Analysis of common defects in scouring and bleaching of silk fabrics

1. Gray damage

(1) reason

① The scouring time is too long.

(2) The boiling liquid has high temperature and excessive boiling, resulting in friction between blanks and filaments.

(3) The raw silk is wound and rubbed against the cloth guide wheel.

④ The degumming rate of blank silk is too high.

(2) Preventive measures

① Reasonably determine the scouring process.

② Reasonable bath ratio and speed.

(3) Avoid knotting and car entanglement when the blank silk runs in the dyeing machine.

④ Reduce the degumming rate appropriately.

2. White fog

(1) reason

(1) When the soap is scrubbed with alkali, the soap meets hard water and adheres to the grey cloth, resulting in insoluble calcium and magnesium.

② After training, it was not cleaned in time, and residues and dirt condensed on the grey cloth.

③ Amphoteric surfactants are used in the same bath. Due to the change of pH value of scouring solution, the polarity of amphoteric surfactant changes, which reacts with polar amphoteric surfactant and adheres to fabric.

(2) Preventive measures

(1) Soft water is needed for refining.

(2) Wash in time after practice and strictly control the temperature. The washing temperature for the first time should not be lower than 80℃, and then gradually cool down.

(3) The reasonable selection of surfactant and the appropriate dosage of sodium silicate should ensure that the refined liquid has good emulsification and diffusion ability.

3. Hard and rough

(1) reason

The amount of scouring AIDS is insufficient, the scouring time is too short and the temperature is too low.

(2) Preventive measures

Make a reasonable process and operate strictly according to the process.

4. Mildew spots and mildew spots

(1) reason

Wet grey cloth has accumulated for too long.

(2) Preventive measures

The stacking time of wet grey cloth shall not exceed 8 hours.

5. Insufficient whiteness

(1) reason