Non-Stretch Cotton Denim Fabric Manufacturers

During the spinning process, how can non-stretch cotton denim manufacturers ensure that the uniformity and strength of the yarn meet the requirements of non-stretch denim?

1. Raw material selection and processing
Select high-quality cotton fiber:
Choose cotton with good maturity and less impurities. Cotton fibers with poor maturity or cotton containing more dead cotton will cause uneven dyeing, affecting the color and fabric quality.
The physical properties of cotton fibers such as length, fineness, and uniformity have a direct impact on the strength of the yarn, so cotton raw materials with excellent physical properties should be selected.
Raw material pretreatment:
In the cleaning and combing process, reasonably select the process parameters for opening and removing impurities, fully open and comb the cotton fibers, and avoid excessive damage to the fibers.
Exclude short fibers and impurities as much as possible to reduce weak links and defects in the yarn.
2. Spinning process control
Optimize the design of the drafting device:
Improve the design of the drafting device of the spinning frame, improve the control ability of fiber movement, and reduce drafting waves and mechanical waves.
According to the characteristics of the product and the properties of the spinning raw materials, reasonable process parameters such as roller spacing, quantitative feeding roving, drafting type, etc. are determined through comparative spinning tests.
Strengthen equipment management:
Ensure that the spinning equipment is in good operating condition and reduce yarn quality problems caused by equipment failure.
Regularly check and maintain equipment to reduce the impact of mechanical fluctuations on yarn uniformity.
Control yarn strength:
Improve yarn strength through reasonable twisting process. Before twisting, it is necessary to ensure that the straight parallelism of the fibers and the arrangement and distribution of the fibers in the yarn are in good condition.
Control the twist size of the yarn so that it meets the strength requirements without affecting the softness and elasticity of the yarn.
III. Yarn quality detection and control
Yarn uniformity detection:
Use advanced detection equipment to detect the uniformity of the yarn to ensure stable yarn quality.
Analyze the causes of the detected uneven sections and take measures to improve them.
Yarn strength test:
Regularly test the yarn strength to ensure that it meets the production requirements of non-stretch denim.
For batches of yarns with insufficient strength, the reasons should be found out and corresponding measures should be taken to rectify them.
4. Other matters needing attention
Control of yarn hairiness:
The amount of yarn hairiness directly affects the quality of downstream products. Measures should be taken to reduce the generation of yarn hairiness, such as using tools such as collectors.
At the same time, the treatment of yarn hairiness should be strengthened in the sizing and warping processes to reduce its impact on the quality of the fabric.
Control of yarn knots and defects:
Denim generally adopts a 3/1 right twill structure, and the knots of the warp yarn are easily exposed on the fabric to form defects. Therefore, it is necessary to strengthen the control of yarn knots and defects.
The generation of knots should be minimized during the spinning process, and the knots generated should be properly handled.

How can suppliers of non-stretch cotton denim ensure that indigo or other dyes penetrate evenly into the yarn while maintaining good color fastness during the dyeing process?

1. Ensure uniform penetration of dyes
Pretreatment:
The yarn needs to be properly pretreated before dyeing, such as cleaning, degreasing, and impurity removal, to remove impurities and grease on the yarn surface, increase the hydrophilicity of the fiber surface, and facilitate the penetration of dyes.
Dyeing solution preparation:
Precisely prepare the dyeing solution to ensure that parameters such as dye concentration, pH value, and temperature meet the process requirements. For indigo dye, due to its large molecular volume and slow penetration rate, it is necessary to appropriately increase the dyeing temperature and extend the dyeing time.
Permeation promotion:
Dye penetration can be promoted by physical or chemical methods, such as physical methods such as ultrasound and stirring, or by adding chemical additives such as penetrants.
Dyeing process control:
Strictly control dyeing process parameters such as dyeing temperature, time, bath ratio (ratio of dye solution volume to yarn weight), etc., to ensure that the dye penetrates evenly into the yarn.
2. Maintain good color fastness
Color fixation treatment:
After dyeing, the yarn needs to be fixed to form a strong bond between the dye and the fiber to improve color fastness. For indigo dye, the oxidation fixation method is usually used, that is, the oxygen in the air is used to oxidize the sodium salt of the leuco into indigo dye and firmly fix it on the fiber.
Reasonable selection of reducing agents and auxiliaries:
In the indigo dyeing process, the amount of reducing agent has an important influence on the dyeing effect. Insurance powder and caustic soda are commonly used reducing agents, and their dosage needs to be precisely controlled. Insufficient use of insurance powder will lead to insufficient reduction and low dyeing rate; excessive use will lead to over-reduction of the dye and reduce color fastness. At the same time, an appropriate amount of auxiliaries, such as sodium sulfate (Na2SO4), can be added to reduce the repulsion between the dye and the fiber and promote dyeing.
Process parameter optimization:
According to factors such as yarn type and dye characteristics, optimize dyeing process parameters, such as adjusting dyeing temperature, time, pH value, etc., to improve color fastness.
Post-treatment:
The dyed yarn needs to be fully washed and soaped to remove floating colors and unfixed dyes to further improve color fastness.
Quality control:
During the entire dyeing process, it is necessary to strictly control the quality of each link, such as raw material quality, equipment status, operating specifications, etc., to ensure the stability and consistency of the dyeing effect.