How To Choose Good Quality Denim Fabric (above) ?
2021-05-17

Choose Good Quality Denim Fabrics


You need to understand how denim is made first.


Denim is the soul of jeans, and you want to know how to choose good quality jeans? Why do jeans lose their color? You need to understand how denim is made.


The Raw Material


The quality of the cotton determines the quality of your jeans. Cotton is the most common textile fiber and the essential raw material needed to make denim. The first requirement for making good quality jeans is good quality yarn, which depends on cotton quality.


Assuming that the denim is made from 100% cotton, the first step is to source the cotton.


In developed countries, cotton is harvested using a selector. In developing regions, such as Africa and South East Asia, harvesting is usually carried out by hand.


There is a wide variation in cotton quality from different origins, with different varieties having other characteristics such as fiber length, fineness, maturity, strength, color, and feel.


Cotton Fabric


Generally speaking, the cotton used in what is considered good quality denim is mainly from American, Egyptian, and Zimbabwean cotton and the Xinjiang cotton mentioned in our last two issues.


Regardless of where the cotton comes from, it must be picked, cleaned, and de-polluted carded and sorted for the next step.

Cotton is, of course, not the only factor that determines the quality of denim.


Spinning


Spinning also affects the style of the fabric and the way the color falls.


Spinning, the spinning of shorter cotton fibers into long yarns (which are twisted to form a continuous, infinitely stretching thread), makes it easier to weave into fabric.


Before the industrial revolution, spinning was done by hand.


Today, the standard spinning methods are ring spinning and airflow spinning. Generally speaking, ring-spun yarns have less hairiness, higher strength, and better quality. Airflow spinning has a shorter process, more raw material staple, hairier threads, cannot be very high in count and twist, and is less expensive.


Airflow spinning is quicker to produce, the yarn is more uniform, and cheaper jeans are often made with airflow spun yarn. Strings made from ring spinning are softer and uneven, have a more bamboo feel, and are less absorbent of indigo dye, so the color drop contrasts.


Denim Spinning



If you want to make stretch denim, add elastane to the spinning process, which works best with ring spinning.


The elastic fibers will be spun directly into the core, while the cotton fibers will be wrapped around the elastic fibers. This maintains the soft touch and drops color properties of cotton while adding elasticity.


Indigo Dyeing


The spun yarn will eventually be woven into denim, but denim is a color woven fabric dyed before woven, so the thread is dyed first.


Traditional denim is only indigo dyed for the warp yarn, while the weft yarn is used in its color. Fabric color depends on the color of the warp yarn, so the front of the denim is blue and white on the reverse.


The three elements of indigo dyeing: indigo dye + caustic soda + safety powder. Under alkaline conditions (caustic soda), the indigo is reduced to a water-soluble crypto phone with an affinity for the fibers, which is then oxidized to an insoluble indigo color and fixed in the yarn to complete the indigo dyeing.


There are various ways of dyeing yarns, the most common being rope dyeing and piece dyeing.


Rope dyeing is currently the most common method of indigo dyeing used in the industry. The warp yarn cylinder is warped at the ball to form a varying number of bundles of yarn, which are dipped into the indigo dye bath like a rope, and immediately take on a yellow-green color when the thread is removed from the tub. The yarns change to blue in the air through redox, and after the dyeing is complete, the whole process is finished by re-winding and sizing.


A certain number of warp beams are introduced into each dye bath, and after repeated dipping, rolling, and oxidation, various dyestuffs such as indigo and sulfur black are dyed. After pre-drying and sizing, the warp yarns are uniformly colored and ready for direct use in weaving.


Blue Denim Fabric


Rope dyeing is more suitable for creating dark indigo shades due to the relatively longer oxidation time in contact with air. In piece dyeing, the yarns are dyed and sized in pieces after the warp beam has been warped, which is a relatively small and short process, making it more suitable for small batches and frequent varieties, as well as for high count yarns.


Rope dyeing has its advantages and disadvantages compared to other dyeing processes, such as piece dyeing, and it depends mainly on the adaptability of the fabric and the style requirements.


However, for the original cattle enthusiast, due to the dyeing characteristics of rope dyeing, the indigo dye cannot fully penetrate the yarn's core, so it is more likely to produce a high contrast color drop effect.


More about Denim Fabric

Please look forward to the following...