Abies are distributed in Asia, Europe, North America, Central America and North Africa, and there are about 50 species in the world. The tree species with high fat yield are balsam fir, Bashan fir, Minjiang fir, Dongling fir, bitter-leaved fir and Siberian fir. Canada first made fir gum from balsam fir resin, hence the name Canadian balsam. In the early 1960s, China made fir gum from Dongling fir resin and Minjiang fir resin and put it into production.
collect
There is no normal resin channel in the xylem of fir, and the resin is stored in the skin tumor or needle in the primary cortex. Skin tumors vary in size and shape, such as spherical and oval. Skin tumors with high resin content are mostly concentrated in the middle of trunk. There are two ways to collect fat: ① Set up trees to collect fat. During May-August, the skin tumor was punctured with a pointed glass cutter, and the resin was squeezed with fingers to make it flow into the receiver. A tree in the forest can produce 50-200 grams of resin every year, and the isolated tree can reach 500 grams. In China, each person can harvest resin 1 kg every day, up to 2.5 kg ... (2) Cut down trees to extract resin. Collect resin from cut tree trunks, or concentrate bark for resin collection after wood making and peeling. In the process of oil extraction, contact between copper, iron and resin should be avoided. If there is bark, moss or other impurities mixed in, it must be filtered with fabric to prevent the color from darkening. Abies resin should be sealed in colored glass bottles, ceramic cans or white plastic pipes and placed in a cool place. Pay attention to sun protection and fire prevention during storage and transportation.
Fresh fir resin is almost colorless, and gradually turns yellow-green after a long time. It is transparent, slightly fluorescent, sticky and has a special smell. Soluble in ether, benzene, ethyl acetate, turpentine and other solvents, insoluble in water.
Abies resin does not contain benzoic acid or cinnamic acid and its esters. It is not a real balsam, but a resin containing essential oil. It consists of 65-80% resin acid, diterpene neutral substance with high boiling point, 18-35% fir oil and a small amount of free organic acid, pectin, tannin and alkali-insoluble resin. Resin acids contain a large number of rosin acids, neorosin acids and pimaric acids. Abies oil is mainly composed of monoterpenoids such as pinene and phellandrene. Abies gum contains diterpene neutrals with high boiling point and has excellent properties such as non-crystallization.
process
The processing flow of fir gum is shown in the figure.
Dissolve 65,438+000 parts of fir resin in 65,438+000 ~ 65,438+050 parts of ethyl acetate, add 65,438+000 parts of 3% brine, fully stir and wash twice to remove impurities such as water-soluble substances and dust. Adding anhydrous sodium sulfate to the resin solution for dehydration. Filter with medium speed filter paper. Concentrate and filtering that olefin resin solution unde reduced pressure. After concentration, filter with No.5 glass sand funnel. The filtered resin is distilled under reduced pressure to remove the solvent and volatile oil in the resin. When the resin reaches the required permeability, the distillation bottle is sent to a clean room, the resin is quickly poured into a packaging container, and the solid fir gum is obtained after cooling. Liquid fir gum is obtained by adding xylene with dry gum content of 1/3 to solid fir gum.
In order to improve the smell, toughness and low temperature resistance of fir gum, spices, essences or fixatives were added to fir gum to suppress its smell when heated. Adding non-toxic, tasteless, light color and chemically stable plasticizer to improve the toughness and low temperature resistance of Chinese fir glue.
Nature and use
Abies gum is a light yellow transparent solid with refractive index n1651351.5200 ~1.5400 and linear expansion coefficient α 0-251.6 ~ 2.0×1
Chinese fir glue has the characteristics of good transparency, no crystallization, strong adhesion and fast curing. The refractive index is similar to that of glass, which is resistant to high and low temperatures and easy to disassemble. Mainly used as adhesive, such as optical instrument lens, geological mineral grinding disc, biological slice and so on. Also used as antibacterial agent and hemorrhoid treatment agent; Root canal sealing material; Fixing agent or essence component of soap, detergent, vanishing cream and perfume; Hair modifier; Treat burns, ulcers, knife wounds and heart and chest pains.
Centrifugal disc spray drying tower
See the production process of tannin extract.
Liang Shizhen (19 16 ~)
Modern wood dryer and forestry educator in China. Born in Shashi, Hubei Province on May 7, 2006, 1965438. 1945 graduated from the Agricultural College of Central University with a master's degree in agronomy. In June 5438+10 in the same year, he went to England, majoring in wood science at Aberdeen University, and graduated from June 5438 +0948 with a doctorate. 1948 to 1954 served as an associate professor of Nanjing university, and successively served as the head of the department of forestry. 1955 ~ 1958 wood drying major, Leningrad Forestry Institute, Soviet Union. 1959- 1960, Dean of Nanjing Forestry College. 1960- 1984, professor of forest products department of Nanjing Forestry College, once the head of wood processing department and doctoral supervisor. He used to be a member of the second and third academic evaluation groups of the State Council Academic Degrees Committee and a director of the Wood Industry Society of China Forestry Society.
Liang Shizhen engaged in the study of wood microstructure in his early years, and published research reports such as Micro-structure of West Sichuan 175 kinds of wood, Micro-structure of domestic coniferous wood and Variation of Micro-structure of larch wood, which promoted the development of wood science in China. After 1949, he engaged in wood drying research and began to translate and publish Soviet wood drying science from 1957; 1960, the first book on wood drying in China was compiled and published. 1964 "Hydrothermal Treatment of Wood" was edited and published. Wood drying editor published in 198 1. He has published papers such as Theory and Practice of Superheated Steam Drying of Wood, Wood Cracking Potential, Expansion and Shrinkage of Sequoia and Its Relationship with High Temperature Rapid Drying.
Liang Shizhen 1978 won the National Science Conference Award, 1982 won the first prize of science and technology popularization by the State Science and Technology Commission and the Agriculture Commission, and 1984 won the title of advanced individual in science and technology popularization by the State Science and Technology Commission, the Economic Commission, the Ministry of Agriculture, Animal Husbandry and Fisheries and the Ministry of Forestry.