1. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
INTERNATIONAL JOURNAL OF ADVANCED RESEARCH IN
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
ENGINEERING AND TECHNOLOGY (IJARET)
IJARET
ISSN 0976 - 6480 (Print)
ISSN 0976 - 6499 (Online)
Volume 4, Issue 7, November - December 2013, pp. 85-91
© IAEME: www.iaeme.com/ijaret.asp
Journal Impact Factor (2013): 5.8376 (Calculated by GISI)
www.jifactor.com
©IAEME
SUPER ABSORBENT FIBRE- OVERVIEW
AYODYA KAVITHA1,
1
DAKURI ARJUN2,
M.N FARHEEN3
Assistant Professor, University college of Technology, Osmania University, Hyderabad- 500 007
2,3
University college of Technology, Osmania University, Hyderabad- 500 007
INTRODUCTION
Super absorbent fibre is a new generation fibre which has gained its prominence for its super
absorption capacity. Super absorbent polymers (SAP) have the ability to absorb and retain large
volume of water and aqueous solution, this unique property makes them use in water absorbing
applications i.e baby nappies. It is white in colour and possesses improved handling properties to be
used in a wide range of fabrics. It provides extreme high rates of water and saline uptake. Because of
its extreme water absorption capacity, it is used widely in diapers and filter products.
Fig: 1. Super Absorbent Material
Courtesy: specialityfabricsreview.com
85

2. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
MANUFACTURING PROCESS
Super absorbent fibre can be manufactured in two ways:
1. By modification of existing fibres or polymers
2. By using super absorbent polymers
By Modification of Existing Fibres or Polymers
In this method fibres are modified by hydrophilic modification i.e. incorpating hydrophilic
polymers in the existing fibre forming polymers. But most of the super absorbent fibres are produced
using super absorbent polymer.
By Using Super Absorbent Polymer
Super absorbent polymers are the polymers which can absorb high amount water/ liquid and
retain them. It can absorb up to 500 times of its own weight of water. Super absorbent polymers are
cross-linked so that they are insoluble in the liquid which they absorb because the liquid absorbed
should be retained strongly and exertion of pressure should not cause the liquid to move out.
Fig: 2. Super Absorbent Polymer
Courtesy: nptel.iitm.ac.in/courses/116102006/17
Super absorbent polymers were earlier made by grafting polyelectrolyte’s onto starch or
cellulose which had good absorption capacity. But now they are made of sodium polyacrylate or
partially neutralised acrylic acid. Depending upon the precise structure of polymer network and cross
link density, the swelling and elasticity properties change from polymer to polymer.
ABSORPTION MECHANISM
The mechanism of absorption of super absorbent polymer is molecular diffusion of water into
the particles of polymer chains. Because of ionization of neutralised acrylic acid, the liquid is forced
86

3. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
to move inside the polymer. This ionization caused by the diffusion of water inside the hydrophilic
polymer results in negative carboxylate ions and positive sodium ions. Mutual repulsion of
carboxylate ions and increase in osmotic pressure in the gel is caused which results in expansion and
swelling of polymer chain. Solubilisation of polymer in water is prevented by cross-links. The crosslinks also control the extent of swelling or absorption by restricting infinite swelling.
Fig: 3. Water Absorption Mechanism in Super Absorbent Polymer
Courtesy: nptel.iitm.ac.in/courses/116102006/17
PREPARATION OF SUPER ABSORBENT POLYMER
Super absorbent polymers are prepared by free radical initiated polymerization of partially
neutralised acrylic acid along with a co-monomer and cross-linker.
Polymerization technique: Bulk polymerization, Solution polymerization and inverse suspension
polymerization, any one of the technique can be used.
•
•
•
Bulk polymerization involves the use of monomer-soluble initiators and it is the simplest
technique.
High degree of polymerization is achieved because of high concentrations of monomer.
This technique produces polymer with high molecular weight and high porosity.
After the polymer is produced the next step is to extrude the melted polymer through
spinnerette with the help of hot air stream and then evaporation (drying and curing) of water
produced cylindrical particles (fibres) of precise diameter. Later these fibres are precisely cut
according to the required staple length.
87

4. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
Process flowchart for manufacturing of SAP
Raw materials
Polymer manufacture
(Acrylic acid and methylacrylate are polymerised to form polymer)
Extrusion
Drying and curing of fibre
Cooling
Cutting to précised staple length
Finishing
(Thermal conditioning)
PROPERTIES OF SUPER ABSORBENT FIBRE
Important properties of super absorbent polymers are listed below
1. Swelling capacity
2. Elastic modulus of the swollen cross linked gel
The above properties are related to the cross link density, the modulus increases and swelling
capacity decreases with increasing crosslink density. The absorption is also increases in the degree of
neutralization of carboxylic acid groups. Fig 4. Shows the change in swelling capacity
Fig: 4. Change in swelling capacity with increase in a) Cross linker concentration
b) Degree of neutralization
88

5. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
The general range of physical properties of super absorbent polymer in Table 1.
Table .1 Physical Properties of Super absorbent polymers
Colour
white
Staple length
6mm, 52mm and 80mm
Moisture regain
10-15 (typically 10)
pH (saline extract)
5.5
tenacity
10cN/tex
extensibility
5%
Courtesy: www.packplus.in/images/Technical-Absorbents.pdf, www.asia.ru
Super absorbent fibre can be converted into numerous fabrics using the following web-forming
processes:
•
•
•
•
Air-laid
Dry-laying – carded
Staple fibre manufacture
Wet-laid
To meet the customer requirements super absorbent fibre can also be blended with a full
range of synthetic and natural fibres. Following the web-forming process, super absorbent fibre webs
can be bonded as follows to allow for the formation of an extremely diverse fabric.
•
•
•
•
•
•
Needle-punched
Thermally bonded
Stitch-bonded
Latex-bonded
Steam/calendar bonded
Bonding combinations
89

6. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
Applications
• Agrotextiles - Agro bags, Water reservoir fabrics
• Construction textiles- Heat insulating fabrics
• Geotextiles - Water proofing fabrics
•
Industrial Textiles - Filter Products
•
Medical textiles - Dental absorbent products, Diaper, Incontinence products, Gauze, Bandages
•
Packaging Textiles - Meat Packaging Bag, Fruit packaging bags, Medical testing Kits,
Diagnosing Packaging
90

7. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 4, Issue 7, November – December (2013), © IAEME
•
•
Protective Textiles - Protective Cables, Flame Retardant fabrics, Ballistic Materials
Sports Textiles- Breathable Fabrics, Phase Change Fabrics
Courtesy: www.jcxw.cn/english/03_products/proshow.asp?ID=215&MaxID=2
REFERENCES
1. B. J. Agarwal, “Eco-Friendly Dyeing of Viscose Fabric with Reactive Dyes”, International
Journal of Advanced Research in Engineering & Technology (IJARET), Volume 1, Issue 1,
2010, pp. 25 - 37, ISSN Print: 0976-6480, ISSN Online: 0976-6499.
2. K.L. Jeyaraj, C. Muralidharan, T. Senthilvelan and S.G. Deshmukh, “A Hybrid Business
Strategy Selection Process for a Textile Company using Swot and Fuzzy ANP–A Case
Study”, International Journal of Management (IJM), Volume 3, Issue 2, 2013, pp. 124 - 143,
ISSN Print: 0976-6502, ISSN Online: 0976-6510.
3. Kh. EL-Nagar and Mamdouh Halawa,, “Effect of Mordant Types on Electrical Measurements
of Cotton Fabric Dyed with Onion Scale Natural Dye”, International Journal of Electrical
Engineering & Technology (IJEET), Volume 3, Issue 2, 2012, pp. 192 - 203, ISSN Print :
0976-6545, ISSN Online: 0976-6553.
4. nptel.iitm.ac.in/courses/116102006/17
5. www.technicaltextile.net/featureproduct/super-absorbent-fibre-saf/
6. www.indiantextilejournal.com/articles/FAdetails.asp?id=1932
7. www.techabsorbents.com
8. www.packplus.in/images/Technical-Absorbents.pdf
9. http://chimianet.zefat.ac.il/download/super-absorbant_polymers.pdf
91