DYEING PROCEDURE

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ii) Pad dyeing method

(1) Pad batch method

Procedure, are padded in the above padding liquor and batched on a plastic sheet and kept for about 20 hours and then washed. However, all dyes are not suitable to this method. Hence proper selection must be done.

It is also applicable by using Caustic Soda plus Glauber's salt in place of Sodium Silicate + caustic soda as alkali agent in above padding liquor. This is particularly important to dyeing thick fabric such as, corduroy because removal of silicate is very difficult.

(2) Printing Methods

Bi-functional dyes are applicable by various printing methods on cellulosic material with the following advantages:

1. Suitable for various method of printing with a high fixation degree.

2. Print paste containing alkali has superior storage stability.

3. A smaller amount of alkali is sufficient for dye fixation.

Print - Dry - Steam - Wash - Dry (Bi-functional dye + alkali).

Procedure

The goods are printed with above print paste and dried.

The dried goods are then steamed for 7 to 10Mon. at 100⁰ - 103⁰C in saturated steam and washed.

Print - Dry - Pad - Batch – Wash (Bi-functional dye without alkali (Sodium Silicate)

The goods are printed with paste containing no alkali and dried.

The dried goods are then padded in a sodium silicate solution covered with a plastic sheet and kept for 20 to 24 hours and washed.

Washing off:

To obtain optimum fastness properties a thorough and complete wash off should be given to printed goods. The goods are first washed thoroughly in cold water and then in hot water. Then boil it for about 5Min to anionic detergent 1-2 parts/liter. Finally rinse in cold water and dry. Wherever necessary a treatment with dye-fixing agent may be given with 2-5 parts/liter of final wash liquor.