Manufacturing process of polyester DTY in different colors

1. Basic manufacturing process of polyester DTY:
The production process of polyester DTY generally includes the following steps:
Polymerization reaction: Polyterephthalic acid (PTA) and ethylene glycol (EG) are polymerized under the action of a catalyst to obtain polyester raw materials.
Spinning: The polyester raw materials are stretched into fibers through melt spinning technology and then properly processed.
Stretching: The fibers are further stretched through a hot stretching process to give them false twist characteristics and form DTY (false twist yarn) fibers.
Winding: The fibers are rolled into rolls for subsequent use.

2. Dyeing process of different colors:
The difference in color is mainly reflected in the dyeing process. Common colors of polyester DTY include yellow, gray, white, etc., and the dyeing method for each color is different.

(1) White polyester DTY:
Undyed or pre-dyed: White DTY is usually undyed polyester fiber, which is directly processed by spinning after polymerization of polyester fiber. It can also be used as an intermediate product for further dyeing or printing.
Post-dyeing process: If white polyester DTY is to be dyed later, solvent dyeing or high temperature and high pressure dyeing is usually used to maintain the purity of white.
(2) Gray polyester DTY:
Pretreatment and dyeing: Gray polyester DTY is generally polyester fiber that has undergone some special treatment before dyeing, such as gray pre-dyeing or direct dyeing into gray with different dyes. Gray dyeing can be completed by penetration dyeing or solvent dyeing.
Gray is a neutral tone, so the dyeing process is usually simple. When dyeing, avoid too much color to affect the breathability and comfort of the fiber.
(3) Yellow polyester DTY:
Use of yellow dye: Yellow DTY requires the use of specific yellow dyes. Common dyes include acid dyes, disperse dyes, etc. When using these dyes, it is necessary to control the dyeing temperature and time to ensure uniform color.
Dyeing process: The dyeing process of yellow DTY requires more sophisticated requirements. Especially in large-scale production, it is necessary to control the temperature and pH value of the dyeing process to ensure the stability of the final fiber and the durability of the color.
3. Effects of dyeing and treatment:
The dyeing process of polyester DTY of different colors will have different effects on the performance of the fiber, mainly including:

Color fastness: The depth and fastness of the color directly affect the service life of the finished product. For example, yellow dyes may fade more easily at high temperatures, so special fastness treatment is required.
Hygroscopicity and breathability: Dyeing and post-treatment processes may affect the breathability and hygroscopicity of polyester DTY. Polyester itself has poor hygroscopicity, and if the dyeing process is not handled properly, it may affect its comfort.
Softness: Especially for yellow and gray polyester DTY, the dyeing process may affect the softness of the fiber, which is very important for the comfort of some clothing fabrics.

4. Other processing technologies:
Anti-ultraviolet treatment: Some polyester DTY will add anti-ultraviolet treatment during the dyeing process to make the color more light-resistant, especially in outdoor products.
Antistatic treatment: Antistatic treatment of polyester DTY is also a common post-treatment process to avoid the negative impact of static electricity on the fiber.