Types And Identification Methods Of Quality Denim And Fabrics

1. Authentic jeans are made of indigo dye, colorless or striped.

After the stone mill, it was bright and bright, with a slight red color.

2. After the stone mill, the fabric feels soft, and the cloth is plump and velvet.

The ruffled side of the sewing is whiten, and there is no trace of abrasion on the flat surface, and the color is uniform.

3, sewing double seam, waist chain sewing, and use pure polyester 215/3 strand, sewing firmly, not easy to seam.

4. Metal hooks, buttons and cards are in the gaps. The coating has no wear, and the reverse side pad interlining blocks prevent breakage.

Ring yarn denim

With the development and application of new technology such as ring spinning, high speed, large volume, fine thread connection and no knot yarn, the shortcomings of short spinning yarn, low production efficiency and many knot have been solved.

The situation of denim yarn being replaced by pneumatic yarn is changing rapidly, and the ring yarn is coming back.

Because ring yarn denim is superior to some properties of airflow yarn, such as handle, drape, tear strength, and so on, at the same time, due to psychological return to nature, the influence of cowboy style on original development is more important. The more important reason is that after ring washing, the surface of the cowboy garment will show a hazy bamboo style, which is in line with the personalized demand of today's jeans.

In addition, the slub yarn denim is very popular in the market at present, while the ring slub can produce shorter and denser bamboo knots, and also promote the development trend of ring denim.

Slub denim

When designing slub yarns with different yarns, different slub roughs (ratio to base yarns), slub yarns of bamboo length and pitch, single slant or single weft and slub yarns in both sides of the warp and weft, and suitable proportioning and arrangement with normal yarns of the same number or different numbers, a variety of slub denim can be produced. After washing, the clothes can be made into different kinds of hazy or clearer striped style jeans, which are welcomed by consumers' individualized demand groups.

Early bamboo slub denim almost all used ring slub yarn, because it can be spun shorter length, smaller pitch, relatively large density of slub yarn, easy to form cloth denser effect of ornament, and to the main bamboo.

With the development of market consumption demand, the popular two-way weft denim fabric, especially the two-way slub denim fabric with zonal elasticity, is popular at home and abroad.

Some species can achieve the same effect of longitude and latitude two-way bamboo denim as long as the structure is well designed, the single ring ring yarn can be used in the warp direction, and the slub yarns with suitable proportions in the weft direction.

Weft elastic denim

The adoption of spandex elastic yarn has made the denim variety develop into a new field. It can make the jeans suit both close and comfortable, and with slub or different color and color, so that the cowboy products will be more suitable for the fashionable and personalized consumption demand, so there is great potential for development.

At present, elastic denim is mostly zonal elastic, and the elastic extension is generally 20% to 40%. The size of the elastic extension depends on the fabric design. The smaller the warp and weft tightness of the fabric is, the greater the elasticity. Conversely, when the warp structure is tight and fixed, the greater the tightness of the weft elastic yarn, the smaller the elasticity and the tightness of the weft.

In addition, the prominent problem of elastic denim finished fabric is the excessive shrinkage of the weft, generally over 10%, and even more than 20%.

The instability of cloth volume brings great difficulties to garment production. One solution is to not extend the elasticity in product design. Generally, it takes 20% to 30%, that is, to maintain a certain warp and weft tightness, and to adopt a proper method of increasing tension in pre shrinkage finishing so as to make the cloth bigger shrinkage, thereby obtaining a lower residual shrinkage of finished fabric. Another solution is that the elastic cowboy is treated by heat treatment after preconditioning, so that uniform uniform width and stable and low weft shrinkage rate can be obtained, so as to meet the requirements of garment processing and production.

Special color denim

The garment made of super indigo dye or deep indigo dyed denim can obtain a special effect of bright and bright color after being washed and processed, and it is widely welcomed by consumers.

"Super indigo" dyed denim has two main characteristics: deep dyeing depth and excellent color fastness to abrasion.

The former refers to the amount of indigo dye dyed on the yarn per unit weight (generally expressed as% of the dry weight of the dyed yarn, or for dyeing depth%). For example, the depth of the conventional denim warp yarn indigo dyeing is 1% to 3%, while the "super indigo" dyeing depth needs to reach more than 4%, which can be called super indigo blue or deep indigo blue.

The latter refers to the "super indigo" dyed denim garment which needs to be subjected to repeated washing for more than 3 hours, and its color can still reach or exceed the color depth of the conventional dyed denim, which is much brighter and brighter than the conventional dyed denim.

The color fastness of indigo dyed denim is determined by the degree of penetration of dyestuff to yarn, rather than the color fastness of dyestuff itself (Indigo wet grinding fastness is only 1 grade), that is, the penetration degree is better and the color fastness of washing is better.

In the past, the so-called "Indigo Dyeing fast water washing process", in fact, was in the process of yarn dyeing, intending to make the indigo dye dye the core of the fiber very shallow, so that when the denim garment was scrubbed and processed, a thin layer of dyestuff on the surface of the yarn was rubbed away, exposing more white yarn cores, so that the color and lustre quickly fade, so as to achieve the effect of discoloring immediately after a short time.

However, the "super indigo" dyeing process is the opposite. It requires that the dye penetration is particularly good, so that the jeans can be obtained with deep and bright colors after being washed and processed.

Because the dyeing depth of the "super indigo" dyed denim product is more than 60% higher than that of the conventional traditional denim dyeing, the indigo concentration of the dyestuff will increase exponentially, even reaching 3 ~ 4G / L, so that it is possible to get a deeper color.

In this way, the viscosity of the dyestuff increases, and the fluidity becomes worse, which affects the permeability of the dye leucosomes and reduces the color fastness of the denim.

As a result, some enterprises adopted the design of increasing the dyeing depth again, so that the indigo concentration of dye solution increased again, and the permeability performance became worse.

The higher the indigo concentration in the dye solution, the heavier the red light of the dyestuff and the darker the color, the less the effect of "super indigo".

Therefore, many manufacturers have been or are preparing to rebuild the dyed pulp equipment, and solve this problem by increasing the number of dye channels.

For example, increasing the number of dye channels to 8 or even 10 channels not only increases investment cost and consumption of dyes and chemicals, but also increases the difficulty of operation and increases environmental pollution.

A better way to solve this contradiction is to properly reduce the proportion of the powder or caustic soda, especially the control of the amount of caustic soda, so that the pH value of the dye solution is stable at 11~12, the dyeing rate is the highest and the color is stable, and at the same time, the dyeing tension of the warp yarn is properly reduced, resulting in a better "super indigo" dyeing effect.

Color DENIM DENIM based on indigo

In order to increase the color and color change of indigo blue jeans, all kinds of denim varieties are very popular at present.

For example, indigo dyeing, sulphur black, indigo dyeing, sulphur grass green, sulphur black green, sulphur blue and so on, so as to meet the needs of personalized market.

At the same time, denim production plants have their own patent features of new cowboy varieties to enhance the competitiveness of the market.

In this regard, it is necessary to pay attention to controlling the concentration of mother liquor as much as possible and preventing excessive overflow of dye solution, resulting in the waste of dyes and the environmental pollution.

Colour (DENIM) denim

The main products are bromine indigo (market known as turquoise blue) denim and sulphur black denim, as well as dyed with sulphur dyed coffee, green, gray, khaki, vulcanized blue denim, and a small amount of red, peach and royal jean cloth dyed with NaF dye or reactive dyestuff. Although the production volume is not large, the market demand is more urgent, and often can not meet the need.

The main problem is that the color and luster are not stable enough, the dyeing importance is not good, and the garment factories are not satisfied. This is not related to the small batch production and the excessive color. However, it is difficult to produce the coloured varieties from the combined dyeing machine.

One way to solve the problem is to reduce the number of color matching as far as possible, as far as possible to use two colors, not more than three matching colors, or to replace the other stable dyes to suit the production characteristics of the dyed pulp online, and to achieve a more stable dyeing effect. Two, a more thorough solution is to use the dyed weaving factory's large capacity dyeing of yarn, and the production line of the bar warping is ideal for producing colored denim.