الفهرس | Only 14 pages are availabe for public view |
Abstract Wood and agriculture resisues have been a primary source of fibers for paper making. Before use, raw material must be reduced to the fibrous state;this operation is called pubping.Chemical pulping employs chemical reagents to effect a separation of cellulose fibers from the other components. Raw materials are cooked with suitable chemicals in aqueousw solutions, usually at elevated temperature and pressure. The objective is to dissolve the organic binders termed ”lignin”, along with other polysaccharide type organic molecules and other extraneous compounds leaving the cellulose intact and in fibrous form and liquor which contains some carbohydrates and lignin. |