What is elastic denim? With the adoption of spandex elastic yarn, the variety of denim has become a new category. It can make denim comfortable and close to the body, match with bamboo or different colors, and make denim products more accustomed to fashionable and personalized consumer demand. Therefore, it has great development potential. Now elastic denim is mostly weft elastic, and the elastic stretch is generally 20% - 40%. The elastic stretch depends on the fabric planning, On the contrary, with the fixed warp density, the greater the elastic tightness of the weft, the smaller the elasticity, and the weft tightness will reach a certain degree, and even lose elasticity. In addition, the prominent problem of the elastic denim now is that the weft shortening is too large, generally more than 10%, and even up to 20% of the instability of the fabric brings great difficulties to the production of clothing. The first solution is not to make the fabric stretch too large during product planning, Generally, it is 20% - 30%, that is, adhere to a certain degree of warp and weft weave tightness, add tension appropriately during pre-shrinking and packing, so that the fabric has a large shortening rate, thus reducing the remaining shortening rate of the fabric in the weft direction. Another solution is the elasticity of the pre-shrinking and packing, which can be heat set to make the fabric width uniform, and the weft shortening stable and low, which can meet the requirements of garment processing and production.

Problems in the washing process of elastic denim

There are many practical problems in the washing process. The following are some common problems:

Bath ratio: if the control is improper, that is, too large or too small, the target bath ratio cannot be reached, the concentration of various additives cannot meet the requirements, and cannot play its due role, the bath ratio is too small, the fabric will not turn over smoothly, and it is easy to wash flowers and wrinkle.

Time control: the length of the washing time directly affects the style and color of the fabric, so the time difference is half a minute or even a few seconds, and the results will be different. Surprisingly, we must control the time.

Temperature control: especially for elastic denim, the temperature must be controlled properly. Otherwise, the fabric will wrinkle and shrink at different latitudes after washing.

Rinsing: elastic denim should be put on the rope gradually at a slightly lower temperature. Oxygen bleaching should be carried out as much as possible. Chlorine bleaching should not be used. Chlorine bleaching will cause more serious damage to the spandex, especially the polyurethane structure, and make the fabric lose its elasticity. This is usually called "dead elasticity".

The color of the finished product is different: the effect after washing is different. Especially, if we mistake black and blue for the rated dark blue, there will be no problem with general washing, yeast washing or yeast bleaching. If they are washed or polished, there will be problems because black and blue are mostly dyed with black sulfide first, and then colored with ultra-deep indigo. If they are washed with ultra-dark blue, It will destroy the black sulfide first. It can't match the color at all. So when analyzing the color, we must pay attention not to neglect, otherwise the loss is incalculable.

The article originated from denim millhttp://www.in-it.com.cn