Antimicrobial finish has now become very important and one of the most desirable finishes for textiles, explain SK Rajput, DB Shakyawar and Roli Purwar.
Textile materials and garments are very much susceptible to microbial attack as these provide large surface area and absorb moisture required for microbial growth. Cellulosic as well as protein (keratin) fibres also provide all essential basic requirements such as moisture, oxygen, nutrients and temperature for bacterial growth and multiplication.
This bacterial growth generally leads to objectionable odour, dermal infection, product deterioration, allergic responses and other related diseases. The development of antimicrobial textile finish is highly indispensable and relevant since garments are in direct contact with human body. To provide antibacterial finish textile materials are subjected to various techniques to afford (a) protection for the user of textile materials against bacteria, yeast, dermatophytic fungi, and other related for aesthetic, hygienic or medical purposes; (b) protection of textile itself from biodeterioration caused by mould, mildew and rot proofing fungi and (c) protection of textile from insects and other pests .
In the last few years to meet the above mentioned demand, a range of textile product based on synthetic antimicrobial agents such as triclosan, metal and their salt, organometallics, phenols and quaternary ammonium compounds have been developed and quite a few are also available commercially . But these synthetic antimicrobial agents are not hygienic and cause negative side effects. Hence there is a great demand for antimicrobial agents based on natural products. The use of natural products such as chitosan and natural dyes for antimicrobial finishing has been widely reported [3-6]. Other natural herbal product such as aloe vera, neem extract, tulsi leaf extract, tea tree oil, eucalyptus oil can also be used for this purpose. Recent developments on plant based bioactive agents have opened up new avenues in this area of research. In this paper, antimicrobial finishes based on natural products and nano particles have been critically reviewed and reported in detail.
Microbial problem in textiles
Under the favourable conditions of humidity, heat and nutrition (sweat and urea), bacteria can grow rapidly on the human skin and the textiles upon them. They convert sweat into sticking substances like acids, aldehydes and amines causing undesired side reactions like colour change, mould stains on textiles. The type of textiles which are mostly affected by bacteria attack are sportswear, leisurewear, military garments upholstery fabrics, quilts, carpets and cushions .
When human physical activity increases, heat production and perspiration rates increase and bacterial growth can lead to odour formation and staining. Hence, antimicrobial treatment becomes highly important for general textiles and high performance applications where the chances of bacterial growth are high and the safety is paramount. They may include medical textiles, sanitary napkins, socks, undergarments, disposable wipes carpets. Global warming will accentuate these problems in the future and hence the future for the use of antimicrobial finishes seems assured, as consumers prefer durable freshness in the garments that they purchase .
Anti microbial treatments
There are three mechanisms by which treated fabrics are made resistant to disease causing bacteria . Controlled release finish is considered effective when in the presence of sufficient moisture, the antibacterial agent is released from the fabric at rate sufficient to kill or inhibit the growth of bacteria. Regeneration model is based on application to fabrics of a chemical finish that will produce an active germicidal species continuously- for example addition of bleaching agents during laundering of fabrics, exposure to UV light. This regeneration is achieved by breaking covalent bonds in the chemically modified fibre during laundering or photochemical exposure. Barrier or blocking mechanism for protecting fabric from microorganism is insertion of a physical barrier film or coating that is simply impervious to transmission of microorganisms through fabric and a film or coating that has direct surface contact activity against bacterial growth.
Types of antimicrobials
Antimicrobials are of two types: Leaching type (conventional antimicrobial) and non leaching type :
- •Leaching type: Antimicrobials diffuses from the garment forming a sphere of activity. Any microbe coming in contact with the sphere is destroyed.
- But in the course of time the strength and effectiveness of the antimicrobial decreases as the product is eventually used up by the bacteria.
- •Non leaching type: Antimicrobials being found to the garment do not migrate off but destroy the bacteria coming in contact with the surface of the garment. The chemical gets attached to the substrate either by chemical bonding or by polymerising forming a layer on the surface of the treated fabric. The microbes do not consume the chemical, instead, the chemical acts on the cell membrane of the microbes. Hence the finishing will be permanent and will remain effective for a substantial length of time.
Antimicrobial finishing techniques
In order to increase the durability of the antimicrobial action to washing treatments, a number of approaches can be utilised. According to the chemical nature and mode of action of the antimicrobial agent, techniques are given below. [1, 8 and 9]
- •In-solublisation of the antimicrobial agent either in or on the fibre
- •Use of graft polymers, homo polymers and/or co-polymerisation on to the fibrev •Fibre treatment with resins, condensates or fibre cross linking agents
- •Chemical modification of the fibre by covalent bond formation
- •Coating of the fibre surface
- •Microencapsulation of the antimicrobial agent and durable binding of the microcapsules to the fibre Antimicrobial activities are generally tested by both qualitatively and quantitatively through available standard tests as follows: 
- •AATCC 100-2004 (assesment of antibacterial finishes on textile materials)
- •AATCC 147-2004 (Parallel streak method)
- •AATCC 90-2011 (antibactitial activity assesment of textile materials: Agar plate method)
Antimicrobial agents for textiles
Man has adopted antimicrobial substances since ancient times, a fact that is demonstrated by their use in Egyptian mummies and in similar applications in other cultures. In this regard, the protection and preservation of fabrics, too, have long fulfilled a role of the utmost importance. The need to protect and preserve is still fundamental in many textile applications today. Antimicrobials are protective agents that, being bacteriostatic, bactericidal, fungistatic and fungicidal, also offer special protection against the various forms of textile rotting. Here it is focused on some of important antibacterial agents that are used in textile finishing.
Quaternary ammonium compounds seem attractive because their target is primarily the microbial membrane and they accumulate in the cell driven by the membrane potential. These compounds, particularly those containing chains of 12-18 carbon atoms, have been widely used as disinfectants. They carry a positive charge at the N atom in solution and inflict a variety of detrimental effects on microbes, including damage to cell membranes, denaturation of proteins and disruption of the cell structure . During inactivation of bacterial cells, the quaternary ammonium groups remain intact and retains it antimicrobial activity as long as the compound is attached to textiles .
PHMB is a hetrodisperse mixture of polyhexamethylenebiguanides with an average molecular weight of approximately 2,500 Da. These are known as powerful biocides active against wide variety of bacteria, fungi, allege and viruses. Being a potent and broad spectrum bactericidal with low toxicity (MIC=0.5-10 ppm), it has been used as a disinfectant in the food industry and in the sanitisation of swimming pools and is being used as a biocide in mouthwashes and wound dressing . Due to good absorption onto cellulosic fibre, PHMB is used as germicides wound dressing and hygienic wipes and as an antimicrobial agent for textile as well. Polyhexamide treated cotton fabrics have been reported to maintained bactericidal properties for 10-15 laundry cycles.
Triclosan: Triclosan (2, 4, and 4 –tricloro-2-hydroxydiphenylether) is a broad spectrum antimicrobial agent with a MIC of less than 10 ppm against many common bacterial species.unlike most other cationic biocides used on textiles, triclosan is not ionised in a solution. It has been in use since the 1960s in a wide array of professionals and consumer products including hand soaps, surgical shrubs, shower gels, deodorants, health care hand washes. It inhibits microbial growth by blocking lipid biosynthesis .
Regenerable N-halamine: One route for durable antimicrobial finishing is to make the finishing regenerable by using chlorine containing N-halamine compounds. These are broad spectrum disinfectants that have been used in water treatment and their antimicrobial activity is attributed to the oxidative properties of the halamine bond (N-Cl) .
In deactivating a microorganism, the N-halamine bond is reversibly reacted to N-H. However inactive substances can be recharged with chlorine in a bleaching solution during laundering. Regenerable peroxides: Alternate methods for textiles functional finishing employ renewable antimicrobial agents. One example is N-halamines. Another approach is using peroxydic moieties, such as peroxide and peroxyacids, which have been widely used disinfectants in the food and beverage industries as well as bleaching agents for textiles and paper. A classical example is the peroxyacetic acid which is well known as a powerful disinfectant used in hospitals. As for their mode of action, peroxydic compounds attack the microbe cell membrane, get into the cytoplasm and affect the microorganism enzymes .
Bioactive plant-based antimicrobial agentsv Coating of antimicrobial plant natural dyes and bioactive plant extract onto cotton fabrics is an emerging technology in the production of medical cloths. As many of the identified compounds from plants are colored, they are used as natural antimicrobial dyes and pigments for dyeing natural and synthetic fibres [17-19]. Ecologically friendly pigments have also been produced by the fermentation of microorganisms such as fungi and bacteria [20, 21].
Natural dyes as antimicrobial agents
Dutta et al  reported that many natural dyes obtained from plant materials are having some medicinal values. The dyeing materials were prepared from pomegranate (Punicagranatum), wild maangosteen (Diospryos peregrine), myrabalan (Terminalia chebula), arjun (Terminalia arjuna), betel nut (Areca catech), onion (Allium cepa), tea (camellia sinensis), eucalyptus (Eucalyptus cenerea) and dye flower (Coreopsis basalis). Cotton fabrics were dyed with the extracted coloring materials and evaluated antimicrobial property against Bacillus subtilis (gram positive) and Escherichia coli (gram negative). The cotton fabrics dyed with extracts of arjun, betel nut, pomegranate, tea and onion were found to have antimicrobial activity against both the test bacteria at varying efficiency. The dyed fabrics also showed reasonably good wash fastness; hence have good potential for adding antibacterial properties along with vibrant colors to textiles of medical and other delicate uses .
The dye extracted from bark of Araucaria columnarisis, known as Christmas tree, using two solvents-methanol and ethyl acetate and its antimicrobial activity was tested against major clinical pathogens. The methanol extract showed the maximum antibacterial activity with the inhibition zones ranging from 15 to 20 mm against both gram positive and gram negative bacteria. The extracts were treated with cotton fabrics which showed dark brown colour (methanolic) and light brown color (ethyl acetate) on cotton fabric. A dyed fabric shows interrupted growth underneath the fabrics .
Ramasamy  used natural dyeing solutions obtained from rind of P.granatum for dyeing cotton fabrics. He also confirmed that fabric dyed with the natural colorant from P.granatum extracts displayed excellent antibacterial activity against test organisms S. aureus and E. colli. Mohammad et. Al. reported that natural dye extract obtained from walnut; applied on polymide fabric; showed antibacterial activity against pathogenic strains of gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. Other dyes like kerrialacca, rubiacardiofolia and acacia catachu have also indicated antibacterial activity upto some extent .
Deepti Gupta et. Al  reported the antimicrobial properties of eleven natural dyes against three types of Gram-negative bacteria. Seven of the dyes showed activity against one or more of the bacteria. The minimum inhibitory concentration for three selected dyes was determined. The results demonstrate that certain dyes are able to reduce microbial growth almost completely in the case of Escherichia coli and Proteus vulgaris. Selected dyes would therefore be valuable for the dyeing of sheets and gowns for hospital use, and on articles which are less suitable for laundering such as mattresses and upholstery. The dyes examined exhibited good wash fastness and the antibacterial effect is therefore likely to be durable .
Raja and Thilagavathi  reported that wool fabrics treated with four natural dyes viz. Silver oak, flame of forest, tanner’s senna and wattle bark; having in vitro antimicrobial efficacy to both gram positive and gram negative bacteria with and without the use of enzyme and mordants. The test results showed that the antimicrobial efficacy of dyed wool samples was significantly influenced by enzyme and mordants treatments. The control dyed fabrics showed antimicrobial efficacy only against gram positive S. aureus bacteria whereas the enzyme treated fabrics had antimicrobial efficacy against both S. aureus and gram negative E.coli bacteria. This may be due to 17 per cent higher dye uptake in the enzyme treated materials. The mordant treated wool fabrics generally showed less antimicrobial efficacy against S. aureus compared to control dyed fabrics .
Natural bioactive agents
Natural bioactive agents with antimicrobial properties have become increasingly important for bio-functionalisation of textile fibres because they enable the production of safe, non-toxic, skin- and environment-friendly bioactive textile products. These antimicrobial compounds, which are mostly extracted from plants, include phenolics and polyphenols (simple phenols, phenolic acids, quinines, flavonoids, flavones, flavonols, tannins and coumarins), terpenoids, essential oils, alkaloids, lectins, polypeptides and polyacetylenes [28-30].
Joshi et. Al.  studied on development of bio-functional polyester-cotton blended fabric using seeds of neem tree (Azadirachta indica) as antimicrobial agent. Thilagavathi et. Al.  imparted antimicrobial finishes on cotton fabric using extracts of neem and Mexican daisy by direct application and by microencapsulation using pad-dry-cure method. Microcapsules are produced using herbal extracts as core and acacia as wall material. They observed that the microencapsulated herbal extracts possess a very good resistance for microbes even after 15 washes.
Mahesh et. al.  reported that pomegranate rind extract coated on cotton fabric is an effective as antimicrobial finishing of textile, followed by neem and turmeric. Among various methods tested exhaust coating was found to be more effective than dip coating. The pomegranate, neem and turmeric extracts coated on fabrics exhibit more antimicrobial efficiency on gram negative bacteria than gram positive bacteria.
Application of glycyrrhiza glabra (yashtimadhu) roots, herbal solution to cotton fabric imparts functional properties of antimicrobial and thermal resistance.
They reported that 50 per cent conc. treated fabric proved to possess best antimicrobial and coolant properties.
The treated fabric is found to be very hygienic with less fungi and bacteria as well as making the cloth much softer than before. They also concluded that this herbal treatment give better coolant effect and reduce the heat on the human eyes .
Jothi  applied aloe gel to cotton fabric to develop antimicrobial fabric. Cotton fabric was treated with aloe vera extract (aloe barbadensis mill) at various concentrations by pad-dry-cure method. Methanol was used as a solvent for aloe gel extraction from aloe vera plant. The aloe gel (5 gpl) treated fabrics exhibited antimicrobial activity against the staphylococcus aureus. The wash durability of the treated samples was found good even after 50 wash . The Aloe Vera extract applied on the cotton in various concentrations in presence of eco-friendly cross linking agent glyoxal in pad-dry cure technique. M. Joshi et al reported that various natural products based bioactive agent such as chitosan, natural dyes, neem extract and other herbal products may also be used as antimicrobial agent .
Rajendran et al.  studied on application of natural silk protein- sericin as antimicrobial finish on cotton. They extracted sericin with ice cold ethanol and coated onto cotton fabric by a pad-dry-cure method. Quantitative assessment by percentage reduction test showed a reduction percentage of 89.4 per cent and 81 per cent for S. aureus and E. coli, respectively. They suggested that sericin might be a valuable ingredient for the development of antimicrobial textiles. Purwar et al.  reported washing durability of natural and synthetic antimicrobial finishes against Escherichia coli, Staphylococcus aureus, Aspergillus niger and Aspergillus fumigates. Antimicrobial agents were applied on the cotton fabric by pad-dry-cure and exhaustion method. They observed that the samples treated with antimicrobial agents considerably retained antimicrobial properties up to 15 washes.
Chitosan based antimicrobial agents Chitosan have been found to inhibit the growth of microbes. It has a MIC of 0.05-0.1 per cent (w/v) against many common bacterial species, although the activity can be affected by its molecular weight and degree of deacetylation. The antimicrobial ability, coupled with non –toxicity biodegradability and biocompatibility is facilitating chitosans emerging applications in food science, agriculture, medicine, pharmaceuticals and textiles. Chitosan has also been reported as a binder and thickener for pigment printing of polyester and polyester/cotton blends. Antibacterial properties of prints showed a 95 per cent reduction of S. aureus colonies within one hour. Both wet and dry crock fastness of the print was found to be good .
Nano-particles as antimicrobial agent
Nanotechnology is an important technology and has wide variety of potential applications. Silver nanoparticles as one of nanotechnology products have extensive medical, industrial and agricultural applications.
Windler et. Al.  reviewed main compounds used for antimicrobial textile functionalisation. Triclosan, silane quaternary ammonium compounds, zinc pyrithione and silver-based compounds are the main antimicrobials used in textiles. They reported that nanoscale silver and silver salts achieved functionality with very low application rates offer clear potential benefits for textile use. Silver is by far the most widely used antimicrobial as well as in wound dressing. It has a MIC value of 0.05-0.1 mg/l against E. Coli .
In situ synthesis of nano-ZnO onto 100 per cent cotton fabrics (terry or woven) by spraying or dipping process resulted in durable antibacterial and UV protection finishes. The nano-sized pore structure of cellulosic fibrils acted as nucleation site for formation of nano-ZnO from the precursors, zinc nitrate and sodium hydroxide. Both the processes resulted in excellent antibacterial activity (>98 per cent) against two representative pathogens, Staphylococcus aureus (Gram-positive) and Klebsiella pneumoniae (Gram-negative) even after 50 wash cycles. The UV protection factor (UPF) was maintained above the minimum accepted level of 50 till 50 wash cycles. Spraying process resulted in 3 times less uptake of nano-ZnO than that of dipping process, without significant reduction in functional properties. The water absorbency and colour of the terry cotton fabrics remain unaffected in the developed processes . Ag-NPs with highly pure silver stabilised by PEG-600 which has an excellent water solubility, biocompatible lubricity, thermal stability along with its non-toxic, nonirritating, and moisturising features, were firmly incorporated onto cotton fabrics using an impregnation method. XPS results indicated that only one state of silver was present on the surface of the antimicrobial textile. Ag-NPs of 3-20 nm in diameter were confirmed by TEM analysis. The antimicrobial test results showed that the treated textile has an excellent antimicrobial effect and laundering durability. The bacteriostatic circles against E. coli and S. aureus are both more than 1 mm as the antibacterial fabric was washed for 50 times on the basis of the disc-diffusion test . Eco-friendly nano particle
Krishnaraj et al.  investigated the biosynthesis of silver nanoparticles and its activity on water borne bacterial pathogens. Silver nanoparticles were rapidly synthesised using leaf extract of Acalypha indica and the formation of nanoparticles was observed within 30 mins. The size of the silver nanoparticles was measured 20-30 nm. Further, the antibacterial activity of synthesised silver nanoparticles showed effective inhibitory activity against water borne pathogens Viz., Escherichia coli and Vibrio cholerae. Silver nanoparticles 10 microg/ml were recorded as the minimal inhibitory concentration (MIC) against E. coli and V. cholerae.
Alteration in membrane permeability and respiration of the silver nanoparticle treated bacterial cells were evident from the activity of silver nanoparticles.
Singhal et.al.  reported biosynthesis of stable silver nanoparticles using Tulsi (Ocimum sanctum) leaf extract. They observed that O. sanctum leaf extract can reduce silver ions into silver nanoparticles within 8 min of reaction time. Thus, this method can be used for rapid and ecofriendly biosynthesis of stable silver nanoparticles of size range 4–30 nm possessing antimicrobial activity suggesting their possible application in medical industry. Peter et. Al.  used plants extract from Ocimum tenuiflorum, Solanum tricobatum, Syzygium cumini, Centella asiatica and Citrus sinensis for the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution. They found silver nanoparticle with an average size of 28 nm, 26.5 nm, 65 nm, 22.3 nm and 28.4 nm corresponding to O. tenuiflorum, S. cumini, C. sinensis, S. tricobatum and C. asiatica.
Antimicrobial activity of the silver bio-nanoparticles was performed by well diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsi-ella pneumoniae. The highest antimicrobial activity of silver nanoparticles synthesised by S. tricobatum, O. tenuiflorum extracts was found against S. aureus (30 mm) and E. coli (30 mm) respectively. The Ag NPs synthesised in this process has the efficient antimicrobial activity against path-ogenic bacteria. Saxena et. Al.  developed a green synthetic method for silver nanoparticles using Ficus benghalensis leaf extract which acts as a reducing and capping agent. It was observed that use of Ficus benghalensis leaf extract makes a fast and convenient method for the synthesis of silver nanoparticles and can reduce silver ions into silver nanoparticles within five minutes of reaction time without using any harsh conditions.
These nanoparticles show effective antibacterial activity toward E.coli due to high surface to volume ratio.
Geethalakshmi et. Al.  studied antimicrobial properties of the Trianthema decandra L. (Aizoaceae) against ten bacterial and two fungal strains. Chahardooli et. al.  reported a novel rapid and ecofriendly method for green synthesis of silver nanoparticles from aqueous solution of silver nitrate using oak leaf and fruit extracts (Quercus infectoria) in a single pot process. They observed that the use of oak leaf and fruit extracts makes a fast and convenient method for the synthesis of silver nano particles and can reduce silver ions into silver nano particles within 80 min of reaction time without using any severe conditions. AgNPs showed an effective antibacterial activity toward plant pathogenic bacteria.
Ravindra et. Al. investigated the antimicrobial efficiency of cotton fibres loaded with silver nanoparticles (AgNPs) developed by “green process” using natural extracts, of Eucalyptus citriodora and Ficus bengalensis. The size of silver nanoparticles was found to have about 20 nm. They suggested excellent antibacterial activity by the incorporation of 2 per cent leaf extracts on cotton fibres. They also observed that these fibres exhibited superior antibacterial activity even after several washings indicating their usage in medical and infection prevention applications.
Mittal et.al. used biomolecules present in plant extracts to reduce metal ions to nanoparticles in a single-step green synthesis process. This biogenic reduction of metal ion to base metal is quite rapid, readily conducted at room temperature and pressure, and easily scaled up. Silver (Ag) and gold (Au) nanoparticles have been the particular focus of plant-based syntheses. Extracts of a diverse range of plant species have been successfully used in making nanoparticles.
When Cu nano particles were applied separately and simultaneously with maleic acid (cross linking agent) on cotton fabric, the separate method of Cu nano particles treatment of cotton fabric showed more weight gain and more antibacterial activity as compared with simultaneous method .
The fabrics treated with the in-situ synthesis of silver nano particles displays good sustainable bactericidal properties even after repeated washing cycles .
Xu QuingBo et. al.  applied Ag NPs in presence of carboxymethyl chitosan (CMCTS). Here CMCTS acts as a binder. As a result, the coating of Ag NPs on the cotton fabric showed excellent antibacterial properties and laundering durability. Anu misra et.al.  found that introduction of small amounts (= 100 ppm) of silver in the form of AgNO3 during hydrothermal treatment causes doping of TiO2, which imparts strong antimicrobial character to the fabric without causing much discoloration. Doping with silver can also be used to enhance the UPF of the fabric dramatically.
N. Ditaranto et. Al.  told that different surface loadings of textiles with copper and zinc oxide NPs could be easily deposited on the surface of the products of interest in order to inhibit the growth of microbes such as bacteria. This surface deposition improves the antimicrobial functionality thus providing a quick solution to the quest of novel antibacterial textiles.
Yanfei Ren  suggested a novel method of dyeing cotton with prodigiosins was developed. The dye liquor was the nanosuspension of prodigiosins micelles, which was produced by the fermentation of Serratia marcescens. The optimum dyeing process was obtained and the dyed cotton fabric possessed good rubbing, washing and perspiration fastness. In addition, the antibacterial activity of dyed cotton against S. aureus was outstanding while it was mediocre against E. coli.
Kyung Hwa Hong  conducted a two steps process; the first to incorporate a cross linker onto cotton cellulose, and the second to bond the phenolic compound to the cross linker already anchored onto the cotton fabrics. After the finishing process, the cotton fabrics treated with phenolic compounds were investigated by FT-IR, SEM, an antibacterial test, and an antioxidant test. It was discovered that cotton fabrics treated with the two-step process showed >99.9 per cent of antibacterial ability and >80 per cent of antioxidant ability, even at lower concentrations of the crosslinker and phenolic compounds.
E Pakdel et. al.  observed that the antimicrobial activity of cotton fabrics successfully increased after doping TiO2 with noble metals particularly silver. Pure TiO2 did not produce any antimicrobial property on fabrics in the absence of light.
Synthetic agents like metal salts, quaternary ammonium compounds, phenolics, triclosan and halogen-based compounds are very much effective products for antimicrobial finishing and commercially available. But the major problems associated with these synthetic agents are skin allergy, water pollution and side effect on non-target microorganism. Future research will be directed at the development of eco-friendly antimicrobial agents that are durable and retain the desirable wear properties of the fabric. Recent developments on plant-based bioactive agents have opened up new avenues in this area of research. There is a vast resource of natural antimicrobial agents that can be used for imparting antimicrobial property to textile substrate. But there are many problems for using these antimicrobial agents such as-selective isolation of bioactive ingredients, dissolution of the agents for textile application, attachment of bioactive substances to the different type of textile substrate, longer durability, etc. To address all these problems, more and more research should be done in the field of antimicrobial textile finishing replacing synthetic antimicrobial agent with natural one.
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The article is authored by SK Rajput, who is assistant professor with Uttar Pradesh Textile Technology Institute, Kanpur; DB Shakyawar is Director of Uttar Pradesh Textile Technology Institute, Kanpur; and Roli Purwar is Assistant Professor with Department of Applied Chemistry, Delhi Technological University, Delhi.
A picture that was irrelevant to the article titled “Air audit finds huge energy savings in Lakshmi Mills” on page 65 of February 2018 edition has been inadvertently published. We regret the error.
In the article titled “Automation is the only way forward: Director of MAG Solvics” on page 55 of February 2018 issue, it was wrongly mentioned that MAG Solvics is a two-year old company. The company has been in the business for over 26 years. We regret the inadvertent error.