3. FUNCTIONAL FINISHES
3. FUNCTIONAL FINISHES: -
3.1 Cool Finish (Snocool): -
When temperature rises, we tend to sweat. This is a natural reaction of our body to maintain the temperature around 97°F.The sweat when evaporates, takes along with it heat equivalent to heat of evaporation of water, thereby maintaining the temperature of the body. The Snocool finish uses the moisture management route i.e. it will enhance the natural phenomenon of sweat evaporation. This finish absorbs and dissipates sweat evenly throughout and thus gives a cool feeling to the wearer.
Characteristics: -
- Garments finished with Snocool produces a cool effect.
- The finish has two fold effect, it reflects light (special polymer) and transfers moisture faster than normal from body to fabric and finally to the atmosphere.
- These finishing agents can be manufactured with or without fragrance.
3.2 Thermocat Finishing: -
- A finishing agent for producing heat retaining effect.
- This type of finishing when applied to the fabric keeps it warm.
- Produces heat retaining effect due to infrared radiation owing to its porosity.
- Especially suitable for 100% cellulose and its blends.
3.3 UV Protective Finish: -
The protection offered by UV cutting fabrics is expressed in terms of UV protection factor (UPF) or sun protection factor (SPF), which are equivalent to the user. UPF of 40 for a garment means the wearer can stay 40 times longer in the sun before skin reddening (erythema) sets in. other words if skin reddens in 15 minutes without UV cutting garment, the same level of reddening would take 10 hours, when UV cutting garment is worn. This means that UPF is a ratio of the time taken for skin reddings with and without protection.
Some facts and figure about UV cutting fabrics:
Cotton and silk display a high degree of UV transmission, hence the wearer needs more UV protection wool displays a low degree of UV transmission., hence the wearer may not need extra UV protection polyester fiber absorb UV rays by virtue of its chemical nature and the de-lust rant which it contains, hence the wearer may not need protection from UV.
Cotton fabric with porosity higher than 5% cannot have UPF of >20, despite the application of a UV absorber. If fabric porosity is too high, the UV absorber will not be effective even if applied in high concentration.
- For textiles needing UPF of 40+, the porosity must be <2%.
- Thicker textile materials have higher UPF
- Textiles treated with OBA show high UPF
- Textile dyed in dark shades display higher UPF
- UPF drops at least by half when fabric is stretched by say 10%
- UV absorbers are applied in higher than required dosages to minimize the risk of loosing UV protection when the garments get wet.
Japanese have though of “endless effect” meaning the “value-addition” to last the life of a textile material is mixed into the fiber core at the melt spinning process. This can absorb UV rays (UV cut effect) and also can reflect visible rays (heat shielding effect).
Characteristics: -
A specialty finishes for protecting the fabric from UV radiation. Protects human's underlying tissues from UV radiation. Protects against short wavelength radiation i.e. from 100 - 400 nm, Non-yellowing. Should be applied during dyeing under a reductive process Applicable by exhaust as well as padding method.
3.4 Flame Retardant Finish: -
Flame retardant finishing is not any finish used for textiles, but it is the need of an hour. The finished material is used not only to produce garments but carpets, curtains, etc. which are used in public places like hotels, theatres etc. The effective flame proofing of the materials used in these areas are of paramount importance.
Characteristics: -
Can withstand at least 50 washings. It also exhibits excellent fastness to dry cleaning using chlorinated solvents. Its application practically does not cause yellowing and modifies the handle of the articles. It is recommended to apply Flame shield CV 20 with thermosetting resins. Any change of the mechanical resistance of the articles treated with Flame shield CV 20 is generally low. However, the simultaneous use of thermosetting resins may result in an important loss of the strength, up to 20% of the initial value. In such cases, the use of polyethylene emulsion allows a significant minimization of the tensile strength loss.
3.5 Peach Skin Effect: -
In classical finishing of lyocell, peach skin effects are produced in rope form using Airflows and Air tumblers. Alternatives are produced in open - width finishing with special emery finishes e.g. emery papers coated with diamond dust are recommended which imitate effects comparable with the classical method.
Apart from Peach Skin effects, various finishes can naturally be applied to fabrics of Lenzing Lyocell such as calendaring, embossed effects, crepe or other special effects. With a liquor ratio of
Enzymatic treatment: (Machine: Thies Roto Stream)
- Fibrolube HML: - 3.0 - 4.0 gpl
- Kleerix CR: - 0.5 - 1.0 gpl
- Genecel GLA: - 2.0 - 3.0 gpl
pH is adjusted to 5 with acetic acid and sodium acetate. Fabric is treated at 60°C for 60 min. Enzyme activity is inhibited by heating up to 85°C. Warm and cold rinsing is finaly given to the fabric.
3.6 AquaTex Finish: -
Traditional finishing processes for these fabrics usually require the addition of chemicals, in reality; however, these chemical compounds cause a shortening of the life span of such a fabric, its performance, and prohibit the possibility of recycling, and frequently involve significantly higher additional expenses for wastewater treatments.
The AquaTex system or for the enhancement of woven and some knit fabrics has been developed In lieu of these chemicals, which frequently are environmentally undesirable, the AquaTex system only uses regular water at ambient temperature to achieve accept ability of such fabrics in the trade and actually make them more marketable.
Main advantages of the aqua-tex system: -
- Increased thickness and density - the weave construction can usually be reduced significantly - and (he physical properties remain the same or actually improve.
- Softness - the fabric usually does not need any additional processes to obtain this property.
- Improvement In abrasion resistance - up to 50 % higher.
- A permanent mini-velour can be obtained in fabrics, which have spun weft or warp yarns.
- The fabric surface is very clean.
- Improved definition and clarity of the design and the colors.
- Reduced or eliminated use of environmentally harmful chemicals.
- More cost effective - elimination of traditional finish¬ing processes.
3.7 Feather touch & ultra soft touch: -
Feather touch & Ultra soft touch finishes are commercial names produced by treating with Amino, carboxy, or Epoxy Silicones alone or in successive treatments. Amino Silicones Extensively available in market are widely used in softening. They impart excellent softness With Bounciness when used in concentration 2.5 –3% of in garment finishing. Yellowing and some level of hydrophobic are the disadvantages. Epoxy silicones, which are most compatible with most of the other finishing chemicals, Impart softness without yellowing and improved fabric strength. They play a vital role in Wrinkle free finishes by imparting improved tear strength.
3.8 Rubbery touch: -
Rubber latex provide glossy, crispy handle with characteristic rubbery effect, which are durable. This effect gaining much more importance among the youngsters. In leather finish they are applied as final finish treatments after enzyme or stone wash or after mechanical abrasion and enzyme treatments. Many catching names such as “Bio polished &rubbery touch finish”, enzyme Bio polish & rubbery touch finish”, are quite common.
Preparation and application of emulsions: -
For finishing of textiles it is necessary to prepare aqueous baths with emulsions or micro- emulsions of silicone softener. The advantage of micro-emulsions is their thermodynamic stability and the drawbacks are higher fraction of surfactants and lowering of softness effect. Using non-ionic surfactants it is possible to prepare stable dilute micro-emulsions with more than 40% strength. The softness produced by micro-emulsions is similar to that of solvent solution. During application on jets it is necessary to control the liquor ratio as well as temperature and shear forces, to prevent the separation and silicone oil and formation of spots. The finishing of synthetics is less sensitive than that of cotton.
3.9 Non-stick Teflon spray: -
This is anew generation multipurpose lubricant based on poly tetra fluoro ethylene (PTFE). In service this lubricant forms a tenacious non-stick coating of the fluoro-polymer, which does not allow dirt and dust to settle on the textile surface. This makes the product ideal for cement plants, textile mills and industries etc. where constant flow of dust and contaminants affect the conventional lubricants.
3.10 Wrinkle free finishes: -
Easy care finishes producing cross-linking agent to avoid crease formation. It gives improved dimensional stability to the garments. But crease recovery property should with stand for repeated washes. They must suitable for cotton, P/C, P/V, blended fabric.
3.11 Water repellent finishes: -
Water and stain resistant finishes on fabric has gained considerable popularity amongst youngsters Water resistant finishes can be produced using Metal salts paraffin dispersion, Poly silioxanes, Fluorocarbons, These auxiliaries impart hydrophobic character; and of the above fluoro carbon polymers are extensively used in fabric finishing. They form a film where the fluorocarbon redials are perpendicular to the fiber axis and prevent wetting of the fiber surface. Their high hydrophobic & oleo phobic action is explained by the extremely low interfacial tension of fluorocarbon chain towards all chemical compounds. In actual practice fabrics are bio polished first with enzyme and fluorocarbons are applied either by spray method or dip method and fabrics are finally cured at 1500C for 10 minutes.
Fluorochemicals are organic compounds consisting of per fluorinated carbon chain. This is a film former that reduces the surface energy of a substrate, thereby providing one or more of the following properties:
- Oil Repellency
- Soil Resistance
- Water Repellency
How do fluorocarbons affect the surface tension?
Fluorocarbon from a thin film around the fiber, thus providing the fiber with a lower surface tension, is lower than most liquids. Finishing the fabric with Hydroguard makes the fabric sufficiently water repellent so that it can imitate the lotus leaf. Hydroguard is a special fluoro polymer manufactured by processes that do not produce any by-product.
3.12 Water resistant breathable finish: -
Present trend is to impart water-repellency without affecting water vapor permeability of fabric and garments for use in out door activities; weather-clothing etc. improving the transpiration rate of perspiration through the textile material is particularly important in sports activities where the relative metabolic rate is high. Water droplets but allow the escape of water vapor. Such types of garments are designed for sports-wear, tracksuits, clothing for mountaineering etc.
The chemicals consist of Quaternary ammonium Salt with the pyridine Base and a compound is formed with cellulose in the presence of sodium acetate.
The process sequence employed is pad –Dry –Cure-Soap-Rinse
Pad - water repellent chemical
Drying - 60-70 °C
Curing - 1200C for 2-3 mins.
3.13 Soil release and stain release finish: -
Soil release and stain release and stain release finishes are particularly important where leisure or sports are activities may lead to greeter incidence of soiling and staining. Another factor is the trend towards lower temperature washing of garments where the removal of persistent soil and stain removal becomes more problematic.
On this principle three major groups of finishes are developed.
- Finishes containing carboxylic groups.
- Finishes containing oxy ethylene and/ or hydroxyl groups.
1 comment:
GOOD ARTICLE.SOME GRAMMER MISTAKES ARE THERE.
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