Dyeing and finishing Process (2)

Dyeing is a processing process through the physical or physical chemical combination of dyes (or pigments) and textile materials to make textile materials obtain bright, uniform and firm color.

The textile material is immersed in the dye aqueous solution at a certain temperature, the dye moves from the water to the fiber, at this time the dye concentration in the water gradually decreases, while the amount of dye on the textile material gradually increases, after a period of time, the amount of dye in the water and the amount of dye on the textile material no longer changes, the total amount of dye does not change, that is, the dyeing reaches a state of equilibrium.

The dye that is removed from the water is the dye that moves onto the fiber. Take out the fiber at any time, even if twisted, the dye still remains in the fiber, and can not simply make the dye completely out of the fiber, this dye combined in the fiber phenomenon, is called dyeing.

According to the different dyeing processing objects, dyeing methods can be mainly divided into clothing dyeing, fabric dyeing (main extension fabric dyeing, knitted fabric dyeing and nonwoven materials dyeing), yarn dyeing (can be divided into Hank dyeing, bobbin dyeing, warp yarn dyeing and continuous warp dyeing) and loose fiber dyeing four categories.

Among them, fabric dyeing is the most widely used, garment dyeing refers to the method of dyeing textile materials after processing into clothing, yarn dyeing is mostly used for color loom fabrics and knitted fabrics, and loose fiber dyeing is mainly used for color textile materials.

According to the different ways of contact between dye and fabric (dyeing process), it can be divided into two kinds of immersion dyeing and pad dyeing.

1. Print flowers

Printing is the process by which dye or paint forms a pattern on a fabric. Divided into flat screen printing, circular screen printing, transfer printing, digital printing and so on. Printing is local dyeing, requiring a certain color fastness. The dye used is basically the same as dyeing, mainly using direct printing process, can also use paint printing, paint printing process is simple, but printed large area pattern feel hard.

2.Finish

Textile finishing, also known as finishing. It is the processing process of improving the feel and appearance of the fabric (such as stiff finishing, soft finishing, calendering or raising, etc.), improving the quality of the fabric and giving the fabric new functions (such as anti-wrinkle, waterproof, anti-fouling, anti-corrosion, anti-mildew, anti-moth and anti-bacteria, etc.) through physical, chemical or both physical and chemical methods.

Generalized: All the processing processes that improve and improve the quality after weaving.

Narrow: fabric in practice bleaching, dyeing and printing process called textile finishing.

The purpose of finishing

(1) Make the fabric size and shape stable

Through finishing, the door width is stabilized and the shrinkage rate is reduced, so that the fabric door width is neat and uniform, and the fabric size and organization form meet the prescribed standards.

For example: stentering - using fiber, silk, wool and other fibers in wet or humid conditions have a certain plasticity, the fabric width gradually pull to the specified size and stability of drying the finishing process, also called tentering.

Heat setting - refers to the processing technology of synthetic fiber fabric under a certain tension for heat treatment to make its size and shape stable.

(2) Improve the appearance of clothing fabrics

Improve the whiteness and drape of the fabric, improve the surface gloss of the fabric and give the surface pattern effect of the fabric.

Calender finishing - by calender, for example, mechanical stress, the action of hot and humid, with the help of the fiber plasticity, make the fiber surface presents parallel arrangement, in order to improve the smooth surface roughness, light reflection rules, and then enhance the fabric colour and lustre.

Calender finishing - Calender finishing machine is composed of a hot hard roll and a soft roll. The surface of the hard roll is engraved with a Yang pattern, and the soft roll is engraved with a Yin pattern, which is consistent with each other. With the help of the plasticity of the fabric under hot and humid conditions, the effect of embossing pattern on the fabric is produced by the use of yin-yang roller rolling.

Grinding - After finishing the fabric can produce suede, feel improved, comfortable to wear, can be done on the drawing machine, fabric after repeated friction to produce suede.

4. Improve the feel of clothing fabric

To give a soft, plump or firm feel to the fabric.

For example: the soft finishing - is make up the fabric feel stiff and rough defects make the soft fabric processing procedure. Including mechanical soft finishing, chemical soft finishing and stiff finishing.

Mechanical soft finishing is mainly the use of mechanical methods to knead the fabric several times in the tension state to reduce the rigidity of the fabric and restore it to the appropriate softness.

The chemical method uses the action of softener to reduce the coefficient of friction between fibers to obtain a soft effect.

Stiff finishing - is to make the fabric smooth, stiff, thick, full feel, and improve strength and wear resistance, can also improve the hanging and appearance.

Stiffening finishing processing is generally combined with fixed width, adding softener to the slurry to improve the comprehensive feel, similarly, simple soft finishing, to add stiffening agent to enhance its body bones.

5. Give fabrics special properties

To give a fabric certain protective properties or improve the wear performance of the fabric.

For example: waterproofing, is for fabric coating, water and air can't through; Water repellent finishing is to change the hydrophilic surface of the fiber into hydrophobic, and the fabric is both breathable and not easily wetted by water.

Flame-retardant finish - the finished fabric has varying degrees of ability to prevent the spread of flame, and can quickly stop burning after leaving the fire source.