Determination of changes at the swelling properties of bleached sulphate pulp treated by various chemical agents

Determination of Changes at the Swelling Properties of Bleached Sulphate Pulp Treated by Various Chemical Agents In this study, the bleached sulphate pulps produced by SEKA-Dalaman paper mill were used as raw material. These pulp samples were treated with 1%, 3% and 5% concentration of NaOH and ethyl alcohol at 5 min., 10 min. and 15 min. Firstly, the properties of pulps treated with NaOH and alcohol at various reaction time were determined such as water retention values, fiber width, wall thickness, lumen diameter, energy consumption during refining. Then, physical and mechanical properties of papers obtained from treated these pulps were tested by using Tappi and Scan test methods. As the results of this study, It is explained that the swelling of fiber, fiber width, wall thickness, lumen diameter are increased with increasing concentration of chemical agent and reaction time. On the other hand, It were found that the physical and optical properties of paper obtained from these pulp samples were changed with increasing reaction time and chemical agent concentrations, and the breaking length, burst index and tear index of paper were increased and brigthness of paper was decreased by increasing chemical agent concentration and reaction time. In addition, It were determined that the values of energy consumption to per °SR were decreased at 5% NaOH and ethyl alcohol, while same values didn't change other chemical concentrations. The most suitable parameters determined related to energy consumption for beating of pulp, water retention values of fibers, wall thickness, lumen diameter, breaking length, tear index, burst index are as in follow. Chemical agent: NaOH, Concentration: 5%, Reaction time: 15 min. Whereas, for brightness of paper, suitable chemical agent, concentration of agents and reaction time were found to be ethyl alcohol, 1% and 10 and 15 min. respectively. Key Words: Swelling, Cellulose, Fiber Morphology, Water Retention Value, NaOH, Ethyl Alcohol Vm ftJKfiMAlfllAfWtl MOUtUi