What is Printing of silk fabric with acid dyes and advantages and disadvantage.
Printing of Silk Fabric with Acid Dyes
Introduction:
Dyeing causes the physical and
chemical changes of the fabric, reflecting the lightness of the fabric and
making it look radiant. Currently dyeing and printing fabrics is a very
important issue. In ancient times, silk was printed in natural colors. But with
the advent of modern technology, there are major changes in dyeing and
printing. Currently the efficiency of silk fabric printing with acid dye is
very popular.
What is acid dye?
Acid dyes are composed of acids or chemical salts. This type of
dye is called acid dye because different acids are used in dyeing cloth or
cloth. Acid dye has a complete chromatogram and bright color properties.
Chemical acid dyes are divided into different types such as nitro,
nitroso, monoazo, diazo, xanthane, azine, quinoline, anthraquinone etc. They
can melt in water and become addicted to wool, silk and nylon fibers. They are
used in fiber for neutral or acidic dye containers.
Silk dye with acid dye:
Direct use of acid dyes is dangerous in the presence of cellulose
fibers. This is because the presence of acid can have a negative effect on
cellulose color. Acid dyes are best suited for nylon, silk and various animal
fibers. The effectiveness of acid dyes in silk animal fiber is excellent; the
color is ripe and brighter than the special field wool.
Pre-treatment of silk fabric before printing:
Silk consists of two single
filaments, its main body sericin, and the outer layer is coated with sericin.
Most paints, oils, waxes and inorganic salts are present in sericin. This stain
has a significant impact on the printing and dyeing process, so it should be
removed before dyeing. The removal of sericin from silk is called silk
degumming. Gray silk fabric is durable, not shiny and slightly white due to the
presence of sericin. Therefore, before printing silk fabric, pre-treatment is
done with the following:
§ Soap… … … … … … … … …> 0.5 to 2.0 G/L
§ Sequestarent… … … … … > 0.5 to 1.0 G/L
§ Sodium bi- carbonate … > 0.5 to 2.0 G/L
§ Temperature … … … … > 50 to 70°C
§ Time … … … … … … …> 20 to 25
minute
Print of silk fabric containing acid dye:
Normal silk color is not
white. When real silk is required, the fabric is mixed with hydrogen peroxide
as a white ingredient. The following ingredients are used to make silk fabric
printing paste.
§ Acid dye……………………> 40 gram
§ Boiling water…………….> 335 gram
§ Glycerin……………………> 25 gram
§ Gum tragacanth…………> 550 gram
§ Tartaric Acid………………> 50 gram
—————————————————————–
………..Total
= 1000 gram
Pre-treated silk fabric is printed with the above adhesive.
The silk printing method is
almost like wool. In this process one has to make a soft alcohol soap. To make
this solution, 25% of normal alcohol soap or liquor soap (boiled - closed -
alcohol) should be mixed with 75% water. In the first case, the soapy water
obtained by boiling silk with soap is called an alcoholic soap. In the case of
silk, this soft soap should be mixed with acetic acid instead of sulfuric acid.
The temperature of the mixture is gradually increased to 40 ° C. Now you have
to add the color solution of the selected acid gradually. The fabric can be
soaked in a bathtub and the temperature can be gradually increased to 85 ° C.
However, it is best to keep the temperature within 80 ° C. The silk fabric is
then dried and steamed for 60 minutes under cottage steam and atmospheric
pressure. Then wash thoroughly with cold water. When everything is dry it is
finally ironed.
Working Process:
§ Acetic Acid: 4%
§ Soft soap liquor: 25%
§ Water: 30%
§ Temperature: 80°- 85°C
§ Time: 30 minute to 1 hour
After treatment:
The strength of the silk
print is enhanced by first treating it with 4% tannic acid and 1% amniotic
tartar. The product can be processed with a 4% acetic acid solution to increase
light. And when processed in a turkey oil solution (T.R. Oil), the smoothness
of that silk fabric increases several times. The acid dyeing method is used for
commercial dyeing. In the textile industry, this color is called commercial
color.
Conclusion:
The process of printing
silk fabric containing acid dyes plays an important role in the textile
industry. This is because it increases the lightness of the silk many times and
the fabric is very smooth. As a result, the market value of silk has increased
a thousandfold. Although silk dyeing and printing were commonplace in ancient
times, now silk printing with acid dye is a popular method. Because dyeing and
printing are inherently difficult and time-consuming, they are quite effective
in printing silk with acid dye.
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