How to Remove Ink and Bleach

For the production of white A4 copy paper, deinking and bleaching are key steps that determine the quality of the final product. Modern waste paper deinking technology has evolved from traditional high-alkali processes to weakly alkaline and neutral deinking methods.

 

In the neutral deinking process, a neutral deinking agent is added to a drum pulper, and pulping is carried out at a temperature of 45℃-50℃. Ink particles are detached from the fiber surface under the action of chemical agents and then removed by flotation deinking. The flotation process utilizes the hydrophobic properties of ink particles; tiny air bubbles are introduced into the pulp, and the ink particles adhere to the bubbles, float to the surface, and are scraped off.

 

To improve pulp brightness, production lines are typically equipped with hydrogen peroxide bleaching systems. After the pulp is concentrated to 25% using a screw press, it undergoes hydrogen peroxide bleaching in a bleaching tower, which can increase the pulp brightness to over 60% ISO. A thermal disperser then uses mechanical action to disperse residual ink particles and adhesives into microparticles invisible to the naked eye, ensuring a clean and flawless final paper surface.

 

Leizhan paper machinery company supply high quality remove ink and bleaching machine, welcome to contact us for more details. Email address: leizhanchina@gmail.com.