INVESTIGATION OF PROPERTIES OF ETHANOL-ALKALI, KRAFT AND SODA PULPS PREPARED FROM WHEAT STRAW

Global concerns for preservation of forests and elimination of pollution from pulping and papermaking processes has led us to explore alternate fibrous resources other than wood and new environmentally begin pulping and bleaching processes for papermaking without sacrificing quality. Various alternate fibrous resources such as agricultural residues are already in use in many countries and considerable research have been undertaken to produce pulps by conventional and non-conventional processes. Wheat straw has high quantity among agricultural residues in Iran. Kraft, Soda and Ethanol-alkali pulping were carried out after sampling and preparing of wheat straw. Retention of carbohydrates is improved compared to the alkaline pulping processes, resulting in about 8 to 15 % higher yield at the same level of residual lignin. There was lower energy consumption for refining Ethanol-alkali pulps. There were no statistical differences among the physical properties. The strengths of Ethanol-alkali pulps consist of tear index, burst index and breaking length were lower than alkaline pulps, but all of the strength properties were higher than kraft and liner paper except tear index that addition of some long fiber can solve the problem