Optical brightener for acrylic fiber

The best choice of optical brightener for acrylic fiber is BAC-L . It is a cationic dye with a transparent brown liquid appearance. Here is a brief introduction to its chemical properties:

The common method of using optical brightener for acrylic fiber

1. Whitening of pure acrylic fiber

(1) Pure acrylic fiber whitening in separate bath

Process flow: Acrylic fiber → whitening → cooling → softening → washing → drying → finished product (formula based on fiber weight)

(2)Pure acrylic fiber with bleaching and whitening in one bath

Bleaching and whitening of acrylic fiber in one bath can achieve the best whiteness. Optical brightener BAC-L performs excellently in chlorinate bleaching. It is suitable for bleaching and whitening in one bath.

Process flow: Acrylic fiber → bleaching, whitening → washing → dechlorination → softening → washing → drying → finished product (formula based on fiber weight)

2. Whitening of acrylic and wool blended (50:50) fabrics

Regarding acrylic and wool blended fabrics (including yarn and wool), wool has poor whiteness and must be bleached before fluorescent whitening. There are two treatment methods: the same bath method and the separate bath method, and the separate bath method is more commonly used .

Process flow: wool/acrylic blended fabric → pre-bleaching treatment → oxidative bleaching → whitening → washing → drying → finished product (formula based on fiber weight)

(1) Pre-bleaching treatment

(2) Oxidative bleaching

(3) Acrylic whitening (based on fiber weight)

(4) Wool whitening (based on fiber weight)

3. Whitening of acrylic and polyester blended fabrics

Whitening of acrylic and polyester blended fabrics can be done by the same-bath method and the separate-bath method.

(1) Same-bath method

Same-bath method is a new process that combines the three processes of bleaching, acrylic whitening, and polyester whitening into one, and has the characteristics of a simple process, high productivity, and low cost.

Process flow: Acrylic/polyester blended fabric → bleaching → whitening → dechlorination → washing → drying → finished product (Formula based on fiber weight)

Note: In the above formula, adding polyester dyeing carriers, such as methyl salicylate, can increase the amount of dispersed whitening agent absorbed by the fiber.

(2) Separate-bath method

Separate-bath bleaching and whitening processes generally have higher whiteness than the same-bath process Process flow: Acrylic/polyester blended fabric → bleaching → whitening → washing → whitening → washing → drying → finished product ① Bleaching, acrylic whitening Formula (based on fiber weight)

② Polyester whitening Formula (based on fiber mass)

4. Whitening of acrylic and cellulose fiber (cotton, viscose, etc.) blended fabrics

Acrylic and cellulose fiber (cotton, viscose, etc.) blended fabrics are generally refined before bleaching. Since cotton fibers generally contain cotton scraps, wax, etc., pure cotton fabrics are often smelted at high temperatures with strong alkalis such as sodium hydroxide to remove these impurities. However, this treatment method will damage acrylic fibers and cause yellowing, so it is not suitable for acrylic/cotton and blended fabrics. Generally, the refining of acrylic/cotton blended fabrics is often done by washing with non-ionic detergents and treating with sodium hypochlorite. Since sodium hypochlorite has a bleaching effect, it is not necessary to bleach after such treatment, and fluorescent brighteners can be used directly for whitening.

Process flow: Acrylic/cotton blended fabric → refining → dechlorination → whitening → washing → drying → finished product

Formula (based on fiber mass)

Note: In order to increase the whiteness of the fabric, after dechlorination treatment, anionic whitening agents can be used at a temperature of 30-40℃ for 20-30min to whiten the cotton fibers.