a fibrous sheet is solved by a steam box having a steam header, a diffuser housing disposed within the steam header, wherein walls disposed in the diffuser housing divide an inside of the diffuser housing into multiple diffuser chambers, wherein a valve is configured to fluidly and programmatically communicate with each of the multiple diffuser chambers, such that a steam from the header box may selectively enter one of the diffuser chambers depending upon the valve's orientation in an open or closed position; and multiple orifices of different sizes per diffuser chamber. Ideally, exemplary steam boxes may also comprise a diffuser plates per diffuser chamber. Preferably, the diffuser plates may be located at a bottom of the diffuser chamber. Exemplary steam box systems may further comprise control equipment to manage the flow of steam from the steam header into the diffuser chambers.

The machine (10) comprises a Yankee cylinder (35), having a cylindrical side surface (35S), rotating around an axis (35A) thereof, and a continuous flexible member (17) comprising a first surface (17A) suitable to receive a layer of cellulose pulp (S), comprising cellulose fibers and water, and a second surface (17B), opposite to the first surface (17A). A guide roller (31) is also provided, around which the continuous flexible member (17) is driven. The second surface (17B) of the continuous flexible member (17) is in contact with the first guide roller (31). The machine further comprises a first pressure roller (33) around which the continuous flexible member (17) is driven, arranged downstream of the guide roller (31) with respect to a feeding direction of the layer of cellulose pulp (S). The first pressure roller (33) and the Yankee cylinder (35) define a first pressure nip (34), inside which the continuous flexible member (17) is pressed by means of the first pressure roller (33) against the cylindrical surface (35S) of the Yankee cylinder (35) in order to remove water from the layer of cellulose pulp (S) through the continuous flexible member (17).

A web manufacturing apparatus includes a transport section configured to transport a web containing fiber, a web humidifier configured to humidify the web, and a control section configured to control operation of the transport section and the web humidifier. When transportation of the web by the transport section is stopped, the control section causes the transport section to recommence transportation of the web after the web is humidified by the web humidifier. The control section may also cause the web humidifier to stop humidification of the web after the web humidifier starts humidification of the web and a predetermined duration elapses.