Textile finishes

Textile finishes- calendaring, stiffening,decanting etc

1. Textile finishes Presented by : Ms.K.Kathiroli Asst Prof Dept of fashion technology and costume designing Bon secours college for women – Thanjavur

2. Textile finishing Textile finishing is a process used in manufacturing of fiber. Fabric, or clothing.In order to impart the required functional properties to fIber or fabric, it is customary to subject the material to different type of physical and chemical treatment It can be classified into following classes: Mechanical finishing Chemical finishing Enzyme finishing

3. Textile finishing process Calendaring Stentering Decanting Beetling Glazing Schreinerizing Embossing Moiering Ciering Raising Napping Gigging Shearing Water proofing Water repellency Sanforizing Wash and warp Fire proofing Crepe and crinkle effect

4. Calendaring Calendering  of textile   is a finishing process used to smooth, coat, or thin a material. With textiles, fabric is passed between calendar  rollers at high temperatures and pressures. Calendering is used on fabrics such an moire   to produce its watered effect and also on cambric and some types of sateens

5. Objectives Calendering is a finishing process used on cloth, paper or plastic film. A calendar is employed, usually to smooth, coat or thin a material.  To upgrade the fabric hand and to impart a smooth silky touch to the fabric. To improve opacity of fabric. To compress the fabric and reduce its thickness. To impart the different degree of luster to the fabric. To reduce  yarn  slippage.

6. Preparation For Calendering The fabric is folded lengthwise with the front side or face inside and stitched together along the edges. The fabric is then run through rollers that polish the surface and make fabric smoother and lustrous. High temperature and high pressure required. Fabric that goes through calendering process feel than, glossy and papery.

7. Advantages Improved appearance – Lustre, Whiteness etc., Improved Feel which depends on the handle of the fabric and its Softness, Suppleness, Fullness etc., It improves the wearing qualities – Nonsoiling, Anti-crease. It gives special properties required for particular uses – Water proofing, Flame proofing etc., It covers the faults of the original cloth. It increases the weight of the fabric. It increases the sale value of the material. It improves the natural attractiveness of the fabric. It improves the serviceability of the fabric.

8. Applications Calendering is used for manufacturing sheet rubber in various thicknesses, for plasticizing and heating rubber stock, and for rubberizing fabric. In textile manufacturing, calendering is used for packing cotton, linen, and jute fabrics, adding luster to them, and applying embossed patterns.

9. Stentering Process:  Stentering is a mechanical  finishing process of textile. It is done for the stretching of fabric by the stenter machine. In other words we can say stentering is done for gripping the edges of a moving web to support the web during heating and stretching operations.

10. Working Procedure of Stenter Machine:  The fabric is collected from the batcher to the scray and then it is passed through the padders where the finishes are applied and some times shade variation is corrected.The fabric is entered into the mahlo (weft straigtner) the function of the mahlo is to set the bow and also weave of the fabric is griped by the clips and pins are also provided but the pins has a disadvantage that they pins make holes at the selvedge but the stretchning of the pins are greater than the clips.these clips and pins are joined to endless chain.there are 8 to 10 chambers provided on the machine each chamber contains a burner and filters are provided to separate dust from air.the circulating fans blow air from the base to the upper side and exhaust fans sucks all the hot air within the chambers. Attraction rollers ar provided to stretch the warp yarn. 

11. Functions of Stenter Machines: Heat setting  is done by the stenter for  lycra fabric , synthetic and blended fabric. Width of the fabric is controlled by the stenter. Finishing chemical apply on fabric by the stenter. Loop of the knit fabric is controlled. Moisture of the fabric is controlled by the stenter. Spirility controlled by the stenter. GSM of the fabric  is controlled by stenter. Fabric is dried by the  stentering process . Shrinkage  property of the fabric is controlled. Curing treatment for resin, water repellent fabric is done by the stenter.

12. Stiffening Some fabric need to be made stiffer and more crisp as per as the end use. Stiffering agent are applied to cloth to build up the following properties To increase the weight of the fabric. To improve the thickness. To improve luster But, their effect is temporary and once the fabric is washed, most of the finishes are removed.

13. Decanting Decating is a process applied to woollens and worsteds, man-made and blended fibre fabrics, and various types of knits. It involves the application of heat and pressure to set or develop lustre and softer hand and to even the set and grain of certain fabrics. When applied to double knits it imparts crisp hand and reduces shrinkage. In wet decating, which gives a subtle lustre, or bloom, fabric under tension is steamed by passing it over perforated cylinders.

14. Beetling mechanical treatment that uses beetlers or fallers to give fabric surfaces a flattened appearance. The spaces between warp and filling are covered up and tend to produce a high gloss to the material. A method of creating a firm lustrous fabric, mainly used once. Cellulosic based fabrics. A process in which round-thread linen or cotton fabric is pounded to give a flat effect. Beetled linen damask has an increased luster and a leather-like texture. Beetling is also used to give a thready or linen-like appearance to cotton.

15. Glazing Glazing is a textile finish that adds luster and smoothness to the surface of the fabric. Many glazed fabrics are plain-woven cotton. A specialized calender (set of metal rollers) called a friction calender, literally rubs the fabric lustrous. Glazed chintz and polished cotton are examples of glazed fabrics.

16. Process of glazing The fabric is first impregnated with wax, starch, or a resin solution using a pad machine. The fabric passes through the solution in a bath, then through pad rollers. Pressure is applied so that the solution is forced into the fabric. The pressure on the pad roller squeezes the excess solution out of the fabric. The fabric is partially dried and passed through a friction calender. The friction calender is made up of three rollers. One roller is a padded roller that moves the fabric slowly between two metal rollers. As the fabric moves slowly between the rapidly moving heated metal rollers, the friction creates heat. The fast moving metal rollers polish the fabric. The glaze will be temporary if the fabric has been treated with wax or starch. The finish will be durable if the fabric has been treated with resins. The glazing will be durable on thermoplastic (heat sensitive) fiber fabrics because the friction rollers produce heat.

17. Schreinerizing Scheriner finishes on fabric produce soft luster and hand by flatting the yarn and surface of a fabric through calendaring. The schreiner calendar has a metal roller engraved with 200-300 fine diagonal lines per inch that are visible only under magnifying glass. A schreiner finish is used on cotton sateen and table demask to make them more lustrous and on nylons tricots to increase its cover.

18. Embossing Embossing is a particular calendaring process through which a simple pattern can be engraved on the cloth. The machine is made up of a heated and embossed roller made of steel, which is pressed against another roller coated with paper or cotton, its circumference being exactly a whole multiple of the metal roller. A gear system drives the harmonized motion of the roller. A gear system drives s the harmonized motion of the rollers, preventing them from sliding and granting a sharp engraving of the patterned design. After being engraved, the pattern can be stabilized by means of an appropriate high-temperature treatment or by applying suitable starchy substances.

19. Embossing machine

20. Moiering The moire finish produces a wood-grain design on the face size of the fabric Moire finish can be temporary, durable or permanent. Cotton or rayon moire finish is temporary without pretreatment with resin. Durable moire finish requires initial resin treatment followed by calendering. Moire finish on thermoplastic fiber fabrics are permanent if a heated roller is used for calendaring. Methods of producing moire Using engraved cylinder Using smooth calendar roller

21. Raising Raising machine is using in textile mill by fabric manufacturers which is an industrial equipment of textile industry used in textile finishing process  of textile sectors. This machine raises the surface of fiber passage using the method of  textile technology over rapidly revolving cylinders covered with metal points or teasel burrs. This is a very old technique known also to romans is used for textile design. During those last years this process has also been apply on viscose blends and acrylic fabrics in  textile mill.  This machine is used after  Open Width Compactor  or  Tubuler Compactor. 

22. Raising machine

23. Napping Napping is chiefly used to obtain a relatively deep hairy surface, but the degree of depth depends upon the technique used. When a fabric is to be napped, the yarns intended for the construction of the cloth are given only a slack twist in the spinning process. The fabric is passed under a roller that has fine steel wires with small hooks on the ends. The hooks scrape the surface of the fabric pulling up fibre ends out of the yarn. 

24. The fuzzy finish, produced by napping makes a soft fabric, which provides warmth because of the insulative air cells in the nap. The thicker the nap, the more air cells, and the warmer the fabric. In men’s suiting’s, where long wear is desired, a napped surface acts as a protection against objectionable luster. The fact that stains can be removed more readily from a napped surface is an additional advantage. On the other hand, napping may also serve to cover up a sleazy construction and weaving imperfections. It is generally considered that excessive napping tends to weaken the fabric, especially where a heavy nap has been produced, and to increase any propensity to pill. Single napping signifies that both sides of a cloth have been napped in one direction; double napping signifies that both surfaces have been napped in opposite directions, which produces greater surface density, increased firmness, and greater warmth. Flannelette, wool flannel and duvetyn exemplify napped fabrics. Cotton and spun rayon fabrics are napped when a soft, fuzzy surface is desired. V egetable bars called teasels have been used for napping finer grades of wool fabrics. Long cylindrical rollers containing closely set wires, which act like brushes, also perform the teaseling operation. As the brushes slide over the revolving fabric, they pull the top fibres and raise the protruding ends above the surface of the cloth in the form of a fleece like nap. If a heavy nap is desired, teaseling is repeated several times.

25. Shearing Shearing is an important preparatory stage in the processing of cotton cloth. The objective of "Shearing" is to remove fibres and loose threads from the surface of the fabric, thus improving surface finish.

26. Water proofing Waterproofing is nothing but preventing the passage of both air and water through a fabric. Purpose of Water Proofing: For certain uses such as Tarpaulin, Umbrella cloth, Rain coat fabrics etc., it is required to give this type of finish as these type of fabrics are generally used against the air and water in the normal life. So they should have some property to prevent both air and water passing through them.  This finish makes the wearer feel uneasy and uncomfortable as the air circulation is not there. 

27. Principle of Water Proofing:  A film on the surface of the fabric should be formed for the prevention of air and water.  When a uniform coating of suitable substances such as rubber is produced on the surface of a fabric, the interstices between the warp and weft yarns are blocked by the continuous film or substance and both water and air not pass through the treated fabrics.  It is a chemical and property giving finish. 

28. Water repellency Water-repellent finishes resist wetting. If the fabric becomes very wet, water will eventually pass through. Applied to fabrics found in raincoats, all-weather coats, hats, capes, umbrellas and shower curtains.

29. Crease Resistant or Crease Proofing Crease Resistant Finishes are applied to cellulose fibres (cotton, linen and rayon) that wrinkle easily. Permanent Press fabrics have crease resistant finishes that resist wrinkling and also help to maintain creases and pleats throughout wearing and cleaning.

30. Sanforizing Sanforizing  is a process where by the fabric is run through a sanforizer; a machine that has drums filled with hot steam. This process is done to control the shrinkage of the fabric.The fabric is given an optimum dimensional stability by applying mechanic forces and water vapour