What is Pigment?
The colored substance which is insoluble in water or other solvents is called a pigment. Thus the application of dye and pigment will be different. A dye is applied in the form of a solution, whereas the pigment is applied in the form of a paste in a drying oil, in which it is insoluble. Pigments are insoluble powders of very fine particle size, i.u., as small as 0.01 micron, which are used in paints, plastics, rubber, textiles, inks and other materials to impart color, opaqueness and other desirable properties to the product. There are various types of pigment and widely used in textile dyeing and printing.
Pigment comes from Latin word pigner which means Paint. Colorants can be either dyes or pigments. There are organic or inorganic colorant materials. Pigments are insoluble coloring matter mostly of mineral origin which have no affinity for fiber, are fixed onto the textile substrate with a binding agent in the pattern required. It has only chromophore group but no auxochrome group. So, it has no affinity for the fiber. They are applied by using dispersion in a suitable medium. Generally, pigment retain essentially their particulate or crystalline form during application.
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. The appearance of pigments is intimately connected to the color of the source light. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light. Many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have special properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors. It must be stable in solid form at ambient temperatures. For industrial applications, as well as in the arts, permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken. Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food and other materials. Most pigments used in manufacturing and the visual arts are dry colorants, usually ground into a fine powder. This powder is added to a binder (or vehicle), a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.
Classification / Types of Pigment:
There are two types of Pigment. They are-
- Natural pigment.
- Synthetic pigment.
Natural pigment are divided by two types.
- Organic pigment (chlorophyl Indigo)
- Inorganic pigment (inonoxide)
Synthetic pigment also divided by two types.
- Organic pigment. (litholred, peocockblue etc.)
- Inorganic pigment. (sulphide, chromate etc.)
Organic pigment are two types. Such as-
1. Natural organic.
- Vegetable organic.
- Animal organic.
2. Synthetic organic.
Azo and Non-azo types are given below-
- Pigment dye.
- Percipited azo.
- Precipited Basic dyes.
- Precipited Acid dyes.
- Phthalocyanic pigment.
- Quinonoid vat dyes
Properties / Qualities of a Good Pigment:
- Pigment should have minimum particle sizes (0.2-0.4).
- Pigment should have maximum covering power.
- Pigment should have freely mixing power.
- Pigment should be chemically inert.
- Pigment should have good resistance to chemicals.
- Pigment should be resistance to solvent.
- Pigment should have acceptable brilliance, hardness and stability on dyed and printed goods.
- Pigment should have good wet, light, and abrasion resistance.
Pigment should have good characteristics for excellent dispersion including:
- Particle size and distribution
- Electrical charge
- Specific gravity
- Purity and crystalline structure
- Condition of precipitation
- Should be applied to all fiber
- Should be cheap
Trade / Commercial Names of Pigments:
- Acron——————–Parckh dye corp——W.Germany
- Helizarine—————-BASG, AG————-Germany
- Syntrofix—————–Syndex pvt ltd———India
- Seabond,Lifebond——-Hdc company———USA
Uses of Pigments:
- Use in natural, synthetic and glass fiber dyeing.
- It is mostly use for printing.
- Use for blended fabric dyeing.
- Use in dope dyeing
- It also used for the coloration of metal, wood, stone, soap, detergent, colored pencil, PVC, rubber, paper and other surfaces as paint.
Advantages of Using Pigments
- Applicable to all kinds of fibers and fiber blends
- Compound shades are produced with ease
- Easy and cheap process
- Easy shade matching
- Environment friendly
- The full-color range is available
Disadvantages of Using Pigments
- Depth of shade usually limited to light to medium
- Make the fabric stiffer and so uncomfortable
- Sometimes fastness to washing and rubbing is not so good
You may also like:
- Chrome Dyes: Features and Chemical Classification
- Reactive Dyes: Classification, Dyeing Mechanism, Application & Stripping
- Different Types of Reactive Dyes: Properties, Structures and Factors
- Disperse Dyes: Properties, Classification, Dyeing and Printing Method
- Sulphur Dyes: Properties, Classification, Mechanism, Stripping & Defects
- Vegetable Dyes | Different Types of Vegetable Dye and Structure
- Different Types of Dyes with Chemical Structure
- Different Types of Dyestuffs in Relation to the Fiber Substrate
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.