denim

(Denim) is a thicker color-dyed warp-faced twill cotton fabric . The warp yarn is dark in color, generally indigo , and the weft yarn is light in color, generally light gray or cooked white yarn. Also known as indigo labor cloth. began in the western United States, and herdsmen got their name for making clothes. The warp yarn adopts the pulp dyeing combined one-step dyeing process . The special numbers are 80tex (7 British branch), 58tex (10 British branch), 36tex (16 British branch), etc.,

and the weft yarn special numbers are 96tex (6 British branch), 58tex (10 British branch) Branch), 48tex (12 British branch), etc., using 3/1 structure, and also using, plain or crepe texture denim, the gray fabric is shrink-proofed, the shrinkage rate is smaller than that of ordinary fabrics , the texture is compact, thick, bright color, woven The lines are clear. Suitable for men’s and women’s jeans, tops, vests, skirts, etc.Chinese name Foreign name Denim nickname Crack Birth place Western America

table of Contents

1. 1 background
2. 2 Evolution history
3. 3 kind
4. ▪ Slub
5. ▪ Ring yarn

1. ▪ Weft elasticity
2. ▪ chromatography
3. ▪ Special colors
4. 4 color
5. 5 specification

1. 6 Washing process
2. 7 common sense
3. 8 weight
4. 9 image

background

【Denim-Background】(French: Denim), also transliterated as denim , a cotton quality thick body thick gauze, designed to make jeans. fabric was originally only blue, originally used only as canvas , but now there are many different colors that can be used to match different clothing accessories . Denim English name fabric originates from Nîmes ( Nim City) in France , so the locally produced cloth is called de Nim , which is “from Nîmes”. ‘After entering the United StatesThe warp yarn adopts the pulp dyeing combined one-step dyeing process.

The special numbers are 80tex (7 British branch), 58tex (10 British branch), 36tex (16 British branch), etc., and the weft yarn special numbers are 96tex (6 British branch), 58tex (10 British branch) Branch), 48tex (12 British branch), etc., using 3/1 structure, and also using, plain or crepe texture, the gray fabric is shrink-proofed, the shrinkage rate is smaller than that of ordinary fabrics , the texture is compact, thick, bright color, woven The lines are clear. Suitable for men’s and women’s jeans, denim tops, denim vests, denim skirts, etc.In the 1980s, US denim production was 50% of global production, but in the last decade, China, India, Pakistan , Malaysia, Turkey and Mexico have established a large number of production plants, the United States and even The focus of the world’s production has shifted to countries with low labor costs in Asia. 

Production

In 2000, the production of denim in China was about 2424t, and the import of indigo dye was 759t, while in 2001, its output had risen to 2717t, and the imported indigo dye fell to 702t.In the market, although cotton is undoubtedly the most important, there are also a series of blended fabrics, such as cotton/polyester (50/50) blended fabrics, and cotton and other fibers such as Tencel, linen, and even jute, Wool yarn is woven together.

These products are different from the many products in the market, it gives consumers a high level of product design and high value-added clothing. The use of mercerized stretch and ring-spun yarn can also enhance the value of the product, and some companies have invested in these areas. Ring-spun yarns have higher strength, soft feel and the appearance of a slubby yarn on the surface of cotton denim.The output of ball denim exceeds 2 billion meters, and there are air spinning or ring spinning yarns. 

In the past, the United States mainly produced weft-stretch denim, while Europe mostly used warp – stretch or warp – weft bi-stretch denim; people have continuously developed denim with fashion changes to obtain novel appearance, feel and performance through dyeing and finishing.

Thickly organized cotton denim has been used as a fabric for pants and jackets, but in the 1990s, consumers put forward higher requirements for the softness, comfort and ease of care of fabrics, so denim organizers must Respond to these requests.Through various chemical treatments, as well as the use of effects such as flocking, embroidery and coatings, research to change the appearance of denim has continued. 

In addition, the products developed include indigo-dyed jacquard fabrics, woven or knitted fabrics of linen and cotton , laser beams on denim, dim gloss patterns, and more personalized products.

Evolution history

More than five hundred years ago, the Italian navigator Columbus discovered the New World. The sails used by sailing ships at that time were made of a very tough and practical rough cloth. 

This rough fabric was originally produced in NIMES, a small town in France, so it was named “Serge De Nimes” in French, and was later referred to as DENIM.And three hundred and sixty years later, Levi Strauss , a Jewish businessman in the United States, introduced a rough-textured canvas into the United States, thus creating a historic page for jeans and establishing a mythical kingdom of cowboy culture.

Denim Brands

Levi’s cowboy’s mythical kingdom began in San Francisco, the United States. The rough canvas originally used to make tents made the first LeviS jeans for the miners at that time, a tough and durable workwear , which was very suitable for the needs of workers. It was quickly welcomed, which triggered a series of evolutions. The jeans were primarily brown , but later changed to dark blue twill denim.

Denim is mainly made of cotton, and it has also developed a variety of raw material structures, including cotton, wool, silk, hemp natural fiber blended, and chemical fiber blended, as well as elastic yarn, tight twist yarn, fancy yarn and other raw materials. The higher the spandex content, the greater the elasticity. 

Yarn count has 7*7, 7*6, 7*8, 10*7 and other specifications. The structure is generally twill (2/1, 3/1, 1/3), broken twill, radial tightness is greater than Weft direction.The color of denim has developed from vulcanization and indigo to light blue, black, white, and color.There are many finishing processes for denim, which is an important part of developing denim series varieties. Among them are: enzymes, stone mills, sand blasting, cat whiskers, silicone oil, bleaching, color registration, snowflake washing.

Denim Kind

Since the late 1970s, after many major developments in China, denim has become an important international producer of denim. A large number of more advanced denim and denim apparel companies have basically been in line with international standards in terms of quality and variety, and have initially reversed the concept that Chinese denim products are “low-end” in the international market.

Although the development and production of denim products in China started late, but the starting level is relatively high, with air spinning , automatic winding, ball warp dyeing, and shuttleless looms (a large number of rapiers, followed by grippers, and air jets again) , Heavy-duty pre-shrinking finishing machine and other advanced equipment, thus creating good conditions for the development of denim varieties and improving the quality level. 

However, for a long time, some high-performance, fully-functional equipment such as electronic dobby, multi-color, uneven winding, rapid variety change and unmanned operation of rapier looms have not attracted enough attention and caused waste of functions. This situation needs to be resolved urgently in order to better serve the development of varieties, improve quality and labor productivity.

Slub

When the design uses different yarn numbers, different slub thickness (compared to the base yarn), slub yarn with slub length and pitch, single warp or single weft direction and bidirectional warp and weft are equipped with slub yarn, the same as

When the proper ratio and arrangement of the normal yarns of different sizes or different sizes can be produced, a variety of slub denims can be produced, and after washing the clothing, a variety of hazy or clear stripe style denims can be formed , Welcomed by the consumer demand group. Early slub denims were mostly made of ring-spun slub yarns.

Because they can spin slub yarns with shorter lengths, smaller pitches and relatively higher densities, it is easy to form a more dense embellishment on the fabric, and Mainly to the meridian bamboo. With the development of consumer demand in the market, especially the bidirectional slub denim products with weft elasticity, the domestic and foreign markets are very popular. 

For some varieties, as long as the structure is well designed , a single variety of ring-spun yarn can be used in the warp direction, and a slub yarn in an appropriate ratio in the weft direction can also achieve the effect of two-way slub denim.

Denim Ring Yarn

With the development and application of new technology equipment such as high-speed ring spinning, large package, fine winding, and no-knot yarn, the short spinning length of coarse yarn, low production efficiency, and many knots have been solved. 

The situation where denim is replaced by air-jet yarn is rapidly changing, and ring-spun yarn is likely to make a comeback. Because ring-spun denim is superior to air-jet yarns in some properties, such as feel, drape, tear strength, etc.,

but also because of the psychological return of people to nature, the pursuit of the original development of denim styles, the more important reason is the ring After the spindle denim clothing is washed and processed, the surface will show a hazy slub style, which is in line with the personalized needs of today’s denim clothing. 

The ring-bonded slub can produce shorter and denser slubs, which also promotes the development of ring-spun denim.

Denim Weft elasticity

The use of spandex elastic yarn has made denim varieties develop into a new field, which can make denim clothing close to the body and comfortable, and with a slub or different colors, so that denim products are more suitable for fashion and personalized consumer needs, so there are Great potential for development. The elastic elongation is generally between 20% and 40%.

The size of the elastic elongation depends on the design of the fabric. The smaller the tightness in the warp and weft direction on the cloth machine, the greater the elasticity.

On the contrary, in the condition of fixed warp yarn tightness Next, the greater the tightness of the elastic yarn in the weft direction, the smaller the elasticity, and the tightness in the weft direction reaches a certain level, and even a loss of elasticity may occur. 

In addition, the outstanding problem of stretch denim finished fabrics is that the weft shrinkage rate is generally more than 10%, and even as high as more than 20%. Unstable fabric width brings great difficulties to garment production.

The first solution is to avoid excessive elastic elongation during product design, generally 20% to 30%, that is, to maintain a certain degree of tightness in the warp and weft direction, and During pre-shrinking, a proper method of increasing tension is adopted to make the fabric width shrink more, so as to obtain a lower residual shrinkage rate of the finished cloth weft.

Another solution is to heat-set the denim after pre-shrinking. In this way, a more uniform and uniform fabric width and a more stable and lower weft shrinkage rate can be obtained to meet the requirements of garment processing and production.

Denim chromatography

In order to increase the color and shade of indigo denim varieties. For example, indigo over-dye sulfide black, indigo over-dye sulfide grass green, sulfide black green, sulfide blue, etc., to meet the market’s individual needs. 

At the same time, each denim production plant has its own patented new denim varieties to improve the competitiveness of the market. In this respect, it is necessary to control the concentration of the mother liquor as much as possible to prevent excessive overflow of the dye liquor and cause waste of the dye and increase pollution to the environment.

Special colors

Because garments made of super indigo dyed or extra-deep indigo dyed denim are washed and processed, they can obtain the special effect of rich and bright color, and are widely welcomed by consumers. 

“Ultra Indigo” dyed denim has two major characteristics: the dyeing depth is particularly deep and the color fastness to scrubbing is particularly good. The former refers to the amount of indigo dye dyed on a unit weight of yarn (generally expressed as% of the dry weight of the yarn, referred to as dyeing depth %).

For example, the dyeing depth of conventional denim warp yarn is 1% to 3% The “super indigo” dyeing depth needs to reach more than 4% before it can be called super indigo or extra deep indigo. 

The latter refers to “super indigo” dyed denim clothing that needs to be subjected to repeated grinding and washing for more than 3 hours, and its color can still reach or exceed the color depth of conventional dyed denim without unwashing, and its color is better than conventional dyed denim Thick and bright.

The color fastness to washing of indigo dyed denim depends on the degree of dye penetration of the yarn, not the dye itself (wet fastness to indigo is only level 1), that is, through core The better the degree, the better the color fastness to rubbing.

In the past, the so-called “fast washing process of indigo dyeing” was actually in the dyeing process of yarn, and the penetration of indigo dye to the fiber was deliberately very light, so that when the denim clothing was washed, the surface of the yarn was extremely thin.

After the layer of dye is removed, more white yarn cores are exposed, which quickly fades the color, so as to achieve the effect of fading immediately after a short time of washing. The “super indigo” dyeing process is contrary to this.

It requires a particularly good degree of dye penetration to enable denim clothing to be washed and processed to obtain a deep and bright color.Because the dyeing depth of “super indigo” dyed denim products is more than 60% higher than that of conventional traditional denim dyeing, the indigo concentration of the dyeing solution will also increase exponentially, even reaching 3-4g/L. Strong color. 

In this way, the viscosity of the dyeing liquid increases and the fluidity becomes worse, which affects the penetration ability of the dye leucobody, which reduces the color fastness of denim washing and fails to meet the final depth requirements of clothing production. 

So some companies have adopted the design of increasing the depth of dyeing again, so that the concentration of indigo in the dye liquor is increased again, and the penetration performance becomes worse.

In this way, a vicious circle is formed, and the requirement of “super indigo” is still not met. The higher the concentration of indigo in the dye liquor, the heavier the red light of the dye, and the darker the color, there is no “super indigo” effect. 

This problem is solved by increasing the number of dyeing lanes. For example, increasing the number of dyeing lanes to 8 or even 10 lanes not only increases the investment cost and consumption of dyeing and chemical materials, but also increases the difficulty of operation and increases environmental pollution. 

The better way to solve this contradiction is to appropriately reduce the proportion of safety powder or caustic soda, especially the control of the amount of caustic soda, so that the pH value of the dyeing solution is stable between 11-12, the highest dyeing rate and stable color, while Appropriately reduce the dyeing tension of the warp yarns, so as to obtain a better “super indigo” dyeing effect.

Denim Colours

There are mainly bromine indigo (commonly known as emerald blue in the market) denim and vulcanized black denim, as well as coffee, emerald, gray, khaki, sulfide blue denim mixed with sulfur dyes , and a small amount of nafto dye or reactive dye Dyeing scarlet, pink, princess denim, etc.,

although the production volume is not large, but the market demand is more urgent and often cannot meet the demand. The main problem is that the color and shade are not stable enough, the importance of dyeing is also poor, and the garment production plant is not satisfied.

This is certainly related to the small production batch and too many colors. However, it is more difficult to produce a variety of colors by the dyeing and pulping machine. Large, high cost, and difficult to treat sewage, etc., also have a certain impact. 

The first solution is to reduce the number of Colours in the design as much as possible, use two colours as much as possible, and no more than three colours , or use other more stable dyes to replace, in order to adapt to the production characteristics of the dyeing pulp online station, obtain more Stable dyeing effect; second, a more thorough solution is to use dyeing factory yarn with large capacity dyeing , and the production process route of slitting and warping is ideal for producing dyed denim.

Denim Specification

The texture of traditional and colored denim is made of pure cotton indigo dyed warp yarns and natural weft yarns, which are woven with three-to-one right twill weaves.

They are generally divided into three types: light, medium and heavy. Weighing 200-340 grams/square meter (6-10 ounces/square yard), medium-sized cloth weighs 340-450 grams/square meter (10-13 ounces/square yard), heavy-duty cloth weighs more than 450 grams, yarn count is thick; heavy 7×6 , Medium size 10×10, light type 12×12 (British branch) or more. The width of the cloth is mostly between 114-152 cm.

In addition to the above traditional products, there are also color denim;⒈Color denim with different raw material structure;(1) A small proportion of spandex yarn (approximately 3-4% of the yarn weight) is used as the core-covered elastic warp or weft of the warp yarn, and the elastic denim is woven.

⑵ Using low proportion of polyester and cotton blended as warp yarn, the snowflake denim with white effect after dyeing.(3) High-grade denim made of cotton, linen and cotton wool blended yarn .⑷Denim woven with medium and long fibers (T/R).⒉Color denim made by different processing techniques⑴

Bark crepe denim made of high twist weft yarn⑵When dyeing warp yarns, first use vulcanization or Haichanglan and other dyes to dye the indigo overdye denim⑶Color stripe denim with color warp embedded in the indigo warp⑷ Hang white or print on indigo denim.

Denim Washing process

1. General washing means ordinary washing. Just change the washing we are familiar with on a daily basis to be mechanized.

Its water temperature is about 60°-90°C, add a certain amount of detergent, after about 15 minutes of ordinary washing, add water and softener to make the fabric Softer, more comfortable, more natural and cleaner visually. 

Generally, according to the length of washing time and the amount of chemicals used, general washing can be divided into light general washing, general washing and heavy general washing. 

Usually light general washing is about 5 minutes, general washing is about 15 minutes, heavy general washing is about 30 minutes (this time is not accurate), these three washing methods have no obvious boundaries.2. Stone washing / Stone grinding (STONE WASH) Stone washing is to add a certain size of pumice stone in the washing water to polish the pumice stone and clothes.

The water level in the grinding tank is carried out at a low water level that is completely saturated with clothing, so that the pumice stone can be well Contact with clothing. It can be washed or rinsed before stone grinding, or rinsed after stone grinding. 

According to the different requirements of customers, yellow stone, white stone, AAA stone, artificial stone, rubber ball, etc. can be used for washing to achieve different washing effects. The cloth surface is gray and old after washing, and the clothing is slightly to severely damaged .

3. Enzyme wash (ENZYME WASH) Enzyme is a kind of cellulase, which can degrade the fiber structure under a certain PH value and temperature, so that the fabric can be faded gently, and the hair can be faded (produce “peach skin”) Effect), and get a lasting soft effect. Stones can be used together or instead of stones. If used together with stones, it is usually called enzyme stone wash (ENZYME STONE WASH). 

The former is to spray each potassium permanganate solution on the garment according to the design requirements with a spray gun, and a chemical reaction occurs to discolor the fabric. 

Use the density and spray volume to control the degree of fading. Sandblasting is also called beating sand. Use special equipment (the image is a large electric toothbrush, just a roller type) to polish the fabric. There is usually an inflatable model to match. 

From the point of view of effect, the former fades evenly, the surface layer and the inner layer are faded, and a strong fade effect can be achieved. The latter is only discolored on the surface layer, and physical damage to the fiber can be seen.

4. Sand washing (SAND WASH) Sand washing uses some alkaline and oxidizing additives to make the clothes have a certain fading effect and old feeling after washing.

If it is equipped with stone grinding, a soft and frosted layer will be produced on the surface of the cloth after washing . The fluff, plus some softener, can make the fabric soft and soft after washing, thereby improving the wearing comfort.

5. Chemical washing (CHEMICAL WASH) Chemical washing mainly uses strong alkaline additives (NaOH, NaSiO3, etc.) to achieve the purpose of fading.

After washing, the clothes have a more obvious sense of oldness. Adding a softener will make the clothes soft, Plump effect. If stone is added to chemical washing, it is called CHEMICAL STONE WASH, which can enhance the effect of fading and abrasion, so that the clothes have a strong sense of wear.

Fossil washing combines chemical washing and stone washing in one. After washing, it can achieve a distressed and fluffy effect.

6. Rinse (BLEACH WASH) In order to make the clothes have a white or bright appearance and soft feel, the clothes need to be rinsed, that is, after being washed with ordinary water, warmed to 60°C, according to the depth of the bleaching color, add an appropriate amount Bleaching agent, make the color consistent with the board within 7-10 minutes. 

During operation, the direction of the bleaching agent should be consistent with the direction of the rotating cylinder, so as to avoid the bleaching agent falling directly on the clothes due to the fact that it cannot be diluted with water as soon as possible, causing local bleaching. Before bleaching, the water level in the tank should be slightly higher so that the rinsing water is diluted. 

After the clothes are bleached, the residual bleach in the water is neutralized with large (small) soda (Na2CO3, NaHCO3) to stop the bleaching completely. 

After cleaning the water, add detergent, fluorescent whitening agent, hydrogen peroxide, etc. to the final washing at 50°C water temperature, neutralize the PH value, fluorescent whitening, etc., and then just soften it. 

Rinsing can be divided into oxygen bleaching and chlorine bleaching. Oxygen bleaching utilizes the oxidation of hydrogen peroxide at a certain pH value and temperature to destroy the dye structure, so as to achieve the purpose of fading and whitening.

Generally, the surface of the bleaching cloth will be slightly reddish. Chlorine bleaching utilizes the oxidation of sodium hypochlorite to destroy the dye structure, thereby achieving the purpose of fading. The bleaching effect of chlorine bleach is rough, and it is mostly used for rinsing of indigo denim. 

After bleaching the board, the residual chlorine in the water and clothing should be neutralized with sea waves to stop bleaching, and then stone grinding after bleaching

is called BLEACH STONE7, destroy wash (DESTROY WASH) clothing after grinding and pumice processing aid, a certain degree of damage to certain parts (bone bits, lead angle, etc.), washed clothes will be worn more obvious effect.

8. Snowflake washing Soak the dried pumice stone with potassium permanganate solution, and then directly grind the clothes in the special rotating cylinder.

Grind the clothes on the clothes by the pumice stone, so that the potassium permanganate will oxidize the friction points, so that the cloth surface is not The rules fade, forming white dots that resemble snowflakes.

The general process of snowflake washing is as follows: Pumice stone soaked potassium permanganate-dry grinding of pumice stone and clothing-snow flake effect on the plate-take out the laundry and wash off the stone dust on the clothing with clean water in the washing tank-oxalic acid neutralization -Washing-Apply softener.

9. MOUSTACHE EFFECT is WHISKER, but WHISKER is more professional. Cat whisker is a kind of hand sand (hand rub, hand brush), it is just grinded into the shape of cat whisker.

10. Sandblasting, also called sandblasting (SPRAY STONE WASH / SAND BLAST), is to use special equipment (image is a large electric toothbrush , but only a roller type) to polish on the fabric, usually with an inflatable model .

11. The essential difference between MONKEY WASH and sand blasting is that the former is chemical and the latter is physical. Spraying the horse is to spray the potassium permanganate solution on the clothing according to the design requirements with a spray gun, and a chemical reaction occurs to discolor the fabric. 

Use the concentration of potassium permanganate and spray volume to control the degree of discoloration. 

From the point of view of effect, the color of the spray horse is evenly faded, the surface layer and the inner layer are faded, and a strong fade effect can be achieved. The sandblasting only faded on the surface, and physical damage to the fibers could be seen.

12. Pigment wash (pigment wash / pigment dyed wash) is also called “single-sided coating / paint dyeing”, which means that this washing method is designed for clothing dyed with paint, and its role is to consolidate the original The bright color and softness of the touch.

Denim common sense

As a super fan of jeans, I certainly know the brand, style, model, and version of jeans. A good jeans cannot be separated from good workmanship, but the most basic part is denim fabric. The more the fabric goes through the fit, the more it has a charm, and the longer it wears, the more it feels like a denim. 

And if the fabric is poor, you can’t wear it after washing it a few times, and it’s about the same as a mop.

1. First look at the characteristics of traditional denim fabricPure cotton coarse yarn twill , easy to absorb moisture, moisture permeability, sweat absorption, good breathability.

very comfortable to wear and thick texture, clear texture after proper treatment, can be wrinkle-proof shrink-proof deformation-proof Indigo is a coordinated color A variety of color tops match, suitable for all seasons. Indigo is a non-firm color.

The more washed, the lighter, the lighter, the more beautiful.

2. Then look at the color denim fabric with different raw materials.A small proportion of spandex yarn (approximately 3-4% of the weight of the yarn) is used as the core- covered elastic warp or weft of the warp .

The stretch denim is woven with a low proportion of polyester and cotton as warp. The dyed snowflake produces a white effect.

Denim fabric made of cotton and linen, high-grade denim fabric woven with cotton-wool blended yarn, denim fabric woven with medium and long fibers (T/R)

3. Look at the color denim fabric woven by different processing techniques The bark crepe denim made of high-twist weft yarns is dyed with vulcanized or Haichanglan dyes before being

dyed with indigo overdye denim. The color of the colored warp yarn is embedded in the indigo warp yarn. Denim is hung on white or printed on indigo denim.

4. Denim is made of pure cotton indigo dyed warp yarn and natural weft yarn. It is made by interweaving the right twill of the upper and lower three. It can be generally divided into light, medium and Three types of heavy. 

The width of the cloth is mostly between 114-152 cm.Cloth weight (grams/square meter) Yarn count (British count) Lightweight 200-340 grams/square meter (6-10 ounces/square yard) 12×12 above Medium size 340-450 grams/square meter (10-13 ounces/square yard) 10×10 Heavy-duty over 450 grams 7×6

Denim Weight

[Weight of denim]The unit of cloth weight is (g/m², ie g/㎡) The unit of yarn count is (British branch, ie S)The weight of heavy cloth is above 450g/㎡, weaving is 7×6SThe weight of medium-sized

cloth is between 340-450g/㎡ (10-13 ounces/square yard), and the weave is 10×10 SThe weight of the light cloth is 200-340g/㎡ (6-10oz/flat