Finishing (textiles)

Last updated
Textile finishing machinery, Red Bridge Mills, Ainsworth, 1983 Textile finishing machinery, Red Bridge Mills, Ainsworth - geograph.org.uk - 1584753.jpg
Textile finishing machinery, Red Bridge Mills, Ainsworth, 1983

In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finish textile or clothing. [1] [2] The precise meaning depends on context.

Contents

Fabric after leaving the loom or knitting machine is not readily useable. Called greige cloth at this stage, it contains natural and added impurities. Sometimes it is also processed at fiber or yarn stages of textile manufacturing. Grey fiber or yarn or fabric goes through a series of processes such as wet processing and finishing. Finishing is a broad range of physical and chemical treatments that complete one stage of textile manufacturing and may prepare for the next step, making the product more receptive to the next stage of manufacturing. Finishing adds value to the product and makes it more attractive, useful, and functional for the end-user. Improving surface feel, aesthetics, and addition of advanced chemical finishes are some examples of textile finishing. [3]

Some finishing techniques such as bleaching and dyeing are applied to yarn before it is woven while others are applied to the grey cloth directly after it is woven or knitted. [4] Some finishing techniques, such as fulling, became outdated with the industrial revolution while others, such as mercerisation, are developments following the Industrial Revolution.

Introduction

In order to impart the required functional properties to the fiber or fabric, it is customary to subject the material to different types of physical and chemical treatments. For example, wash and wear finish for a cotton fabric is necessary to make it crease-free or wrinkle-free. In a similar way, mercerising, singeing, flame retardant, water repellent, waterproof, anti-static and peach finishing achieve various fabric properties desired by consumers.

The use of 100% synthetic textiles has increased considerably since the development of textured yarns made of filaments and the growing production of knit goods. The use of open weave has enabled the production of lighter, breathable, fabrics to ensure better wearing comfort.

The properties of petroleum-based synthetic fibers, most important among them being polyamide, polyester and polyacrylonitrile, are essentially different from those of natural cellulosic and protein-based (wool) fibers. Hence the sequence of finishing operations is likely to be different. While cellulosic fabrics require a resin finishing treatment to impart easy-care properties, synthetic fibers already exhibit these easy-care criteria and require only a heat setting operation.

Finishing of cotton

Purification and preliminary processes

The greige cloth—woven cotton fabric in its loom-state—not only contains impurities, including warp size, but requires further treatment in order to develop its full textile potential. Furthermore, it may receive considerable added value by applying one or more finishing processes. [5] [6]

Singeing

Singeing is a preparation method of textiles; it is applied more commonly to woven textiles and cotton yarns. Singeing in textiles is a mechanical treatment or finish to obtain a neat surface of the fabric or less hairy yarn. In a singeing machine, the yarns or fabrics are exposed to direct flames to burn the protruding fibers of the textile materials. Hence, also called "gassing". [7] [8] [9] [10]

Desizing

Depending on the size that has been used, the cloth may be steeped in a dilute acid and then rinsed, or enzymes may be used to break down the size. [10]

Scouring

Scouring is a chemical washing process carried out on cotton fabric to remove natural wax and non-fibrous impurities (e.g. the remains of seed fragments) from the fibres and any adventitious oil, soiling or dirt. Scouring was used to carry in iron vessels called kiers. The fabric was boiled in an alkali, which forms a soap with free fatty acids (saponification). A kier is usually enclosed, so the solution of sodium hydroxide can be boiled under pressure, excluding oxygen which would degrade the cellulose in the fibre. If the appropriate reagents are used, scouring will also remove size from the fabric although desizing often precedes scouring and is considered to be a separate process known as fabric preparation. Preparation and scouring are prerequisites to most of the other finishing processes. At this stage even the most naturally white cotton fibres are yellowish, and bleaching, the next process, is required. [10]

Bleaching

Bleaching improves whiteness by removing natural coloration and remaining trace impurities from the cotton; the degree of bleaching necessary is determined by the required whiteness and absorbency. Cotton being a vegetable fibre will be bleached using an oxidizing agent, such as dilute sodium hypochlorite or dilute hydrogen peroxide. If the fabric is to be dyed a deep shade, then lower levels of bleaching are acceptable, for example. However, for white bed sheetings and medical applications, the highest levels of whiteness and absorbency are essential. [11]

Mercerising

A further possibility is mercerizing, during which the fabric is treated with a caustic soda solution to cause swelling of the fibres. This results in improved luster, strength, and dye affinity. Cotton is mercerized under tension, and all alkali must be washed out before the tension is released or shrinkage will take place. Mercerizing can take place directly on grey cloth, or after bleaching. [12]

Coloration

Color is a sensation caused when white light from a source such as the sun is reflected off a pigment on the surface. The pigment selectively reflects certain wavelengths of light while absorbing others. A dye can be considered as a substance that can be fixed to a material that has these properties. The colour it reflects is defined by the structure of the molecule, and particularly the parts of the chromogen molecule called the chromophore group. [13] There are two processes used to apply colour:

Dyeing

Cotton is an absorbent fibre which responds readily to colouration processes. Dyeing is commonly carried out with an anionic direct dye by completely immersing the fabric (or yarn) in an aqueous dyebath according to a prescribed procedure. For improved fastness to washing, rubbing, and light, other dyes such as vats and reactives are commonly used. These require more complex chemistry during processing and are thus more expensive to apply. [14]

Printing

Printing is the application of colour in the form of a paste or ink to the surface of a fabric, in a predetermined pattern. It may be considered as localised dyeing. Printing designs on to already dyed fabric is also possible. The common processes are block printing, roller printing and screen printing

Finishing

Mechanical finishing

Mechanical finish refers to machine finishes such as embossing, heat setting, sanforizing, sheering, various, luster imparting, surface finishes, and glaze finishes. [15] [16]

Mechanical Finishes [16]
Raised surface finishesLuster impartingGlaze and design
Gigging Calendering Embossing
Napping Beetling Moire
 Sueding
Flocking
Raising

Another finishing process is raising. During raising, the fabric surface is treated with sharp teeth to lift the surface fibres, thereby imparting hairiness, softness, and warmth, as in flannelette.

Shearing

Shearing is a kind of mechanical finish in which the appearance of the fabric is enhanced by cutting the loops or raised surface to a uniform and even height. The machine may have a spiral blade similar to a grass cutting machine. [17] [18] A Shearing machine can cut the loop or the pile to a desired level. [19]

Peaching

Peaching is also a mechanical finish comparable to raising but very gentle. The peach effect on fabrics is obtained by sanding the fabrics slightly; it imparts a protruded surface and soft feel. The peaching finish is also possible with certain chemicals or laundry abrasion. [20]

Calendering

Calendering is the third important mechanical process, in which the fabric is passed between heated rollers to generate smooth, polished or embossed effects depending on roller surface properties and relative speeds. [21]

Chemical finishing

Many other chemical treatments may be applied to cotton fabrics to produce low flammability, crease resist and other special effects.

Shrinking

Mechanical shrinking (sometimes referred to as sanforizing), whereby the fabric is forced to shrink width and/or lengthwise, creates a fabric in which any residual tendency to shrink after subsequent laundering is minimal. [22] Fibers to fabric conversion lead to many mechanical tensions and forces during manufacturing, which includes following steps for fibre to yarn conversion with spinning then fabric with weaving, and knitting. When the products are immersed in water, the water acts as a relaxing medium and all stresses and strains get relaxed and try to come back to its original relaxed state. Even after finishing with sophisticated finishing machines, some residual shrinkage remains, which is carried forward to the garment stage. This residual shrinkage may cause deformity or de-shaping of the products after domestic laundry. There are certain acceptance limits of shrinkage levels for every product. Abnormal shrinkage levels are considered a non-conformity to quality standards.


Standard finishes

Quality-oriented

Design-oriented

Handle-oriented

Special finishes for natural fibers

Special finishes for synthetic fibers

See also

Related Research Articles

<span class="mw-page-title-main">Textile</span> Various fiber-based materials

Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the only manufacturing method, and many other methods were later developed to form textile structures based on their intended use. Knitting and non-woven are other popular types of fabric manufacturing. In the contemporary world, textiles satisfy the material needs for versatile applications, from simple daily clothing to bulletproof jackets, spacesuits, and doctor's gowns.

<span class="mw-page-title-main">Yarn</span> Long continuous length of interlocked fibres

Yarn is a long continuous length of interlocked fibres, used in sewing, crocheting, knitting, weaving, embroidery, ropemaking, and the production of textiles. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework. Yarn can be made of a number of natural or synthetic materials, and comes in a variety of colors and thicknesses. Although yarn may be dyed different colours, most yarns are solid coloured with a uniform hue.

<span class="mw-page-title-main">Fiber</span> Natural or synthetic substance that is significantly longer than it is wide

Fiber or fibre is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.

<span class="mw-page-title-main">Woven fabric</span> Textiles formed by weaving

Woven fabric is any textile formed by weaving. Woven fabrics are often created on a loom, and made of many threads woven on a warp and a weft. Technically, a woven fabric is any fabric made by interlacing two or more threads at right angles to one another. Woven fabrics can be made of natural fibers, synthetic fibers, or a mixture of both, such as cotton and polyester.

<span class="mw-page-title-main">Dyeing</span> Process of adding color to textile products

Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fiber by absorption, diffusion, or bonding with temperature and time being key controlling factors. The bond between the dye molecule and fiber may be strong or weak, depending on the dye used. Dyeing and printing are different applications; in printing, color is applied to a localized area with desired patterns. In dyeing, it is applied to the entire textile.

<span class="mw-page-title-main">Mercerisation</span> Chemical treatment for cellulosic yarns

Mercerisation is a textile finishing treatment for cellulose fabric and yarn, mainly cotton and flax, which improves dye uptake and tear strength, reduces fabric shrinkage, and imparts a silk-like luster.

<span class="mw-page-title-main">Textile manufacturing</span> The industry which produces textiles

Textile manufacturing or textile engineering is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful goods such as clothing, household items, upholstery and various industrial products.

<span class="mw-page-title-main">Nonwoven fabric</span> Sheet of fibers

Nonwoven fabric or non-woven fabric is a fabric-like material made from staple fibre (short) and long fibres, bonded together by chemical, mechanical, heat or solvent treatment. The term is used in the textile manufacturing industry to denote fabrics, such as felt, which are neither woven nor knitted. Some non-woven materials lack sufficient strength unless densified or reinforced by a backing. In recent years, non-wovens have become an alternative to polyurethane foam.

The manufacture of textiles is one of the oldest of human technologies. To make textiles, the first requirement is a source of fiber from which a yarn can be made, primarily by spinning. The yarn is processed by knitting or weaving, which turns it into cloth. The machine used for weaving is the loom. For decoration, the process of colouring yarn or the finished material is dyeing. For more information of the various steps, see textile manufacturing.

<span class="mw-page-title-main">Textile bleaching</span> Textile wet process that improves whiteness by removing natural color

The textile bleaching is one of the steps in the textile manufacturing process. The objective of bleaching is to remove the natural color for the following steps such as dyeing or printing or to achieve full white. All raw textile materials, when they are in natural form, are known as 'greige' material. They have their natural color, odor and impurities that are not suited to clothing materials. Not only the natural impurities will remain in the greige material, but also the add-ons that were made during its cultivation, growth and manufacture in the form of pesticides, fungicides, worm killers, sizes, lubricants, etc. The removal of these natural coloring matters and add-ons during the previous state of manufacturing is called scouring and bleaching.

<span class="mw-page-title-main">Ainsworth Mill, Breightmet</span> Cotton mill in Greater Manchester, England

Ainsworth Mill, Breightmet is a mercerising mill near the Breightmet neighborhood of Bolton, Greater Manchester. It was bought by the Lancashire Cotton Corporation in the 1940s as an attempt to develop a cotton finishing presence.

Dimensional stability pertains to a fabric's ability to maintain its initial size and shape even after undergoing wear and care, which is a desirable property. Textile manufacturing is based on the conversion of fiber into yarn, yarn into fabric, includes spinning, weaving, or knitting, etc. The fabric passes through many inevitable changes and mechanical forces during this journey. When the products are immersed in water, the water acts as a relaxing medium, and all stresses and strains are relaxed and the fabric tries to come back to its original state.

Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.

<span class="mw-page-title-main">Fabric treatment</span>

Fabric treatments are processes that make fabric softer, or water resistant, or enhance dye penetration after they are woven. Fabric treatments get applied when the textile itself cannot add other properties. Treatments include, scrim, foam lamination, fabric protector or stain repellent, anti microbial and flame retardant.

<span class="mw-page-title-main">Greige goods</span> Woven or knitted fabrics which are not yet dyed or finished.

Greige goods are loom state woven fabrics, or unprocessed knitted fabrics. Greige goods undergo many subsequent processes, for instance, dyeing, printing, bleaching, and finishing, prior to further converting to finished goods such as clothing, or other textile products. "Grey fabrics" is another term to refer to unfinished woven or knitted fabrics.

Singeing is a preparation method of textiles; it is applied more commonly to woven textiles and cotton yarns where a clean surface is essential. Singeing in textiles is a mechanical treatment or finish to obtain a neat surface of the fabric or less hairy yarn. In a singeing machine, the yarns or fabrics are exposed to direct flames or to the heated plates to burn the protruding fibers. It is also called "gassing."

<span class="mw-page-title-main">Scouring (textiles)</span> Chemical washing process

Scouring is a preparatory treatment of certain textile materials. Scouring removes soluble and insoluble impurities found in textiles as natural, added and adventitious impurities: for example, oils, waxes, fats, vegetable matter, as well as dirt. Removing these contaminants through scouring prepares the textiles for subsequent processes such as bleaching and dyeing. Though a general term, "scouring" is most often used for wool. In cotton, it is synonymously called "boiling out", and in silk, and "boiling off.

A blend is a mixture of two or more fibers. In yarn spinning, different compositions, lengths, diameters, or colors may be combined to create a blend. Blended textiles are fabrics or yarns produced with a combination of two or more types of different fibers, or yarns to obtain desired traits and aesthetics. Blending is possible at various stages of textile manufacturing. The term, blend, refers to spun fibers or a fabric composed of such fibers. There are several synonymous terms: a combination yarn is made up of two strands of different fibers twisted together to form a ply; a mixture or mixed cloth refers to blended cloths in which different types of yarns are used in warp and weft sides.

<span class="mw-page-title-main">Aesthetics (textile)</span> Concept of serviceability of textiles

Aesthetics in textiles is one of the basic concepts of serviceability of textiles. It is determined by the perception of touch and sight. Aesthetics imply the appearance and attraction of textile products; it includes the color and texture of the material. It is a statement about the end user (consumer) and the target market. When combined with fabric construction, the finish of the clothing material, garment fit, style, and fashion compatibility, colours create an aesthetic comfort. All of these elements work together to satisfy our visual perception. Aesthetics incorporates the role of evaluation also.

<span class="mw-page-title-main">Textile testing</span> Process of measuring the properties and performance of textiles

Textile testing is the process of measuring the properties and performance of textile materials—textile testing includes physical and chemical testing of raw materials to finished products.

References

  1. Collier 1970, p. 154.
  2. Kadolph 2007, pp. 330–341.
  3. Principles of Textile Finishing. Woodhead. 29 April 2017. pp. 1–10. ISBN   9780081006610.
  4. Collier 1970, p. 246.
  5. "Finishing", Spinning the Web, Manchester City Council: Libraries, archived from the original on 2008-10-24, retrieved 2009-01-29
  6. GREENHALGH, DAVID (2005), Cotton finishing, archived from the original on 2009-02-12, retrieved 2009-02-12
  7. Kadolph 2007, p. 334.
  8. Tortora, Phyllis G.; Johnson, Ingrid (2013-09-17). The Fairchild Books Dictionary of Textiles. A&C Black. p. 564. ISBN   978-1-60901-535-0.
  9. Adanur, Sabit (1995-10-06). Wellington Sears Handbook of Industrial Textiles. CRC Press. p. 162. ISBN   978-1-56676-340-0.
  10. 1 2 3 Collier 1970 , p. 155
  11. Collier 1970 , p. 157
  12. Collier 1970 , p. 159
  13. Collier 1970 , p. 160
  14. Collier 1970 , p. 161
  15. Schindler, W. D.; Hauser, P. J. (2004-08-10). Chemical Finishing of Textiles. Elsevier. pp. 1, 2. ISBN   978-1-84569-037-3.
  16. 1 2 Joseph, Marjory L. (1992). Joseph's introductory textile science. Internet Archive. Fort Worth : Harcourt Brace Jovanovich College Publishers. pp. 337, 338, 339, 340. ISBN   978-0-03-050723-6.
  17. Elsasser, Virginia Hencken (2005). Textiles : concepts and principles. Internet Archive. New York, NY : Fairchild Publications. p. 197. ISBN   978-1-56367-300-9.
  18. Joseph, Marjory L. (1992). Joseph's introductory textile science. Internet Archive. Fort Worth : Harcourt Brace Jovanovich College Publishers. p. 392. ISBN   978-0-03-050723-6.
  19. Purushothama, B. (2019-01-31). Handbook of Value Addition Processes for Fabrics. Woodhead Publishing India PVT. Limited. p. 243. ISBN   978-93-85059-92-6.
  20. "Product Guides - Glossary". 2012-05-10. Archived from the original on 2012-05-10. Retrieved 2020-10-27.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  21. Collier 1970 , p. 172
  22. Collier 1970 , p. 175
  23. Roy Choudhury, Asim Kumar (2017). Principles of textile finishing. Elsevier Science. p. 55. ISBN   9780081006610.
  24. Iyigundogdu, Zeynep Ustaoglu; Demir, Okan; Asutay, Ayla Burcin; Sahin, Fikrettin (2017). "Developing Novel Antimicrobial and Antiviral Textile Products". Applied Biochemistry and Biotechnology. 181 (3): 1155–1166. doi:10.1007/s12010-016-2275-5. PMC   7091037 . PMID   27734286.
  25. Wu, Deyong; Long, Mingce (2011-12-28). "Realizing Visible-Light-Induced Self-Cleaning Property of Cotton through Coating N-TiO2 Film and Loading AgI Particles". ACS Applied Materials & Interfaces. 3 (12): 4770–4774. doi:10.1021/am201251d. ISSN   1944-8244. PMID   22066707.
  26. "Self-cleaning cotton nanoparticle coating invented". BBC News. 2012-03-08. Retrieved 2020-10-05.

Biography