Experiment Name: Printing of 100% silk woven fabric with acid dye, by screen method.
Theory:
The Printing of textile materials is the application of colour according to a predetermined design. The printing paste which applied to textile material consists of dye, water, thickener and hydrocarbon solvent or oil. After the printing paste is applied, the textile material is usually steamed. Once the acid dye printing paste has been applied to the textile material, steaming of printed pattern is necessary. The steam provides the water molecules and heat energy to enable the dye molecules of the printing paste to transfer from the fibre surface into the polymer system.
Nature of Sample :
Pre-treated woven fabric contains 100% silk fibre.
Apparatus Required :
1. Beakers.
2. Glass Rod.
3. Pipette.
4. Measuring Cylinder.
5. Balance.
6. Tri-pod Stand.
7. Printing Screen Board.
8. Pot.
9. Gas Burner.
Method Of Printing:
We used here screen printing method. Screen printing is by far the most common technology today. There are two types of screen printing system i) Rotary screen printing. II) Flat screen printing. The working principle is a blade squeezes the printing paste through openings in the screen onto the fabric.
Style of Printing:
We used here direct style for printing which means the dyes are printed directly at the required places of fabric and leaving the other portion unprinted or white.
Process Sequence:
Collection of pre-treated 100% silk fabric
.
Preparation of print paste with thickener
.
Application of print paste on pre-treated sample according to printing method
.
Drying at 100deg C for 3-5 minutes
.
steaming at 110deg C for 5 minutes.
After Treatment
Recipe of Printing:
Acid Dye : 20 parts
Acetic acid : 20 parts.
wetting agent : 20 parts
Thickener(Sodium Alginate) :750 parts.
Water : As Required.
Function Of chemicals:
Acid Dye: The Particle which produce suitable color on the surface of fabric.
Acetic Acid: Acid dye required acetic medium. This acid ensure acetic medium.
Wetting Agent: Wetting agent is substances that reduce the surface tension of water to allow it to spread drops onto a surface, increasing the spreading abilities of a liquid. Lowering the surface tension lowers the energy required to spread drops onto a film.
Comments:
The fabric printed using screen method. We Observe some uneven printing done due to uneven pressure applied.
Pre-cautions:
All chemicals measure are taken properly.
Temperature maintain properly.
Burner used very carefully.
Viscosity of print paste maintain properly.
Applied even pressure during printing process.
Conclusion: ...........................................
