Yarn dyeing

Yarn (including filament) dyeing has a history of nearly a thousand years and has long been dyed using twisted yarn. It was not until 1882 that the first cylinder dyeing patent was granted in the world, followed by warp dyeing.

1.Twisted yarn dyeing

The dyeing method of converting short or long fibers into a twisted yarn connected in a frame on a yarn shaking machine, and then immersing them in various forms of dyeing machines is called twisted yarn dyeing. Due to the existence of multiple specialized books on yarn dyeing in the past, this book will not elaborate further.

2.Tube dyeing

Wrap short or long fibers onto a tube filled with holes (requiring appropriate and uniform winding density, generally referred to as a "loose tube"), then place it on the dyeing column (also known as a bamboo, spindle, insert rod, etc.) of the dyeing machine (also known as a flat plate, hanging disc, yarn frame, etc.), and put it into the tube dyeing machine. With the help of the main pump, the dye solution penetrates and circulates between the yarns or fibers in the tube, achieving tube dyeing.

3.Warp dyeing

According to the requirements of the color and quantity of the warp yarn in the colored fabric, the original yarn is wound on perforated coils in a loose warp machine to form a loose warp (which can be seen as a large tube), and then installed on the yarn carrier of the dyeing machine and placed in the warp dyeing machine. With the help of the main pump, the dye penetrates and circulates between the warp yarns or fibers to achieve immersion dyeing and obtain uniformly colored warp yarns. This method is called warp dyeing.

The warp pad dyeing is mainly used in the production and processing of denim fabric with color warp and white weft. It involves introducing a certain number of dilute shafts into each dyeing tank, and after repeated immersion, rolling, and air oxidation, it achieves the dyeing of indigo (or sulfide, reduction, direct, coating) dye. After pre drying and sizing, a uniformly colored warp yarn can be obtained, which can be directly used for weaving. The dyeing tank during warp rolling can be multiple (sheet machine) or one (ring machine), and this equipment used in conjunction with sizing is called a sheet dyeing and sizing combined machine.

4.Yarn bundle dyeing (ball dyeing)

This is also a special dyeing method for denim warp yarn. The dyeing process involves first bundling 400-500 strands of raw yarn into a spherical shape, and then repeatedly immersing, rolling, and oxidizing several bundles (such as 12 bundles, 18 bundles, 24 bundles, and 36 bundles) of yarn in multiple dyeing tanks to achieve indigo dye dyeing, followed by warp and sizing. Acrylic fiber bundles can also be subjected to bundle dyeing.

5. Special dyeing method for yarn

Like fabrics, yarns also have localized dyeing, such as knot dyeing, segment dyeing, tie dyeing, printing, discharge dyeing, gradient dyeing, etc.

1. Printing Festival

According to the design requirements, print a small section (such as 0.5-1cm) of color on the unfolded yarn at a set distance, which can be the same color, but mostly in five colors. It must be noted that the spacing must be irregular and uneven, otherwise "turtle backs" or "landscape paintings" will appear on the fabric.

2. Duan dyeing

Drip several dyes onto different parts of the unfolded yarn at the same time, vacuum absorb or roll the liquid, and then fix and wash. Compared with the printing section, the color segment is longer, the spacing between white yarns is smaller, and even adjacent colors may appear "color matching" on the yarn. Duan dyed yarn is commonly used on knitted fabrics.

3. Tie dye

Tie the local part of the twisted yarn tightly with ropes (or wrap it with plastic film), and then immerse it in dye. As a result, there is white space left at the tied part, and there is some color bleeding from deep to light at the tied part. The unbound part is uniformly colored, and the product has a unique charm.

4. Printing (printing)

This method is generally used for producing warp knitted fabrics. Print patterns on the warp yarn (not on the weft yarn), the product style is hazy, resembling flowers but not flowers. When printing warp, it is possible to first fake weave (knitting method involves printing first and then warping, while machine weaving method involves warping fake weaving printing), or directly print on the warp yarn. For example, synthetic fiber warp yarn can be printed on a transfer printing machine.

5. Gradient dyeing (rainbow silk)

Soak different parts of the twisted yarn (silk) in the dye solution for different times, so that each frame of yarn presents a gradient color without clear boundaries from light to deep, such as traditional Chinese embroidery seven color silk thread. In addition, there are also half dyeing, spray spot dyeing, single yarn continuous immersion dyeing, etc.