| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing deinked pulp having high whiteness at a low cost in a method for producing deinked pulp using waste paper as a raw material. SOLUTION: This production of deinked pulp included (i) a process to prepare low water content fibers by disintegrating wastepaper in water, removing foreign materials and dehydrating, (ii) a process to add a bleaching agent to the low water content fibers and mix the bleaching agent with the fibers by opening the fibers with adding a shearing force in the range to practically give no damages to the fibers in a space between a stator and a rotor using a mixer comprising the stator and the rotor, (iii) a process to age the product obtained in the opening process in a aging tower and (iv) a kneading process to strip off an ink from the fibers by giving a shearing force 4-400 times larger than that given by the mixer to the product obtained in the aging process by using a kneading device comprising a stator and a rotor in a space between the stator and the mixer.</p> |
