The yarn is dyed into the chosen color before being woven. Generally used for fabrics, sweaters or directly using yarn, etc. Yarn dyeing is the basis of dyeing and weaving.
01 Characteristics of yarn dyeing
In the production process of textiles, at which stage is dyeing performed? , affected by several factors.
From an economic point of view, dyeing is performed at the front of the weaving production process, and its cost is the lowest. When dyeing yarns in the pre-weaving process, dyes with better fastness can be used, and some colors can be improved in subsequent weaving processes. Yarn dyeing can generally achieve good and firm leveling effects, and can be woven with natural yarns according to different design requirements, thereby obtaining higher economic value and shortening the delivery cycle, so the product has high reproducibility.
It is generally believed that products obtained from yarn dyeing are more bulky and fuller than products obtained from fabric dyeing. Advantage, this may be because when the skein is suspended on the rod of the dyeing machine, it is free to fully relax without any restrictions, not only allowing the yarn to be fully bulked, but also allowing the yarn to untwist freely to achieve the twist Balanced, thus eliminating tension during spinning.
Another form of yarn dyeing is cheese dyeing. Technically speaking, it used to be considered that only skeins were used Only by dyeing by dyeing can a satisfactory product be produced, but this traditional view is gradually changing with the emergence of cheese dyeing.
Generally speaking, the cost of yarn dyeing is higher than that of fabric dyeing. However, because it has the advantage of fast delivery, it is easier to adapt to changes in popular colors and to meet the needs of small batches and multiple varieties. In addition, yarn dyeing machinery is relatively simple and therefore economical in terms of maintenance.
02 Yarn dyeing method
Yarn (including filament ) dyeing has a history of nearly a thousand years, and hank dyeing has been used for a long time. It was not until 1882 that the world’s first bobbin dyeing patent was issued, and later beam dyeing appeared.
1 Hank yarn dyeing
The short fiber yarn or filament The dyeing method of converting the yarn into a frame of skein connected together on the yarn machine and then dip-dying it in various forms of dyeing machines is skein dyeing.
2 Package dyeing
Wrap the short fiber yarn or filament on a bobbin full of holes (the winding density is required to be appropriate and uniform, generally called a “loose bobbin”), and then put it on the yarn carrier of the dyeing machine (also known as flat plate, hanging plate, creel, etc.), put it into the package dyeing machine, and use the action of the main pump to make the dye liquid flow on the package yarn or yarn Penetrating circulation between fibers and dyeing are achieved through bobbin dyeing.
3 Beam dyeing
Press According to the requirements on the hue and quantity of the warp yarns of the dyed fabric, the raw yarn is wound on the coiled tube with holes on the loose warping machine to form a loose warp beam (can be regarded as a large bobbin), and then it is installed in the dyeing machine On the yarn carrier, put it into the warp beam dyeing machine, and use the action of the main pump to make the dye liquid penetrate and circulate between the warp beam yarns or fibers to achieve dip dyeing, so as to obtain warp yarns with uniform color and luster. This method is called warping. Shaft staining.
4 Beam pad dyeing
Warp beam pad dyeing is mainly used in the production and processing of denim with colored warp and white weft. It introduces a certain number of thin shafts into each dyeing tank, and after repeated multiple dipping, multiple padding, and multiple ventilation and oxidation, the dyeing of indigo (or vulcanization, reduction, direct, paint) dye is achieved. After pre-drying and then sizing, the warp beam yarn with uniform color can be obtained, which can be directly used for weaving. The dye tanks during warp beam pad dyeing can be multiple (sheet machines) or one (ring machine). This equipment used in combination with sizing is called a sheet dyeing and sizing combined machine.
5 Yarn bundle pad dyeing (ball warp dyeing)
This is also a special dyeing method for denim warp yarns. The dyeing process is to first bundle 400 to 500 raw yarns into a ball shape, and then bundle several bundles (such as 12 bundles, 18 bundles, 24 bundles, 36 bundles) of yarn The thread is repeatedly dipped, rolled, ventilated and oxidized in multiple dyeing tanks to achieve indigo dyeing, and then divided into warps.,sizing. Acrylic tows can also be pad-dyed.
6 Special yarn dyeing method
Like fabrics, yarns also have partial dyeing, such as knot printing, space dyeing, tie dyeing, printing, discharge dyeing, gradient, etc.
No.1 Seal Festival
According to the design requirements, a small section (such as 0.5 ~ 1cm) of color is printed on the spread yarn at a set distance. It can be the same color, but most of them are five colors. It must be noted that the spacing must be irregular and unequal, otherwise “turtle back” or “landscape painting” will appear on the canvas.
No.2 Section dyeing
Pour several dyes at the same time Different parts of the spread skein are vacuum-absorbed or squeezed, then fixed and washed. Compared with the printing section, the color sections are longer, the distance between the white yarns is smaller, and even two adjacent colors will appear “color matching” on the yarn. Space-dyed yarn is commonly used in knitted fabrics.
No.3 Tie-dye
Use part of the skein The ropes (or wrapped with plastic film) are tied tightly and then dip-dyed. As a result, the tied areas are left white, the tied areas have partial bleeding from dark to light, and the untied areas are evenly colored, giving the product a unique charm.
No.4 Stamping (Printing Scripture)
This method Generally used in the production of warp printing machine fabrics. Patterns are printed on the warp yarns (not on the weft yarns), and the product style is hazy, looking like flowers but not flowers. When printing warp, you can first fake weave (knitting method is printing first and then warping, weaving method is warping-fake weaving-printing), or you can print directly on the warp yarn. For example, synthetic fiber warp yarn can be printed on a transfer printing machine.
No.5 Gradient dyeing
Gradient dyeing (colorful silk) Dip different parts of the skein (silk) into the dye solution for different times, so that each frame of yarn presents a gradient color from light to dark without obvious boundaries, such as traditional Chinese embroidery seven-color silk threads. In addition, there are half-side dyeing, spray-point dyeing, single yarn continuous dip dyeing, etc. </p
