TH7113B - Ink removal and second fiber bleaching - Google Patents

Abstract

The brilliance and bleaching of the recycled second-layer fibers are enhanced by pre-rinsing the pulped fibers in a water-based surfactant. and/or post-oxygenated dispersed in alkaline medium, dissolved in water.

Claims (3)

1.Methods for removing ink and bleaching pulp Containing two layers of cellulose fibers Which includes the process of removing the concentrated suspension That has an alkaline activity in the aqueous medium of such pulp To react with gases that contain oxygen Next, the bleached pulp is rinsed with water containing surfactants. Non-holding type Anion type Which has been added to the pulp suspension before Or during such washing. 2. Method as described in claim 1, where the pulp is washed with a surfactant. Followed by the reaction with gas containing oxygen as such 3. Method as defined in claim 1, where the pulp is added to the chlorine-added reaction. Before being reacted with gases containing oxygen, 4. Method as described in claim 1, where pulp is rinsed with non-ionic surfactants. Before and after the reaction with oxygen-rich gases 5. Methods as set out in claim 4, where the reaction with oxygen-rich gases is performed. In conditions of higher loudness than the atmosphere At compartment temperature from 60 to 130 ° C and process time of 0.1 to 2 hours 6. Method as set out in claim 1 where the pulp is added to the chlorinated medium in the aqueous medium. Containing approximately 0.5 to 5% chlorine for approximately one hour at atmospheric pressure. Before the reaction With gases containing oxygen as such. 7. Methods as set out in claim 6, where pulp washing is performed. After the reaction with gases containing oxygen With 0.1 to 2% non-ionizing surfactants as compared to the pulp chamber drying weight 8. Method as set out in claim 1, whereby the surfactant is The non-charge type 9. Method as described in claim 1, where pulp is rinsed with a surfactant referred to. Followed by a chemical bleaching process At least one step 1 0. Method as described in claim 1, whereby a liquid containing a surfactant is Brought back from washing the bleached pulp Returns the steps selected in the toner removal order. Which has been used with pulp before that 1 1. Method as set out in claim 10 where the order of disposal of the said ink Including the process of floating The washing liquid containing the surfactant is fed back to the flotation stage in the ink removal process as described above 1. 2. Method as set out in claim 10 where, in the initial pulping process of the second cellulose fiber Washing liquids containing the recycled surfactant were used. At least part 1 3.Process applied with second stage cellulose fibers By making these fibers into pulp And then taken through the process of removing the ink Followed by one or more bleaching steps. Improvement, which has one such used bleaching step Consists of the removal of ink pulp. It is processed in a solution with a surfactant in aqueous medium. In the presence of oxygen in the form of molecules Washing of the pulp that has passed Process oxygen already And reusing the filtered washing liquid And feeding at least part of the filtered washing liquid Go through the ink removal process