People.com.cn Beijing August 31st news two Chinese researchers used eight years time to complete from roots, stems and leaves, flowers, fruit pigment extraction from high-end technology, make the plant color in the textile, food, beverage, pharmaceutical, paper, building materials and other fields applied to become a reality.
The application of color in the long-standing plant. Thousands of years ago, human ancestors in decocting traditional Chinese Medicine found soup colored juice can be used to stain, so this finding is widely used in dyeing, ancestors clothing also began a riot of colours. This staining technique used for more than four thousand years.
In 1956 the British scientific expert Bai Jin in the development of Western Medicine found purple crystal, referred to as aniline purple synthetic dyes which is a basic dye, 1868 German chemists Grabe and Li Xiaoman produced the lawn grass red ( synthetic ) this is the first artificial replacement plant dyes dye, the dye was born in chemistry. Because at that time the British Industrial Revolution, the birth of advanced textile machinery and equipment, chemical dyes as can be quantified, good color fastness is suitable for modernized production, greatly improving the printing speed and quality, so the traditional plant dye technology be mercilessly eliminated, gradually forgotten. Only a handful of remote and backward areas used for home printing, as well as some clothing designers involved occasionally. Dyeing plants are eliminated, the main plant dyeing can not be quantified, the ancients used cauldron big cylinder containing pigment plant inside, the plant pigment in boiled, then the dyed cloth or clothing and knitting wool, cotton yarn in cooking, as to how long the number temperature, dyeing, all by the master's experience. The dyed cloth, cotton, wool, color, poor color fastness. This artificial staining technique can not be applied to the modern dyeing equipment.
In recent years, scientists have found that printing and dyeing plant toxic wastewater into the river, lake, sea, pollution degree is amazing, devastating environmental disaster, sewage discharged into the river after floating foam be riotous with colour, and contains a strong acid, alkali and formaldehyde, and many other toxic substances, waste water through the rivers, dissolved oxygen is almost zero, fish and other creatures died, eutrophication aggravating changed turbidity malodorous, flows through the sides of desertification of land, plant all gone. On the ground, underground water pollution makes water reach the safety standards, people in anhydrous drinking status, has reached alarming proportions. At present, China has 700000000 population is not up to the standard for safety of drinking water. Many Asian countries is similar to those of textile production.
Chemical dyes textile for enhancing color fastness using phenol formaldehyde fixing agent, and the use of formaldehyde finishing. Cause of textiles containing formaldehyde and many other harmful substances, so that a considerable part of a person wearing out, skin irritation, allergic after inflammation, pus, airway inflammation and even cancer phenomenon.
The European Union has publication does not allow textile containing azo dyes in the 23 intermediates, if found to contain one is substandard products are not allowed to enter the EU market.
Banned azo dyes dyeing clothing and human body after long exposure, in the metabolic process with the release of the ingredients are mixed, and produces a reduction reaction, the formation of carcinogenic aromatic amine compounds, such compounds are absorbed by the human body, through a series of activation of human cells of DNA structure and function changes, become human lesion causes.
Chemical dyes malpractice already caused each country government and scientists' attention, but the solution is simply limited printing and dyeing industry wastewater emissions and limit of formaldehyde content in textile, these approaches can not fundamentally solve the problem of chemical dyes serious pollution to the environment and harm human health problems. Human consumption is increasing on textiles. Special emphasis is placed on the printing and dyeing industry wastewater reuse rate is less than 7%, and a ton of sewage pollution in 20 tons of clean water.
Vegetable dyes and its process since it is environmentally friendly, can once again return to the life of human beings instead of chemical dye? Many experts and scholars in this effort, but so far no one can solve vegetable dye purification to quantify and improve colour fastness problem, just found some containing different pigment plant and demonstration plant color dye is healthy, is the future development direction.
Zhou Lingxiao and Zhang Meizhi after many years of hard work, finally completed the plant color extraction, purification, quantification and improve colour fastness to tackle key problem, published " the plant color extraction, purification and application ". They say, plant color not only can be used in textile dyeing and printing industry, in others such as food, beverage, paper, plastics, building materials, pharmaceutical and many other fields have a wide application prospect, and can completely replace the chemical color, the benefit of mankind.
