Fabrics generally carry various microorganisms which cause several problems to the wearer. The speedy growth in the textile industry has created many opportunities for variety of innovative finishes.
In today’s world, naturally renewable resources are increasingly required as a result of human dedication to protect environment. Apart from new innovations using fabric, value-added finishing gives add up value to the fabric. During finishing process, the fabric attains beneficial characteristics like resistance to fire, wrinkle, mildew etc.
These high value-added fabrics have generated consumer market demand. In the recent past, there is a growing awareness about the necessity of healthy and hygienic surrounding, about how diseases usually spread from person to person like touch of the infected person’s hands, clothes etc. Hence, antimicrobial fabrics have its large share as surgical clothes, undergarments, baby clothing, etc. The antimicrobial finishing treatment is now extended to the traditional clothing and the home textiles.
The antimicrobial agents kill or inhibit the growth of pathogens to control their effect. The natural fibres like cotton get easily attacked by the microbes, because of the presence of carbohydrates in the fibre. Antimicrobial finished fabrics have wide variety of applications in sports clothing, footwear, medical textiles, furniture, automotive textiles, intimate apparels etc.
The presence of microorganism in the fabric causes unpleasant odour, staining and also causes health problems.
Microbial infections cause some danger to the skin and therefore, the garment which is worn next to the skin requires antimicrobial finish. To protect the skin of the wearer, the application of antimicrobial finish is done using some herbs.
Antimicrobial agents are of two types:
The synthetic antimicrobial agents such as quaternary ammonium compound, triclosan and many others are used for the antimicrobial finish. However, these synthetic antimicrobial agents are durable but they cause many side effects.
Currently, the synthetic antimicrobial agents are banned according to the US and European standards, there is an increasing demand for ecofriendly antimicrobial textiles depend on natural antimicrobial agent such as Chitosan which does not cause any harm to the wearer. There are a variety of herbs those are widely used as a traditional medicine in countries like America, Africa, and Europe, for treating various types of diseases.
Different parts from the organic plants such as Papaya, Aloe Vera, Neem, Banana, Hemp extracts shall also be used for the purpose of antimicrobial finish. Many plants in the world contain the compound which is responsible for antimicrobial activity.
There are various compounds in the plants that are responsible for the antibacterial activity such as tannin, flavanoids, and terpenoids that are both bacteriocides (which kills the micro-organism) and bacteriostatic (which inhibit the growth of microorganism).
Environment-friendly antimicrobial textile can be produced by the use of plant extracts. Various plants have been gathered and they are tested for their antimicrobial activity. An effective study was regulated to evaluate the plant extracts both qualitatively (AATCC-147) and quantitatively (AATCC-100) for their antimicrobial activity. Although, the plant extracts have shown effective antimicrobial activity, the vital issue is the wash durability.
The durability of antimicrobial ?nishing against washing is assessed using quantitative (ICP-OES) and semi-quantitative (LA-ICP-TOF-MS) methods. The physical properties like weight, thickness, fabric structure, count, EPI and PPI of the fabric before and after the application of the finish are also analysed. There are various natural antimicrobial agents available, but only limited studies have been carried out to identify their antimicrobial activity on the textile materials.
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Processing of fabric with different plant extracts
The papaya seed and leaves are collected and washed thoroughly, and are dried for 15 days and ground to powder form. 5 gms of powder is mixed in 100 ml of distilled water, and to prepare the solvent extract 70% methanol is used. The solvent extract is kept in the water bath for 1hr at a temperature of 400C. The extract is then filtered using filter paper to reduce the volume to 10% and the filtrate is collected. It is not applied on the textile substrate due to the absence of OH groups in ortho position, which is responsible for binding the extract to the fabric.
Aloe Vera
Neem
The methanol extract is carried out using the Neem powder and it is left for 48 hours. Then, the methanol is vaporized using rotary evaporator. The extract is applied on the fabric using dip padding technique.
Banana (Leaf and Peel)
100g of banana peel is cut into small pieces and boiled in 1L of a solution of 0.1% NaOH. The solution is filtered using filter paper and the extract is collected. The banana peel extract is used in the dyeing bath at 800C for 90 minutes under continuous stirring. After dyeing, the fabrics are washed with water and it air dried.
Mango
The leaves are collected and washed thoroughly with water, dried under direct sunlight and ground into fine powder using grinding machine. The extract is carried out using aqueous extraction method at a temperature of 980C for 60 minutes. Then the extract is filtered thrice using filter paper to get a clear solution. Dyeing is done at 800C for 60 minutes at MLR 1:50 in the water bath. The dyed fabric is then dried at 800C for two minutes.
Pomegranate
Pomegranate is collected and the rind part alone is separated and dried for 3 days and it is ground to fine powder. The ethanol extract is made using the pomegranate powder and it is left for 5 hours. The extract is collected and the solvent is vaporized using rotary vacuum evaporator. The dyeing of fabric with extract is carried out at 10% of weight of the fabric for 30 minutes at 800C at MLR 1:30. After dyeing, the fabric is washed with cold water and dried.
Combinations
Pomegranate + Onion
The peel of onion and pomegranate are dried in shade and crushed for extraction. The 10 gm powder of select plants is soaked in 100 ml of distilled water in a round-bottomed flask for a night. The extract is made through soxhlet extraction method and the extract is vaporized and concentrated using the rotary evaporator at 500C.
Neem + Aloe Vera
Aloe Vera gel is extracted by removing the outer layers of leaves. The gel is mashed for 90 minutes and then filtered. The Neem leaves are collected, dried and ground to fine powder. Then, the methanol extract is made and collected.
The bleached samples are treated with 5, 7 and 10% concentrations of the Aloe Gel and Neem extract separately. The same samples are treated with combined Aloe Gel and Neem extracts of 5, 7 and 10% concentration at 800C for 30 minutes and then dried at 800C for 15 minutes.
Tulsi + Turmeric + Neem
1g powder of each plant is taken and added to distilled water. Also, 1% of chloroform is added to each in the distilled bath and allowed to dissolve for 24 hours. The solution is then filtered using filter paper and the filtrate is collected. The extract is applied to the fabric by pad-dry-cure method at MLR 1:20.
Conclusion
The plant extract treated fabrics, when subjected to the antimicrobial activity test against the E-coli and S.aureus (Staphylococcus aureus) bacteria and also to the analysis for durability of the finish by standard methods, it will show no bacteria found on the surface of the fabric. Instead, the treated fabrics will show appreciable zone of inhibition against both gram positive and gram negative bacteria. On the other hand, the combined plant extracts show very good zone of inhibition, when compared to individually treated fabrics. The treated fabrics also have greater durability. The finish which is applied on the fabric does not affect any physical properties of the fabric. Since, these plants are extensively available in the market, the opportunity for implementing this antimicrobial finish in the textile industry is high.
About the Author
Dr Subrata Das has a doctorate in Textile Technology with specialisation in Textile Chemical processing, Quality assurance, Colour management, Garment Product Evaluation, Product safety, Order risk review and Management of Restricted Substances in textile and apparel supply chain. The author can be reached at subratadas@bitsathy.ac.in