Step 1: Silk Reeling
Silk is extracted from the cocoon and becomes the raw material for weaving silk. One cocoon can extract about 1000 meters of cocoon silk, and several cocoon silk is combined into raw silk. The process of extracting cocoons from silk is generally called silk reeling. The original silk reeling method was to immerse the cocoon in a hot pot soup, draw the silk by hand and wind it on the silk basket. Pots and baskets are primitive silk reeling utensils. The process of extracting cocoons from silk is generally called silk reeling.
Step 2: Weaving
After processing, raw silk is divided into warp and weft and interwoven with each other according to a certain organization law to form a silk fabric, which is the weaving process. The production process of all kinds of silk fabrics is different, which can be divided into raw weaving and cooked weaving.
Raw weaving is to make warp and weft silk into fabric without refining and dyeing, which is called blank silk, and then refine and dye the blank silk into finished products. This production mode has low cost and short process. It is the main mode used in silk weaving production at present.
Mature weaving means that the warp and weft silk is dyed before weaving, and the finished blank silk does not need to be refined and dyed. This method is mostly used in the production of high-grade silk fabrics, such as brocade and taffeta.
Before weaving, preparations need to be made, such as impregnation to soften sericin, yarn merging and twisting that can improve product performance, warping and weft winding, etc. At the same time, due to the strong moisture absorption of silk, moisture-proof work should be done well. At present, the automatic looms used in silk weaving production mainly include water jet looms for producing synthetic fiber filament fabrics and rapier looms for producing multi-color weft jacquard fabrics.
Step 3: Dyeing And Finishing
The printing process plays an important role in the production of silk. Because only by using dyeing and finishing technology can we perfectly reproduce our favorite colors and patterns on the blank, to make the fabric more artistic. The process mainly includes four processes: refining, dyeing, printing, and finishing of raw silk and fabric.
( 1) Refined silk is composed of two monofilaments, the main body is silk prion, and the outer layer is wrapped with sericin. Most pigments, oils, waxes, and inorganic salts exist in sericin. These impurities have a great impact on the printing and dyeing effect, so they must be removed before dying. In long-term practice, people have mastered the characteristics that sericin is easy to dissolve in hot water under the action of chemical agents or enzymes. Taking advantage of the weakness of sericin, green silk or raw silk is heated in a mixed solution containing soap (or synthetic detergent) and soda (sodium carbonate), and sericin is hydrolyzed after heating. After such refining, sericin is removed to preserve silk prion, and impurities such as pigment, grease, and wax are removed, to obtain white silk products. Raw silk after degumming is called cooked silk. The degumming degree of raw silk shall be determined according to the production requirements.
After refining, the white green silk will enter the dyeing stage. Dyeing is the process of making dyes react with silkworm and green silk to dye green silk with various colors. Because silk belongs to protein fiber and is not alkali resistant, dyeing should be carried out in acidic or near neutral dyeing solution. At present, the main dyes used for silk fabrics are acid dyes, reactive dyes, direct dyes, and vat dyes. The color dyed with acid dyes is bright. After dyeing, it is treated with a cationic fixing agent to improve the washing fastness of the product. Reactive dyes have good washing fastness on silk. The dyeing methods of fabrics vary with the variety of fabrics. For example, crepe and yarn fabrics are dyed with rope or overflow jet dyeing, while spinning, silk, and satin fabrics are dyed with flat hanging or roll dyeing.
After all, one color is monotonous. In addition to dyeing, people also use printing technology to make silk colorful. Printing refers to the process of printing dyes on fabrics according to the designed designs and colors. The commonly used printing processes include direct printing, pull-out printing, and anti dyeing.
Direct printing refers to that the color paste is directly printed on silk fabrics through a screen printing plate. It is one of the basic printing methods. It can be printed with a variety of dyes.
Discharge printing, also known as engraving plate printing, is a discharge process using an engraving agent. Before printing and dyeing, the silk fabric is dyed with acid dyes and reactive dyes with azo structure, and then the engraving (discharge) slurry made of engraving agent containing damaging pigment is printed on the colored silk according to the pattern needs. After steaming, the ground color of the printing slurry will appear white, which is called “engraving white”.
Anti dyeing printing is to print silk fabrics with “anti-white” pulp or “color anti” pulp according to patterns and then dye them after drying. As the pattern part has “anti-white” pulp or anti dye in “color” pulp, it will not be dyed, while the rest will be colored.
After scouring, dyeing and printing, silk fabrics can be finally finished. The finishing process mainly solves the problems of moisture, wrinkles and uneven door width left by the previous processes highlights the soft characteristics of silk fabric, and increases its wearing function. It mainly adopts two methods: mechanical finishing and chemical finishing.
Mechanical finishing includes stretching weft finishing, steam ironing finishing, calendaring, and other methods; Chemical finishing is mainly to add chemical agents, such as softener, antistatic agent, fireproof agent, sand lotion composed of soda ash and trisodium phosphate, to achieve the effect of anti-wrinkle, anti-shrinkage, softness, and thickness. The treated fabrics are not only more suitable for wearing, but also broaden the consumption field of silk. When the printed silk is made, you can start making exquisite handicrafts and noble, gorgeous, and Oriental Dresses.