Detergent:
Detergents are surface active compounds which get orient at the interface (between water and air) and reduce interfacial tension. It removes dirt from the surface of the textile material by emulsification and suspends the dirt in cleaning liquid.
Classification of Detergent:
Detergents are classified mainly in two- 1. Ionic 2. Non-ionic.
Ionic detergent also divided into three – 1. Anionic 2. Cationic 3. Amphoteric.
1. Anionic Detergent: After being ionized, anion is the dominating ion. For example – Soap. The reaction is-
C17H35CooNa C17H35Coo- + Na+
C17H35Coo- this portion is very large and dominating ion.
2. Cationic Detergent: After being ionized, cation is the dominating ion. Example- Catyl Pyridinium Chloride.
3. Amphoteric Detergent: Soluble in water and produces both cation & anion. This detergent –a) posses affinity to wool and cellulose fibres. B) Has lubricating properties. C) Behave like anionic in the alkaline solution.
4. Non-ionic Detergent: When dissolved, get oriented at the surface and reduce surface tension. Don’t get ionized and contains hydrophilic head and hydrophobic tail.
Here Hydrophobic means it does not attract the water and the Hydrophillic means it attracts the water
Friday, December 18, 2009
Digital Printing
Due to the complexity of the printing with several so called dyes the printer are inclining to the pigment printing. Now a day, the percentage of using the pigment printing are increasing day by day because of the abundance of organic pigments and the binders that are used during printing textiles. There is always having a risk with using general dyestuffs as printing in case of the finishing treatment like fixing steam and washing that must have to be implemented. Dyes are selected for printing by following the ability of the dyes that they are reproducible or not in case of different variations or the fabric and color condition. Researchers found from a survey that, the Azoic dyes is used in textile printing industry about 3%, disperse dyes are used about 10%, Vat dyes are used about 9%, Reactive Dyes are used about 25%. And the extent of the using of pigments in printing is about 50%. Pigment printing has wide range of uses. The garments of the women which are made by cotton, polyester or viscose blends are printed by pigments if the medium color depths are needed. Decorative curtain, towels are printed by pigments. Pigment printing also used in bed linen, aprons, children’s garments, night wear dresses, various cottons and cellulose materials.
Some advantages of pigment printing:
1. The great advantages of pigment printing are, if any mistakes are found during printing process, it can be easily detected.
2. The process of pigment printing is very fast and economical as sampling can be done quickly and don’t need the washing.
3. If the pigment print paste are created by proper process by selecting materials than it will have exclusive light fastness and other basic fastness properties also.
4. Pigment print is very reliable and needs less labors and equipments.
Some disadvantages of pigment printing:
1. Handling properties of the pigment printing is rough because of having excessive cross linking agents.
2. Creates problem on the roller printing because of the bulky products and more engraved rollers.
3. It is not possible to apply it directly on the fabric. Binder must be used to apply the pigment dye on the fabric. Thus, a coat is created on the surface of the fabric.
4. During second time printing it has very low effect that is not desirable.
Some advantages of pigment printing:
1. The great advantages of pigment printing are, if any mistakes are found during printing process, it can be easily detected.
2. The process of pigment printing is very fast and economical as sampling can be done quickly and don’t need the washing.
3. If the pigment print paste are created by proper process by selecting materials than it will have exclusive light fastness and other basic fastness properties also.
4. Pigment print is very reliable and needs less labors and equipments.
Some disadvantages of pigment printing:
1. Handling properties of the pigment printing is rough because of having excessive cross linking agents.
2. Creates problem on the roller printing because of the bulky products and more engraved rollers.
3. It is not possible to apply it directly on the fabric. Binder must be used to apply the pigment dye on the fabric. Thus, a coat is created on the surface of the fabric.
4. During second time printing it has very low effect that is not desirable.
Tuesday, December 8, 2009
Dabu Printing
Dabu Printing
"Dabu" a mud resist process by using wood block.
The Process of Dabu Printing starts with the preparation of mud resist the clay is prepared by finely sieving it. Calcium hydroxide (Chuna in Hindi), naturally pounded wheat chaff (Beedan in hindi), and gum (gound in hindi) are the main interdients to make the mud resist. The dug out mud from the dry pond is soaked in water in a separate tank overnight. The mud resist is freshly prepared before every printing. A mixture of beedan and gound are along with mud are doughed to make a sticky paste.
Application of mud resist onto fabric TThe mixture is now ready for dabu printing. The mud resist being applied onto the fabrics using wood blocks. Either the dabu printing is done ona single table while sitting or on a running table. This depends upon the space availability and comfort an individual printer. To quickly dry the paste, saw dust is being applied to places where the mud resist is printed. The saw dust also acts as a binder which prevents color penetration while dyeing. The application of mud resist onto the fabric is followed by dyeing the fabric in a cauldron of dye. The process may be repeated for double dabu and triple dabu and hence forth. After every dyeing the fabric is thoroughly washed so as to remove the mud application. Finally the non dyed part where the resist has been applied is revealed after the washing. some of the color penetrates onto the fabric caused by mud cracking. The result is veining which gives it batik like look to the fabric.
"Dabu" a mud resist process by using wood block.
The Process of Dabu Printing starts with the preparation of mud resist the clay is prepared by finely sieving it. Calcium hydroxide (Chuna in Hindi), naturally pounded wheat chaff (Beedan in hindi), and gum (gound in hindi) are the main interdients to make the mud resist. The dug out mud from the dry pond is soaked in water in a separate tank overnight. The mud resist is freshly prepared before every printing. A mixture of beedan and gound are along with mud are doughed to make a sticky paste.
Application of mud resist onto fabric TThe mixture is now ready for dabu printing. The mud resist being applied onto the fabrics using wood blocks. Either the dabu printing is done ona single table while sitting or on a running table. This depends upon the space availability and comfort an individual printer. To quickly dry the paste, saw dust is being applied to places where the mud resist is printed. The saw dust also acts as a binder which prevents color penetration while dyeing. The application of mud resist onto the fabric is followed by dyeing the fabric in a cauldron of dye. The process may be repeated for double dabu and triple dabu and hence forth. After every dyeing the fabric is thoroughly washed so as to remove the mud application. Finally the non dyed part where the resist has been applied is revealed after the washing. some of the color penetrates onto the fabric caused by mud cracking. The result is veining which gives it batik like look to the fabric.
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