A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 2001

Between different recycled fiber grades, the packaging products have the highest utilization rate. Although the strength is a critical requirement for packaging products, recycling reduces its strength properties. Fractionation technology is a well-established process for packaging industry to remedy for the strength loss caused by recycling . . Many different scenarios have been practiced in packaging industry. One general approach is to fraction<\te fiber into long and short fiber fraction, then remix them after refining the long fiber fraction. Although this scheme has been supported, the number of works to verify its advantageous or disadvantageous is scarce. This thesis work has been undertaken to address this issue. Optimum operational conditions required for fractionation using laboratory pressure screen was sought and the finding were applied in processing the present project. The OCC pulp collected directly from the local mill fractionated into long and short fiber fractions using laboratory pressure screen. The long fiber fraction was refined at laboratory scale and remixed with the short fiber fraction. The strength properties of the fractionated and refined stock were measured and compared with those of refined feed stock (unfractionated stock). It was observed that the over all strength performance of refined feed stock is better compared fractionated and refined stock.