High-temperature and high-pressure dyeing is an important dyeing method for polyester fibers. Due to the dyeing characteristics of polyester fibers and the special method of high-temperature and high-pressure dyeing, it also has special requirements for levelling agents for high-temperature dyeing, and also because of textile semi-products. The difference in form category has further produced different special individual requirements for high-temperature levelling agents. Therefore, in addition to the basic properties such as slow dyeing and migration dyeing suitable for high temperature conditions of 130℃, there should also be special varieties that meet the dyeing characteristics of various polyester fiber semi-products. Otherwise, specific applications will be difficult. It is well aimed at the individual characteristics of various types in high temperature and high pressure dyeing, which greatly reduces the applicability.
Different dyeing characteristics of different fiber semi-product categories
The various semi-finished textile types of polyester fibers also come in various forms such as loose fibers, yarns, and fabrics. Bulk fiber dyeing is required for dyed spinning. Yarn dyeing is mainly used for yarn-dyed weaving, followed by sewing and embroidery; the dyeing of fabrics is used for garments, home textiles, and industrial fabrics. The dyeing of fabrics is divided into various forms such as loose dip dyeing, open-width jig dyeing and beam dyeing. Although the same high temperature and high pressure method is used for dyeing, different forms of fiber semi-finished products must be matched with different dyeing equipment that meets the characteristics of their respective forms; otherwise, the style, characteristics, and product quality of the textile will be obviously serious. Damaged, or even non-staining feasibility.
The loose dip dyeing machine is suitable for weft-knitted, warp-knitted knitted fabrics, and wool-like woven fabrics. Open-width jig dyeing is suitable for woven fabrics with no elastic requirements, especially for filament-like thin woven fabrics, which are generally not necessary for this type of machine. For the sparse warp knitted fabrics of the grid type (such as mosquito nets, etc.), the warp beam dyeing machine is suitable.
Yarn is mainly dyed in a bobbin or caged hank method. Although loose fiber is also dyed in a caged method, it is also quite different from the caged dyeing of yarn.
Basic functions of high temperature levelling agent
Hydrophobic disperse dyes are suitable for dyeing hydrophobic polyester fibers, but the hydrophobic nature of the dye determines its low water solubility. This is a matter of contradictory nature in the dyeing process using water as the medium. For this reason, in commercial disperse dyes, a large amount of surfactants such as diffusing agents not less than the proportion of the dye are blended. Generally dye: filler=1:1~1.5. As an additional high-temperature leveling agent added to the dyeing working bath, it also has a certain auxiliary and supplementary effect to promote the suspension and diffusion of the disperse dye particles in the dyeing working bath and maintain a uniform and stable distribution. This is particularly important for light and medium shades with a small amount of dyes, because the amount of light and medium shades of dyes is correspondingly less, and the diffusing agent brought from the dyes is also reduced simultaneously. High-temperature levelling agents are necessary Provide a certain degree of compensation.