classify
According to plant families: Larix gmelinii and Picea crassifolia of Pinaceae; Citrus of Euphorbiaceae; Black wattle of mimosaceae; 159 129 lacquer wood; Quercus variabilis, Quercus chuanensis and Castanea mollissima of FAGACEAE; Casuarina and so on. According to their utilization parts, such as larch, spruce, black wattle and Casuarina equisetifolia; Woody 159 129 wood, chestnut, etc. Rubber bowls and terminalia chebula with shells; Lacquer leaves of leaves; Red root, Rumex root, etc. According to tannin structure, it is classified as condensed black wattle, larch, bayberry, spruce, 159 129, etc. Hydrolyzed rubber bowls, chestnuts and terminalia chebula (table 1).
collect
Different raw materials adopt different collection methods. ① Leather raw materials: manual or mechanical peeling. Manual peeling methods vary with tree species, such as black wattle bark, long fiber, thin bark, etc., and strip peeling is used. Deciduous pine bark has short fibers and many corks, so it can only be peeled off with tools. Mechanical peeling is divided into cutting method and friction method. The former method has low productivity, the cut bark contains about 10% of wood, and the bark quality is poor, so it is not suitable for use. The latter method is better, and chain and cam peelers can be used. The chain peeler consists of a frame, a peeler rotating tray and a feeder. Driven by a motor, it can peel logs with a tree diameter of 6 ~ 25 cm. The machine is equipped with a circulating chain, which is fixed on the lever, and the rotary joint is installed on the end face of the flat plate. The chain clings to the log and peels off the bark by friction. Cam-type peeler uses cam instead of easy-to-wear chain. The cam is made of alloy material and its cross section is triangular. It is fixed on a roller that rotates around the log, and it is pressed against the log by a spring to peel the bark. ② Wood raw materials: manual or mechanical logging is adopted. After the trees are cut down, the branches and bark are removed, sawed to a specified length, and transported on the forest road. ③ Shell material: such as rubber bowl. Quercus alpina in Turkey is a small tree, which is mainly picked by hand. The new oak barrels are laid flat on the ground, dried and transported to the factory. China mainly receives floor-mounted plastic bowls, which are collected in August and September every year, operated by purchasing stations and then resold to factories. The former method has light color, less impurities and high tannin content. The rubber bowl harvested by the latter method has dark color, many impurities and low quality. (4) Rhizome raw materials: Through artificial harvesting, shallow roots such as Dioscorea cirrhosa and Red Roots can be pulled out by hand or dug with claw tools, and deep roots such as tare and Rumex can be dug with iron harrow. If it is planted artificially, a harvester will be used to dig a ditch 40 cm deep and then harvest it.
Italy and France are brown trees with good penetration and combination. 10 has been used for about 50 years. 14 Hydrolyzed Castanea henryi Paraguay is used as a woodworking adhesive. Argentina has fast penetration, good combination, light brown color and can be a big tree. It will be used in about 200 years. Concentrated heartwood, Acer truncatum Bunge of Ururachus family in Kenya, Brazil is good, and can also be used as woodworking adhesive. Black wattle with concentrated bark of mimosaceae is light brown and yellow in Turkey, with good tanning property of 25? Quercus variabilis with hydrolyzed bowl shell bucket has good filling performance. After 8 to 50 years, the color of China is brown to yellowish brown, converging and combining with trees, wild or artificial planting. 18? Hydrolyzed cork oak (Phyllanthus embllica)China has light brown color, quick penetration and good tanning property. Shrubs, small trees, wild 2 1? 33 Concentrated Bark Citrus (Myrica rubra) China of Euphorbiaceae has light brown color, quick penetration and good tanning property. Shrubs, small trees, wild 15? 18 Myrtaceae concentrated bark Myrica rubra has good heat resistance. The color of China and Soviet Union is reddish brown, which is used for tanning insole leather to leather trees. About 100 years ago, 12 18 tannin content (%) of condensed bark tree species of Larix gmelinii in main producing areas; tannin is utilized by some families and species.
Table 1 After harvesting, the water content of bark, wood and shell is about 60%, and the water content of fresh roots is above 60%. It must be dried as soon as possible to prevent the deterioration of raw materials. Generally, natural air drying is used to reduce the moisture in raw materials to below 16%. If necessary, it can also be dried by hand and baked below 50℃. This method can shorten the time, but it is more laborious and costly than natural air drying.
grade
The dried raw materials can be classified according to color depth, moisture content and tannin content. For example, the bark of deciduous pine is divided into two grades according to the wood, appearance and inner surface color in the bark. The quality of primary and secondary wood is ≤0.5 and 0.8 respectively; The color is brownish red to dark gray. China rubber Bowl is divided into three grades (Table 2).
Table 2 Shipment
Before shipment, the bark shall be bound into bundles (90×60×50 cm) manually or mechanically, and the weight shall not exceed 80 kg. Bark that has been cut or cannot be bundled can be packed in sacks or other packaging (such as containers). Each bundle or bag should be marked, indicating the variety, bundle weight and grade. All kinds of raw materials are transported according to local transportation conditions and distances.
Inspection before acceptance
Each batch of tannin extract raw materials shall be sampled and inspected according to the relevant sampling and inspection methods of national standards. Check whether the raw materials are mildewed, doped and adulterated, and whether the appearance color is consistent, so as to determine the grade of the raw materials entering the factory.
shop
Raw materials are stored indoors and outdoors. Indoor warehouses are mainly simple, and the warehouse volume depends on the quantity of raw materials stored, generally 200 ~ 300 tons is appropriate. The ground should be paved with boards or bricks, kept dry, and 1.5m channels should be set every 6m. Keep good ventilation at the top and around the warehouse, and the top and walls shall not leak water. Outdoor stacking forms, such as conical, pyramid and rectangular stacking, are adopted, and the stacking height can reach more than10m. The bottom of the pile is lined with wooden strips and cement strips, more than 30 cm from the ground, and it is ventilated and moisture-proof. Cover the top with waterproof material (such as linoleum) to prevent the deterioration of raw materials. Air-dried raw materials should be stored indoors for about a year. Because of long-term storage, the quality of raw materials has changed, which shows that the total extract in raw materials is reduced and the color is deepened. If the rubber bowl is stored for one year, the total extract will be reduced by about 4%. The color of orange peel (red+yellow) is 5 ~ 6 before storage and 17 after storage for 2 ~ 3 years. Rubber bowl before warehousing 14, after warehousing 40. Raw materials stored in the open air and exposed to wind, rain and sunlight are more likely to deteriorate and should not be used.
Koch, P.Peter Koch, 1920 ~ a famous American timber scientist. Born in 1920, 10, 15. 1954 graduated from the university of Washington, USA, with a doctorate in wood science. He served as the project director of the Southern Forestry Experimental Station and the Mountain Forestry Experimental Station of the US Forest Service. 1972- 1973 was the president of American forest products research society, 1974 was elected as an academician of international timber institute, and 1985 was an adjunct professor of Nanjing Forestry University in China. He has been engaged in the research of rational utilization of pine broad-leaved trees for a long time, and has obtained many patents, such as chipping cutter head device, gluing pine veneer square wood and various equipment for whole tree utilization. Won the USDA Excellent Service Award twice in a row (1968, 1973). He has published more than 0/00 papers/kloc. The main monographs are * * * 2 Volume "Utilization of Southern Pine" (1972) and * * 3 Volume "Utilization of Broadleaf Trees in Southern Pine Land" (1985). (Wang Wei)
Coleman, 1906 ~ A famous wood scientist in the Federal Republic of Germany. Born in190665438+1October 65438+May. 1932 received a doctorate in engineering from Berlin technical university. 1934 ~ 1939 professor and director of prussian timber research institute. 1940 to 1945 as the director of the national timber research institute. 1949 ~ 1954 Professor of Wood Technology, University of Hamburg. 1954 ~ 1982 professor and director of wood research institute of Munich university. 1986 retired as honorary professor of the school. Coleman is also a foreign academician of the School of Engineering of the Royal Swedish Academy, an honorary doctor of Stockholm University of Science and Technology, a consultant of Swedish Timber Research Institute and the first president of the International Timber Society. 1970 won the Grand Cross of the Federal Republic of Germany.
Coleman has published hundreds of papers on wood science and wood technology. The main monograph is principles of wood science and wood technology (with W.A.C? Té, Jr., et al., 1975), ***2 volumes, of which the second volume has been translated into Chinese.