A process for producing dissolving pulp from comminuted wood-based fibrous material. The process includes the following consecutive stages: cooking comminuted fibrous material with alkaline cooking liquor in a kraft cooking process to produce pulp; treating the cooked pulp in caustic extraction at a temperature of 70-110 C. and in an effective alkali concentration of 60-120 g/l for at least 5 minutes, and washing and oxygen delignifying the caustic extracted pulp.

A process for producing dissolving pulp from comminuted wood-based fibrous material. The process includes the following consecutive stages: cooking comminuted fibrous material with alkaline cooking liquor in a kraft cooking process to produce pulp; treating the cooked pulp in caustic extraction at a temperature of 70-110 C. and in an effective alkali concentration of 60-120 g/l for at least 5 minutes, and washing and oxygen delignifying the caustic extracted pulp.

A wet laid process includes a method for making paper in which a composition containing co-refined cellulose fibers and cellulose ester fibers made into a thick stock composition in a machine chest, the thick stock is fed to a cleaning/screening zone through a device that regulates the flow rate of thick stock, the consistency of the thick stock fed to the screening/cleaning zone is reduced to form a thin stock composition; the thin stock composition is subjected to a process for cleaning the thin stock and feeding the cleaned thin stock through screens to form a cleaned and screened thin stock composition, and the cleaned and screened thin stock composition is fed to a headbox.

A wet laid process includes a method for making paper in which a composition containing co-refined cellulose fibers and cellulose ester fibers made into a thick stock composition in a machine chest, the thick stock is fed to a cleaning/screening zone through a device that regulates the flow rate of thick stock, the consistency of the thick stock fed to the screening/cleaning zone is reduced to form a thin stock composition; the thin stock composition is subjected to a process for cleaning the thin stock and feeding the cleaned thin stock through screens to form a cleaned and screened thin stock composition, and the cleaned and screened thin stock composition is fed to a headbox.

A method to treat fibrous materials for use in the formation of a biocomposite material that significantly reduces or eliminates the odors emitted from the fibrous materials is provided. In the method, the fibers or fibrous materials are initially treated to extract the raw fiber from the source plant material and the remove unwanted fractions of the fiber, such as the hemicellulose, lignin, and pectin, among others, leaving only the intact cellulose fibers. These cellulose fibers are then further processed in a second step to remove the odor from the cellulose fibers. The second step includes a combination of a second chemical treatment, dehumidification, and/or a cold plasma modification to render the cellulosic fibers odorless.

A method to treat fibrous materials for use in the formation of a biocomposite material that significantly reduces or eliminates the odors emitted from the fibrous materials is provided. In the method, the fibers or fibrous materials are initially treated to extract the raw fiber from the source plant material and the remove unwanted fractions of the fiber, such as the hemicellulose, lignin, and pectin, among others, leaving only the intact cellulose fibers. These cellulose fibers are then further processed in a second step to remove the odor from the cellulose fibers. The second step includes a combination of a second chemical treatment, dehumidification, and/or a cold plasma modification to render the cellulosic fibers odorless.

A method for processing pulp in an apparatus for washing and dewatering pulp, and a system for controlling this apparatus, the apparatus comprising two rotatable press rolls (102, 104) having a permeable outer surface (106, 108), and a vat (114, 116, 118), the press rolls (102, 104) defining a press nip (112) between them. The processing is determined by a set of variable operating parameters, which are adjusted and/or maintained during operation in response to deviations of measured values of control parameters in relation to their respective predetermined threshold values. The variable operating parameters include rotation speed of the press rolls. The control parameters include vat pressure and/or linear load.

A method for processing pulp in an apparatus for washing and dewatering pulp, and a system for controlling this apparatus, the apparatus comprising two rotatable press rolls (102, 104) having a permeable outer surface (106, 108), and a vat (114, 116, 118), the press rolls (102, 104) defining a press nip (112) between them. The processing is determined by a set of variable operating parameters, which are adjusted and/or maintained during operation in response to deviations of measured values of control parameters in relation to their respective predetermined threshold values. The variable operating parameters include rotation speed of the press rolls. The control parameters include vat pressure and/or linear load.

A pulp-filter arrangement (1) comprises a rotatable drum (10) and a non-rotating valve arrangement (30). The rotatable drum (10) has a cylindrical water-permeable pulp-supporting shell (14), a plurality of drain pipes (16) and a rotating hollow shaft (18). The plurality of drainpipes (16) connects the rotating hollow shaft (18) with a collecting channel (22) situated radially directly inside the cylindrical water-permeable pulp-supporting shell (14). The non-rotating valve arrangement (30) is disposed within the rotating hollow shaft (18) for sealing off the rotating hollow shaft (18) from a radially inner outlet (24) of the drain pipes (16) when respective radially inner outlet (24) is situated within a sealed zone. The non-rotating valve arrangement (30) is further arranged to, in a transition zone immediately following the sealed zone, open a throttled passage between the rotating hollow shaft (18) and the radially inner outlet (24).

A pulp-filter arrangement (1) comprises a rotatable drum (10) and a non-rotating valve arrangement (30). The rotatable drum (10) has a cylindrical water-permeable pulp-supporting shell (14), a plurality of drain pipes (16) and a rotating hollow shaft (18). The plurality of drainpipes (16) connects the rotating hollow shaft (18) with a collecting channel (22) situated radially directly inside the cylindrical water-permeable pulp-supporting shell (14). The non-rotating valve arrangement (30) is disposed within the rotating hollow shaft (18) for sealing off the rotating hollow shaft (18) from a radially inner outlet (24) of the drain pipes (16) when respective radially inner outlet (24) is situated within a sealed zone. The non-rotating valve arrangement (30) is further arranged to, in a transition zone immediately following the sealed zone, open a throttled passage between the rotating hollow shaft (18) and the radially inner outlet (24).