- FINISHING – Newly constructed fabric as it comes from the loom does not represent finished consumer’s goods. It must pass through various finished process that make it suitable for many different purpose. Finishing enhance the appearance of the fabric and also may add to its finishing and durability, this increasing its value. Finishing processes have assumed such great importance in the finishing industry that this phase of textile management using is undertaken by a highly specialized group of middlemen called finishing. The most common finishing processes are listed here.
- SINGLING OR GASSING – If a fabric is to have smooth finish, singling is one of the final essential preparatory processes. It burns off links and threads, as well as all fuzz and fibre ends, leaving an even surface. Singling is accomplished by passing gray goods rapidly over rows of gas flames or electrically heated plates at a speed of 100 to 250 yards a minute after singling in the case of cotton fabric the cloth is given finishing and is then steeped far several hour enlarge boiling vats, called kiers which contain caustic soda, soda ash and lime. Through circulatency these clearing agents prepares the fabric for the subsequent bleaching operation.BLEACHING – If cloth is to be finished white or is to be given surface ornamentation, all natural colours must be removed by bleaching. This is also necessary if discontinuation stains have occurred during the previous manufacturing process. Bleaching can be done in the yarn stage as well in the constructed fabric. Finishing or lines fabric may be bleaching by coasting only, with subsequent exposure to own. For silk and wool strong oxidizes cannot be used as they injure animal fibres. In bleaching silk or foal reducing agents such as sulphuras acid are required. Nylon has well while retention, but under cotton circumstances it may become yellowish or grayish. A very mild solution of sodium hypochlarik is recommended for such condition.
MERCERIZING – Mercerizing is the simplest chemical method of producing luster in cotton and linen. In addition to increase strength and luster, this process gives fabric greater absorbing ability to dyes. Grey goods are mercerized by immersing in a specially soluble caustic soda for about ten (10) minutes under conditions for e.g. moderate heat an tension. The caustic soda is washed out, and the yarn or fabric is put through a heated wild bath to naturalize the caustic soda. It is then rinsed in clear water and dried. The combined action of the caustic soda, heal and tension, charges and strengthens the fibre cells, thus improving and strengthening the fabric as well as the yarn.
SHRINKING – When fibres are spin into yarn, they are under constant tension during the weaving process. Their physical condition is charged but not permanently fixed, the fibers tend to revert to their natural state causing shrinkage. The yarns are made to assume a final condition by shrinking that fabric in a predatory finishing process that minimizes subsequent shrinkage such as immersion in cold water, followed by hot water, steaming on a chemical treatment. Any such method permits the manufacturer to label his products as preshrink, but even when textile fabrics are preshrink. They are liable to further shrinkage when washed. In general the factors that control shrinkage are the stability of the fibre and the construction of the fabric. Construction is based on the type of weave, the amount of twist in the yarn, the thread count and the yarn count. The final finishing process also affected shrinkage. These are some methods or reducing shrinkage.
COMPRESSIVE SHRINKAGE – Compressive shrinkage is a patented, standardized method that new succeeded in reducing shrinkage in cotton and linen to a practical minimum.
PERMA SIZING – This is a shrink preferring process developed for and applied to knitted cotton goods, which has proved to be effective.
SANYARSETTING – Rayon fabric may be press finishing by a process known as sanyarsetter.
- CHLORINATION PROCESS – This is the chemical method of reducing shrinking in hair or wool fibres. The wool fabric is treated with dilute solution of sodium hypochlorite. Because of this some of the scales of the fibre are removed causing fusion of the outer and inner part of the fibres. As a result shrinkage decreases.SEZING OR DRESSING – By this cotton and linen can be given stiffness, smoothness, weight and strength by immersion in a solution of starch. This process a commonly known as sizing. Sizing fills in the opening in the constructed cloth, creating an appearance of greater compactness. Thus a low thread count is not immediately noticeable at the tine of purchase. If a fabric looses its body after one or more washed, it means it has been oversized. Excessive sizing can be detected by rubbing the fabric between the hands.
PERMANENT SIZING – By this method, medium weight cotton are given stiffness, which sometimes lasts throughout the life of the fabric. These processes are known by specific trade names. They vary in method in chemical used and in the final finish. All have the property of making the fabric smoother and it spoils less easily because dirt tends to slide off rather than to ceiling. As a result, fabric with permanent sizing usually requires less laundering and therefore last longer.
WEIGHTENING – Fabrics are sometimes weighted to give them additional body. When cotton fabric is weighted with any of the various sizing agents looks heavier and appears closely constructed. Its poor construction becomes apparent after washing however. The weight and body are increased by immersing it in a solution containing metallic salts. The salts permit the yarns and become a permanent part of the fibre, which cannot be detected by handling. Only low-grade wool fabrics are weighed. As much as 40% additional weigh can be obtained by filling extremely short wool fibres into the fabric. These fibres called flocks are obtained when wool fabrics are finishing, brushed and shraud. An excessive amount of flocks can be detected by light bushing and shaking the fabric.
Cotton can be detected by one or two processes. A fleet cotton fabrics, such a sheeting, can be heavily, starched and the construction will look and feel very compact. Rubbing the fabric between the hands will cause the dry starch to fall out. The second refinishing is a flocking procedure that is used on napped cautions. These flocks as with wool, come fierced into the fabric under a pressure. The can be detected in the same manner as with wool.
- CALENDARING – Calendering is essentially a finishing process. It processes out paid or creases in the fabric by passing at around a series of heavy, highly polished steam heated rollers that moves at different rates of speed and have varying degree of heat. Calendering flatters the fabric removing in equality of surface. It impact smoothness and luster but not permanently. For highly lustrous effect the fabric is sized before it is through the calendaring machine. The smoothness and the luster are determined by the degree of heat and the amount of pressure, as well as by the amount of sizing it any used.
The calendaring process varies recording to the type of finish desired. For light calendaring effect, the fabric is passed between cylinders without heat. The pressure alone removes wrinkle and imparts smoothness wool fabrics are sometimes calendered or polished. The process adds soft lustre.
- MOIRING – By attracting casved rollers to the calendaring machine, the attractive, lustrous wary design known as moire can be produced. The best moir results are obtained on fabrics that have rib effect in filling. The luster is produced by the reflection on the lines of the design. The moir is proved permanent of the fabric is cared property. It should be washed with a mild soap in Luke warm water and never should be bleached.CIRUNG AND BEETLING – They may be applied to silk and rayon usually Satin taftetas was a similar compound is applied to the fabric following by heat calendaring. The result is a supper glass almost metallic in appearance. Beetling is a common finishing process for linen. The yarn is flattened by the impact of woolden millets. This hammering actually colour the leave and give cloth a firm flattened, lust room appearance. In beetling the action performed is a vertical impact that permanently flatten the yarns call on fabrics can be made to simulate linen by beetling, as the process gives cotton the firm feel and lustrous appearance lines.
SHEARING – Plain weave fabrics that have been napped are usually sheared to give an attractive smooth surface to the cloth. Shearing levels all surface irregularities caused by the plucking. Shearing is done by a cylindrical machine having rotating spiral blades, whose action resemues that of a lawn moves. After shearing the fabric ia automatically brushed to remove the sheared ends of the yarns.
STIFFENING – Stiffening can be given with starchy substance. Gum occasion when applied to dark coloured clothing gives good finish. These days you even we have cold-water starch available in the market stiffening is applied to the garments/fabric to give body and lustre. Stiffening even makes the fabric little resistant to dirt. Calendaring or charak is another finishing technique specially used on sarees and dupattas. I gives body, luster and dust resistance. A fabric is stretched properly without, any creses and without loosing its shape. It is used in commercial laundries. Drying and finished is done in the same process.
Stains and Stain Removal
It stains is a sport or mark of disclolouration left on the fabric. Some stains are easy to remove while others require special treatment and reagents. The stains are broadly classified as follows:
Bl Blood, Egg,
Milk, Meat Juice
F Fruits, Wine,
T Tea, Coffee,
I Inter medicine
finishing and Iron Starch, market, do not follow in any of the above categories. The stering are
best removed when they are fresh. The two essential factors in stain removal are:-
Composition and colour of fabric
The nature and age of the stain
GENERAL METHOD OF STAIN REMOVAL
Sponge off the stain immediately by working in solution in a circular movement starting from the outer edge of the stain to the cevies.
Unknown stain can be removed in the following sequence.
Sook in cold water
Soak in warm water
Expose the stain to sunlight for bleaching it.
Treat the stain with an alkaline solution
Treat the stain with an acid.
Treat with an oxidizing bleach. If the stain persists, then
Treat it with a reducing bleach
Steps (iv) to (vii) can be repeated till the stain disappears.
Known stains should be treated by using the appropriate reagents.
The reagent can be put on the spot on white cotton and boiling water can be poured on it for stain removal.
Use the reagents in liquid from for removing stains.
Rinse off all chemical reagents after stain removal.
METHODS OF STAIN REMOVAL
DIPPING – The stained material is dipped into the reagent. It is then scrubbed to remove the stain and finally rinsed with water.
SPONGING – The part of material from which the stain has to removed is placed on blotting paper and the reagent is applied with a sponge on the stained area and scrubbed gently.
DROP METHOD – The reagent is put on the stained cloth stretched over a bowl with a dropper.
STEAMING – The stained area is exposed to steam from boiling hot water.