Types of dyeing

Dyeing of textiles can be done at any stage, including fibers, yarns, fabrics, and finished garments. We usually refer to the first two methods as "pre-dyeing" and the latter as "post-dyeing."

(1) Staple Fiber Dyeing Dyeing of fibers or staple fibers before spinning, placed in a large dye vat, and dyed at an appropriate temperature. Most color-spun yarns use the method of staple fiber dyeing (there are also effects of dyeing different fibers separately), commonly used for coarse wool fabrics.

(2) Wool Sliver Dyeing This also belongs to fiber dyeing before yarn formation, with the same purpose as staple fiber dyeing, which is to achieve a soft mixed color effect. Wool sliver dyeing is generally used for worsted yarns and wool fabrics.

(3) Yarn Dyeing Dyeing of yarns before weaving, generally used for colored fabrics, wool sweaters, etc., or directly using yarns (such as sewing threads). Yarn dyeing is the foundation of dyeing and weaving. There are three common methods of yarn dyeing:

① Hank Dyeing - Loose hanks of yarn are immersed in a specially designed dye vat; this is a costly dyeing method.

② Tube Dyeing - The yarn for tube dyeing is wound around a perforated tube, and then many tubes are placed in the dye vat, with the dye solution circulating. The fluffiness and softness are not as good as hank dyeing.

③ Beam Dyeing - This is a large-scale package dyeing. Before weaving, a beam (warping) is made, and the yarns of the entire beam are dyed, such as using a combined sizing and beam dyeing machine. Since it is a beam, it is mostly suitable for woven dyeing. However, with the advent of beam-to-tube systems, we can convert the dyed yarns on the beam into tube yarns, which expands the range of use for dyed yarns. For example, indigo dyeing mostly uses reduction dyeing methods, which can only be effectively solved by beam dyeing. Without beam-to-tube systems, it is very difficult to achieve.

(4) Piece Dyeing The method of dyeing fabrics is called piece dyeing, with common methods including rope dyeing, jet dyeing, pad dyeing, and beam dyeing. These will not be introduced one by one here.

(5) Garment Dyeing Garments are placed in nylon bags, and a series of bags are put into the dye vat, where they are continuously stirred (using paddle-type dyeing machines). Garment dyeing is more suitable for knitted socks, T-shirts, and most knitted garments, as well as simple garments like sweaters, pants, and shirts. We will also introduce garment dyeing in detail in the chapter on "Advanced Technologies and Special Processing Techniques in Garment Manufacturing."

Currently, the dyeing and printing industry is undergoing technological innovation, increasing demand, and intensifying market competition. With the recovery of the global economy, the demand for textiles continues to grow, and the dyeing and printing industry, as an important link in the textile industry chain, is also showing a steady development trend.

Current Situation of the Textile Printing and Dyeing Industry

The textile dyeing and printing industry is an important sector that is widely involved and closely connected to people's lives. Currently, with the development of the global economy and the improvement of living standards, the status of the textile dyeing and printing industry is also constantly changing. Below is a brief overview of the current situation in this industry.

Textile Printing and Dyeing Waste Gas Treatment Technology Solutions

The textile printing and dyeing industry generates a large amount of waste gas during the processing, which not only pollutes the environment but also poses a threat to human health. Therefore, adopting effective waste gas treatment technologies is crucial for the textile printing and dyeing industry. Below are some technical solutions for treating waste gas in textile printing and dyeing.

The three major processes of dyeing and printing.

The preparation of raw fabric includes raw fabric inspection, re-rolling (by batch, by box, printing), and seam sewing. The purpose of raw fabric inspection is to check the quality of the grey fabric and to address any issues promptly. The inspection content includes physical indicators and appearance defects. Burning off the fluff aims to remove the fluff on the fabric surface, making it smooth and aesthetically pleasing, and to prevent uneven dyeing and printing defects caused by the presence of fluff during dyeing and printing. To facilitate smooth weaving, textile factories often apply sizing to the warp yarn to enhance strength and abrasion resistance. The sizing on the grey fabric affects the fabric's water absorption properties, impacts the quality of dyed and finished products, and increases the consumption of dyeing chemicals. Therefore, the sizing should be removed before boiling and processing, a process known as desizing.

Types and Characteristics of Textile Coating and Finishing

Coating finishing is a common textile post-finishing technique, which generally includes the following methods.

The principle of dyeing

The dyeing process of fiber fabrics generally goes through three stages: surface adsorption, internal diffusion, and dye fixation.