24 Questions
What is the purpose of a Colour Index Generic Name for a dye?
To provide a unique identifier for a dye based on its application and hue
What type of dye is CI Reactive Blue 4?
A reactive dye
Which of the following is NOT a classification of dyes according to chemical constitution?
Reactive dyes
What type of information is tabulated for each dye listed?
Dyeing methods and fastness properties
What is the difference between CI Acid Red 1 and Orange II?
CI Acid Red 1 and Orange II have similar dyeing properties
What is the term for a subgroup of dyes that includes a number of different subgroups containing heterocyclic systems?
Heterocyclic dyes
How are dyes classified according to textile usage?
By their dyeing methods
What is the purpose of classifying dyes according to chemical constitution?
To understand their chemical properties
What is the result of precipitation of a dye inside the fibre or its chemical reaction with the fibre?
Better fastness to washing
What form must dyes be in to diffuse into a fibre?
Individual molecules
What is the term for a dye's attraction to a fibre during the dyeing process?
Substantivity
What is the primary purpose of the Colour Index?
To catalogue dyes and pigments
How many subgroups of dyes are classified according to usage in the Colour Index?
19
What is the characteristic of dyes that allows them to maintain their colour during washing?
Reasonable fastness properties
What type of dye is Congo Red?
Anionic dye
What is the term for the process of a dye becoming depleted in solution during the dyeing process?
Exhaustion
What is the CI Constitution Number of the direct dye Congo Red?
22120
Which type of dye is used mainly for dyeing cotton?
Reactive dye
What is the purpose of Volume 5 of the Colour Index?
Documenting commercial names used by dye manufacturers
What is the common characteristic of dyes with the same manufacturer's brand name?
Same dyeing class
What is the CI Constitution Number of Indigo, CI Vat Blue 1?
73000
What is the characteristic of Remazol dyes marketed by DyStar?
They are reactive dyes with vinyl sulphone reactive groups
Which of the following is NOT a characteristic of the Colour Index?
It provides a list of all possible dyeing methods
What is the format of the 4th edition of the Colour Index?
Online with registration fees
Study Notes
Dye Classification and Nomenclature
- Dyes have a Colour Index Generic Name based on application and hue
- Dyes are classified according to chemical constitution and usage
- The Colour Index is a major catalogue of dyes and pigments, first published in 1924
- The Colour Index classifies dyes into 30 subgroups by chemical constitution and 19 subgroups by usage
Characteristics of Dyes
- Dyes have four major characteristics:
- Intense colour
- Solubility in water at some point during the dyeing cycle
- Substantivity for the fibre being dyed
- Reasonable fastness properties of the dyeing produced
Dyeing Methods
- Dyeing methods include:
- Direct absorption
- Precipitation of dye inside the fibre
- Chemical reaction with the fibre
- These methods result in better fastness to washing, as they are essentially irreversible processes
Colour Index Constitution Number
- Dyes of known molecular structure are given a 5-digit CI Constitution Number
- Examples:
- CI Direct Red 28 has CI Constitution Number 22120
- CI Vat Blue 1 has CI Constitution Number 73000
- CI Reactive Red 1 has CI Constitution Number 18158
- CI Disperse Blue 14 has CI Constitution Number 61500
This quiz covers the classification and properties of dyes, including their Colour Index Generic Names and applications.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
