The word Denim is believed to have evolved from a French fabric known as serge de Nmes. The cloth from Nmes was a twill woven cloth made of a silk-wool blend; however; the fabric mix of this cloth casts some doubt on this origin since Denim has always been made from cotton. Since the mid-1950s Denim Garments has become a mainstay in the wardrobe of American youth. Denim represents a rugged cotton twill textile, in which the weft passes under two or more warp fibers, producing the familiar diagonal ribbing identifiable on the reverse of the fabric, which distinguishes denim from cotton duck. Denim was traditionally colored blue with indigo dye to make blue jeans though jean represents a different, lighter cotton textile. Although Denim jeans are favorites among the American youth, it has changed style and significance throughout the years. Globally, Denim designers are experimenting with fabric and garment details including embellishments in order to add value to its garments. New add-ons are being incorporated in the form of patches, appliqu, rhinestones and glitter.

The process of adding value to this legendary outfitter enhanced from time and time by devising some new methods such as:

BY CHANGING THE COLOR AND METALLIC SPARKLE SPRAY ON DENIM GARMENTS

Value-addition substantially allows higher earnings in relation to money spent on impartation of the value. It may be either functional or aesthetic. Functional value-addition may not function more effectively on the garment. In many cases, the garment may not look effectively, if it is not treated for value-addition. Aesthetic value-addition is a cosmetic treatment and ornamentation. It attracts the attention and you can see the appealing results at the earliest. This kind of value-addition is governed by latest "trends" and consumer preferences. The color spray gives an aesthetically appealing 'cast', which gives a "consumer-liking" value.

SOFTENERS SHOULD BE USED FOR BULKY FEEL ON DENIM GARMENTS

"Bulky" or "flat and firm" has relation to aesthetics and personal liking as there is no dearth of finishes for such attributes. These finishes are generally applied wet-on-wet at the end of garment washing by exhaust method. It is, therefore, imperative to select a softener/lubricant, which is exhaustible for the best performance of the garment. It is also important to maintain whilst applying the right conditions such as pH, temperature and exhaustion time in order to transfer the maximum softener/lubricant onto garment from the treating liquor. Such products could be cationic softener, exhaustible polyethylene, micro-amino silicone for suppleness, macro amino silicone for surface smoothness and so on. One needs to prepare an atlas of fabrics to assess the degree of bulk with the type of softeners and their concentrations. Further some combination of softeners may show enhanced effect immediately.

APPROACHES TO MILD WASHING EFFECTS ON SULPHUR-DYED DENIM GARMENTS

Garment washing may affect the whiteness level of your garments, as they can look dull or yellow after processing. Most garment washers add whitener to the process to ensure a bright white finished product. Make sure to determine any costs involved and factor them into your product costing. There are many special effects, such as weathering, stone washing, acid washing and distressing that can be produced by garment washers. These effects being very popular have their own drawbacks. They are costly, have higher fallout rates, and are generally rougher on the fabrics. Talk to your garment washer about prices and what to expect of the process you choose to do.

TINT DENIM-GARMENTS WITHOUT CHANGING THE TONE OF INDIGO

Tinting is achieved by application of the direct/reactive dyes. In case of direct dyes, the second application would be that of dye-fixing agent for an adequate fastness. In case of reactives, the fixing chemical goes along with the dyestuff. After the application, the treated garment is dried in the air or in a tumble drier for adequate fastness. If tinting were done by immersion method, the tint would be all over. However, if a localized area is the target, a spray method is used. In either case the tinting, as the term signifies, is done very lightly to achieve a particular cast, either overall or localized. If indigo does not change tone would look like a print with a sharp boundary. When tone changes fad gradient, the effect looks more aesthetically appealing and is considered desirable. The tone-change should be gradual and not abruptive.

SIGNIFICANCE OF OZONE-FASTNESS IN INDIGO GARMENTS

Oxidizing agents have a property of attacking chromophoric group of the dyestuff and destroying-discharging the color. Potassium permanganate is a well-known chemical extensively used for discharge of indigo in denim garments. However, potassium permanganate is used as and when discharge is required and the ultimate purpose is value-addition. Ozone is another strong oxidizing agent, which could discharge indigo in denim-garments. The folds in folded-denim garment otherwise have relatively greater exposure to atmospheric ozone than the rest of the garment, which is protected by virtue of garments being stacked. This results into localized discharge of indigo at the folded marks. There are inorganic as well as organic ozone-seavenger, which protect the indigo in denim garments from the attack of ozone and hence control the value-loss. There are many buyers who ask for denim fabrics/garments finishes with ozone seavenger.

EFFECTS OF PERLITE-CELLULASE TREATMENT ON DENIM GARMENTS

Perlite being used in denim washing is a high-temperature expanded version of natural mineral in granule form of 1.5 mm size. The perlite treatment combined with enzyme treatment for softness, sheen, and mildly abraded surface. Perlite can reduce the enzyme dosage and enhance abrasion. However, the abrasion is quite mild, which gets with pumice stones and only cellulose. Depending upon the degree of abrasion needed, the cellulase - perlite treatment could take 60-120 minutes using liquor ratio and some 100 gm perlite per kg of garment. Since perlite dust causes, sensitization and allergies when inhaled, some standard protective-care needs to be taken during manufacture, packing, storage, transportation, material handling and usage. Further perlite needs to be looked first before cellulose and other chemicals and then the machine run for minutes with water.

TINTING WITH WHITE DISCHARGE EFFECT ON DENIM GARMENTS

The standard route to blasting/discharging/tinting is quite elaborate, in the light of three effects to be imparted on the same garment. There have been short cuts, which may be right/wrong/ingenious. If tinting is done on blasted/discharged areas, it obviously remains a spray method. However, if the tinting is overall, it follows the dyeing route. The process starts on gray garment being hand blasted followed by desizing and biopolishing. After drying the garment, tint-spray is given followed by air/machine drying and finishing. For tinting by dyeing method, the biopolished garment can straight away go for tinting wet-on-wet followed by finishing and drying.

In case of white discharge tinting the route would start with desizing-biopolishing on gray garment, peroxide bleaching after biopolishing being optional. After drying the garment, a potassium permanganate spray is given to areas where white discharge is aimed at. After air-drying for about 10-15 minutes, a neutralization step consisting of provide-acetic acid is given which is followed by hot and cold rinses. In case of spray tinting the garment will have to be dried first, whereas for overall tinting, dyeing the method could be followed wet-on-wet. Finally the finishing and drying would complete the process.

GETTING REVERSE EFFECT ON DENIM IN DISCHARGE PROCESS

In spray process, first apply neutralizer where you want the resist effect and thereafter, spray potassium permanganate on applied portion and its surrounding area. Then, neutralize the garment to remove potassium permanganate. It gives a halo effect to denim garments.

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