Abstract: A method for producing micro fibrillated cellulosic material from pulp in which a pulp feed material is pre-treated by passing through a high consistency refiner a single time, followed by dilution and multiple passes through low consistency refiners.

Abstract: A method for producing micro fibrillated cellulosic material from pulp where multiple passes through a medium consistency refiner are made either singularly or in combination with low consistency refiners and high consistency refiners.

Abstract: Methods of producing mechanical pulps from lignocellulosic material including partial defibration of lignocellulosic material in a chip press followed by liquid impregnation, preheating the lignocellulosic material for 20 seconds or less at a pressure between 7.5 and 12 bar (gauge) prior to mechanically refining the lignocellulosic material in a primary mechanical refiner at a pressure between 7.5 and 12 bar (gauge), thus obtaining a high freeness pulp.

Abstract: A thermomechanical pulping method including: refining pulp with a high consistency refining stage, and a medium consistency refining stage processing the refined pulp discharge from the high consistency refining stage. Chemical pretreatments for improving pulp quality development during medium consistency refining can be optionally added at the pressurized chip press, fiberizer pre-refining step, primary high consistency refining step, and/or the standpipe feeding the medium consistency refiner.

Abstract: A method for producing micro fibrillated cellulosic material from pulp where multiple passes through a medium consistency refiner are made either singularly or in combination with low consistency refiners and high consistency refiners.

Abstract: A mechanical pulping apparatus including: a pre-treatment defibration device receiving comminuted cellulosic material; a primary refiner receiving the comminuted cellulosic material discharged from the pre-treatment defibration device; a source of a biological agent; a first conduit from the source of the biological agent coupled to pre-treatment defibration device, wherein the first conduit delivers the biological agent to or immediately upstream of an inlet to the defibration device; a source of a chemical agent, and a second conduit from the source of the chemical agent coupled to primary refiner, wherein the second conduit delivers the chemical agent to the primary refiner.

Abstract: A mechanical pulping method including: defibrating a comminuted cellulosic material; mechanically refining the defibrated cellulosic material in a primary refining step; introducing to the cellulosic material at least one of a chemical agent and a biological during the defibration step or the mechanical refining step, and producing pulp from the refined and defibrated cellulosic material.

Abstract: Methods of producing mechanical pulps from lignocellulosic material including partial defibration of lignocellulosic material in a chip press followed by liquid impregnation, preheating the lignocellulosic material for 20 seconds or less at a pressure between 7.5 and 12 bar (gauge) prior to mechanically refining the lignocellulosic material in a primary mechanical refiner at a pressure between 7.5 and 12 bar (gauge), thus obtaining a high freeness pulp.

Abstract: A thermomechanical pulping method including: refining pulp with a high consistency refining stage, and a medium consistency refining stage processing the refined pulp discharge from the high consistency refining stage. Chemical pretreatments for improving pulp quality development during medium consistency refining can be optionally added at the pressurized chip press, fiberizer pre-refining step, primary high consistency refining step, and/or the standpipe feeding the medium consistency refiner.

Abstract: A mechanical pulping method including: defibrating a comminuted cellulosic material; mechanically refining the defibrated cellulosic material in a primary refining step; introducing to the cellulosic material at least one of a chemical agent and a biological during the defibration step or the mechanical refining step, and producing pulp from the refined and defibrated cellulosic material.

Abstract: A steam explosion pulping method including: impregnating a cellulosic biomass feed material in a pressurized reactor vessel; discharging the impregnated feed material from the vessel to a high pressure compressor; elevating a pressure of the feed material in the compressor; discharging the pressurized feed material from the compressor to a conduit coupled to a blow valve; rapidly reducing pressure of the pressurized feed material as the feed material passes through the blow valve, and pulping the feed material by expansion of fluid in the feed material during the rapid pressure reduction.

Abstract: A chip pretreatment process which comprises conveying the feed material through a compression screw device having an atmosphere of saturated steam at a pressure above about 5 psig, decompressing and discharging the compressed material from the screw device into a decompression region, feeding the decompressed material from the decompression region into a fiberizing device, such as a low intensity disc refiner, where at least about 30 percent of the fiber bundles and fibers are axially separated, without substantial fibrillation of the fibers. In a more specific form the invention is directed to a process for producing mechanical pulp, including the steps of fiberizing wood chip feed material in a low intensity disc refiner until at least about 30 percent of the fibers are axially separated with less than about 5 percent fibrillation, and subsequently refining the fiberized material in a high intensity disc refiner until at least about 90 percent of the fibers are fibrillated.

Abstract: A system for thermomechanical refining of wood chips comprises preparing the chips for refining by exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a solids consistency above 55 percent, and diluting the destructured and dewatered chips to a consistency in the range of about 30 to 55 percent. The destructuring partially defibrates the material. This diluted material is fed to a rotating disc primary refiner wherein each of the opposed discs has an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves. The destructured and partially defibrated chips are substantially completely defibrated in the inner ring and the resulting fibers are fibrillated in the outer ring.

Abstract: A chip pretreatment process which comprises conveying the feed material through a compression screw device having an atmosphere of saturated steam at a pressure above about 5 psig, decompressing and discharging the compressed material from the screw device into a decompression region, feeding the decompressed material from the decompression region into a fiberizing device, such as a low intensity disc refiner, where at least about 30 percent of the fiber bundles and fibers are axially separated, without substantial fibrillation of the fibers. In a more specific form the invention is directed to a process for producing mechanical pulp, including the steps of fiberizing wood chip feed material in a low intensity disc refiner until at least about 30 percent of the fibers are axially separated with less than about 5 percent fibrillation, and subsequently refining the fiberized material in a high intensity disc refiner until at least about 90 percent of the fibers are fibrillated.

Abstract: A system for thermomechanical refining of wood chips comprises preparing the chips for refining by exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a solids consistency above 55 percent, and diluting the destructured and dewatered chips to a consistency in the range of about 30 to 55 percent. The destructuring partially defibrates the material. This diluted material is fed to a rotating disc primary refiner wherein each of the opposed discs has an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves. The destructured and partially defibrated chips are substantially completely defibrated in the inner ring and the resulting fibers are fibrillated in the outer ring.

Abstract: Plate elements, a plate configuration, and associated system for thermomechanical refining of wood chips wherein destructured and partially defibrated chips are fed to a rotating disc primary refiner, where opposed discs each have an inner band pattern of bars and grooves and outer band pattern of bars and grooves, such that substantially complete fiberization (defibration) of the chips is achieved in the inner band and the resulting fibers are fibrillated in the outer band. One embodiment is directed to a pair of opposed co-operating refining plate elements for a flat disc refiner wherein the bars and grooves on each of the inner bands form an inner feed region followed by an outer working region, the bars and groove on each of the outer bands form an inner feed region followed by an outer working region, and the gap and/or material flow area formed when the plates are placed in front of each other increases between the inner working region and the outer feed region.

Abstract: Plate elements, a plate configuration, and associated system for thermomechanical refining of wood chips wherein destructured and partially defibrated chips are fed to a rotating disc primary refiner, where opposed discs each have an inner band pattern of bars and grooves and outer band pattern of bars and grooves, such that substantially complete fiberization (defibration) of the chips is achieved in the inner band and the resulting fibers are fibrillated in the outer band. One embodiment is directed to a pair of opposed co-operating refining plate elements for a flat disc refiner wherein the bars and grooves on each of the inner bands form an inner feed region followed by an outer working region, the bars and groove on each of the outer bands form an inner feed region followed by an outer working region, and the gap and/or material flow area formed when the plates are placed in front of each other increases between the inner working region and the outer feed region.

Abstract: A system and method for thermomechanical refining of wood chips comprises preparing the chips for refining by exposing the chips to an environment of steam to soften the chips, compressively destructuring and dewatering the softened chips to a solids consistency above 55 percent, and diluting the destructured and dewatered chips to a consistency in the range of about 30 to 55 percent. The destructuring partially defibrates the material. This diluted material is fed to a rotating disc primary refiner wherein each of the opposed discs has an inner ring pattern of bars and grooves and an outer ring pattern of bars and grooves. The destructured and partially defibrated chips are substantially completely defibrated in the inner ring and the resulting fibers are fibrillated in the outer ring.

Abstract: A chip pretreatment process which comprises conveying the feed material through a compression screw device having an atmosphere of saturated steam at a pressure above about 5 psig, decompressing and discharging the compressed material from the screw device into a decompression region, feeding the decompressed material from the decompression region into a fiberizing device, such as a low intensity disc refiner, where at least about 30 percent of the fiber bundles and fibers are axially separated, without substantial fibrillation of the fibers. In a more specific form the invention is directed to a process for producing mechanical pulp, including the steps of fiberizing wood chip feed material in a low intensity disc refiner until at least about 30 percent of the fibers are axially separated with less than about 5 percent fibrillation, and subsequently refining the fiberized material in a high intensity disc refiner until at least about 90 percent of the fibers are fibrillated.