1748results about "Pulp beating/refining methods" patented technology

A method for producing a microfibrillated cellulose, which comprises subjecting a slurry containing a pulp having a solids concentration of 1 to 6 wt % to the treatment with a disc refiner repeatedly ten times or more, to thereby prepare a microfibrillated cellulose having a number average fiber length or 0.2 mm or less and an amount of water hold of 10 mL / g or more, the amount representing the volume of water capable of being held by a unit weight of the cellulose fiber. The method allows the production of a microfibrillated cellulose having high quality with stability and with good efficiency.

The present invention aims to provide cellulose-based fibrous materials for obtaining papers and sheets having low density, high surface quality, good size stability despite of high strength, and high opacity. Cellulose-based fibrous materials having external fibrils consisting of an assembly of scale-like microfibrils exhibit a higher fiber stiffness, a lower water retention value and a higher specific surface area as compared with fibrous materials having filamentous external fibrils at the same freeness. Papers and sheets having low density, high surface quality, good size stability and high opacity can be obtained by using such fibrous materials.

To provide a paper recycling device capable of recycling paper of increased whiteness level that can be widely used for applications other than paper for newspapers, the paper recycling device of the present invention has a dry type defibrator for crushing and defibrating paper, a first transport pipe for transporting defibrated material that was defibrated by the dry type defibrator, a cyclone for air classifying and deinking the defibrated material transported by the first transport pipe, a second transport pipe for transporting the defibrated material that was deinked by the cyclone, and a paper forming machine for forming paper with the defibrated material transported by the second transport pipe.

A process for making fibrillated fibers includes preparing a fluid suspension of fibers, low shear refining the fibers at a first shear rate to create fibrillated fibers having a reduced CSF, and subsequently higher shear refining the fibers at a second shear rate, higher than the first shear rate, to increase the degree of fibrillation of the fibers. The refining at the first shear rate may be with a rotor at a first maximum shear rate and the refining at the second shear rate may be with a rotor at a second maximum shear rate, higher than the first maximum shear rate. The process may further include pre-treating the fibers by high shear refining with impact to stress the fibers prior to low shear refining.

An improved brush cutter having an upper feed control member with stop, forward, neutral, and reverse positions also has a lower feed stop member with selectable sensitivity. Another aspect of the invention is to predict the feed roller shutoff point according to the rate of engine deceleration. According to another aspect, when the feed rollers stop feeding material into the cutters, to overcome drag on the cutters, a controller stops the feed rollers and then reverses them for a short time, and then reverses the rollers again if the problem is still present. To prevent jamming, a pressure switch senses when oil in a hydraulic motor system for rotating the feed rollers is too high and the controller momentarily reverses the feed rollers and then causes them to go forward, a cycle which can occur several times until the feed rollers are no longer stalled. By another aspect of the invention, the controller senses characteristics of the brush cutter and chooses an operating system based on the characteristics sensed. The controller can also sense if the brush chipper has not been used for a predetermined period of time and automatically reduce the idle speed of the engine until the brush chipper is used again, and then automatically return the engine to a normal idle speed before the feed rollers will pull brush into the brush chipper.

A method to produce on a commercial scale, high aspect ratio cellulose nanofilaments (CNF) from natural lignocellulosic fibers comprises a multi-pass high consistency refining (HCR) of chemical or mechanical fibers using combinations of refining intensity and specific energy. The CNF produced represents a mixture of fine filaments with widths in the submicron and lengths from tens of micrometers to few millimeters. The product has a population of free filaments and filaments bound to the fiber core from which they were produced. The proportion of free and bound filaments is governed in large part by total specific energy applied to the pulp in the refiner, and differs from other cellulose fibrillar materials by their higher aspect ratio and the preserved degree of polymerization (DP) of cellulose, and are excellent additives for the reinforcement of paper, tissue, paperboard and the like. They display exceptional strengthening power for never-dried paper webs.

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. Preferably, the fibers are axially separated with less than about 5 percent fibrillation, and subsequently the fiberized material is refined in a high intensity disc refiner until at least about 90 percent of the fibers are fibrillated. In another form the invention combines chip fiberizing with chemical treatments, for improving the pulp property versus energy relationships.

A sheet manufacturing apparatus includes: a defibrating unit which defibrates a defibration object including fibers; a cylinder unit which allows a defibrated material which is defibration-processed in the defibrating unit and introduced via an introduction port to pass through a plurality of holes that is on a cylindrical surface by rotating; a supplying unit which is provided with a supply port which supplies additive agents that bond the plurality of fibers in the cylinder portion; and a bonding unit which forms a sheet by bonding the fibers and the additive agents.

A method for preparing an aqueous suspension comprising microfibrillated cellulose and inorganic particulate material, the method comprising a step of microfibrillating a fibrous substrate comprising cellulose in an aqueous environment in the presence of an inorganic particulate material.