A B S T R A C T
Looking for solutions related to the pandemic and being safe, towels should also be considered an essential item. An everyday item that can deteriorate rapidly, as a result of bacteria forming in wet textiles. The quality diminishes as a result of foul smell and becomes unhygienic. Currently, it plays a bigger part, washing our hands and bodies to be protected will also need drying or wiping.
Exploring principles of fundamental physics, chemistry, and engineering to understand how liquids soak, flow, and remain in the nanoporous fibrous structure. It can provide aid to developing a product for industrial and commercial application.
This eco-friendly superabsorbent finish on terry towel fabric is the answer. This process is not harmful to the environment. It uses natural aloe vera as an anti-bacterial finish.
Awareness of eco-friendliness in textiles must be created to meet the demand of global consumer to be eco conscious and green.
I N T R O D U C T I O N
Terry towel has pile loops on one or both sides covering the entire ground surface. Different concentrations of aloe vera finish with cross linking agents i.e. citric acid and sodium hypophosphite are introduced on it.
This finish can improve the absorbancy, softness, anti-bacterial properties of the terry cotton fabric. Evaluation of the same is done by standardized testing.
With high concentration of aloe vera, there was reduced growth of bacteria. Absorbency was improved because of cross linking agents. Water moves around in the fibre matrix due to which there is a rise in capillary action. Resulting in swelling of fibre, which can hold more quantity of water.
A G E N T S U S E D
Fabric used – scoured and bleached Terry towel, woven in jacquard terry loom, 250 g.
Chemicals used – Citric acid, sodium hypophosphite as a catalyst.
M E C H A N I SM
The relationship between water molecules and long chain molecules in the fibre determines the uptake of liquid. Aiming for superabsorbency, to restrict the liquid’s movement and prevent it from being squeezed out under pressure instead of increasing absorbent capacity. This finish absorbs recurrently, more than its weight and holds on to the absorbed liquid when pressure is applied.
Structure and Functioning
Absorbency depends on osmotic pressure, ionic impulsion, elasticity of the intra molecular structure of polymers and density of its hydrophilic groups. Superabsorbents are dense cross-linked three-dimensional network of hydrophilic polymers.
Fluid is locked and kept away from the skin, minimizing irritation and providing comfort.
The small-scale arrangement of cellulose molecules is due to its structure, minimal in crystalline regions and higher in amorphous region. Pile height can cause changes in capillary action.
P R O C E S S
Fabric was previously scoured and bleached. Followed by, treatment with citric acid (absorbency increasing agent) and Sodium hypophosphite (catalyst), applied with the concentration of 2%, 4%, 6%, 8 % and 1%, 2%, 3%, 4%, respectively. With MLR of 1:30. Keeping temperature of 90° C for 60 minutes to use pad – dry – cure method with the help of Padding mangle.
Anti – Microbial Treatment
Further, this sample was treated with Aloe Vera gel (anti-microbial), having concentration 3%, 6%, 9% and 12%. Followed by cold wash and then hot wash with the padding mangle.
Aloe vera was found to be the best to restrict the growth of bacteria or microorganism on fabrics. It stops bad odour which is released after several uses. It also improves the quality of the fabric.
T E S T I N G M E T H O D S
The following are absorbency test methods as per ASTM961 standards.
- Spray Test – Sample treated with 8% concentration of citric acid and 4% concentration of sodium hypophosphite was best. High concentration created room for the water to stay in the internal structure of the fibre.
- Wicking Test – Sample with 6% concentration of citric acid and 3% concentration of sodium hypophosphite considered best. Formation of capillaries in the internal structure of cotton fibre which led to the increase of height. The untreated sample does not show any increase.
- Sinking Test – Untreated sample float on the water surface longer. Treated samples sink faster to the bottom. Higher absorbency shown because of opening of spaces in the fibre structure, water molecules rush inside the piles structure.
- Drop Test – The time needed for the water molecules to seep through and pass inside the piles is noted. Treated sample has good absorbency as pores open up. Untreated sample does not show much difference.
The sample was introduced to an E-coli culture in a pharmacy lab. It was kept for seven days in room temperature. Then, antimicrobial property was tested, under microscope for growth of the microbes. Prompted with water, a necessary condition for growth of microbes.
Untreated sample – High level of bacterial growth caused more formation of colonies. As a result, fabric starts to smell, fabric quality degrades. Overall, an unhygienic item. Sample A, treated with 3% concentration of aloe vera shows good result comparatively. Has good anti-microbial properties, as it did not show growth of microbes. In Sample B, bacteria is spotted after 7 days. Low level of colony formation. Sample C, treated with 9% concentration of Aloe Vera, kept for 7 days. More growth of bacteria compared to sample A and sample B. Increasing concentration of aloe vera does not ensure anti-microbial behavior. In Sample D, more colonies formed compared to the other 3. However, untreated sample showed much higher number of colonies. Higher concentration of aloe vera does not restrict the growth of this microbes.
A P P L I C A T I O N ( E N D U S E R B A S E D )
As towels and robes for homes and hotel industry. As Sportswear apparel and athletic wear like sweat and moisture absorbing socks. Quick absorbing robes for swimmers.
Application in the health industry such as baby diapers, feminine hygiene products, hospital textile products. Usage as mop and wipes, as part of the cleaning industry.
S U M M A R Y
Advantage of this finish is that it is nature friendly along with having exquisite absorbency powers, more than its weight. Opportunity for various applications. Microbial growth is limited to none. Softer fabric absorbs much quicker and more liquid. No harmful chemicals are used.
R E F E R E N C E S
- Daberao, A.M. Nadiger, V.G. Raichurkar, P.P. Shivankar, V.S. (2017). Eco-friendly finishes applied on Terry Towel fabrics. February issue. 40-47. https://www.researchgate.net/profile/Vijay_Shivankar/publication/315379547_Eco-friendly_finishes_applied_on_Terry_Towel_fabrics/links/58ce27a7a6fdcc5cccbbe971/Eco-friendly-finishes-applied-on-Terry-Towel-fabrics.pdf
- Daberao, A.M. Raichurkar, P.P. Shivankar, V.S. (2017). Hygienic Super Absorbent Terry Towel. Biochemistry: an Indian journal. 11(1). 1-12. https://www.tsijournals.com/articles/hygienic-super-absorbent-terry-towel.pdf
- All pictures/tables used are part of the experiment.
Article by Nafeesah Ahmed