Polyester, whose chemical name is polyester fiber, has the advantage of good wrinkle resistance and shape retention, and high strength. Polyester is widely used in the textile industry because of its durability, anti-wrinkle and non-ironing properties. In addition to being used to make clothing fabrics, polyester is widely used in the carpet industry.

Ordinary polyester can only be dyed with disperse dyes. Due to the characteristics of polyester fibers, polyester carpets have poor dyeing property, and it is difficult for dye molecules to enter the fibers, resulting in more floating colors, poor hygroscopicity, easy to be electrostatically charged, and not resistant to stains. In order to improve these shortcomings of ordinary polyester, asymmetric third monomers or polar groups are introduced into the macromolecular chain of polyester fiber. Modified polyester fibers can be dyed and printed with cationic dye inks.

Cationic dyes are dyes that exhibit a cationic state in aqueous solution, also known as basic dyes and base dyes. Cationic dyes are soluble in water and ionize in aqueous solution to produce positively charged colored ions. The cationic dye can combine with the acidic group of the third monomer in the fabric to dye the fiber. Cationic ink for carpets has the advantages of good permeability, bright color, and good sunlight fastness. Some carpets don’t need to be washed by water after color fixation, reducing the pollution discharging pressure for enterprises.

Cationic dye inks are mainly used in the dyeing and printing of acrylic fibers and modified polyester fibers in industries such as clothing, carpets, and shoe materials.

As a professional digital textile ink manufacturer, Hongsam Digital continues to develop innovative products that meet social needs and assists the digital transformation in the textile printing field. In order to solve the pain points of the textile industry, Hongsam Digital increases investment in research and development and developed cationic dye inks. 

Digital printing with cationic dye ink can be divided into two types: digital printing on cloth and digital printing on carpets.

A. Digital Cloth Printing with Cationic Dye Inks:
Cloth preparation - (starching) - printing and drying - evaporation and color development (100-105℃ 25-40min) - cold water washing - soaping (50℃, soaping agent 3g/L) - warm water washing (40- 50℃)—cold water washing and drying—finished product
1. Cloth starching: Customers can decide whether to starching according to the weight of the fabric. If the weight of the fabric is small and the printing is easy to bleed, starching is required. When starching, customers should ensure that the fabric has the same fluid content on the left, middle and right sides to avoid poor printing effect caused by uneven starching.
2. Washing after printing: cold water washing - soaping (50℃, soaping agent 3g/L) - warm water washing (40-50℃) - cold water washing
Note: If necessary, soaping agent can be added during the first cold washing process to prevent the fabric from staining.

B. Digital Carpet Printing with Cationic Dye Inks:
Carpet prewetting - printing and drying - evaporation and color development (100-105℃, steaming for 15-25 minutes, spray fixing agent during the process) - (washing) - drying and shaping - finished product
1. Carpet washing solution: Customers decide whether to wash the carpet. Carpet washing is limited by equipment, it is generally sufficient to rinse by a cold running water.
Note: The carpet that has just evaporated and developed color must be cooled by air before being rinsed with cold water. Otherwise, the carpet temperature will be too high and the cold water will turn into warm water, causing the white carpet to be stained.
2. Carpet color fixing: Carpet color fixing is generally carried out by spraying AA-03, a special color fixing agent for carpets (1%-2% diluted), in the middle of evaporation and color development. AA-03, a special color fixing agent for carpets, has the characteristics of obvious fastness improvement, no color change before and after color fixing, safety and environmental protection.
Note: The dilution rate of AA-03 can be adjusted appropriately according to your own requirements on fastness. When spraying the color fixing agent AA-03, make sure the amount is evenly applied on the left, middle and right sides.

According to the weight and color of the carpet, increase or decrease the amount of fixing agent appropriately.

Due to the increasing use of modified polyester in the carpet industry, the disadvantages of disperse dyes on printing modified polyester will become more and more prominent, and the advantages of cationic dyes will become more obvious. With the development of dye technology, cationic dyes will surely shine in the carpet industry.