1 The snowflake washing mechanism of knitted garments
Pure cotton plain knitted garments use pumice stone to absorb strong oxidant, and through the reciprocating movement of mechanical equipment, the strong oxidant on the pumice stone is evenly transferred to the surface of the fabric. Under certain conditions, the dye on the fiber is oxidized by the oxidizing agent to produce a snowflake-like stone grinding process.
2 Determination of the snowflake washing method
There are usually two ways to wash snowflakes. One is a strong oxidant prepared by pre-mixing potassium permanganate and phosphoric acid or sodium hypochlorite. It is mainly suitable for the dyes to be divided into different structures of the snowflake washing, which can produce a uniform flat snowflake style. The other is a mixture of sodium hypochlorite and shuttle methyl cellulose. It is mainly suitable for the snowflake washing with similar dye molecular structure, which can produce three-dimensional snowflake style.
3 Choice of dyes and auxiliaries
Because the molecular structure of some dyes (such as the yellow onion monomer) is difficult to oxidize, dyes that are easy to oxidize and quickly decolor should be selected when the knitted garments are washed. At the same time, according to the dye type of the dyed fabric, choose different snowflake washing auxiliaries.
3.1 Dyes suitable for decolorization of potassium permanganate and phosphoric acid mixture
Sulfur dyes, such as Sulfur Black BRN, Sulfur Bright Green 511
3.2 Dyes suitable for decolorization of potassium permanganate and sodium hypochlorite mixture
Reactive dyes, such as reactive brilliant blue X-BR, reactive dark green KE-4BD, reactive turquoise blue KN-G
Sulfur dyes, such as Sulfur Black BRN
3.3 Dyes suitable for the decolorization of the mixture of sodium hypochlorite and shuttle methyl cellulose
Reactive dyes, sulfur dyes, direct dyes.
3.4 Dyes that are not suitable for the decolorization of the above three mixed solutions, such as reactive yellow dyes, X-type, K-type, KE-type, etc., direct yellow dyes