Application of Ultrasound in the Preparation of Cotton and Silk Fabric (Part-3)

Application of Ultrasound in the Preparation of Cotton and Silk Fabric (Part-3)
Utpal Mondal
Govt. College of Engineering and Textile Technology
Berhampore, Murshidabad, India
Email: utpal.khs.gcettb07@gmail.com


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4. Application of Ultrasonic Sound in Textile Processing
The effect of ultrasound on textile substrates and polymers has started after the introduction of the synthetic materials and their blends to the industry. These include application in mechanical processes (weaving, finishing, knitted & non-woven fabric etc.) and wet process (desizing, scouring, bleaching, dyeing etc). It deals with application of ultrasound in the mechanical processes of industry and apparel textiles.

4.1 Desizing:
In a study on desizing of textiles with starch, size removal was affected by means of ultrasonically accelerated techniques. It was found that the use of degraded starch followed by ultrasonic desizing could lead to considerable energy savings when compared to conventional starch sizing and desizing.

Valu et al, in their investigation of the use of ultrasonics in the desizing of woven cotton fabric, achieved a savings in chemicals and energy as well as reduced fibre degradation. The final whiteness and wet ability of the fabrics were the same as those obtained without ultrasonics. These investigations were carried out on an industrial jig in which ultrasonic transducers were mounted on the walls. Power varied from 2kW to 4kW for different transducer position [10].

4.2 Scouring and Bleaching:
The scouring of wool in a ultrasonic bath in neutral and very light alkaline bath reduces the fabric damage and enhance rate of processing. The bleaching rate of cotton fabric was increased by using 20 KHz frequency for peroxide bleaching. The degree of whiteness also increased as compared to that of conventionally bleached sample.

The function of ultrasonic wave can make use of acoustic cavitation effect to produce impact on sericin, improving the removal efficiency of sericin at crossing points & achieving uniform silk fibre degumming. The function of ultrasonic wave can cut down the time process and avoid the damage of fibroin through controlling the temperature and loss of chemical agent [10].

4.3 Dyeing:
The possibility of dyeing textile using ultrasonic sound was started in 1941. This can be used for dyeing of cotton using direct dyes, wool with acid dye, polyamide and acetate fibre with disperse dyes. Significant increase rate of dyeing with disperse dyes on polyamide and acetate were obtained. Ultrasound is more beneficial for the application of water insoluble dyes to the hydrophobic fibres. Ultrasound irradiation also produces a greater evenness in colour. The dyeing results are affected by frequency of used ultrasonic sound [10].

4.4 Finishing:
Finishing of textiles involving ultrasonics has been studied by several researches. Applied ultrasound at 8 and 18 kHz frequency to formaldehyde resin treatment of cotton fabric and measures the change in physical properties before and after 60 washing cycles. The crease recovery angle, even after 60 washings, is much higher than without ultrasound but resulted in a small decrease in tensile strength. In the studies of Simkovich and Yastrebinski, cotton fabric was treated with urea-formaldehyde resin in an ultrasonic field of 8 kHz frequency. The isolated fabric improved crease recovery properties.

A U.S. patent describes the method and apparatus for treating military fabrics with a liquid repellent fluoro chemical finish in the presence of high frequency ultrasonic waves. This method produced an increase in finish add-on. Another patent by Carpenter for applying a fluid treatment to textiles describes a material that is passed through a chamber in which a dispersion of fluid treating medium is ultrasonically generated. The results are claimed to be fully comparable to padding and drying and are said to be capable of producing greater levels of treatment because this method can effectively handle treating media of higher solid contents [10].

4.5 Washing:
According to the laboratory test reports washing time of wool after different wet processing can be reduced effectively for an equivalent whiteness. According to the results of a statistically planned experimental, the washing of flax can be improved by ultrasonic vibrations. This removes non-cellulosic material more effectively than mechanical agitation and improves whiteness of the flax fibre [10] 

5. Planning of future work
A preliminary trial has been carried out by carrying out scouring in an ultrasonic bath under the conditions, as given in Table 1.

Parameters
Values
TRO
A few drops
A few drops
Temperature(°C)
29(31*)-39
29(31*)-48
Time (min)
60 minutes
90 minutes
Surfactant concentration (g/L)
15 g/l
15 g/l
Alkali concentration (g/L)
0
Liquor ratio
≈1:120
1:120
 

Experimental conditions of ultrasonic cotton scouring trial

*At first room temperature was 29°C and after de-aeration for 3 minutes the temperature was 31°C.

From the above mentioned trial it was observed that ultrasonic scouring has some promises. Hence, it is proposed to carry out some in-depth studies regarding this as per conditions given in Table 2.

Parameters
Values
TRO
A few drops
Temperature(°C)
Room temperature
60, 70
Time (min)
60, 90
60, 90
Surfactant concentration (g/L)
15
Alkali concentration (g/L)
20
30
Liquor ratio                          
1:120
 

Table. 2: Conditions for proposed ultrasonic cotton scouring

Similarly, works carried out by Mahata et. al. on ultrasonic assisted degumming operation with some encouraging results. In continuation of this study Table gives the conditions of this experimentation.

Another is degumming of silk in room temperature and higher temperature (<=80°C) for 60 minutes and 90 minutes (tentatively) with chemicals and without chemical.

Parameters
Values
Temperature(°C)
Room temperature
45,55
Time (min)
50,60
60,70
Surfactant concentration (g/L)
20
Alkali(g/l)
15
Liquor ratio
1:120
Table. 3: Conditions for proposed ultrasonic cotton degumming

We also wish to do scouring and degumming in conventional method and compare the results with scoured and degummed sample which was done by ultrasound process [11].

6. References
  1. http://www.nidcd.nih.gov/health/education/video/pages/sound_vid.aspx
  2. http://textilelearner.blogspot.in/2013/08/application-of-ultrasonic-in-textile_28.html
  3. Mason T. J. & Lorimer J. P., Introduction to Applied Ultrasonics, Applied Sonochemistry: Uses of Power Ultrasound in Chemistry and Processing, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2002
  4. http://en.m.wikipedia.org/wiki/liquid_bubble.com
  5. http://en.wikipedia.org/wiki/Ultrasound
  6. http://www.acronymfinder.com/Ultrasound-Identification-(USID).html
  7. http://www.smtcorp.com/acoustic-microscopy-imaging
  8. http://americanpregnancy.org/prenatal-testing/ultrasound/
  9. http://www.whisperingpinespc.com/wp/ultrasound-veterinary-medicine/
  10. Smith C. B., Clapp T. G., Thakore K., Cato M. J., Hite D., Application of Ultrasound in Textile Wet Processing Phase 1, Compliments of EPRI TEXTILE OFFICE College of Textiles North Carolina State University Raleigh, 1992
  11. Mahata C., Das A., Chatterjee D., Roy F., Paul P, Application of ultrasonic sound in textile processing, a B.Tech minor project dissertation submitted at G.C.E.T.T.B, 2013 
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