Yarn dyeing method: yarn (including filament) has been dyed for nearly a thousand years and has been used for a long time. It was not until 1882 that the world had the first package dyeing patent, and then there was warp dyeing.
1： The hank dyeing method is to change the staple fiber yarn or filament into a skein yarn connected by frames on the spinning machine, and then conduct dip dyeing in various forms of dyeing machines. Since there have been many monographs on hank dyeing before, this book will not be repeated.
2： In package dyeing, the staple fiber yarn or filament is wound on the bobbin covered with eyelets (the winding density is required to be appropriate and uniform, generally referred to as "loose drum"), and then it is put on the dyeing column (also referred to as yarn bamboo, spindle rod, insert rod, etc.) of the dyeing machine (also referred to as flat plate, hanging plate, yarn frame, etc.), and put into the package dyeing machine. With the function of the main pump, the dye liquor can penetrate and circulate between the package yarn or fiber, and the way to achieve dyeing is package dyeing.
3： According to the requirements of the color and quantity of the warp yarn of dyed fabrics, the raw yarn is wound on the perforated coil on a loose warping machine to form a loose warp (which can be regarded as a large package), and then it is installed on the yarn carrier of the dyeing machine, and put into the warp dyeing machine. With the function of the main pump, the dye solution penetrates and circulates between the warp yarn or fibers to achieve the dip dyeing, so as to obtain the uniform color of the warp yarn. The method is called warp dyeing.
4： Warp pad dyeing Warp pad dyeing is mainly used in the production and processing of colored warp and white weft denim. It is to introduce a certain number of dilute shafts into each dyeing tank, and realize the dyeing of indigo (or vulcanization, reduction, direct and coating) dyes after repeated soaking, rolling and ventilation oxidation. The warp yarn with uniform color can be obtained by pre-drying and sizing, which can be directly used for weaving. The dyeing trough during warp pad dyeing can be multiple (sheet machine) or one (ring machine). This equipment used in combination with sizing is called sheet dyeing and sizing combined machine.
5： Bunch pad dyeing (ball warp dyeing) is also a special dyeing method for denim warp yarn. Its dyeing process is to first bundle 400~500 raw yarns into a ball shape, and then several bunches (such as 12, 18, 24, 36) of yarns are repeatedly dipped, rolled, and oxidized in multiple dyeing tanks, to achieve indigo dye dyeing, then warp and sizing. Acrylic tow can also be pad dyed.
6： The special dyeing method of yarn is the same as that of fabric, and the yarn also has local dyeing, such as knot printing, section dyeing, tie dyeing, printing, discharge dyeing, gradient, etc.
1). According to the design requirements, a small section (such as 0.5~1cm) of color can be printed on the spread skein every set distance, which can be the same color, but most of them are five-color. It must be noted that the spacing must be irregular and uneven, otherwise "turtle back" or "landscape painting" will appear on the cloth surface.
2). In stage dyeing, several dyes are simultaneously dripped on different parts of the spread hank yarn, and then fixed and washed after vacuum absorption or rolling. Compared with the printing section, the color segment is longer, the white yarn spacing is smaller, and even the adjacent two colors will appear "color matching" on the yarn. Segment-dyed yarn is widely used in knitted fabrics.
3). Tie-dyeing tightens the part of the hank yarn with rope (or wrapped with plastic film), and then carries out dip dyeing. As a result, the tightly bound part is left blank, and some parts of the binding part are colored from deep to light, and the unbound part is evenly colored, and the product has a unique charm.
4). Printing (warp printing) This method is generally used to produce warp printed woven fabrics. The pattern is printed on the warp (not on the weft), and the product style is hazy, like flowers but not flowers. When printing the warp, you can fake weave first (knitting method is printing first and then warping, weaving method is warping - fake weaving - printing), or you can print directly on the warp, for example, synthetic fiber warp can be printed on the transfer printing machine.
5). Gradual dyeing (seven-color silk) will dip different parts of the hank yarn (silk) in the dye solution for different times, so that each frame of yarn will show a gradual color from light to deep without obvious boundaries, such as traditional Chinese embroidery seven-color silk thread. In addition, there are half-edge dyeing, spray point dyeing, single yarn continuous dip dyeing, etc.
