What is dye?
A dye or dye stuff is usually a colored organic compound or mixture that is used for imparting color to a substrate such as cloth, paper, plastic or leather in a reasonably permanent fashion.
In other words, a dyed substrate should be resistance to a normal laundry or cleaning procedures.
Dye can be synthetic or natural i.e. it can be collected from nature or can be made by chemical. Traditionally natural dye was used but in 19th century synthetic dye produced in a large scale and created demand in the market. Now for dying purpose most of the cases synthetic dye is used rather than natural dyes. Synthetic dye is human made dye getting very popular because of low cost and availability.
White dye is one kind of commonly used dye. Some colorless compounds are used as the optical brightness. They may also be called white dye. They have the special properties of absorbing uv light & re-emitting the visible light so that the fabric appears bright Example: OBA that means optical brightening agent.
Selection of dye
There are numerous factors involved in the selection of dyes for coloring a fabric in a particular shade. Some of important factors that need to consider before selecting dye are:
- Types of fibre
- Form of textile materials
- Fastness properties
- Method of dyeing
- Available machine
- Available of dyes.
Samina Ferdous (pue)
Chittagong textile engineering college (CTEC) 6th batch.