A method for recycling paper to produce a less white and clean office paper product for paper printing and writing, said method comprising the steps of: collecting waste papers; sorting said collected papers waste without the need to separate between the various paper grades; pressing said sorted recycled paper; pulping said sorted recycled paper by a pulper which contains water turns into a mixture; said pulper chops said sorted recycled paper into small pieces; heating said pulp mixture breaks said recycled paper down more quickly into tiny strands of cellulose or fibers to eventually, said sorted recycled paper turns into a pulp; sieving, said pulp is forced through sieves containing holes and slots of various shapes and sizes, said sieves remove small contaminants; cleaning, said pulp spinning around in large cone-shaped cylinders; heavy contaminants are thrown to the outside of the cone and fall through the bottom of the cylinder; lighter contaminants collect in the center of the cone and are removed; refining, said pulp is beaten to make said recycled fibers swell for papermaking; if said pulp contains any large bundles of fibers, said refining step separates said bundles into individual fibers; dewatering, said watery pulp enters a headbox at a paper machine, and then is sprayed in a continuous wide jet onto a huge flat wire sieve which is moving very quickly through said paper machine; on a sieve, water starts to drain from said pulp, and said recycled fibers quickly begin to bond together to form a watery sheet; said sheet moves rapidly through a series of felt-covered press rollers which squeeze out more water; said sheet, which now resembles paper, passes through a series of heated metal rollers which dry said paper’, said dried paper is wound into a giant roll and removed from the paper machine; the roll of said paper is cut into smaller rolls, or sometimes into sheets and made into said paper product.

A method for recycling paper to produce a less white and clean office paper product for paper printing and writing, said method comprising the steps of: collecting waste papers; sorting said collected papers waste without the need to separate between the various paper grades; pressing said sorted recycled paper; pulping said sorted recycled paper by a pulper which contains water turns into a mixture; said pulper chops said sorted recycled paper into small pieces; heating said pulp mixture breaks said recycled paper down more quickly into tiny strands of cellulose or fibers to eventually, said sorted recycled paper turns into a pulp; sieving, said pulp is forced through sieves containing holes and slots of various shapes and sizes, said sieves remove small contaminants; cleaning, said pulp spinning around in large cone-shaped cylinders; heavy contaminants are thrown to the outside of the cone and fall through the bottom of the cylinder; lighter contaminants collect in the center of the cone and are removed; refining, said pulp is beaten to make said recycled fibers swell for papermaking; if said pulp contains any large bundles of fibers, said refining step separates said bundles into individual fibers; dewatering, said watery pulp enters a headbox at a paper machine, and then is sprayed in a continuous wide jet onto a huge flat wire sieve which is moving very quickly through said paper machine; on a sieve, water starts to drain from said pulp, and said recycled fibers quickly begin to bond together to form a watery sheet; said sheet moves rapidly through a series of felt-covered press rollers which squeeze out more water; said sheet, which now resembles paper, passes through a series of heated metal rollers which dry said paper’, said dried paper is wound into a giant roll and removed from the paper machine; the roll of said paper is cut into smaller rolls, or sometimes into sheets and made into said paper product.

A method for defibrating a fiber body includes: a supply step of supplying a liquid to a fiber body containing fibers; and a defibrating step of defibrating the fiber body to which the liquid is supplied, and in the supply step, the liquid is supplied to the fiber body so that a rate in tensile strength of the fiber body immediately before defibrated in the defibrating step to the fiber body before the liquid is supplied thereto is 60.0% or less.

A method for defibrating a fiber body includes: a supply step of supplying a liquid to a fiber body containing fibers; and a defibrating step of defibrating the fiber body to which the liquid is supplied, and in the supply step, the liquid is supplied to the fiber body so that a rate in tensile strength of the fiber body immediately before defibrated in the defibrating step to the fiber body before the liquid is supplied thereto is 60.0% or less.

The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

The present invention aims to develop a technique for efficiently preparing deinked pulp from prints made with UV-curable inks. According to the processes for preparing deinked pulp of the present invention, high quality deinked pulp can be obtained by performing the steps of: disintegrating printed waste paper containing UV prints in water to give a waste paper slurry; and applying a mechanical process to the waste paper slurry using a rotary disintegrator.

A defibrating apparatus includes a screen and housings, and side walls of the housings have inner surfaces that define the inner surface of a discharge path. Let communication hole be any through-hole that interconnects the defibrating chamber and the discharge path, and let discharge path-side opening edge be the opening edge, close to the discharge path, of the through-hole, then the screen has through-hole rows, each of which is formed by a plurality of communication holes arranged at an interval in a circumferential direction, and the through-hole row is provided at a position where the discharge path-side opening edge of the communication holes is overlapped with the inner surface as seen in a radial direction.

A defibrating apparatus includes a screen and housings, and side walls of the housings have inner surfaces that define the inner surface of a discharge path. Let communication hole be any through-hole that interconnects the defibrating chamber and the discharge path, and let discharge path-side opening edge be the opening edge, close to the discharge path, of the through-hole, then the screen has through-hole rows, each of which is formed by a plurality of communication holes arranged at an interval in a circumferential direction, and the through-hole row is provided at a position where the discharge path-side opening edge of the communication holes is overlapped with the inner surface as seen in a radial direction.

A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.

A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.