造纸原料概述课件.ppt

造纸原料概述,沈静 东北林业大学,Four Great Inventions of Ancient China,Papermaking Printing technique Compass Gunpower,,Pre-Paper Media,The following is a list of pre-paper media developed by early humans: Wood Metal Stone Leaves Ceramics Bark Papyrus Parchment Cloth,http://www.appstate.edu/craftjr/paper1/sub_in1c.ppt,Egyptians and Papyrus,The papyrus (莎草纸) developed before 2,200 B.C. by the Egyptians was not considered true paper. In fact, the very word paper is derived from its name.,http://www.appstate.edu/craftjr/paper1/sub_in1c.ppt,,Image of a papyrus plant,http://legacy.earlham.edu/seidti/iam/papyrus.html,http://legacy.earlham.edu/seidti/iam/tc_pap66.html,http://en.wikipedia.org/wiki/Papyrus,It appears similar to cloth.,http://www.appstate.edu/craftjr/paper1/sub_in1c.ppt,Manufacture of papyrus,Papyrus is made from the stem of the papyrus plant. The outer rind is first stripped off, and the sticky fibrous inner pith is cut lengthwise into thin strips of about 40cm (16in) long. The strips are then placed side by side on a hard surface with their edges slightly overlapping, and then another layer of strips is laid on top at a right angle.,http://en.wikipedia.org/wiki/Papyrus,It is also possible that the two layers were glued together. While still moist, the two layers are hammered together, mashing the layers into a single sheet. The sheet is then dried under pressure. After drying, the sheet of papyrus is polished with some rounded object, possibly a stone or seashell or round hard wood.,http://en.wikipedia.org/wiki/Papyrus,It is widely accepted that Tsai Lun, a Chinese court official, invented paper in 105 AD.,Abbreviation for Anno Domini - Latin for The Year Of Our Lord,Tsai Luns Paper,Mulberry bark Hemp waste Old rags Fish nets,Difference between paper and papyrus,Paper differs from papyrus in that the plants have been beaten to separate the fibers, suspended evenly in water, placed on a webbing to drain off the water, and dried. The beating allows a hydrogen bonding to form between the fibers. This hydrogen bonding gives paper its cohesion and tearing strength.,http://www.ipst.gatech.edu/amp/general/museum_faq.htm,原料？,Starting materials Raw materials Feedstocks Basic materials,A raw material or feedstock is the basic material from which a product is manufactured or made, frequently used with an extended meaning.,.,(Third edition, August 2010; online version November 2010 ed.). raw material n.: Oxford University Press),原料是一切工业生产的基础。

造纸原料的基本要求 （一）原料质量要好 （二）原料资源要丰富、集中 （三）原料价格要低廉,From Prof. Gang Yu at NEFU,造纸纤维原料的分类,植物纤维原料Plant/vegetable fibers --木材-Wood --竹材-Bamboo --禾草-Grass --韧皮-Bast --籽毛/种毛Seed hair --叶-Leaf 矿物纤维原料-Mineral fibers 合成纤维原料-Synthetic fibers 动物纤维原料-Animal fibers,Fibers for Papermaking,Fibers are defined as “...tough threadlike substances capable of being spun or woven, whether they be natural (vegetable, mineral, animal) or man-made.” In papermaking, animal fibers are generally not used at all, and mineral fibers are used only occasionally. Vegetable fibers (cellulose) wet easily in a water medium and will form a strong bond to each other when dried in contact.,http://www.appstate.edu/craftjr/paper1/sub_in1c.ppt,造纸纤维原料中的细胞,The cell is the basic structural and functional unit of all known living organisms.,造纸纤维原料中细胞的功能,On the basis of functions, the cells can be divided into three groups: conducting cells, supporting cells, and storage cells.,(Timell, T. E. (ed.). Fiber atlas: identification of papermaking fibers. Springer, 1995.),Conducting and supporting cells are elongated, axial cells (按轴向排列). In hardwoods, the conducting cells consist of vessel elements, and the supporting cells consist of fibers. In softwoods, tracheids perform both of these functions. Conducting cells and supporting cells are dead cells whose cell cavities are filled with water and air.,(Timell, T. E. (ed.). Fiber atlas: identification of papermaking fibers. Springer, 1995.),Storage cells consist of short, thin-walled parenchyma (pE5reNkimE) cells.,薄壁细胞,植物纤维原料中的细胞类型,管胞-Tracheid 薄壁细胞-Parenchyma 导管-Vessel 木纤维Fiber 表皮细胞Epidermal cell 石细胞Stone cell,The rays of softwoods are composed either of parenchyma cells alone or of parenchyma cells and ray tracheids.,(Timell, T. E. (ed.). Fiber atlas: identification of papermaking fibers. Springer, 1995.),Softwoods are simple and regular in their structure. Their wood substance is composed mainly of two kinds of cells: longitudinal (lCndVi5tju:dinl) tracheids (treikiid) and ray parenchyma (pE5reNkimE). Approximately 90-95% of the wood volume is occupied by the longitudinal tracheids.,(Timell, T. E. (ed.). Fiber atlas: identification of papermaking fibers. Springer, 1995.),,管胞,Tracheids (or fibers) are needle-like cells which transport fluids through the tree and provides strength.,(,The average length of tracheids varies from about 2 to 6 mm,(Timell, T. E. (ed.). Fiber atlas: identification of papermaking fibers. Springer, 1995.),阔叶木原料中的细胞,导管-Vessels 木纤维--Fibers --韧型纤维-Libriform 5laibrE7fC:m fi。