Define wet processing? | Its main divisions? | Process sequence of wet processing technology?

The process by which the textile materials are treated associated with water is called wet processing.

There are mainly 3 (Three) divisions of wet processing:-

’1)Pretreatment: The processes, which are done to make the textile materials, suitable for dyeing & printing, are called pre-treatment, Such as- DE sizing, Scouring, Bleaching etc.  

‘2) Dyeing & printing: The process by which the textile material are colored by different types of dye or pigments, related chemical related chemicals required water is called dyeing. Localized application of dyestuff or pigments on fabric according to the pre-determined design is called printing.

Ring spinning | Production flow chart of ring-spun cotton & Wool yarn?

Ring spinning is currently the most widely used yarn production method. Initially developed in America in the 1830s, its popularity has survived the emergence of much faster spinning technologies. In addition to the superior yarn quality, ring spinning is extremely versatile. It is capable of producing yarns with wide ranges of linear density and twist from a great variety of fibre materials. It is also used for doubling and twisting multifold and cabled yarns.

Fibre materials must be properly prepared before they can be used on the ring spinning machine. The preparation processes are dependent on the fibre material. Figures 3.1 and 3.2 illustrate the typical process routes for cotton and wool. The ultimate objectives of the many preparation processes are to produce a feed material for the final spinning process that is clean, even, homogeneous and free from fibre entanglement. The fibres must also be in the preferred orientation.

ISO, Classification, guideline and principles of ISO

ISO: 

ISO means ‘International Organization for Standardization’ This standard is a guideline for companies to make their organization capable of designing and producing goods/ products of higher quality acceptable to buyers. ISO standards are guidelines which compel the manufacturers to put into effect quality assurance system to work at all stages of manufacturers and service so that only quality goods and services are produced.

Classification, guideline and principles of ISO

a.     ISO 9001:  This standard is applicable for companies which are involved from designing to manufacturing of goods. This is the most comprehensive method.

b.     ISO 9002: This standard is applicable for companies which manufacture goods with buyers or other specification. This is applicable for export oriented garments industry.

Flow chart of Textile Manufacturing Process

Textile Manufacturing Process is done some regular processes. Each process of textile manufacturing is maintained with a per-defined sequences and the textile engineers usually follow the flow chart step by step to produce the better textile products according to buyers requirement. Usually, the whole textile manufacturing process is divided by four sector. These are-

• Spinning or Yarn Manufacturing 
• Fabric Manufacturing  (weaving or knitting)
• Dyeing, Printing & Finishing
• Garments Manufacturing or Clothing.

What is Textile? | Textile Raw Materials | General Process Sequence of Textile Manufacturing

What is Textile?

The word ''textile'' comes from the Latin word "textiles" and the French "texere", which means, in general and broad sense, woven fabrics. But the term textile is now applied to fibers,filaments and yarns, natural and manufactured and most products for which these are the principal raw materials. 

Textile Raw Material:

Textile raw materials are materials that can be converted into yarns and fabrics of any nature or character. Fiber is the raw material used in textile manufacturing. 

General Process Sequence of Textile Manufacturing:

CLASSIFICATION OF DYES

The English chemist William Perkins accidentally discovered the synthetic dye, mauve, in 1856, while he was trying to synthesize quinine in aniline. Before that time, all coloring materials were extracted from barks, roots, seeds, leaves and shellfish. Most synthetic dyestuffs are made from coal-tar derivatives. Their manufacture is a highly complicated technical operation, which is constantly changing. There is variation in the manner in which different fibers respond to dyestuffs and even the same fibers do not produce a full range of colors with a particular type of dye.

Basic or Cationic Dyes

This group was the first of the synthetic dyes to be taken out of coal-tar derivatives. As textile dyes, they have been largely replaced by later developments. However, they are still used in discharge printing, and for preparing leather, paper, wood, and straw. More recently they have been successfully used with some readymade fibers, especially the acrylics. The name means that these are dyes with an organic material, which is soluble in a simple acid. Basic dyes were originally used to color wool, silk, linen, hemp, etc., without the use of a mordant, or using agent. With a mordant like tannic acid they were used on cotton and rayon. Basic dyes give brilliant colors with exceptional fastness to acrylic fibers. They can be used on basic dyeable variants of nylon and polyester.

Explanation of different types of yarn

1. Single yarn

Single yarn is the simplest continuous strand of textile mtl composed of one of the following: 

(i) Continuous filament

Filament consists of very long, thin cylinder type fibre twisted together. Continuous filament yarns are the simplest in the structure but can be subjected to many modifying process for changing their texture, extensibility, bulk and other properties. In the manufacture of man made filaments, a solution is forced through very fine holes of spinneret, at which point the solution solidifies by coagulation, evaporation or cooling.

Continuous filament yarns in fabric form usually have excellent strength & uniformity. This yarn can be made much finer in linear density and diameter than staple yarns. In an untextured form, continuous filament yarns are not posses a combination of good covering power tactile qualities, comfort and a pleasing appearance. Silk is a natural filament, synthetic filament yarn is used to produce silk like effect.

Filament yarns are two types:-

a) Monofilament: Which containing one filament. e.g. Silk.

b) Multifilament: Which contains two or more filaments e.g. Nylon.

Types of Natural Dyes

Natural dyes can be sorted into three categories: natural dyes obtained from plants (Indigo), those obtained from animals (cochineal), and those obtained from minerals (ocher). Although some fabrics such as silk and wool can be colored simply by being dipped in the dye, others such as cotton require a mordant.

A mordant is an element, which aids the chemical reaction that takes place between the dye and the fiber so that the dye is absorbed. Containers used for dying must be non-reactive (enamel, stainless steel.) brass, copper or iron pots will do their own mordanting. Not all dyes need mordants, such as lichens and walnut hulls, they are called substantive dyes. If they do need a mordant, they are called adjective dyes.

DYES APPLIED TO FIBER CLASSES

Dyes for Cellulosic Fibers

Cellulosic fibers can be dyed readily using a number of dye classes. The less crystalline regenerated cellulosic (rayon) dye more readily than the more crystalline natural cellulosic fibers such as cotton. Cellulosic can be dyed or printed using direct, reactive, basic, vat, sulfur, or azoic dyes.

Cellulosic can also be colored using pigment-binder systems. Mordanting of direct and basic dyes on cellulosic improves overall fastness. Since the hydroxyl groups in cellulosic are less reactive than many functional groups found in protein fibers, reactive dyes such as the dichlorotriazine (Procion M) or dichloroquinoxaline (Levefix) dyes are often used on cellulosic fibers due to their higher reactivity.

Objectives of implementing TQM in textile factories?

To reduce work in process ( WIP) : 

Work in process means a material that has entered in production process but is not yet a finished product . It is necessary to reduce work process for maintain total quality management that’s why management get output of entered product as soon as possible within required time.

To maintain Critical Path Method ( CPM) : 

Critical path method means how any work or production is complete in accurate but short way by considering all the quality and other factors of production . Management must be walk out by using CPM.

To reduce wastage  : 

Wastage is a common factor for any production . In textile sector , costing of a product is calculated smaller then smallest  . How much you can reduce wastage , you will save more costing which is profitable for company . so that it is necessary to reduce wastage