Analysis of colourfastness of fabrics treated with dyes extracted from Roselle calyces

The dyeing potential of roselle (Hibiscus sabdarifa) extract variously extracted by boiling, steeping and ethanol solvent were evaluated with three dye fixatives (potassium aluminum sulphate (alum), tannic acid, and citric acid), to study their effects on cotton (100%), stone silk (60% silk:40% polyester) and polyester (100%) fabrics. Colourfastness to sunlight, washing, perspiration (acid and alkali) and rubbing (crocking) were studied on the individual fabrics as 1 × 4 factorial involving three dye extracts (1 dye source × three extraction methods) and three dye fixatives plus a non mordanted control in a completely randomized design (CRD) of three replications. Data on degree of fastness were generated as scores through 1 (excessive colour fade or stain) to 5 (no colour fade or stain) using Gray scale and fastness test rating scale (FTRS) evaluation instruments. Data were analyzed using descriptive statistics (means and standard deviations) and general linear model for factorial experiments of statistical package for social sciences (SPSS) version 16.0. Three null hypotheses were tested using analysis of variance (ANOVA). Treatment means were compared using Scheffe’s test at 0.05 probability level. Findings include: Roselle calyces extracts showed reasonable colourfastness on cotton prototypes. The effects of dye extraction procedures did not significantly differ (p>0.05) on the colourfastness of cotton prototypes to sunlight (p=0.33), washing (p=0.39), alkali perspiration (p=0.06) and dry rubbing (0.59). The effects of mordant/dye fixatives did not significantly differ (p>0.5) on the colourfastness of cotton prototypes to washing (p=0.95) and rubbing or crocking (p=0.68), but differed significantly (p<0.05) on colourfastness to sunlight (p= 0.00), acid perspiration (p=0.00) and alkali (p=0.00). Tannic acid and alum mordant were the source of difference. Roselle calyces extracts exhibited much to excessive fade and stain of colour and poor fastness to all parameters tested except rubbing fastness.


INTRODUCTION
Fabric is a flexible material made up of a network of natural or manufactured fibres formed by any of weaving, knitting or ot her fabrication techniques (Vanderhoff et al., 1985).Natural fibres are processed from animals' bodies, plants' cellulose and mineral.The major fabrics from animal sources are silk from silk worm and wool from *Corresponding author.E-mail: ozougwusu@yahoo.com.
Author(s) agree that this article remain permanently open access under the terms of the Creativ e Commons Attribution License 4.0 International License sheep.Major plant, vegetable or cellulose fibres are from cotton and linen from flax plants.Asbestos is a mineral fibre from rock formations.Rayon, acetates, triacetat es, cupramonium are some regenerated, transitional or cellulosic-based manufactured fibres while purely synthetic fibre fabrics are nylon, polyester, acrylics, olefin, spandex among others.The type of fabric is determined to a large extent by the nature of fibre, fabrication and finishing.Various finishes are applied to fabric to improve its aesthetics and functions.One of such finishing is colour application.Dye is a coloured substance that imparts permanent colour to other substances (Finar, 1973).A good dye is characterized by being soluble in water or dispersible in solvent and trans ferable to the fabric or other mat erials to be dyed by the process of absorption and exhaustion.Dye must have affinity to the fabric, be colourfast and organoleptically acceptable to consumers.
Colourfastness is the ability of a dye to resist fading or staining caused by sunlight, was hing, perspiration (dilute acids and alkalis), crocking or rubbing and other organic solvents used in laundering and dry-cleaning (Marshal et al., 2000).A single dye may not be fast in all circumstances.However, a dye should remain viable and gracefully age with the product (Weber, 1990).The fastness or stability of a dy e in fabric is determined by the type of fabric fibre (natural or synthetic); method of dye application (for instanc e, conventional exhaust procedure) and class of dye (acidic, basic, direct, vat, fibre reactive, dispers e, azoic or mordant dye).A mordant is an element that quickens the chemical reaction taking place between a fibre and a dye.Mordant helps to open up the fibre to enable the dye absorbed and improve the fastness of the dye on the fibre.They also deepen t he shade of dye and can change the final colour giving rise to a new colour.The application of dy e to a textile with which the dye does not combine readily can sometimes be improved by using a mordant.Some mordant are heavy metals such as chrome and are destructive to fibre and toxic to skin.Aluminum sulphate (alum), ferrous sulphate and other acidifying dye fixing agents including tannic and citric acids act as intermediary between fibre and basic dye (Finar, 1973).Natural dyes are classified as mordant dyes.They do not dye fibres directly but require mordant.
Presently, the global interest in natural dye has increased tremendously.Natural dyes perform very crucial educational, economic, pharmac ological, sociocultural, political, religious as well as psychological roles.They are highly commended for their health and environmental benefits over some synthetic dyes which are toxic, non-biodegradable and carcinogenic.Natural dyes are also valued for the preservation of traditional dyeing arts and crafts.The very high demand for safe dyes in sustainable supply to meet the ever increasing volume required in the wood, food (Obadina and Oyewole, 2007), paper and photography industries, pharmacology (Chenghaiah et al., 2010;Owoade et al., 2015), educational institutions (Spenser, 2011;Bassey et al., 2012), homes, leather and leather product, textiles and clothing industries (Onwualu, 2006;Jothi, 2008), requires more research and development efforts in sourcing dyes from nat ural sources.No fabric dyeing or printing can be successfully achieved without sustainable supply of quality dyes.
Globally, clothing and textile sector has played major roles in employment and income generation for many nations.In Nigeria, for instance, within the past 15 years, there were up to 180 functional textile mills in the country employing about 800,000 people.A vailable report showed that out of 13 subsectors in the manufacturing sector, the textile sector comprising cotton textile and synthetic fabrics continued to account for a significant proportion of the overall growth of manufacturing production (Central Bank of Nigeria (CB N) Annual report, 1995).Similarly, textile and apparel sector contribut ed 34.49% to the rebased nominal GDP in Q1 2014 ranking 3 rd after Chemicals and Pharmaceutical sector (41.61%) and Nonmetallic product sector (35.69%) using 2010 as a base year (National Bureau of Statistics Data Release Calendar, 2014).However, in recent years clothing and textile sector had faced major challenges which precipitated to shutting down of about 155 textiles mills, leaving only 25 mills with low capacity utilization, and 776,000 citizens jobless; Osagie, 2013).In educational institutions, unavailability of non-toxic dyes in sustainable supplies hinder effective teaching and learning and acquisition of skills in arts, craft and science practical classes involving dye utilization.Acquisition of skills predisposes graduates to unemployment, a precurs or to poverty, crime and other antisocial behaviours.More so, unemployment leads nations to trade deficit and under development.The Federal Government of Nigeria through the Raw Materials Research and Development Council (RMRDC) has continued to advocate the exploit ation of locally available raw materials to substitute or supplement the imported and expensive ones.Dyes, tanning chemicals , cotton, hides and skin are some agro-based raw material inputs into the nation's textiles and leather industries reported to be import ed as local supplies are low (Onwualu 2006).The sector has the potential to grow and achieve competitiveness if there is adequate and sustainable supply of these inputs.
Nigeria is blessed with abundant species of plants capable of yielding dyes.Plant dyes can yield variety of exquisite and interesting colours.Janseen and Cardon (2005) identified a number of 43 local plants with potentials of yielding dyes for fabric colouration which could be found in tropical A frica, including Nigeria yet unexplored.One of such plants includes Roselle.
Roselle (Hibiscus sabdarifa) plant, a tetraploid belonging to the family Malvaceae is also known as Soursour in Sierra Leone, dab or bissap in Senegal and surrounding countries, oseille de Guinean or Roselle in Frenc h, marakwanga in Northern Uganda, Jamaic an sorrel or Florida crambery in the Caribean areas (Schippers, 2000).Roselle is also called karkadeh in Arabic (Ali et al., 2005).In Nigeria, Roselle is known as isapa in Y oruba and zobo in Igbo lands.Roselle is a fibre and an ancient crop widely grown in Cent ral and West Africa and South East Asia (Murdock, 1995).Roselle has varieties whic h differ in colour of calyces ranging from green, red and purple.Roselle is also used for its paper and ornamental values (Schippers, 2000; The Tec hnical Cent er for Agricultural and rural Co -operation ACP -EU, 2006).
A comprehensive review of different studies of the constituents of different parts of Roselle plant and its phytochemical, pharmacological and toxicological properties has been documented by Ali et al. (2005).Roselle is a rich source of plant polyphenols such as flavonoids and phenolic acids (Ali et al., 2005).A recent study on phytochemical constituents of Roselle calyces extract reveal t he following; carotenoid (1.96%), flavonoid (0.02% ), lutein (0.03% ), polyphenol (0.12% ), tannin (0.88% ) per 100 g.Roselle calyx contains anthocyanins which are polyphenolic compounds responsible for cyanic colours ranging from salmon pink through red and violet to dark blue of most flowers, fruits, leaves and stems (Peng-Kong, Salmah, Ghazali and Che, 2002), and comprise the largest group of the water-soluble pigments in the plant kingdom (Clydesdale et al., 1990;Owoade et al., 2015).
Raselle is valued in pharmacology in drug and cosmetic productions (Egbujo et al., 2008) Anthocyanins are in recent times regarded as nutraceuticals due to their potential healt h and possible antioxidant effects, and have been given a potential therapeutic role related to cardiovascular diseases, cancer treatment, inhibition of certain types of virus including the human immunodeficiency virus type 1 (HIV-1), and improvement of visual acuity (Cecchini et al., 2005;Cooke et al., 2005;Talavera et al., 2006in Owoade et al., 2015).Roselle has also been found useful as food beverage, wine, gel and as food colorant.The production of roselle powder has also been done.
Various studies have been done on Roselle's potentials as refreshing beverages (Clydesdale et al., 1990), food colourants (Hassan and B akri, 1990), and cosmetics purposes; however, research into fabric colouration using Roselle extract is scarce despite its large anthocyanin property.The organleptic attributes of Roselle dye, including colour hue, value, chroma, odour, texture and evenness of shade on cotton fabric were found to be good and acceptable to consumers.The study on t he colourfastness of roselle dyed fabrics is imperative.The focus of this present study was therefore, to analyze fabrics treated with dyes extracted from roselle (H.sabdarifa) calyces.Specifically, the study sought to: 1. Extract three different dye extracts from roselle calyces Ozougwu and Anyakoha 135 using boiling, steeping and solvent techniques.2. Mordant samples of cotton (100%), stone silk (60% silk: 40% polyester), and polyester (100% ) fabrics with alum mordant, tannic and citric acids dye fixing agents.
3. Dye the mordant ed fabrics and no-mordant sample (control) with the roselle extracts using normal dyeing conditions to study their dye ability.4. Assess the effects of dye extraction methods on t he colourfastness of the dyed fabrics (prototypes) to sunlight, washing, perspiration (acid and alkali) and crocking or rubbing. 5. Assess the effects of dye fixati ves on the colourfastness of dyed fabrics to sunlight, washing, perspiration (acid and alkali) and crocking or rubbing.

Hypotheses
Three null hypotheses were tested by the study at 0.05 level of significance: H01: There is no significant differenc e in the mean rating effects of dye extraction met hods and fixatives on t he colourfastness of roselle dyed samples of cotton fabrics to sunlight, washing, perspiration and rubbing.H02: There is no significant differenc e in the mean rating effects of dye extraction met hods and fixatives on t he colourfastness of roselle dyed samples of silk fabrics to sunlight, washing, perspiration and rubbing.H03: There is no significant differenc e in the mean rating effects of dye extraction met hods and fixatives on t he colourfastness of roselle dyed samples of polyester fabrics to sunlight, washing, perspiration and rubbing.

MATERIALS AND METHODS
The study adopted completely randomized ( CRD) experimental design.Dye extraction and fabric dyeing (prototype development) were done at the University of Nigeria, Ns ukka, Enugu State w hile colourfastness tests w ere conducted at the International Textiles Industries (ITI), Limited, Lagos State, Nigeria.Red dry roselle calyces w ere collected from Ogbete, Enugu.Alum, citr ic acid, tannic acid, Sodium carbonate ( Sal soda) and ferrous sulphate ( FeSO4) w ere collected at Ugo chemical store, UNN.Fabrics studied w ere cotton (100% natural fibre), stone silk (blend of 60%silk: 40% polyester) and polyester (100% synthetic) fabrics w ere collected at Enugu.Other materials used include; distilled w ater, heater, ther mometer, rubber hand gloves, Shirley Development Limited (SDLA) A merica w ashing machine (auto wash), Thomas Willey milling machine, electronic crock meter, Gray scale, stainless and plastic bow els and spoons, ITI black carbon, transparent glass, ethanol (analytical grade).Their uses w ere explained follow ing the procedures of the w ork.

Dye extraction procedures
About 3 kg dried red roselle calyces w ere further dried under room temperature in the Green House for 40 min at 40°C to facilitate milling.The dr ied calyces w ere milled into fine pow der using Thomas Willey milling machine.

Dye extraction by boiling
Extraction of dye from roselle calyces by boiling w as done using boiling method as described by Kolender (2003).About 80 g of roselle calyces pow der w as dissolved in 160ml distilled w ater in the ratio 1:2 ( W/V).It w as heated at 80 to 90°C for 20 mins and allow ed to cool.The solution w as filtered w ith 0.5 meshes (particle s ize) to collect the dye liquor and labeled roselle dye extracted by boiling (RDB).

Dye extraction by steeping
About 80 g of roselle calyces pow der w as steeped in 160ml distilled water in the ratio 1:2 ( W/V) and allow ed to stand overnight allow ing fermentation to take place w ithout heating.The solution w as stirred thoroughly and filtered us ing 0.5 meshes ( Particle s ize) to collect the dye liquor and labeled roselle dye extracted by steeping (RDST).

Dye extraction by solvent
A 100 g roselle calyces pow der w as dissolved in analytical grade ethanol ( 98% absolute) in the ratio of 1:4.5 (W/V) in an air tight container.For thorough extraction, the mixture w as shaken properly and allow ed to stand for 24 h and then filtered w ith cheese cloth.Ethanol w as evaporated to dryness on a rotary evaporator under vacuum at 45°C.Roselle paste extracted w as labeled roselle dye extracted by solvent (RDSV) (Figure 1).

Mordanting cotton (100%) fabric sam ples
Four pieces of cotton fabric samples measuring 24 by 24 (15g) inches each w ere scoured or w ashed thoroughly in w arm w ater three times w ith detergent to remove all sizing.In four different stainless pots containing 1500 ml distilled w ater and 0.3g sodium carbonate ( NaCo3) each, 4g Aluminum sulphate (AlSO4, alum) w as dissolved in the first pot, 4g tannic ac id w as dissolved in the second pot and 4g citric acid in the third.The forth stainless pot containing 0.3g sodium carbonate and 1500 distilled w ater w as not added any dye fixing agent or mordant (control).The four w et scoured cotton fabric pieces w ere immersed in each of the solution and gently but thoroughly stirred so that the fabrics w ere opened out in the solution.Each w as then heated, held at boil at 80 to 90°C for 1 h and allow ed to cool overnight in the solution.The mordanted cotton fabric samples w ere labeled; alum mordanted cotton (A C), citric acid treated cotton ( CC), tannic acid treated cotton ( TC), and nonmordant cotton (NC).

Mordanting stone silk (blend of 60%silk:40% polyester) fabric
Four pieces of stone silk fabric samples measuring 24 by 24 (15 g) each w ere w ashed thoroughly in w arm w ater three times w ith detergent to remove all siz ing as in cotton sample above.In four different stainless pots containing 1500 ml distilled w ater and 0.3g sodium carbonate ( NaCo3) each, 4g Aluminum sulphate (AlSO4 alum) w as dissolved into the first pot, 4g tannic acid w as dissolved into the second pot and 4g citric acid in the third.The forth stainless pot containing 0.3g tartaric ac id, 1500 distilled w ater w as not added any dye fixing agent or mordant (control).The four w et scoured stone silk fabric pieces w ere immersed in each of the solution and gently but thoroughly stirred so that the fabrics w ere opened out in the solution.They w ere allow ed to stand in the solut ion overnight w ithout heating.The mordanted fabric samples w ere labeled: Alum mordanted silk (AS), citric ac id treated s ilk (CS), tannic acid treated cotton (TS), and non-mordant cotton (NS).

Mordanting polyester (100%) fabric sam ples
Four pieces of polyester fabric samples samples (24" x 24":15g) each w ere also scoured thoroughly in w arm w ater w ith detergent three times to des ize them.Distilled w ater (1500ml) w as heated and 4g Aluminum Carbonate (AlCO3, alum) and 0.3g Sal soda or sodium carbonate ( NaCo3) w as thoroughly dissolved in.The four wet scoured polyester fabric samples w ere immersed separately into each of the pots and gently but thor oughly stirred so that it is opened out in the solution.They w ere then heated at 80 to 90°C for 1 h and allow ed to cool overnight in the solution.They w ere brought out from the solution drained and labeled thus; alum mordanted polyester (A P), citric acid treated silk ( CP), tannic ac id treated cotton (TP), and non-mordant cotton (NP) (Figure 2).

Cotton prototypes
Each of the roselle extracts or dye liquor ( RDB and RDST) w as divided into four portions in different dye pots.About 15 ml additional w ater w as added to the dye bath so the fabric could move freely.The colour of each sample w as modified by dissolving 0.5 g ferrous ( II) sulphate ( Fe2 SO4) into the dye bath.Each of the alum, citr ic acid, tannic acid and non mordanted (control) samples of cotton w as then immersed separately into a pot containing each of the roselle dye bathes and heated 1 h at 80°C by conventional exhaust dyeing method.Samples w ere taken out after completion of dyeing.The dyed fabric samples (prototypes) w ere rinsed to remove excess dyes and dried under a shade.A total of 36 prototype samples made up of cotton (12 prototypes), stone silk (12 prototypes) and polyester (12 prototypes) fabrics, w ere developed.
The dyed prototypes w ere replicated in triplicates making a total of 108 prototype samples tested for colourfastness.

Fastness to sunlight
Strips of each of the dyed cotton, stone silk and polyester prototypes measuring 2" × 5" w ere arranged vertically on a flat wooden surface.The fabrics w ere covered halfw ay top w ith ITI industr ial black car bon leaving halfw ay dow n exposed.All the prototypes w ere placed behind transparent glass to prevent direct sun rays w hich might be har mful to the fabric fibres.The specimen was made to stand outside on nor mal day sunlight for 72 h according to ISO, 105/A03: 1993 after w hich the samples w ere collected for rating the degree of fade.

Fastness to washing
Using the Shirley Development Limited, A merica ( SDLA) auto w ash electronic w ashing machine according to ISO, 1993 each of the prototype samples (2" × 5") w as covered w ith plain w hite fabric, tightly tied and fed into the 4-rack testing pots bit by bit at a temperature of 32 ± 2°C for 45 min.The samples w ere brought out, allow ed to cool and untied.The extent of staining w as checked off using the Gray scale and triplicate samples recorded w ith FTRS.

Fastness to acid perspiration
About 5.5 g sodium chloride w as dissolved in a solution of 1 L distilled w ater and 5 g disodium hydrogen orthophosphate dodecahydrate ( NaH2 PO4.12 H2 0) w ith 5 g histidine.0.1 N acetic acid w as dissolved into the solution to bring the acidic pH to 5.5.The different prototype samples (2" × 5" each) w ere dipped into the solution, allow ed to dry and covered w ith plain w hite fabric and tied

Fastness to alkali perspiration
This test w as done using similar procedure w ith acid perspiration test but alkaline medium w as achieved by dissolv ing 0.I N Sodium hydroxide ( NaOH) in 1 L distilled w ater to br ing the pH of the solution to 8.0.The prototype samples w ere treated as in acidic perspiration test, rated and results recorded w ith FTRS.

Fastness to crocking/dry rubbing
The different prototypes (2" × 5") w ere covered w ith plain w hite test cloth, tightly tied and fed into the nozzles of the electronic crock meter machine.The machine scrubbed each sample 15 times for 5 min.The samples w ere then brought out, untied and the extent of staining w as recorded.

Fastness index of the prototypes
Tw o types of instruments w ere used to record the fastness index of the prototype fabrics.They include Gray scale, a standardized scale used to rate the degree of colour fade or stain of one prototype fabric due to sunlight, w ashing, perspiration (acid and alkali) and rubbing or crocking.Fastness test rating scale ( FTRS) was developed by the researchers to record the triplicate mean results of the fastness tests done w ith Gray scale.The fastness and range of means for taking decisions are show n in Table 1.

Data analysis
General linear model for factorial experiment w as used for data analysis using statistical package for social sciences version 16.Any sample w ith mean score 3 or above w as regarded as a colourfast sample w hereas any sample w ith score below mean 3 was regarded as a non-fast sample.Analysis of variance (ANOVA) was used to test three null hypotheses w hile Scheffe's post hoc test compared the treatment means at 0.05 level of significance.

RESULTS
1. Roselle calyces extracts showed reasonable colourfastness property to rubbing/crocking, sunlight and acid perspiration on cotton prototypes but were generally non-fast to washing and alkali perspiration (Table 2).
3. The effects of mordant/dye fixatives did not significantly differ (p>0.5) on the colourfastness of cotton prototypes to washing (p= 0.95) and rubbing or crocking (p=0.68),but differed significantly (p<0.05) on colourfastness to sunlight (p=0.00),acid perspiration (p=0.00) and alkali (p=0.00).Tannic acid and alum mordant were the source of difference (Table 3).4. Roselle calyces extracts dye potentials on stone silk and polyester prot otypes were generally poor.They exhibited much to excessive fade and stain of colour and poor fastness to all parameters tested except rubbing fastness (Tables 4 and 6) 5.The effects of dye extraction methods did not differ significantly (p>0.05) on the stone silk and polyester prototypes colourfastness paramet ers assessed.Though the effects of dye fixatives significantly differed (p<0.05) with tannic acid and alum mordant the source of differenc e, they were not able to improve the stability or colourfastness of the prototypes (Tables 5 and 7).Data in Table 1 reveals that six out of 12 cotton prototypes were fast to sunlight.They include -alum and tannic acid mordanted prototypes (RDB -AC, RDB -TC, RDS T -A C, RDS T -TC, RDSV-A C and RDSV-TC).Alum and tannic acid prototypes dyed with roselle extracted by steeping had the highest fastness index (3.33±0.000).They exhibited slight fade in colour when exposed to sunlight as shown by their mean ratings (3.00±0.000 to 3.33±0.000).For washfastness of cotton prototypes, only RDS T-AC and RDS T-TC prototypes were fast (3.33±0.000and 3.00±0.00,respectively) with RDS T-A C rating higher.They showed slight stain or bleeding of colour in washing while others exhibited much to excessive stain (2.67±0.58 to 1.67±0.58).Three prototypes were fast to acid perspiration (3.00±0.00 each).They include; RDB-A C, RDS T-AC and RDSV -AC.They showed moderate fastness and slight change or fade in colour.None of the prototypes was fast to alkali perspiration as none was rated up to the mean cut off.All the prototypes were fast to dry rubbing except RDSV-NC (2.33±0.155)and RDSV-CC.The fastness ratings range from very slight to slight stain, implying good and fair colourfastness.

Deci sion rule:
The null hypothesis which states there are no significant differenc es in mean rating effects of dye extraction methods and dye fixatives on fastness of all cotton prototypes to sunlight, washing, acid/alkali perspirations and rubbing are accepted (p>0.05) for dye extraction methods since p-values are greater (p>0.05)than 0.05 probability level.For dye fixatives, null hypothesis was rejected for effects of dye fixatives on fastness of cotton prototypes to sunlight, acid and alkali perspirations (pF<0.05)but accepted for washing and rubbing.P-values are greater than (p>0.05)significant level.Data in Table 3 indicate that majority of the stone silk prototypes were fairly fast only to dry rubbing but were non fast to other silk fastness parameters.Silk prototypes that showed slight stain included RDB-AS (3.33), RDB-TS (3.33±.56),RDS T-AS (3.00.58),RDS T-CS (3.00±.51),RDS T-TS (3.33), RDSV-AS (3.67±.57),RDSV-CS (3.00±.000),RDSV-TS (3.67±.62).All the non mordant ed prototypes showed much fades or stain to the different fastness parameters as shown in their low mean ratings.

H02:
There is no significant difference in the mean rating effects of dye extraction methods and dye fixatives on colourfastness of ros elle dyed cotton Prototypes to sunlight, washing, and acid and alkali perspiration.
The effects of steeping extraction was not significantly different from et hanol and boiling techniques but were comparable to each other in improving the rubbing fastness of silk prototypes.There were no significant differenc es in the effects of ethanol dye extraction on the colourfastness of silk prototypes to sunlight (p=1.00),washing (p=7.20),alk ali (p= 1.00), rubbing (p=0.22).Though tannic acid and alum had more positive effects on the fastness of silk prototypes, their effects are not significantly different from citric acid and no mordant on fastness to sunlight (p=0.141),rubbing (p=0.053).Non mordanted silk prototypes were the source of the differenc e (p=0.001) on prototypes fastness to washing.They exhibited the poorest washingfastness ratings..The P and F-values of acid and alkali fastness of silk prototypes could not be computed with alpha =0.050 of the general linear model for factorial experiments of the SPSS for social scienc es version 16.0 used since t he means of t he different prototypes were homogenous indicating no significant differences.

Deci sion:
The null hypot hesis which states there are no significant differenc es in mean rating effects of dye extraction methods and dye fixatives on fastness of silk prototypes to sunlight, washing, acid/ alkali perspirations and rubbing are accepted (F>0.05) for dye extraction methods since F-values are greater (F> 0.05) than 0. 05 probability level.For dye fixatives, null hypot hesis was rejected for effects of dye fixatives on fastness of silk prototypes to washing, acid and alkali perspirations (F<0.05) but accepted for sunlight and rubbing (p>0.05).F-values are greater than (F>0.05).05significant level.
Data on colour fastness of polyester prototypes revealed general poor colourfastness to sunlight, washing, acid and alkali.This is seen in the very low mean ratings of the fastness paramet ers.Prototypes showed slight fade and stain to rubbing fastness in nine out of 12 prototypes as seen in Table 6.

H03:
There is no significant differenc e (p≥0.05) in t he mean rating effects of dye extraction methods and dye fixatives on colour fastness of polyester prototypes to sunlight, washing, acid and alkali perspiration and rubbing.
The Scheffe's post hoc homogenous subsets of dye extraction effects on colour fastness of polyester prototypes reveal no significant differenc es in prototypes fastness to sunlight (p= 0.78), washing (p=0.08),alkali perspiration (p=0.32) and rubbing (p=1.00)but significant differenc es exist in mean rating effects of dye fixatives on prototypes' fastness to sunlight (p=0.05) and rubbing (p=0.00)but for washing (p= 0.08) and alkali (p=1.00),there were no significant differences (p>0.05).

Deci sion:
The null hypothesis stating no significant differenc e (p≥0.05) is accepted in instances of effects of all dye extraction methods, and dye fixatives effects on prototypes fastness to washing and rubbing fastness.The p-values are greater (p>0.05)than 0. 05 probability level but rejected for dye fixatives effect on polyester prototypes to sunlight and rubbing since p-values are less (p<0.05)than 0.05 probability level.

DISCUSSION
The study assessed the effects of three dye extraction procedures (boiling, steeping and ethanol) on the colour fastness of 100% cotton, silk (60% silk: 40% polyester) and 100% polyester fabrics mordanted with three dye fixatives (alum, tannic and citric acids and no mordant control) t o sunlight, washing, perspiration and rubbing or crocking.Findings revealed that cotton prototypes especially those mordanted with alum and tannic acid treated with dyes extracted by steeping exhibited very slight stain in colour when s ubjected to dry rubbing, slight fade when exposed to normal sun rays for 72 h and slight stain when subjected to acid medium perspiration stressor.This finding indicates that ros elle calyces extract has dye potential.This result is not surprising as phytochemical constituents of rosell e reveal very high anthocyanin contents as high as 25 g kg -1 which is responsible for its red colour (Owoade et al., 2015).The dye ability and stability of a dye on fabric is also determined by dyeing procedure adopted.When a textile material is dyed by a conventional exhaust procedure (gradual heating of the dye bath by a dwell time at the temperature), the dyeing cycle involve three stages: transportation of the dye through the bulk of solution of the dye bath to the surface of the fibre; absorption of the dye molecule from the surface to the interior of the fibre; diffusion of the dye molecules from the surface to the interior of the fibre, How rapidly and evenly stage (1) proceeds depends on the state of heating, and speed of replacement of dye liquor at the fibre surface (Finar, 1973).The frequency of contact per unit time between the material and fresh liquor affects the rate of dyeing and the degree of levelness obtained.Stage II according to Finar is virtually instantaneous.In stage III, the dye originally adsorbed only on the fibre surface penetrate in the int erior of the fibre and redistributes itself evenly throughout the fibre cross-section.This phase is dependent upon both time and temperat ure but is unaffected by the speed of liquor circulation.Migration starts at the same time as diffusion and dye molec ule moving from sites with a high dye concentration until an even dye distribution is finally achieved.This may offset any local concentration differences in the material which may have formed at the early stages.The rate of migration varies with the type of dye used and application temperature.
The analysis of variance (A NOVA) results on effects of dye extraction technique on the colourfastness of cotton prototypes indicated no significant difference (p> 0.05) at 0.05 level of significance.This implies that steeping, ethanol and boiling (temperature not exceeding 90°C) are comparable and did not alter the stability or fastness of the dye.This finding is in line with the findings of Mady et al. (2001), who studied the impact of extraction procedure (cold or hot extraction with or without pasteurization) on the kinetics/stability of anthocyanin and colour degradation of roselle extracts during storage at 4 to 45°C.The res ults showed that anthocyanin content and initial colour were not modified but the extraction conditions especially temperature greatly affected the stability of the extracts during storage.However, sublimation study on roselle dyed cotton fabric is imperative to investigate t he colour degradation during storage.
For the effects of dye fixatives, tannic acid and alum mordant were found to improve the fastness of t he prototypes more than citric acid and the control (non mordanted) prototypes.This finding supports those of Ali et al. (2010) and Kulkarni et al. (2011).They agreed that attachment of mordants to dyes is by means of a covalent bond with a hydroxyl group and coordinate bond with another oxygen (the electron donor).In eac h case, double bonded oxygen and a hydroxyl group (or carboxyl group) are involved.The covalent bond forms between the hydroxyl oxygen and the metal while the coordinate bond forms between the double bonded oxygen and t he metal (Llewellyn, 2000), thus bringing about stability of dye and fibre.The high fastness ratings of cotton prototypes to sunlight could be attributed to the substitution pattern of dyes which plays vital role in determining their light fastness and the formation of a complex with transition metal thereby protecting the chromophore of the dye from photolytic degradation (Jothi, 2008).This is the case with prototypes that showed good light fastness.
The colourfastness of stone silk and polyester prototypes to sunlight, washing and perspiration (acid and alkali), was generally poor as seen by their mean ratings in Table 2.The only fastness property which alum and tannic acid mordanted stone silk and polyester prototypes showed slight stain of colour was crocking/rubbing fastness.However, the finding on very poor fastness of silk and polyester prototypes is contrary to Len 72 88 (2009), who affirmed that mordant could be used to improve the stability of dy es on fabrics.Though a fabric may not be colourfast in all circumstances, stability of a dye in fabric to only one fastness paramet er cannot qualify a substance to be a good dye.This finding supports Finar (1973), who emphasized that most natural dyes have more affinity to natural fibres while synthetic dyes do better in synthetic fibres.The fibre content of locally available stone silk fabric used in this study comprising 60 perc ent silk and 40 percent purely synthetic polyester had probably, explained the reas on for the non-fastness of stone silk.Moreover, the rationale for selecting polyester fabric for this study was based on the fact that application of a natural dye to a type of fibre (natural or synthetic) with which dye does not combine readily can sometimes be improved by using a mordant as suggested by Finar (1973).
The poor fastness of stone silk and polyester prototypes in this study failed to agree with Finar (1973), while the finding on alum mordanted and tannic acid treated cotton prototypes worked out with roselle dye.It could be observed that all the P-values for acid perspiration fastness of cotton, silk and polyester prototypes were not displayed.Subsets could not be computed with alpha = 0.05, indicating homogeneity of subsets as shown in Table 2.The null hy pothesis which states there is no significant difference in mean rat ing effects of dye extraction methods and dye fixatives on fastness of all prototypes to acid perspiration are accepted.

Conclusion
It could be deduced from the present study that roselle calyces extract has dye potential on cotton fabric when mordanted wit h alum or t reated with tannic acid since prototypes showed fastness to rubbing, sunlight and acid perspiration with.Though steeping extraction method rated highest its mean effects were not significantly different from boiling and ethanol solvent in improving t he colourfastness of cotton fabric prototypes to sunlight, rubbing, washing and alkaline perspiration.Stone silk and polyester fabrics treat ed with roselle dy es showed poor fastness to parameter except rubbing which alone cannot qualify it to be a good dye.It is concluded therefore that with good and acceptable organoleptic attributes, roselle dye could be a verit able colourant for fabric colouration for textile industries, dyers, home mak ers, teachers and students in educational institutions and other dye utilizing sectors if improved.

RECOMMENDATIONS
The following recommendations are made: 1.The effects of different ratios of alum and tannic acid or other non-harmful but human and eco friendly mordant on the colourfastness of fabrics dyed with roselle calyces extract or other natural dyes should be studied by students and teachers in relat ed fields who either produce or utilize dyes.This will contribute to ensuring sustainable supply of dyes for both privat e and commercial dyeing purposes.2. Follow up study should be carried out to investigate the sublimation and shelf life properties of the dyed fabrics by teachers and their students or textile chemist.3. The large scale textiles and clothing industries should through t heir textile chemist find ways of exploring and improving the quality of natural dyes for maximum utilization.4. Traditional dyers, home makers, small and medium scale entrepreneurs should explore plant dyes from the environment not only for economic gains but for the preservation of the prestigious traditional dyeing arts and crafts.
Key: X-Mean SD-Standard Deviation RDB-AC-Alum mordanted cotton fabric treated with roselle dye extracted by boiling.RDB-CC -Citric acid treated cotton fabric dyed with roselle extracted by boiling.RDB-NC -Non mordanted cotton fabric treated with roselle dye extracted by boiling.RDB-TC -Tannic acid treated cotton fabric dyed with roselle extracted by boiling.RDST-AC-Alum mordanted cotton fabri c treated with roselle dye extracted by steeping.RDST-CC -Citric acid treated cotton fabric dyed with roselle extracted by steeping.RDST-NC -Non mordanted cotton fabri c treated with roselle dye extracted by steeping.RDST-TC -Tannic acid treated cotton fabric dyed w ith roselle extracted by steeping.RDSV -AC-Alum mordanted cotton fabric treated with roselle dye extracted by solvent.RDSV-CC -Citric acid treated cotton fabric dyed with roselle extracted by sol vent.RDSV -NC -Non mordanted cotton fabric treated w ith roselle dye extracted by solvent.RDSV -TC -Tannic acid treated cotton fabric dyed with roselle extracted by solvent.
Key: X-Mean SD-Standard Deviation RDB-AS-Alum mordanted stone silk fabric treated w ith roselle dye extracted by boiling.RDB-CS -Citric acid treated stone eilk fabric dyed with roselle extracted by boiling.RDB-NS -Non mordanted stone silk fabric treated with roselle dye extracted by boiling.RDB-TS -Tannic acid treated stone silk fabric dyed with roselle extracted by boiling.RDST-AS-Alum mordanted stone silk fabric treated with roselle dye extracted by steeping.RDST-CS -Citric acid treated stone silk fabri c dyed w ith roselle extracted by steeping.RDST-NS -Non mordanted stone silk (control) fabric treated with roselle dye extracted by steeping.RDST-TS -Tannic acid treated stone silk fabric dyed with roselle extracted by steeping.RDSV -AS-Alum mordanted stone silk fabri c treated w ith roselle dye extracted by by sol vent.RDSV -CS -Citric acid treated stone silk fabric dyed with roselle extracted by solvent.RDSV-NS -Non mordanted stone silk fabric treated with roselle dye extracted by solvent.RDSV-TS -Tannic acid treated stone silk fabric dyed w ith roselle extracted by solvent.
Key: X-Mean SD-Standard Deviation RDB-AP-Alum mordanted cotton fabri c treated with roselle dye extracted by boiling.RDB-CP -Citric acid treated cotton fabric dyed w ith roselle extracted by boiling.RDB-NP -Non mordanted cotton fabri c treated with roselle dye extracted by boiling.RDB-TP -Tannic acid treated cotton fabric dyed with roselle extracted by boiling.RDST-AP -Alum mordanted cotton fabric treated with roselle dye extracted by steeping.RDST-CP -Citric acid treated cotton fabric dyed w ith roselle extracted by steeping.RDST-NP -Non mordanted cotton fabric treated w ith roselle dye extracted by steeping.RDST-TP -Tannic acid treated cotton fabric dyed with roselle extracted by steeping.RDSV -AP-Alum mordanted cotton fabric treated with roselle dye extracted by sol vent.RDSV -CP -Citric acid treated cotton fabric dyed w ith roselle extracted by solvent.RDSV -NP -Non mordanted cotton fabric treated w ith roselle dye extracted by solvent.RDSV-TP -Tannic acid treated cotton fabric dyed w ith roselle extracted by solvent.

Table 1 .
Colourfastness tests and range of means for taking decisions.as in w ash fastness tests.They w ere fed into the oven and allow ed to stay for 4 h at the temperatur e 32 ± 2 °C.The prototypes were allow ed to cool; untied and the extent of staining w ere checked off w ith Gray scale and recorded w ith FTRS. strongly

Table 2 .
Mean ratings of the colourfastness of cotton Prototypes to sunlight, w ashing, acid /alkali perspiration and rubbing.

Table 3 .
F-values and Scheffe's post hoc homogenous main effects of dye extraction methods and dye fixatives on the colourfastness of cotton fabric prototypes to sunlight, w ashing, acid /alkali perspiration and rubbing.
H01:There is no significant difference in the mean rating effects of dye extraction methods and dye fixatives on colour fastness of roselle dyed cotton Prototypes to sunlight, washing, acid and alkali perspiration.Scheffe's post hoc multiple comparisons interaction main effects of dye extraction method indicate that though steeping extraction technique rated highest (2.75), its effects are not significantly different from those of boiling and ethanol extraction in improving the prototypes fastness to sunlight (p=0.33),Washing(p=0.29),alkali perspiration (p=0.06), and rubbing (p=0.59),respectively.For dye fixative interaction main effects, tannic acid and alum had comparable positive effects significantly

Table 4 .
Mean ratings of the colourfastness of stone silk prototypes to sunlight, w ashing, acid /alkali perspiration and rubbing.

Table 5 .
F-values and Scheffe's post hoc homogenous main effects of dye extraction methods and dye fixatives on the colourfastness of silk prototypes to sunlight, w ashing, acid /alkali perspiration an rubbing

Table 6 .
Mean ratings of the colourfastness of polyester Prototypes to sunlight, w ashing, ac id /alkali perspiration and rubbing.

Table 7 .
Scheffe's post hoc homogenous main effects of dye extraction methods and dye fixatives on the colourfastness of polyester prototypes to sunlight, w ashing, acid /alkali perspiration and rubbing.: Means for groups in homogenous subsets are displayed.Values are means of triplicate determination.Means w ith the same superscript letter grades are not significantly different from each other at P≤0.05 using Scheffe's test. Key