There are two reactive groups in Bi functional Dyes. These two reactive groups are well known for their excellent dyeing activity. But bifunctional Dyes with excellent dyeing capacity can be only created through correct selection process of appropriate reactive groups and appropriate chromophores. A few bifunctional reactive dyes had been developed which carried mono-chlorotriazine and sulphato ethyl sulphone reactive.

As Bi functional Dyes contain two reactive groups either identical in nature or not so these dyes have higher degree of fixation over all other kinds of dyes.

• The stability that is exist in the dye-fiber bond between the Vinyl sulphone group and cellulose against acid hydrolysis gives extra stability to these dyes in the acidic environment of the industry and makes the dyeing effect more lasting.
  
  
• The portion of bi functional dyes that doesn't fix during the dyeing process can be removed easily. This is because of the low substantivity of the hydrolysis dye. This reduces the risk of staining of the adjacent whites.
  
  
• The leveling properties are also excellent. The reproductivity of dyeing is also good.
  
  
• The fastness quality is also get improved.