Explanation On Dyeing And Printing Process Of Real Silk Fabrics

Before the invention of synthetic dyes in 1856, all silk dyeing and printing were made of natural pigments derived from plants, animals and minerals. Natural dyes It can be coloured in real silk, and its color fastness is not inferior to the synthetic dyestuffs used nowadays. There are more kinds of natural dyes from plants. Indigo, ruby, safflower, shikonin, green grass and gardenia are commonly used in ancient China. Animal origin dyes are less, mainly lac purple, carmine: and so on. Mineral pigments are Dan Sha, powder tin, lead Dan, Daqing, green house, ocher and so on. In addition to cylinder dyeing, ancient printing and dyeing methods include drawing, tie dyeing, batik, letterpress and printing.

However, the extraction and matching of natural dyes and their application in textile dyeing are not as convenient as synthetic dyes, and natural dyes are difficult to be prepared to be used as stabilizers at any time. Therefore, natural dyes are quickly eliminated by synthetic dyes. Moreover, many kinds of plants that can extract dyes are also effective herbs, which can make fabrics obtain certain health care functions. Many consumers who prefer natural dyes and textiles are attracted by this unique fragrance. Therefore, in recent years, there has been a fashion trend of textiles returning to natural dyes and natural fibers in the world. Natural textiles such as silk and cotton, which are dyed by natural dyes, become fashionable products with high added value, and their market prospects are promising. The natural dyes used in modern times are mainly disseminated and screen printing. The most widely used natural dyes are plant source dyes.

　　 Botanical dyes It is extracted from plant roots, leaves, bark, stems or fruits. According to its chemical composition, it can be divided into: carrot B, curcumin, anthraquinone, indigo, chlorophyll and tannin (also called tannins). Carotene B is widely found in plant leaves, tubers and fruits. It contains two kinds of chlorophyll and lutein. It is easy to oxidize and fade under acidic conditions. Curcumin is found in rhizomes of Curcuma longa and Rhizoma Curcumae longs, and is not resistant to light. Anthraquinone dyes exist in plant roots, and many important red natural dyes belong to this chemical composition. Anthraquinone dyes have good fastness to light and are easy to form metal compounds. Indigo dyes are mainly used for cotton printing and dyeing. For example, the traditional technology of blue printed cloth, which is currently popular in the market, is produced by indigo dyeing and printing. Chlorophyll is a green dye extracted from plant leaves and stems. It is bright but easy to oxidize. Tannin plant dyes usually contain hydrolyzed tannins, which are easy to hydrolyze to produce bis gallic acid, etc., which will complexing all kinds of metal ions to dye the fibers. For example, the traditional silk products, the sweet potato silk, is dyed black with tannin iron complex.

The extraction of plant dyes usually takes advantage of local resource rich plant species. India is a rich country of plant resources. Therefore, the research of plant dyes is quite active, and its development and utilization are earlier and widely used. India is in Real silk The main dyes used in printing and dyeing are: Jatropha curcas, Lantana camara, India Berberis roots, Euphorbia leaves, madder leaves, walnut bark. Jatropha curcas is a tropical evergreen tree or large shrub with a height of lO and 15 feet. It belongs to Euphorbia, with many branched stems and dark green leaves, and pink and yellow flowers when it first opens, then red or orange. Use their flowers to dye pure white to lavender series. Euphorbia is a tall shrub that can grow to 2 lOm. This deciduous shrub usually has long leaves in winter. Its oval leaves are rich in colourful natural pigments in deep red, red, white or yellow in winter.