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.

The purpose of the present invention is to provide a recycled pulp fiber manufacturing method with which it is possible to easily obtain recycled pulp fibers containing less of a high water-absorption polymer without requiring any mechanical equipment such as an ozone generation apparatus. This method is for manufacturing recycled pulp fibers from used sanitary goods including pulp fibers and a high water-absorption polymer, and is characterized by comprising: an inactivation step (S1) for immersing a sanitary goods constituent material in an acid-containing aqueous solution so as to inactivate the high water-absorption polymer; a high water-absorption polymer degradation step (S3) for generating chlorine dioxide by adding a chlorine dioxide generating material, which is capable of generating chlorine dioxide through reaction with an acid, to the acid-containing aqueous solution that has undergone the inactivation step (S1), and then degrading the inactivated high water-absorption polymer using said chlorine dioxide; and a recycled pulp fiber recovery step (S4) for recovering the recycled pulp fibers from the acid-containing aqueous solution that has undergone the high water-absorption polymer degradation step (S3).

The purpose of the present invention is to provide a recycled pulp fiber manufacturing method with which it is possible to easily obtain recycled pulp fibers containing less of a high water-absorption polymer without requiring any mechanical equipment such as an ozone generation apparatus. This method is for manufacturing recycled pulp fibers from used sanitary goods including pulp fibers and a high water-absorption polymer, and is characterized by comprising: an inactivation step (S1) for immersing a sanitary goods constituent material in an acid-containing aqueous solution so as to inactivate the high water-absorption polymer; a high water-absorption polymer degradation step (S3) for generating chlorine dioxide by adding a chlorine dioxide generating material, which is capable of generating chlorine dioxide through reaction with an acid, to the acid-containing aqueous solution that has undergone the inactivation step (S1), and then degrading the inactivated high water-absorption polymer using said chlorine dioxide; and a recycled pulp fiber recovery step (S4) for recovering the recycled pulp fibers from the acid-containing aqueous solution that has undergone the high water-absorption polymer degradation step (S3).

A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.

A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.

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 method and device for separating a printing ink and a fiber by dry-process magnetic force difference coupled vibration. The device comprises a fiber crushing machine unit (1), a magnetic force difference coupled vibrator (2), an acceleration fan (3), a ballistic rebounding and resorbing device (4), a material settling and conveying pipe (5), and a cylindrical separator (6) which are sequentially connected by means of pipes. According to the method and the device, separation of printing inks and fibers in waste paper can be implemented by means of dry-process magnetic force difference coupled vibration, and recycling of waste paper products is implemented.

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.