Conventional Sulphur dyes
• Conventional Sulphur dyes are used by this method:
• These are insoluble or partly soluble in water. They have variable but slight affinity for the textile fabric
• Before dyeing the dyed are pasted with a little amount of cold water, the required amount of sodium sulphide is added and dissolved by adding water
• Boiling for about 10 mins completes the dissolution process
• This is then added to the dyebath with soda ash finally the material to be dyed is entered to the dyebath
Properties of Sulphur dyes
• From the name it is clear that these dyes contain little amount of sulphuric acid. The fibers those can be dyed by these dyes are Viscous, Staple fibers, Yarn, any materials which give a resin finish, silk etc. These dyes have an excellent light fastness properties.
• Dyeing temperature: 80‐95 degree C (Optimum) but sometimes at cold temperature also.
• It is a good soluble in Na2S.
• It has a good exhaustion.
• Its dyeing rate is moderate.
• It is a soluble in water.
• Make rapid black on cellulose materials.
• Sometimes create direct prints on cellulose