Document Type : Research Paper

Authors

• Mahid Farzi ¹
• Ali akbar Enayati ²
• Davood Parsa paghoh ³

¹ MSc., Wood and Paper Science and Technology, Faculty of Natural Resources, Tehran University. Iran.

² Professor, Dept. of Wood and Paper Sciences and Technology, Faculty of Natural Resources, Tehran University. Iran.

³ Professor, Wood and Paper Science and Technology, Natural Resources Faculty, Tehran University, Iran

Abstract

In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight  of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the weight of the rag). After pulping, hand sheets were made and then both strength and optical properties of hand sheets were measured. It was revealed that, the optimum condition for rag pulping was; 8% active alkali and 120 minutes. At this pulping conditions, the pulping yield and mechanical and optical properties of pulp were measured as yield; 86.46 %, tear index; 20.12 mN.m²/g, burst index; 2.09 kPa.m²/g, breaking length; 1.96 km, brightness; 95.86 % and opacity: 96.39

Keywords

• Rag
• SODA
• active alkali
• yield
• Strength properties
• Optical properties