JIANGYIN HUAHONG CHEMICAL FIBER CO., LTD.

Molecular structure: Both are modified polyesters, but they have different monomer compositions. Cationic dyeable polyester is usually a ternary copolymer obtained by adding a third monomer (such as sodium dimethyl isophthalate - 5 - sulfonate) during the polycondensation of polyethylene terephthalate. ECDP is a quaternary copolymer, which is obtained by further adding a fourth monomer (such as polyethylene glycol, dimethyl isophthalate, adipic acid, 1,4 - butanedioic acid, etc.) on the basis of the ternary copolymer. The introduction of the fourth monomer in ECDP changes the molecular chain structure, making it more conducive to cationic dyeing. Dyeing conditions: Cationic dyeable polyester generally needs to be dyed at a temperature of about 120°C or under pressure. In contrast, ECDP can be dyed under normal pressure and boiling conditions, that is, at about 100°C. This is because the molecular structure of ECDP is more open and loose, and the dye molecules are easier to penetrate into the fiber, so it can achieve good dyeing results at a lower temperature and pressure. Dyeing effect: Both can be dyed with cationic dyes to obtain bright colors. However, due to the special molecular structure of ECDP, it has a higher color absorption rate and can show more vivid and deep colors. At the same time, the color fastness of ECDP is also relatively good, and it can maintain bright colors after multiple washes and usages. Production process: The production of cationic dyeable polyester only requires the addition of a third monomer in the polymerization process. While the production of ECDP requires the addition of a fourth monomer on the basis of the third monomer, and the control of the polymerization process is more complex. For example, in the production of ECDP, the selection and dosage of the fourth monomer, as well as the reaction temperature, time and other parameters, need to be strictly controlled to ensure the performance of the product. Performance and application: In addition to dyeing performance, ECDP has some other excellent properties. For example, it has better hygroscopicity and antistatic properties, and the fabric made of it is more comfortable to wear. These properties make ECDP more widely used in the textile industry, especially in the production of high - end clothing, home textiles and other products. Cationic dyeable polyester is also widely used, but in some fields where higher dyeing requirements and comfort are required, ECDP has more advantages.

Dye types: Cationic dyeable polyester: As the name suggests, it is designed to be dyed with cationic dyes. These dyes are positively charged and can form ionic bonds with the negatively charged groups introduced into the polyester during its modification, resulting in bright and vivid colors with high color fastness. Traditional polyester: Usually requires disperse dyes for dyeing. Since traditional polyester has a compact molecular structure and lacks polar groups, disperse dyes, which are small - molecule non - ionic dyes, are used. They enter the polyester fiber through diffusion and mechanical occlusion. Dyeing temperature: Cationic dyeable polyester: Can be dyed at a relatively lower temperature, typically around 100 - 110°C. The modified structure of the fiber allows the cationic dyes to penetrate and bond with the fiber at this temperature range, reducing energy consumption and potential damage to the fabric. Traditional polyester: Generally requires a higher dyeing temperature, usually around 130°C. The high - temperature environment is necessary to increase the mobility of the polyester molecules and enable the disperse dyes to diffuse into the fiber. Use of auxiliaries: Cationic dyeable polyester: May require specific auxiliaries to assist in the dyeing process. These auxiliaries can help adjust the pH of the dye bath, promote the dissolution and dispersion of cationic dyes, and improve the dye - uptake rate and color uniformity. For example, some leveling agents may be used to ensure even dye distribution. Traditional polyester: When using disperse dyes, auxiliaries such as dispersing agents are crucial. They help to evenly disperse the insoluble disperse dyes in the dye bath and prevent dye aggregation. Additionally, carriers may be added in some cases to enhance the dye - uptake of polyester at lower temperatures. Dyeing process: Cationic dyeable polyester: The dyeing process is relatively simple. After preparing the dye bath with the appropriate cationic dyes and auxiliaries, the fabric is immersed in the bath, and the temperature is gradually raised to the desired dyeing temperature. The dyeing time is usually shorter compared to traditional polyester, typically around 30 - 60 minutes, depending on the depth of color and fabric type. Traditional polyester: The dyeing process is more complex. It often involves pre - treatment of the fabric to remove impurities and improve its wettability. Then, the fabric is dyed in a high - temperature and high - pressure dyeing machine with carefully controlled temperature and time profiles. The dyeing time is usually longer, ranging from 60 - 120 minutes, followed by post - treatment processes such as washing and soaping to remove unfixed dyes and improve color fastness.

Composition and Structure Properties Production Process Applications