To Improve the Wettability and Dyeability of Polyester and Polyester Blended (P/C) Fabric by Using Sericin

Last Updated on 31/07/2022

To Improve the Wettability and Dyeability of Polyester and Polyester Blended (P/C) Fabric by Using Sericin

G.Ragavendar
M.Sc. in Textile Chemistry
SSM College of Engineering, Komarapalayam
Department of Textile Chemistry
Anna University, Chennai – 600 025
Email: ragav.gopal@gmail.com

 

ABSTRACT:
Polyester is the most important fabric in textile due to their competitive pricing and multi performance characteristics. It is having high mechanical strength, high chemical and thermal stability, besides that the polyester having many undesirable characters. That is poor water permeability, poor wettability and low moisture regain. So we are using higher temperature for dyeing the polyester.

These disadvantages are overcome by applying the sericin on the surface of the polyester fabric. In the silk processing industry sericin is removed through a process known as degumming prior to dyeing.

Sericin is a second type of silk protein which contain 18 amino acids, including essential amino acids and is characterized by the presence of 32% of sericin. This sericin is a water soluble protein. In this project we have to discuss about the effect of sericin finishing on wettability and dyeability of the polyesterand polyester blended (P/C) fabric. The sericin is applied on the alkali pre-treated polyesterand polyester blended (P/C) fabric with different concentration with the use of cross linking agent isopropyl alcohol. The moisture regain property is analysed. I hope that the moisture regain property of polyester and polyester blended (P/C) will increase after sericin application. Then improvement in the dyeability and fastness properties for different concentration of sericin are analysed after disperse dyeing is carried out.

CHAPTER-1
INTRODUCTION:
Polyester is a term often defined as “long-chain polymers chemically composed of at least 85% by weight of an ester and a dihydric alcohol and a terephthalic acid”. In other words, it means the linking of several esters within the fibers. Reaction of alcohol with carboxylic acid results in the formation of esters.Polyester also refers to the various polymers in which the backbones are formed by the “esterification condensation of polyfunctional alcohols and acids”. Polyester can also be classified as saturated and unsaturated polyesters. Saturated polyesters refer to that family of polyesters in which the polyester backbones are saturated. They are thus not as reactive as unsaturated polyesters. They consist of low molecular weight liquids used as plasticizers and as reactants in forming urethane polymers, and linear, high molecular weight thermoplastics such as polyethylene terephthalate (Dacron and Mylar). Usual reactants for the saturated polyesters are a glycol and an acid or anhydride.Unsaturated polyesters refer to that family of polyesters in which the backbone consists of alkyl thermosetting resins characterized by vinyl unsaturation. They are mostly used in reinforced plastics. These are the most widely used and economical family of resins.

Characteristics of Polyester as follows:

  • Polyester fabrics and fibers are extremely strong.
  • Polyester is very durable: resistant to most chemicals, stretching and shrinking, wrinkle resistant, mildew and abrasion resistant.
  • Polyester is hydrophobic in nature and quick drying. It can be used for insulation by manufacturing hollow fibers.
  • Polyester retains its shape and hence is good for making outdoor clothing for harsh climates.
  • It is easily washed and dried.

Sericin is a protein created by Bombyx mori (silkworms) in the production of silk. Silk emitted by the silkworm consists mainly of two proteins, sericin and fibroin; fibroin being the structural center of the silk, and sericin being the gum coating the fibres and allowing them to stick to each other. Silk sericin has been used for over 3500 years by the world elite to rejuvenate their hair and skin. The chemical composition of sericin is C30H40N10O16. Silk sericin due to its proteinous nature is susceptible to the action of proteolytic enzymes present in body and hence it is digestible. This property makes it a biocompatible and biodegradable material. Because of some additional properties like, gelling ability, moisture retention capacity, and skin adhesion. it has wide applications in medical, pharmaceutical, and cosmetics.

Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approaches. Notably, this hydrogel is found to exhibit photoluminescence, enabling bioimaging and in vivo tracking. Moreover, this hydrogel system possesses excellent cell-adhesive capability, effectively promoting cell attachment, proliferation and long-term survival of various types of cells. Further, the sericin hydrogel releases bioactive reagents in a sustained manner. Additionally, this hydrogel demonstrates good elasticity, high porosity, and pH-dependent degradation dynamics, which are advantageous for this sericin hydrogel to serve as a delivery vehicle for cells and therapeutic drugs. With all these unique features, it is expected that this sericin hydrogel will have wide utility in the areas of tissue engineering and regenerative medicine.

1.1 Objectives of the study:

  • Extraction of the sericin from silk.
  • Application of sericin in the polyester fabric by pad-dry-cure method using different concentration of sericin.
  • To analyse the moisture regain property of sericin treated polyester fabric.
  • Application of reactive dye on the sericin treated polyester fabric at different temperature ranges from 60oC, 80oC and 100oC.
  • Analyse the fastness properties of the reactive dyed samples at different temperature.

1.2 Scope of the study:

  • The sericin extracted from the silk having aspartic acid, and serine. These are very useful for increasing the moisture regain property of the polyester.
  • Using the sericin we are going to improve the moisture regain property of the polyester. And also we are trying to make the polyester fabric dyeable with reactive dyes.

CHAPTER -2:

LITERATURE REVIEW

2.1 TEXTILE FIBRES:
Textile fibres may be defined as units of matters characterized by fineness, flexibility, and high ratio of length to thickness. In order to be use as textiles, the fibres must also have a sufficiently high temperature stability and a certain minimum strength, extensibility, elasticity, and moisture content.

The length to thickness ratio should be at least 500:1. The textile fibres are classified under two categories that are natural fibre, synthetic fibre. [4]

2.1.1 Natural Fibre
A fibre that occurs naturally or is produced by nature is a natural fibre. Natural fibres may be of animal, vegetable or mineral origin, e.g. cotton, wool, silk, etc. [4]

2.1.2 Man-Made Fibre
A fibre manufacture by man, as distinct from a fibre that occurs naturally, is a man- made fibre, e.g. rayon, nylon, polyester, acrylic, acetate, spandex fibres etc.[4]

2.2 MANUFACTURING PROCESS OF POLYESTER:

2.2.1 Polymerisation Process:
Pure Terepthalic Acid (TPA) and ethylene glycol are combined with catalysts to form pet and water. In the first step direct esterification or transesterification results in pre-polymer known as bis (2-hydroxy ethyl terephthalate) (BHET) or diglycol terephthalate(DGT). In the second step, DGT is polymerised, by polycondensation to produce PET polymer and ethylene glycol.[4]

Schematic diagram of extrusion polyester fibre
Figure.2.1 Schematic diagram of extrusion polyester fibre

2.2.2 Polycondensation:
Polycondensation takes place in the same manner like that of transesterification. Several factors are decisive in achieving high grade PET.

The reaction temperature, vaccum in condensation vessel, catalyst all decide the course of polycondensation. The catalysts employed for Trasesterification are effective for poly condensation.

Low concentration of catalyst will result in low viscosity. The temperature remains between 270oC-280oC.[4]

N[HOOC(C6H4)COOH]+N[HO(CH2)2OH]  [OC(C6H4)COO(CH2)2O]N+(2n-1)H2O

…………………..TPA                 Ethylene glycol                       PET                            Water

2.2.3 Extrusion Process Of Polyester:
Polyester fibres are melting spun. The polymer chips taken for melt spinning must be sufficiently dry. If they are not dry enough, they will be degraded the melting and spinning processes due to the action of the oxygen at high temperature.

The dry chips are put into hopper reservoirs, from which they fall on to an electrically heated grid and melt. The melt passes through the grid to a molten polymer pool. It is then pumped by means of a metering pump through a filter and extruded through a spinneret with circular holes. The individual filaments that come out of the spinneret solidify almost immediately due to a blast of cold air that hit them.

They are then collected together haul-off roller and wound on to spools as undrawn yarn by means of a take up/winding device.

The take-up speed is 800-1,200m/min. The spin finish oil is applied to the yarn just before take up to make it suitable for easy processing during further textile processes such as weaving, knitting.

The speed of the metering pump determines the denier of the extruded filaments, the higher the speed, the greater the denier due to the large quantity of polymer melt coming out and vice versa.

The filter ensures that no impurities or improperly dissolved polymer particles are passed on to the spinneret. Both of these would choke some holes in the spinneret and give rise to a variation in the filament denier.

The take up speed determines the degree of orientation of molecules in the filaments. Higher take up speed produces yarn of correspondingly higher degree of orientation. [4]

2.2.4 Uses Of The Polyeste:

  • Used as clothing fabric as 100% polyester and blend with cotton, wool, viscose, and acrylic fibres.
  • Used as a house hold textile in the forms of bed sheets, pillow covers, curtains, etc.
  • It is used as a tyre cord yarn to strengthen tyres, also as reinforcement yarn in v-belts, conveyor belt.
  • It is used as a insulation material in motors and as ropes, fishnets, sail cloth .
  • It is used as a coated fabric for protective clothing gloves, footwear, etc.[4]

2.2.5 Texturising Process Of Polyester Yarn:

Texturising process of polyester yarn
Figure.2.2 Texturising process of polyester yarn

2.2.6 Physical Properties Of Polyester:

  • The normal tenacity of the polyester yarn is 5-6 gm/denier and the elongation at break is 25-30%
  • The high tenacity yarn having the tenacity of 8-9 gms/denier and elongation at break is 10-12%
  • The moisture absorption of the polyester fabric is 0.4%
  • The polyester having the density that is specific gravity of 1.38g/cc
  • Polyester fabric is poor conductor of electricity. So it is used as a good insulator of electricity.
  • Regular polyester fibre has a smooth cylindrical appearance in longitudinal view. And circular shape in cross-sectional view.
  • The melting point of the polyester fibre is 250-260oC.[4]

2.2.7 Chemical Properties Of The Polyester:

  • Regular polyester has an average DP of 115-140. The degree of crystallinity ranging from 65-85%
  • Polyester fabric too lose strength when exposed to sun light for long period, due to the harmful effect of ultra violet rays the chemical structure of polyester will destroyed.
  • The polyester fabric having more resistance to acids. but having low resistance to strong alkalis.
  • The polyester fibres are dissolved by the organic chemicals hot m-cresol, concentrated sulphuric acid, and orthochlorophenol.
  • The insects and micro-organisms do not attack the polyester fabric.[4]

2.2.8 Factors Responsible For Low Moisture Regain For The Polyester:

  • The absence of the water attracting polar group
  • The high degree of crystallinity of the fibre
  • There is no reaction group in the molecular structure.[20]

2.2.9 COTTON:
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of cotton plants of the genus Gossypium in the family of Malvaceae. The fibre is almost pure cellulose. Under natural conditions, the cotton bolls will tend to increase the dispersal of the seeds.

TYPES OF COTTON:
There are four commercially grown species of cotton, all domesticated in antiquity:

  • Gossypium hirsutum – upland cotton, native to Central America, to Mexico, the Caribbean and southern Florida (90% of world production)
  • Gossypium barbadense – known as extra-long staple cotton, native to tropical South America (8% of world production)
  • Gossypium arboreu – tree cotton, native to India and Pakistan (less than 2%)
  • Gossypium herbaceum- Levant cotton, native to southern Africa and the Arabian Peninsula (less than 2%)

The two New World cotton species account for the vast majority of modern cotton production, but the two Old World species were widely used before the 1900s. While cotton fibers occur naturally in colors of white, brown, pink and green, fears of contaminating the genetics of white cotton have led many cotton-growing locations to ban the growing of colored cotton varieties.

Properties of Cotton:
The following properties of cotton fibres are considered for cotton spinning:-

Fiber length:
The average length of spinnable fibre is called staple length. Staple length is one of the most important fibre characteristics. The quality, count, strength etc. depend on the staple length of fibre.

Fiber length influence:

  • Spinning limit,
  • Yarn strength,
  • Yarn evenness,
  • Handle of the product,
  • Luster of the product,
  • Yarn hairiness,
  • Productivity.

The following length groupings are currently used in stating the trade staple:

  • Average : (25-35) mm
  • Short length : 1.010″ or less.
  • Medium length : 1.03″ to 1.13″
  • Long length : 1.16″ to 1.6″
  • Extra long length : 1.6″ to above

Fiber fineness:
Fineness is one of the most important parameter determining the yarn quality characteristics. Fibre fineness influences the number of fibres in the cross section of yarn. Thirty fibers are needed at the minimum in the yarn cross section but there are usually over 100. One hundred is approximately the lower limit for almost all new spinning process. This indicates that fineness will become more important.

Fiber influence primarily:

  • Spin limit,
  • Yarn strength,
  • Yarn evenness,
  • Drape of the fabric product,
  • Handle,
  • Luster,
  • Yarn fullness,
  • Productivity.

Evenness is measured in Micronaire value (MIC).

Rating of MIC value –

MIC value —————–>Fineness

  • Up to 3.1 ————very fine
  • 3.1 to 3.9 ————fine
  • 4.0 to 4.9 ————medium
  • 5.0 to 5.9 ————slightly coarse
  • 5.9 to above ———coarse.

Maturity:
The maturity of cotton is defined in terms of the development of cell wall. A fully mature fiber has a well developed thick cell wall. On the other hand, an immature fibre has a very thin cell. The fibre is to be considered as mature fibre when the cell wall of the moisture-swollen fibre represents 50-80% of the round cross section, as immature when it represents 30-45% and as dead when it represents less than 25%.

Cotton fiber structure
Fig: Cotton fiber structure

Immature fiber leads to:

  • Nepping,
  • Loss of yarn strength,
  • Varying dye ability,
  • High proportion of short fibres,
  • Processing difficulties mainly at the card

Mature fibre → Dye absorb↑ ­
Immature fibre → Dye absorb ↓.

Fiber Strength:
Toughness of fibre has a direct effect on yarn & fabric strength.

Fibre strength ­ ↑→ Yarn & Fabric strength.↑ ­ ­

Very weak cottons tend to rupture during processing both in blow room & carding, creating short fibres & consequently deteriorate yarn strength & uniformity.

The following scale of value is used:

  • Below to 70% → weak,
  • 70% to 74% → fairly strong,
  • 75% to 80% → medium strong,
  • 81% to 86% → strong,
  • 87% to 92% → very strong,
  • 93% & above → excellent.

Fiber cleanness:
In addition to usable fibers, cotton stock contain foreign matter or trash or foreign material of various kinds:-

Vegetable matter:

  • Husk portions
  • Seed fragments
  • Stem fragments
  • Wood fragments.

Mineral material:

  • Earth
  • Sand, dust, coal.

Others:

  • Metal fragments
  • Cloth fragments
  • Packing materials.

Foreign matter causes:

  1. Drafting disturbance,
  2. Yarn breakage,
  3. Filling up of card clothing,
  4. Contaminated yarn.

Accepted the range of foreign matters to the Cotton Bale:

  • Up to 1.2% → very clean
  • 1.2% to 2.0% → clean
  • 2.0% to 4.0% → medium
  • 4.0% to 7.0% → dirty
  • 7.0% & above → very dirty.

2.3 DYEING PROCESS OF POLYESTER:

2.3.1 Carrier Dyeing Method:

Procedure:

  • At first, a paste of dye and dispersing agent is prepared and then water is added to it.
  • Dye bath is kept at 60°C temperature and all the chemicals along with the material are added to it. Then the bath is kept for 15 min without raising the temperature.
  • pH of bath is controlled by acetic acid at 4-5.5.
  • Now temperature of dye bath is raised to 90°C and at that temperature the bath is kept for 60 min.
  • Then temperature is lowered to 60°C and resist and reduction cleaning is done if required. Reduction cleaning is done only to improve the wash fastness.
  • Material is again rinsed well after reduction cleaning and then dried. [20]

Dyeing Curve:

Dyeing process of polyester by Carrier Dyeing Method
Figure.2.3 Dyeing process of polyester by Carrier Dyeing Method

2.3.2 High Temperature Dyeing Method:

Procedure:

  • At first a paste of dye and dispersing agent is prepared and water is added to it.
  • PH is controlled by adding acetic acid.
  • This condition is kept for 15 minutes at temperature 60°C.
  • Then the dye bath temperature is raised to 130°C and this temperature is maintained for 1 hour. Within this time, dye is diffused in dye bath, adsorbed by the fibre and thus required shade is obtained.
  • The dye bath is cooled as early as possible after dyeing at 60°C.
  • The fabric is hot rinsed and reduction cleaning is done if required.
  • Then the fabric is finally rinsed and dried. [20]

Dyeing Curve:

High Temperature polyester Dyeing Method
Figure.2.4 High Temperature polyester Dyeing Method

2.3.3 Dyeing Of Polyester Fabric:
Thermosol dyeing is continuous methods of dyeing with disperse dye. Here dyeing is performed at high temperature like 180-220°C in a close vessel.

Here time of dyeing should be maintained very carefully to get required shade and to retain required fabric strength. [20]

Sequence Pading

Drying

Thermofixing

Aftertreatment

Procedure:

  • At first the fabric is padded with dye solution using above recipe in a three bowl padding mangle.
  • Then the fabric is dried at 100°C temperature in dryer. For dyeing, infra red drying method is an ideal method by which water is evaporated from fabric in vapor form. This eliminates the migration of dye particles.
  • Then the fabric is passed through thermasol unit where thermo fixing is done at about 205°C temp for 60-90 seconds depending on type of fibre, dye and depth of shade. In thermasol process about 75-90% dye is fixed on fabric.
  • After thermo fixing the unfixed dyes are washed off along with thickener and other chemicals by warm water.
  • Then soap wash or reduction cleaning is done if required. And finally the fabric is washed. [20]

2.3.4 Problems Associated With Dyeing The Polyester Using The Disperse Dye:
Polyester are the synthetic fibre. They are essentially undyeable below 70–80 °C, leaving only a 20– 30 °C range for increasing the dyeing rate before reaching the boiling temperature. The rate of diffusion of disperse dyes into the polyester below 100 °C is so low that dyeing at the boil does not give reasonable exhaustion.

The rate of dyeing is higher for dyes of small molecular size that have higher diffusion coefficients. Dyeing is faster when using fiber swelling agents called carriers to improve the fibre accessibility, or when dyeing at higher temperatures above 100 °C to increase the dye diffusion rate. [20]

2.5 FACTORS TO BE CONSIDERED FOR SURFACE MODIFICATION:
Thickness of the surface is crucial. Thin surface modifications are desirable, otherwise mechanical and functional properties of the material will be altered. This is more so when dealing with nano fibers as there is less bulk material present. Sufficient atomic or molecular mobility must exist for surface changes to occur in reasonable periods of time.

The driving force for the surface changes is the minimization of the interfacial energy. Stability of the altered surface is essential, achieved by preventing any reversible reaction.

This can be done by cross-linking and/or incorporating bulky groups to prevent surface structures from moving. In some cases a transparent scaffold is desired, especially in optical sensors or ophthalmology; after surface treatment they should remain transparent. Any cloudiness introduced is of real concern.Uniformity, reproducibility, stability, process control, speed, and reasonable cost should be considered in the overall process of surface modification.

The ability to achieve uniform surface treatment of complex shapes and geometries can be essential for sensor and biomedical applications. Precise control over functional groups. This is a challenging yet difficult scope.

Many functional groups might bond to the surface such as hydroxyl, ether, carbonyl, carboxyl, and carbonate groups, instead of one desired functional group.[14]

2.6 SILK:
The silk is composed of the proteins fibroin, sericin as well as soluble organic matter such as fats, wax sand pigments and minerals.

Silk is a naturally coloured yellow or green and thus contains a small amount of colouring matter. Some ash will remain after silk is burned. The content of all these substances is not constant and varies with in wide limits depending on the species silk worm and on the location and conditions of rearing. [18]

Microscopic view of silk
Figure 2.5 Microscopic view of silk

Silk filament contains are the following:

  • 72%-81% of fibroin
  • 19-28% of sericin
  • 0.8-1% 0f fat and wax
  • 1.4%- Colouring and ash

The molecular – weight of sericin ranges from 10-310kDa and fibroin ranges from 300-450kDa.[18]

2.6.1 Introduction About Sericin:
India is the second largest producer of silk in the world and has the distinction of producing all the four varieties of silk. Presently, India produces nearly16700 mt silk reeled silk prices are in the range of Rs 900-1300/kg, the pierced cocoons and waste silk generated at the rearing are sold at Rs 80-100/kg. This waste contributes nearly 30% of total cocoon production.1, 2 Silk fiber is made of two types of proteins—silk fibroin and sericin. Sericin contributes about 20-30 percent of total cocoon weight.

It is characterized by its high content of serine and 18 aminoacids, including essential amino acids. There are different methods of isolation of sericin from silk filament. Solubility, molecular weight and gelling properties of sericin depend on the method of isolation. Silk is a continuous strand of two filaments cemented together forming the cocoon of silk worm, Bombyx mori. Silk filament, a double strand of fibroin, is held together by a gummy substance called silk sericin or silk gum. Silk fibroin is the protein that forms the silk filament and gives its unique physical and chemical properties.

Silk adapts various secondary structures, including α-helix, β-sheet and crossed β-sheet. Silk sericin, a natural protein obtained from silk-worm cocoon has a combination of many unique properties such as biodegradability, nontoxicity, oxidation resistance, antimicrobial activity, UV resistance, and absorbs moisture.

It is estimated that out of about 1 million tons (fresh weight) of cocoons produced worldwide approximately 400000 tons of dry cocoons are generated, that have 50000 tons of recoverable sericin.Indian production of 1600 tons of silk can be source of about 250-300 tons of sericin per year .

If this sericin protein is recovered and recycled, it would be a significant economic and social benefit. Molecular wt of sericin protein ranges from 24 to 400 kDa with predominant amino acid group’s -serine (40%), glycine (16%), glutamic acid, aspartic acid, threonine, tyrosine. Thus it consists of polar side chain made of hydroxyl, carboxyl and amino groups that enable easy cross-linking, copolymerization and blending with other polymers to form improved biodegradable materials. Various scientists have classified sericin of cocoon shell into two classes: α-sericin and β-sericin. The outer coccon shell is made of α-sericin while inner layer of β-sericin. The α-sericin contains less C and H and more N and O than the β-sericin. Solubility of α-sericin is higher than β-sericin in hot water.[10]

2.6.2 Properties Of Sericin:

Molecular Weight:
Molecular weight of sericin depends on the method of extraction. When sericin is extracted with 1% sodium deoxycholate solution,molecular weightis 17100-18460.

When it is extracted by hot water it shows molecular wt. of 24000 by gel electrophoresis. When it is extracted by enzyme action mol. wt. is 3000-10000 and when it is extracted with aqueous urea mol.wt. is around 50000.[5]

Property Of Gelling:
It consists of random coil and β-sheet structure. Random coil structure is soluble in hot water and as the temperature lowers, the random coil structure convert to β-sheet structure, this results in gel formationof, Sericin has sol-gel property as it easily dissolves into water at 50-600C and again retuns to gel on cooling. [5]

Isoelectric Ph:
In sericin there are more acidic than basic amino acid residues, hence the isoelectric point of sericin is around 4.0 [5]

Solubility:
Solubility of sericin in water decreases when the sericin molecules are transformed from random coil into β-sheet structure. Solubility of sericin may be increased by addition of poly Sodium acrylate and it may be decreased by the addition of formaldehyde, polyacrylamide or resin based finishes .[5]

2.6.3 Different Amino Acids Present In Sericin:[6]

Table. 2.1.Differntiation of Mulberry silk and wild silk

Mulberry silk
Wild silk
Lysine
20-30%
20-30%
Serine
16-20%
7-16%
glycine
8-10%
10-20%
Aspartic acid
8-12%
7-10%
Glutamic acid
4-6%
arginine
5-15%
threonine
4-6%
3-10%
histidine
4-6%
3-6%
tyrosine
4-6%

2.6.4 Method Of Producing Silk Sericin Powder:
The sericin solutions were prepared by dissolving 10g sericin powder in deionized water and stirring for 15 min to form solutions of 10% and 30% concentration. The feed solutions were spray dried with a laboratory-scale spray dryer. The solutions were pumped into the drying chamber at rate of 1.25 x 10-7 and 2.5×10-7 m3/s feed solutions were pneumatically atomized through a nozzle using compressed air at fixed pressure. [13]

2.6.5 Extraction Of Sericin Using Differrent Methods:
Silk sericin was extracted using different methods including heat, acid, alkali and urea treatments as following.

Heat treatment:
A high temperature and high pressure degumming technique was used to prepare heat-degraded silk sericin solution. Cocoons of Bombyx mori silkworms were cut into square pieces (about 5 mm2), and silk sericin was extracted in purified water (1 g of dry silk cocoon: 30 ml of water) using autoclaving at 120 0C for 60 min. The silk sericin solution was filtered to remove fibroin. Hot water extraction of raw silk, followed by evaporation to obtain powder. Boiling of the crude silk in water and renewing the water until the extract no longer gives a precipitate with gallic acid.

Three successive 1 h extractions of silk are simply heating in water at 100ºC or autoclaving at 118°C or autoclaving for 3 h under 2.5-3 atmosphere pressure. Sericin with average molecular weight of 50,000 extracted with aqueous solution of urea at 100ºC from cocoons. Using water at 50-60ºC for 25 d to avoid the decomposition.[26]

Acid treatment:
Citric acid solution was used to prepare acid-degraded silk sericin solution.Cocoons of Bombyx mori silkworms were cut into small pieces, added with 1.25% citric acid solution and boiled for 30 min.

After filtration to remove insoluble fibers, the clear filtrate was immediately dialyzed in distilled water for 3 days using cellulose membrane.[26]

Alkali treatment:
Sodium carbonate solution was used to prepare alkali-degraded silk sericin solution. Cocoons of Bombyx mori silkworms were cut into small pieces and added with0.5% sodium carbonate solution. Other processes are same as acid treatment.[28]

Enzymes Treatment:
Extraction is carried out by using enzyme alkylase or with 2-2.5g/L alkaline protease at 60°C for 90 min, at pH 10. Hydrolysis with trypsin at different concentrations, temperatures and treatment times is employed for extraction of sericin. For 1 per cent of trypsin solution the hydrolysis is almost complete in 10 and 32 h at 20°C.. The amount of sericin obtained by 4 h treatment with 1 and 8 per cent of trypsin solution is 26.4 and 28.7 per cent, respectively.[28]

Ammonium sulfate precipitation:
1.5gm of Ammonium sulfate was added to10 ml of degummed water with continuous stirring. The mixture was left on ice for 30 minutes followed by centrifugation at 8,000 g at 4°C for 10mins. The pellet formed was washed with 95% ethanol, dried and stored at -20°C.[28]

TCA precipitation:
The degummed water was mixed with TCA stock (500g of TCA in 350 ml distilled water) in 1:4 ratio (TCA stock: protein sample) and centrifuged at 8000 g for 10 min. The pellet was washed thrice with ice cold acetone and dried. [28]

Calcium chloride Precipitation:
10 ml of degummed water was addedto varying volumes of 1M calcium chloride (0.5 ml, 1.0 ml, 1.5 ml and 2.0 ml) and the total volume was adjusted to12 ml with distilled water. The solution was left on ice for 30 min and was centrifuged at 8000 g for 10 min. [1]

2.6.6 Application Of Silk Sericin:

As a general adsorbent/biosorbent:
Although ion exchange resins and activated carbons have long been recognized as effective commercial adsorbents for treating industrial wastewaters containing adsorptive pollutants, their high cost and low efficiency have limited their commercial use in actual industrial scenarios. Considering their cost and efficiency, biomass-based adsorbents or biosorbents are more attractive alternatives than ion exchange resins and activated carbons. Silk sericin derived from waste biomass is low cost and effective for removal of acidic dyes and other anionic dyes from water. Sericin is a complex biosorbent rich in amide groups that could be further altered to achieve different adsorption behavior and selectivity for targeted remediation of polluted water.

Sericin biosorbent could selectively adsorb precious metals like gold, palladium etc from solution containing other impurities. The use of biosorbents for the removal of toxic pollutants or for the recovery of valuable resources from aqueous waste waters, is one of the most recent developments in environmental engineering.

The major advantages of this technology over conventional ones include not only its low cost, but also its high efficiency%, the minimization of chemical or biological sludges, the ability to regenerate biosorbents, and the possibility of metal recovery following adsorption.

Adsorptive pollutants like metals and dyes can be removed by living microorganisms, but can also be removed by dead biological material. Feasibility studies for large scale applications have demonstrated that biosorptive processes using non living biomass are in fact more applicable than the bioaccumulative processes that use living microorganisms, since the later require a nutrient supply and complicated bioreactor systems.

In addition maintenance of a healthy microbial population is difficult due to toxicity of the pollutants being extracted and other unsuitable environmental factors like temperature and pH of the solution being treated. Recovery of valuable metals is also limited in living cells, since these may be bound intracellularly. For these reasons attention has been focused on the use of non living biomass as biosorbents. [11]

As A Adsorbent For Removal Of Trivalent Chromium Amphiphilic core-shell PMA-SS (poly methyl acrylate-silk sericin) nanoshperes were prepared by graft copolymerisation of methyl acrylate and silk sericin using tert-butyl hydroperoxide as initiator. FMA-SS nanospheres ranged from 100 to 150 nm, and The diameter o their average size was 115 nm with narrow distribution. The PMA-SS nanospheres were found to be effective in the adsorption of trivalent chromium from aqueous solutions, and the maximum adsorption observed was 4.876 mg Cr3+/g of adsorbent.

The adsorption equilibrium can be reached after about 3 h. With the increase in pH values, the adsorption increased obviously. The addition of KCl had a little effect on the adsorption equilibrium. Furthermore, the values of adsorption obtained with using PMA-SS nanospheres were significantly higher that with SS powder use. The PMA-SS nanospheres are considered to have potential applications in wastewater treatment for the removal of heavy metal ions such as trivalent chromium species.[19]

As A Wound Dressing/Wound Care Material:
Sericin has been found to posses wound healing property and can be used as wound healing covering material in the form of film. Sericin, a silk protein, has high potential for use in biomedical applications. However, increasing the proportion of sericin had decreasing effect on the membrane stability.

Water swelling property of membranes was enhanced with sericin. Wound dressing materials have evolved significantly in the past quarter century.

An ideal wound healing material should be biocompatible, protective from secondary infections and should prevent water loss while controlling water vapor and oxygen permeabilities. In addition to these, wound dressing should have mechanical properties compatible with the skin and improve the healing process by actively attracting the cells to the wound area. Overall results suggest that sericin/collagen membranes would be favorable as wound dressing material when sericin ratio is less than or equal to the collagen component. Fibroin and sericin when sulphonated show antithrombic effect . Silk sericin membranes are good bandage materials and the film has adequate flexibility and tensile strength. Sericin is a novel wound coagulant material because of its biocompatible and infection resistant nature. Its flexibility and water absorption properties promote smooth cure for defects in the skin and do not cause any peeling of the skin under regeneration when detached from the skin.[11]

Improvements In Properties Of Synthetic Fabrics:
High pressure, High temperature extraction technique is the best method of extraction of sericin. It also provides the purest form of sericin. The sericin stored in the dry form (powder) is also an convenient storage method and does not involve any preservative.

Sericin can be fixed by both Formaldehyde and glutaraldehyde fixatives. The change in the concentration of the cross linking agents change the properties of the treated fabrics.

Higher concentrations of Formaldehyde and glutaraldehyde fixatives are not necessary for the optimum cross linking. Higher concentrations of cross linking agents not only change the properties of the treated fabrics but also deteriorate the structure of fabric. Functional properties of some synthetic fibers can be improved by coating with silk sericin protein. Sericin modified polyester is five times more hygroscopic than untreated polyester. [19]

Improvements In Properties Of Woolen Fabrics:
The results of a study showed that sericin has an affinity for wool, whereas it does not have any affinity for cotton. Sericin was fixed on wool fiber under defined conditions with an exhaustion rate of about 48% for a concentration of 2.5% (w/w) (compared to the mass of sample).

Concerning the effect on wool-treated fabrics; a percentage of sericin 5% (w/w) improved the touch of wool fabrics samples until a score of 4 points, as well as the absorption of water with a profit of 0.75%.

The samples also showed an improved antibacterial activity. These analyses reveal the multifunctionality of sericin as a finishing agent, it improve both fabrics absorption and hand with an acceptable clear brown shade. In industry, these finishing effects are typically obtained by the use of toxic chemicals. Thus, sericin could be the investigative focus of interest to be used as a biodegradable product with significant finishing effects, because of its available properties and reactivities.

Yet, it is interesting to improve the sericin exhaustion rate by using more sophisticated treatments such as grafting or cross-linking and to apply it on synthetic fibers such as polyamide and polyester.[19]

Use Of Sericin As A Finishing Agent:
A new approach to use a natural material, sericin or adhesive silk protein to provide healthy environment is a promising future.

Silk sericin could be coated onto nylon and polyster fibers and has a strong potential to be used for indoor air filters to reduce the amount of toxic free radicals, fungi and micrococcus type of bacteria. By using a simple coating technique, the sericin waste can increase the value of air filter.[19]

As A Raw Material For Making Contact Lenses:
Silk sericin has the potential to find application in the development of contact lenses. The graft polymers are prepared with methyl methacrylate or styrene and are also biocompatible. Oxygen permeable membranes are made up of fibroin and sericin with 10-16 percent water and are used for contact lenses and as artificial skin.[19]

As A Medicine For Improving Digestion And Curing Digestive System:
Intake of sericin containing food relieves constipation, suppresses development of bowel cancer and accelerates the absorption of minerals. In rats consumption of sericin elevates the apparent absorption of zinc,iron, magnesium, and calcium by 41,41,21, and 17 % respectively. Sericin when taken orally causes a dose dependent decrease in the development of colonic aberrant crypt foci. The incidence and the number of colon tumers are suppressed by consumption of sericin. Sericin have antitumour activity.[19]

Cosmetic Application:
Hence recovery of silk sericin from degumming liquor or waste cocoons not only helps to reduce the environmental pollution but also is highly desirable as the recovered sericin has a lot of commercial value finding application in creams and shampoos as a moisturizing agent and also an important biomaterial for several applications including textiles.

Sericin alone or in combination with silk fibroin has been used in skin, hair and nail cosmetics. Sericin when used in the form of lotion, cream and ointment shows increased skin elasticity, antiwrinkle and antiageing effects.[19]

Antimicrobial Use:
There is a simple and effective method for extracting sericin from the cocoons of B. mori silkworm using chilled ethanol precipitation method. It focused on studying the antimicrobial property of cotton fabric coated with sericin obtained by this method. The sericin-coated fabric showed a high degree of bactericidal activity against test organisms E. Coli.[19]

Application Of Sericin On Cotton Material:
First the cotton knitted fabric is scoured with lissopal N for one hour at boil by rinsing and drying. The fabric was then bleached with hydrogen peroxide for 45 min at boil then rinsed and dried. Sericin was applied on conditioned cotton knitted fabric by exhaust method in high temperature and high pressure dyeing machine at MLR ratio of 1:20. :Sericin does not have any affinity for cotton fabric. It cannot be directly attached to cotton fabric.So Alum is used as a complexing agent to attach the sericin on cotton surface. Sericin was applied by using optimized conditions and the fabric was post treated by Alum. This treatment is carried out at 60*c for 15 min. It will improve the moisture regain property of the fabric and antimicrobial property of the fabric.[23]

Application Of Sericin On The Polyester Fabric:
First the polyester fabric is scoured with using lissapol N to remove the impurities and temporary spin finishes. Polyester is chemically inert, has no available functional group and no affinity for an ionic protein like sericin. Then it was pre-treated with alkali NaOH at 80oc for 45min.

Alkali treated fabric is padded with sericin using the acetic acid by 2 dip-2nip process. Then the padded fabric was dried at 80oc for 3min and cured at 130oc for 2min. Sericin cannot be attached directly functionalized surface. So the glutaraldehyde was used as a cross linking agent to attach to alkali. Because of pretreated with alkali, carboxyl, and hydroxyl groups are created on the surface of the polyester.[24]

2.7 TYPES OF SURFACE TREATMENT TO INCREASE THE WETTING ABILITY OF THE POLYESTER FABRIC:

2.7.1 Enzyme Application:
Potentially a great variety of enzymes can be used to modify the surface of polyethylene terephthalate. Among these the most important are the esterases, lipases and cutinases. the production of hydroxyl and carboxylic groups due to the hydrolysis of ester linkages in PET and that the enzymatic surface hydrolysis has the advantage of maintaining mechanical stability because the enzyme cannot penetrate the fiber and hence is restricted to reacting on the surface only, thereby increasing the fabric surface wettability.

They studied the ability of six hydrolyzing enzymes to improve the hydrophilicity of several polyester fabrics including sulfonated polyester and micro denier polyester fabrics. Five of the six lipases significantly improved the water wetting and absorbent properties of regular polyester fabrics, and they improve water wetting and water retention more than alkaline hydrolysis.[12]

2.7.2 Application Of Plasma Treatment:
Low temperature plasma is an ionic gas whose components and characteristics are different from the normal gas. With the help of electrical discharge, plasma of different ionization extents can be produced. Since the temperature of plasma is relatively low, the activating species in plasma easily lose their energy once reacting with the material.

It has been used in wide variety of engineering applications in a well-controlled and reproducible way to clean, activate, etch or otherwise modify the surface of the polyester by improving their bonding capabilities or achieve totally new surface property. Low temperature plasma particularly suitable for polyester for achieving functional group on the surface of the polyester.[12]

2.7.3 Application Polyvinyl Alcohol On The Polyester:
The polyester fabric first immersed HCL at 40oc for 1 hour at the same temperature. Then the pre-treated polyester fabric is treated with 1N NAOH solution containing 1.5% of weight of poly vinyl alcohol it is kept in the bath at boil for 1 hour. Then the sample is immersed in water at boiling temperature for 10 min. And soaped and washed. The wetting behaviour of the polyester will increase by linkage between the PVA and the polyester fabric and by the formation of hydroxyl group.[22]

2.7.4 Application Of Micro Cellulose On The Polyester:
The micro cellulose particles are applied on the surface of the polyester fabric by using two methods. In the first method binding the micro cellulose particles directly on the surface of the polyester fabric. In the second method the micro cellulose is mixed with equal proportion of NAOH,urea, thiourea, additives, self cross linking acrylic binder and polyacrylate thickner and stirred mechanically and coated on the surface of the polyester fabric.

Then the fabric is dried at 80oc for 20min and cured for 15 min. This application will improve the hydroxyl group on the surface of the fabric.[3]

2.7.5 Application Of Vinyltriethoxysilane On The Surface Of The Polyester Fabric:
At first the vinyltriethoxysilane is poured into 0.1% of the cetyltrimethylammonium bromide solution. The concentration of the solution varied from 10-40%. The solution was stirred at room temperature for 1 hour. Then the polyester fabric is immersed in the solution using the padder with 95% of the pick up.

Then the fabric is cured at 150ocfor 15 min, after that the sample is washed 3 times with hot water for 30min, dried at 100oc for 2 hours. This treatment will increase the contact angle of water on the surface of the fabric.[8]

2.7.6 Application Of Sodium Hydroxide On Surface Of The Polyester Fabric:
First the polyester fabric is scoured with using scouring agent to remove the impurities and temporary spin finishes. Polyester is chemically inert, has no available functional group. Then pre-treated 100% polyester fabric is treated with sodium hydroxide of 4% concentration around 100oc followed by neutralisation, washing and drying are carried out. Then the treated fabric is treated with mixture of equal proportion of ethoxylated alcohol consisting of fatty alcohol, ethylene oxide, and propelene oxide for 40min at 70oc followed by curing at 140oc for 90seconds. This will produce the hydroxyl, carboxyl group in the surface of the fabric.[7]

Physical Properties Of Isopropyl Alcohol:

Molecular Weight
60.09
Boiling Point
82.5oc
Melting Point
-88.5oc
Flash Point
11.7 oc (closed cup)
Vapor Pressure
44 mm Hg at 25oc
Density/Specific Gravity
0.7851 at 20/4oc
Log/Octanol Water Partition Coefficient
0.05
Dissociation Constants
pka: 17.1 at 25oc
Autoignition Temp
455.6 oc
Henry’s Law Constant
8.07 x 10-6 atm-m3/mole
Vapor Density
2.08
Conversion Factor
1 ppm = 2.45 mg/m3

2.8 DISPERSE DYE FOR POLYESTER:
Disperse dye is a dye that can react directly with the fabric. That means that a chemical reaction happens between the dye and the molecules of the fabric, effectively making the dye a part of the fabric. This is why fiber Disperse dye is permanent; clothes dyed with Disperse dye can withstand many types of washing and still retain same vibrant color.[4]

2.8.1 Properties Of Disperse Dyes:

  • Disperse dye is anionic in nature.
  • Disperse dye is a water soluble dye.
  • They have better wash and light fastness properties.
  • They have better substantivity.
  • They form strong co-valent bond with the cellulosic fiber in alkaline condition.
  • The electrolyte is must for exhaustion of dyes in the fiber.
  • A certain amount of dyes is hydrolyzed during application. (around 15-20%)
  • Wide range of color can be produced with Disperse dyes.
  • Comparatively cheaper in price.[4]

2.8.2 Wettability, Surface Energy And Contact Angle:
Wetting is the spreading and contact of a liquid (adhesive) over a solid surface (substrate). If sufficiently intimate contact is achieved between the two phases, a physical attraction due to inter-molecular forces develops causing the liquid to conform to the surface on a macro and micro scale, displacing air and thus minimising interfacial flaws. Good wettability of a surface is a prerequisite for ensuring good adhesive bonding and hence considerable effort has been expended in developing simple tests to assess surface energy/tension prior to bonding .

Surface energy is defined as the work necessary to separate two surfaces beyond the range of the forces holding them together and is given in energy per unit area. Surface energy is often referred to as surface tension and is often expressed in dynes/cm .

It is dependent on the interfacial intermolecular forces and can be split into contributions from non-polar and polar components. The polar components can be further broken into electron acceptor or electron donor components (or Lewis acid/base components).

Polar molecules have varying proportions of acceptor/donor components and in many cases one component will be much more significant than the other. Water is fairly unusual in having both strong acceptor and strong donor properties.

The quantitative determination of the various components of surface energy of both substrates and adhesives would allow selection of appropriate substrate/adhesive pairs for bonding.

However, this would require considerable effort and would not provide a full answer to the selection of materials since wetting is only one factor in the bond performance.

The surface free energy of a solid can be indirectly estimated through contact angle measurements using the approach of Zisman. The surface energy (and the split between different components of the surface energy) can be quantitatively determined from the interactions between the surface and a series of probe liquids of different interfacial properties.

The determination of contact angle at the solid/liquid phase boundary is one of the most sensitive methods for determining the surface energies of solid materials. However, in most cases the contact angle is used as a relative measure of the surface energy. Contact angles are closely related to wettability, the lower the contact angle the greater the wettability.

A liquid (adhesive) will wet a solid (adherend) when its surface energy is lower than the solid’s surface energy. Force balance or equilibrium at the solid-liquid boundary is given by Young’sequation for contact angles greater than zero.
γ lv cos θ = γsv − γsl (1)

Where θ is the contact angle, and γlv, γsv and γsl are the surface free energies of the liquidvapour, solid-vapour and solid-liquid interfaces, respectively.

The lower the contact angle, the greater the tendency for the liquid to wet the solid, until complete wetting occurs (contact angleθ = 0, cosθ = 1). For complete wetting to occur the surface tension of the liquid should be less than or equal to the critical surface tension of the substrate (γsv-γsl). Large contact angles are associated with poor wettability surface for bonding.

Plastics are often surface treated to increase their surface energy (improve wettability). Surface energy is less useful for the characterisation of metal or metal oxide surfaces. According to ASTM D5946 the following ranges of water contact angle values can be used as a guide for defining the level of surface treatment of polyolefins and many other polymer films with initial low surface energies:

  • Marginal or no treatment >90° (under approximately 34 dynes/cm)
  • Low treatment 85-90° (approximately 36-34 dynes/cm)
  • Medium treatment 78-84° (approximately 39-36cm)
  • High treatment 71-77° (approximately 43-40 dynes/cm)
  • Very high treatment <71° (above approximately 43 dynes/cm)

2.9 TESTING FOR MOISTURE ABSORPTION:

2.9.1 Static Immersion:
The static immersion test is a method for measuring the total amount of water that a fabric will absorb. Sufficient time is allowed in the test for the fabric to reach its equilibrium absorption.

In the test weighed samples of the fabric are immersed in water for a given length of time, taken out and the excess water removed by shaking. They are then weighed again and the weight of water absorbed is calculated as a percentage of the dry weight of the fabric. Four specimens each 80mm X 80mm are cut at 45° to the warp direction.

The first step is to condition the samples and weigh them. They are then immersed in distilled water at a temperature of 20 ± I0C to a depth of 10cm. A wire sinker is used to hold the specimens at the required depth. The samples are left in this position for 20min. After the specimens are taken from the water the surface water is removed immediately from them by shaking them ten times in a mechanical shaker.

They are then transferred directly to pre-weighed airtight container and reweighted.[21]

…………………………Mass of water absorbed  X 100
Absorption = ——————————————————-
……………………………………..Original mass

2.9.2 Sinking Time:
This is a simple test for highly absorbent materials in which a 25mm X25mm piece of fabric or a 50mm length of yarn taken from the fabric is dropped onto the surface of distilled water and the length of time it takes to sink is measured. If the sample does not sink within 1 min it is considered as having floated.[21]

2.10 TESTING FOR COLOUR FASTNESS:

2.10.1 Washing Fastness:

Collecting the sample from bulk and then conditioning for 04.30 to 06 hours

Making a specimen of 04 cm*10 cm in size.

Sewing the specimen with multi-fibre fabric of same size at one corner.

Making the solution of 4gm/litre ECE detergent & 1 gm/litre sodium perborate, (If required SKFL use 0.15 gm/litre TAED).

Putting the specimen with multi-fibre fabric into the solution in Rotawash m/c
Prog.: C2S Temp.: 60OC/ 40oc Time: 30 min Still ball: 25 pcs

Rinsing with hot water respectively.

Squeezing with cold water of the sample is done (Hand Wash).

Then drying is done at a temperature in the air not exceeding 60OC

The drying is then broken out except on one of the shorter end.

Measuring the staining and color change by grey scale & make a test report. [21]

2.10.2 Light Fastness Test:

Daylight:
To test the resistance of a material to fading in daylight a sample of it is exposed facing due south (in the northern hemisphere), sloping at an angle from the horizontal which is approximately equal to the test site latitude. The sample is covered with glass and provision is made for it to be ventilated. Together with the specimen under test eight ‘standard blue wool dyeings’ are exposed. This method gives a true indication of the light fastness of a dyed material but it is slow.[21]

Xenon Arc:
The xenon arc is a much more intense source of light which has a very similar spectral content to that of daylight so that the test is speeded up considerably.

Because of the large amount of heat generated by the lamp an efficient heat filter has to be placed between the lamp and specimen and the temperature monitored. This is in addition to a glass filter as above to remove ultra-violet radiation.[21]

2.10.3 Rubbing Fastness:
In this test the dyed specimens are rubbed 10 times using a Crock meter which has a weighted finger covered with piece of un dyed cotton cloth5 cm X 5 cm. For wet rubbing the cotton cloth is wetted out before being rubbed on the dyed sample. The cotton rubbing cloth is then examined for dye which may have been removed and assessed using the grey scales for staining.[21]

CHAPTER 3
METHODOLOGY

Process Sequence:

Extraction Of Sericin

Apply the sericin Material in RFD Polyester and polyester blended (P/C) Fabric using PAD – DRY – CURE Method by using cross linking agent (ISO PROPYL ALCOHOL).

DYEING OF POLYESTER FABRIC (Finished with sericin):
Process Sequence I.

Take the sericin applied RFD fabric

Take 300 ml of water and also Add acetic acid to maintain PH 4 – 4.5

Add 1 % of dispersing agent and 0.5 % carrier

Add the dyeing solution which we prepared earlier

Raise the temperature to 100 0C

Dyeing At 100 0C for 60 mins

(DYEING OF COTTON PORTION WITH REACTIVE DYE):
Process Sequence II.

Take the sericin applied RFD fabric

Add 300 ml of water and also Add 1% Soda ash PH 6 – 7

Reactive pasted with turkey red oil and add required amount of water

Add the dyeing solution which we prepared earlier

Divide the sodium chloride in to 3 portion and add the salt at 15 min intervals

Raise the temperature to boil

Dyeing At boiling temp for 60 mins

DYEING (Without sericin):
Process Sequence I.

Take the sericin applied RFD fabric

Take 300 ml of water and also Add acetic acid to maintain PH 4 – 4.5

Add 1 % of dispersing agent and 0.5 % carrier

Add the dyeing solution which we prepared earlier

Raise the temperature to 1000 C

Dyeing At 100 0 C for 60 mins

DYEING OF POLYESTER BLENDED (P/C) FABRIC (Finished with sericin):
Process Sequence I.

Take the sericin applied RFD fabric

Add 300 ml of water and also Add acetic acid to maintain PH 4 – 4.
 ↓
Add 1 % of dispersing agent and 0.5 % carrier
Add the dyeing solution which we prepared earlier
Raise the temperature to 100 0C

Dyeing At 100 0C for 60 mins

(DYEING OF COTTON PORTION WITH REACTIVE DYE):
Process Sequence II.

Take the sericin applied RFD fabric

Add 300 ml of water and also Add 1% Soda ash PH 6 – 7

Reactive pasted with turkey red oil and add required amount of water

Add the dyeing solution which we prepared earlier

Divide the sodium chloride in to 3 portion and add the salt at 15 min intervals

Raise the temperature to boil

Dyeing At boiling temp for 60 mins

CHAPTER-4
RESULT AND DISCUSSION:

4.1 Fabric particulars:

1. Polyester fabric:

TYPE OF TEST
WARP COUNT
85.58 D
WEFT COUNT
89.32 D
GSM
48.7

2. Polyester Blended fabric:

TYPE OF TEST
WARP COUNT
146.82 D
WEFT COUNT
11.2S
GSM
186.6
BLEND %
WARP
Polyester (Roto Yarn SD)-100%
WEFT
Cotton (Spun Yarn)-100%

4.1 TESTS CARRIED ON UNFINISHED RFD FABRIC AND THE FINISHED RFD FABRIC:

  1. Water absorbancy of unfinished RFD fabric and finished RFD fabric as per CATTS – 04 (In-House Method)
  2. Washing fastness of unfinished dyed fabric and finished dyed fabric as perCATTS – 04 (IN-HOUSE METHOD)
  3. Rubbing fastness of unfinished dyed and finished dyed fabric as per the AATTC 8 : 2007

4.1.1.Water absorbency of unfinished RFD Polyester fabric as per CATTS – 04 (In-House Method):

SPECIFICATION
DURATION
WRAP /WEFT
After 1 Min
3.3 / 4.2 cm
After 3 Min
5.7 / 6.2 cm
After 5 Min
6.8 / 7.6 cm

4.1.2.Water absorbency of unfinished RFD Polyester blended (P/C) fabric as per CATTS – 04 (In-House Method):

SPECIFICATION
DURATION
WRAP /WEFT
After 1 Min
3.4 / 4.8 cm
After 3 Min
5.6 / 6.5 cm
After 5 Min
6.9 / 7.8 cm

4.1.3. Water absorbency of finished RFD Polyester fabric as per CATTS – 04 (In-House Method):

SPECIFICATION
DURATION
WRAP /WEFT
After 1 Min
4.4 / 5.0 cm
After 3 Min
6.5 / 7.0 cm
After 5 Min
7.6 / 8.1 cm

4.1.4. Water absorbency of finished RFD Polyester blended (P/C) fabric as per CATTS – 04 (In-House Method):

SPECIFICATION
DURATION
WRAP /WEFT
After 1 Min
4.6 / 5.4 cm
After 3 Min
6.4 / 7.1 cm
After 5 Min
7.8 / 8.4 cm

4.1.5 Washing fastness of unfinished Polyester dyed fabric as per ISO 105C-06 : 2010 at 40 oc:

SPECIFICATION
RESULT
change in shade
4
staining on cotton
4

4.1.6 Rubbing fastness of unfinished Polyester dyed fabricas per AATTC 8 : 2007:

SPECIFICATION
RESULT
Wet
4
Dry
3-4

4.1.7 Washing fastness of unfinished Polyester blended (P/C) dyed fabric as per ISO 105C-06 : 2010 at 40oc:

SPECIFICATION
RESULT
change in shade
3.4
staining on cotton
4

4.1.8 Rubbing fastness of unfinished Polyester blended (P/C) dyed fabric as per AATTC 8 : 2007:

SPECIFICATION
RESULT
Wet
4
Dry
4

4.2.1 Washing fastness of finished Polyester dyed fabric as per ISO 105C-06 : 2010 at 40oc:

SPECIFICATION
RESULT
change in shade
4
staining on cotton
4

4.2.2 Rubbing fastness of finished Polyester dyed fabric as per AATTC 8 : 2007:

SPECIFICATION
RESULT
Wet
4
Dry
4

4.2.3 Washing fastness of finished Polyester blended (P/C) dyed fabric as per ISO 105C-06 : 2010 at 40oc:

SPECIFICATION
RESULT
change in shade
4
staining on cotton
4

4.2.4 Rubbing fastness of finished Polyester blended (P/C) dyed fabric as per AATTC 8 : 2007:

SPECIFICATION
RESULT
Wet
4
Dry
4

4.2 DISCUSSION:
From the above tables concluded that the wetability of polyester and polyesterblended (P/C) fabric is considerably increased due to the application of the sericin. But the fastness properties of polyester dyed fabric and polyesterblended dyedfabric are not changed due to the application of the sericin.
So the sericin application is not considerably changed the dyeing properties of polyester fabric.

REFERENCES:

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[2] Seung-roung lee koji miyazaki, kenji hisada, teruo hori, application of silk sericin to finishing of synthetic fabrics. Vol.60.(2004).

[3] Magdi ei messiry, affaf ei ouffy, marwa issa,microcellulose particles for surface modification to enhance moisture management properties of polyester and polyester/cotton blend fabrics. Received 13 August 2014; revised 13 January 2015; accepted 8 March 2015 Available online 7 April 2015.

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[6] Aparupa Borgohain, silk and its biosynthesis in silkworm bomyx mori,Journal of Academia and Industrial Research (JAIR) Volume 3, Issue 12 May 2015.

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[12] Jadwiga Sójka-Ledakowicz, Marcin H. Kudzin, effect of plasma modification on the chemical structure of polyethelene terephthalate fabrics surface. Textile Research Institute (IW),

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[16] Ali Hebeish, Tarek Abou ELmaaty, Mohamed Ramadan and Heba Magdy, Microwave and Plasma Treatments for Functionalization of Polyester Fabrics, ISSN: 2319-7706 Volume 4 Number 7 (2015) pp. 703-715.

[17]  Naseerali m. K. Characterization of plasma treated polyester fabric, journal issn 2321-1075, vol 1 issue 1 july 2013.

[18] M. Mondal, K. Trivedy and S. Nirmal Kumar, The silk proteins, sericin and fibroin in silkworm, Bombyx moriLinn., – a review, Caspian J. Env. Sci. 2007, Vol. 5 No. 2 pp. 63~76.

[19] S. K. Rajput and Mukesh Kumar. Singh,sericin- a unique biomaterial. IOSR Journal of Polymer and Textile Engineering (IOSR-JPTE), Volume 2, Issue 3 (May – Jun. 2015), PP 29-35.

[20] A.A. VAIDYA, chemical processing of synthetic fibres and blends, a wiley –interscience publication, page no 183-195.

[21] B P SAVILE physical testing of textiles woodhead publication limited page no 233-235, 244-246.

[22] Swarna natrajan, jayakodi moses, surface modification of polyester fabric using polyvinyl alcohol in alkaline medium.indian journal of fibre&textile research vol 37 sep 2012.

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