Browsing by Author "Wijayapala, S"

Now showing 1 - 7 of 7

item: Article-Abstract
Dyeing of cotton, wool and silk with extract of Allium cepa
Vankar, PS; Shanker, R; Wijayapala, S
Purpose – The purpose of this paper is to evaluate the efficiency of dyeing on cotton wool and silk fabrics with natural dye obtained from kitchen waste of dry skin extract of Allium cepa. Design/methodology/approach – The dry skin of onion produces natural dye which has been used for dyeing textiles. In the present study, innovative dyeing with onion has been shown to give good dyeing results. Pretreatment with 2 per cent metal mordant and using 5 per cent of plant extract (owf) was found to be optimum and showed very good fastness properties for cotton, wool and silk dyed fabrics. For effective natural dyeing with dry skin extract of Allium cepa, conventional method of dyeing was carried out using metal mordants. The purpose of using this source was with an idea to produce value addition dyed product from kitchen waste as the dye has very good potential of uptake, adherence to the fabric and has good wash and light fastnesses. Results show very attractive hue colours. Findings – The preference of using easily and cheaply available material for dyeing by conventional dyeing lowers the cost of natural dyeing and enhances resource productivity and as a result, reduces waste. This makes onion scale one of the easily available materials for natural dyeing industry. Research limitations/implications – Although metal mordanting with copper sulphate and potassium dichromate are not ecofriendly but we have used only 2 per cent of these metal salts to prepare different shades with dry scales of Allium cepa extract. Practical implications – The method developed for natural dyeing of cotton, silk and wool fabrics using skin extract of allium in conjunction with metal mordanting has shown very deep coloration. The stepwise dyeing of cotton fabric with metal mordant by the natural dye Allium cepa showed that the stepwise dyeing process gave very good result. The dye uptake in case of stepwise dyeing was from 65-68 per cent in the case of cotton, 70-74 per cent in silk and 78-82 per cent in wool with different mordants. Originality/value – The method developed for natural dyeing of cotton, silk and wool fabrics using skin extract of allium in conjunction with metal mordanting has shown marked improvement in terms of dye adherence and fastness properties and can thus be recommended for industrial application.
item: Conference-Full-text
Investigating the ability to transfer antimicrobial properties of neem seed oil to cotton knitted fabrics
(IEEE, 2018-05) Ayomani, MAE; Hansadi, JMC; Wijayapala, S; Chathuranga, D
This research, investigates the ability to transfer antimicrobial properties of Neem (Azadirachta indica) to cotton single jersey knitted fabrics. The effectiveness of two existing application methods, direct application (pad-dry-cure) and application of microencapsulated Neem oil using pad-dry and dip-dry methods were studied. Commercially available Neem seed oil was confirmed to have acceptable level of thermal and light stability through FTIR spectroscopy. (Same tests were repeated for Neemazal-F product; however, the outcomes were less favourable.) Agar diffusion test (BS EN ISO 20645:2004) carried out on specimens also confirmed the antimicrobial efficacy of the pure oil and the treated fabrics against Staphylococcus aureus. However, the fabrics treated with microencapsulated Neem seed oil showed better transfer efficiency, wash fastness properties and aesthetic properties.
item: Thesis-Abstract
Positive environmental management via waste minimisation in a textile washing factory
(6/11/2011) Wijayapala, S; De Alwis, A; De Silva, NGH
Textile and garment Industry is an important industry sector in the Sri Lankan economy. The finishing part comprises the final step in textile processing and it is known as a sector with high polluting potential. In the textile washing sector considerable quantities of water is used only once usually and is discharged without any recovery. To stay competitive this industry needs to be modernized and definitely needs better performance in the environmental management sector. This project was limited to looking at the environmental management aspects and that too with only a single pollutant stream -water. The sector of the textile industry considered is the textile washing industry. A garment washing plant is analyzed with the objective of promoting water recycling and waste minimization practices. Initially typical practices were reported, followed by a water balance for the system . Results of the water audit presented here forms the first essential element of the waste minimization process. Water stream is considered from the inlet to the exit, and the consideration is given to methods of conservation possible of this valuable natural resource while obtaining the optimal use in the process. The time that water was assumed to be a limitless low-cost resource has already passed. Today there is an increasing awareness of the danger to the environment caused by over-extraction and use of water. There is now considerable incentive to reduce both consumption and waste water production. The selection of the washing industry was selected for this study under that consideration. This industry sector today uses significant quantities of water and most of the factories neither utilize waste minimization nor water recycling techniques. The waste treatment methods are also not adequate. Thus there is a tremendous potential on savings on one hand and a need on the other hand. It was shown that it is feasible to utilize groundwater after treatment. Manganese is not appearing to be a major problem. The problem chemical appears to be the presence of iron. Iron can be removed from groundwater using several operations. This eliminates the transport of water from outside and serves many environmental needs such as reduced traffic, removing reliance on outside sources and events etc. A pilot plant was constructed in the laboratory and four methods of iron removal were analyzed. Ozonation was studied as a method of reducing this wastage. In this manner there would be a reduced demand on the freshwater resource as well as reduced discharge of effluents. Thus the situation would lead to a facility whereby the waste minimization has taken place and a facility with positive environmental management. It has been shown that this technology offers many advantages to the industry including the recycling option. Ozonation in addition provided abilities to provide the required input quality as well in addition to being able to reduce COD, BOD and the most importantly Color of effluents. It was seen that processes are carried out with less attention being paid to the overall efficiencies but only towards meeting production targets and/or meeting deadlines. The feasibility of recycling waste water was shown. The practice of this would be a major improvement on the current environmental performance.
item: Conference-Full-text
Positive environmental management via waste minimization in a textile washing facility.
(1998) Wijayapala, S; De Silva, NGH
Existing and developing national environment protection regulations have made it mandatory for all industries to establish a treatment system for wastewater to bring down all toxic, hazardous and offensive components to specified levels before releasing to the environment. The paper looks at the garment washing industry in the textile sector. The industry sector today uses significant quantities of water and none of the factories utilise waste minimisation nor water recycling techniques. A washing plant is analysed with the objective of promoting water recycling and waste minimisation practices. Initially typical practices are given, followed by a water balance for the system. Results of the water audit presented here forms the first essential element of the waste minimisation process. The method suggested look at the iron removal process to utilise ground water and then (eliminating water transport needs) to advance filtration to make recycling feasible. Iron is the key limiting factor in utilising the available ground water supply. These steps would preserve the water resource and would eliminate the current wasteful practices adopted by the industry.
item: Thesis-Abstract
Reliability of visual and digital color assessment in textiles for intimate apparel manufacturing
SampathBandara, TP; Wijayapala, S
Expectations of apparel retailers in international are high quality apparel in low cost align with the fashion trend of the season in narrower lead time. With its aim, the buyers tend to defer buying decision to align with frequent changes in fashion trend and related colour aesthetic to maximize the retail while maintaining the lower inventory levels. With this situation, the garment manufactures required to re-visit garment manufacturing process and implemented new manufacturing systems such as lean manufacturing practices and other operating systems to shorten the production life cycle. Color approval process is one of the key activities and it is identified as nonproductive activity consume considerable time period in the total buying cycle. The objective of the study is to discover a methodology to eliminate color approval process and related timelines by implementing modem technology available. The research is carried out with a statistical analysis to find a numerical value which able to transform through the electronic media by replacing a visual judgment instantly to a decision maker. After a comprehensive literature review, the color difference (the symbol of DE) is identified as the numerical value to transform the decision of accepting the color, which is 0.806 for main raw material used for intimate apparels selected in this study. Further study is recommended to discover DE of various other components used in the industry enabling to eliminate the nonproductive timeline in the color approval process and reduce total buying cycle time.
item: Thesis-Abstract
A Study of indigenous dye producing plants and their derivatives in textile dyeing
(3/28/2011) Gunaratne, KPN; Wijayapala, S; De Silva, NGH
With the discovery of synthetic dyes all colour industries, not only textile industry had turned to the more economical, reproducible, high colour fast and easy to use synthetic dyes and abandoned the natural dyeing tradition which had prevailed as the only colouring technology till then. But recently a revival in the natural dye in technology has occurred as solutions to the environmental pollution arising out of the wet processing of textiles as well as to the growing trend of dye toxicity and all ergie s to the textile consumers. Natural dyes provide not only a good alternative to the environmental pollution arising from synthetic dyes but also provide low toxicity and allergic reactions while giving unique and fascinating colours which are not achieve able from synthetic dyes. A thorough review to the historic background of the origin and progression of natural dyeing techniques in the world with specific concern to Sri Lanka was carried out .During this review a search was also made into the reasons for the erosion of this valuable tradition of natural dyeing. Through a survey of the natural dye producing plants world over, a list of indigenous dye producing plants in Sri Lanka was preparedand investigated the possibility of using one of these plant sources to develop a new natural dye based on its extraction. In selection of this plant source the major concern was given to the fact that it should be abundant as a waste material in Sri Lanka. Black tea, which is highly available as a waste (dust) from tea factories and domestic sources (brewed tea) were used to extract polyphenols, which are an abundant form of natural compounds in tea. These were used as the coupling component to produce a zocompounds by coupling with different diazonium salts. Both polyphenols and azo compounds were separated and solidified and thus obtained azo compounds had variable colour shades depending on their respective diazonium salts. The possibility of applying these azo compounds as in-situ azo dyes on 100% cotton and ready-madeinsoluble disperse azo dyes using HTHP conditions on 100% polyester, 100% nylonand 100% wool were investigated. Different azo compounds produced different colourshades on different fabric types as well as on the same fabric type. Optimisation of dye bath conditions to improve the take up of polyphenols by cotton using the in-situ application of azo dyes was also carried out. The colours produced on cotton were not very bright and showed moderate colour fastness to washing, good colour fastness to rubbing while the brilliant colours produced on polyester showed good to very good wash, rub and sublimation fastness, after reduction clearing. The colour depth and fastness on nylon and wool were better than those on polyester. The light fastness of all the azo dyed samples was poor and should be improved using suitable after treatments. The percentage yield of polyphenols for both used and unused black tealeaves and the percentage yield of different azo compounds obtained from unused black tea leaves were calculated. The study was basically carried out with the aim of investigating the traditional dyeing techniques and indigenous dye producing plant sources in Sri Lanka and to assess the possibility of using polyphenols from one of the selected plant resources. Tea, which is abundantly available as tea waste (dust) from factories and brewed tea leaves fromdomestic sources was selected as the natural source of dye or dye intermediate for textile dyeing.
item: Conference-Extended-Abstract
Tea polyphenols as an indigenous natural plant resource in preparation of azo dyes for dyeing textiles
(2003) Gunararne, KPN; Wijayapala, S; De Silva, NGH
For thousands of years. until as recently as the discovery ofthe first synthetic dye in 1RS6. all colouring substances were of natural (vegetable. animal, lichen and mineral) origin. After the discovery of first synthetic dye, there was a gradual decrease in the use of natural dyes. which were more expensive and in many ways more difficult to use. Today. many of the natural dyes have been replaced by synthetic dyes. The major problem threatening the textile industry today is the environmental pollution, arising out of the wet processing of the textiles. The production of synthetic dyes involves many violent reactions. using. manv hazardous petroleum based primary chemicals as well as the production of hazardous intermediates. Therefore it is high time that the over utilization of synthetic dyestuffs should be thought about in the context of health of the people and environment. Natural dvcs extracted or developed from natural resources exhibit better biodegradability. higher compatibility with the environment and also a lower toxicity and allergic reactions not to mention the unique and fascinating colours.