HIGH CONSISTENCY PULPING OF OLD NEWSPRINT AND ITS FLOTATION PROPERTIES

INTRODUTIONWaste paper is an important recyclable resource. The problems that are concerned with resource, energy and environment can be solved effectively by recycling of the waste paper. In the past decade, countries all over the world have paid great attention to the recycling of waste paper, so its recycling ratio has been increasing year and year. The technologies for waste paper recycling have also been developed and modified. The production and varieties of paper and paperboard mad…

HIGH CONSISTENCY PULPING OF OLD NEWSPRINT AND ITS FLOTATION PROPERTIES

The mechanical and chemical effect on the pulping properties of the old newsprint was studied using a FORMAX Micro-Maelstrom Laboratory Pulper, and the flotation conditions such as velocity of air flow, air pressure and flotation time were also discussed with a FORMAX Deink Cell. The results show that sodium hydroxide, sodium silicate, hydrogen peroxide and deinking agent are the key factors in the chemical effect, and pulping consistency is more important than pulping time and rotation speed in the mechanical effect during the high consistency pulping of the ONP. In general, the chemical effect has a greater influence on the deinked pulp properties than the mechanical effect.