What is steamed yarn? Is steamed yarn also important in the fabric production process?

What is steamed yarn? Steamed yarn is also called twisting. In production, hot steam is used to set the shape of wool yarn and wool blended yarn. During the process of processing woolen raw mater...

What is steamed yarn?

Steamed yarn is also called twisting. In production, hot steam is used to set the shape of wool yarn and wool blended yarn. During the process of processing woolen raw materials into yarn, due to repeated force and friction, the internal stress is unbalanced and deformed. Fatigue and static electricity are generated; after adding twist at the same time. Wool yarn has a huge untwisting torque, which will affect the subsequent production.

A process that uses hot and humid conditions to stabilize yarn twist. After the yarn is fixed, it can prevent kinking and looping when it is relaxed, and avoid defects such as weft shrinkage in the fabric.

Add After twisting, the fibers in the yarn are stretched and produce internal stress that resists twisting, making the yarn twist unstable. Increasing the temperature or moisture regain can weaken the force between fiber macromolecules, relax the fiber, eliminate the internal stress that resists twisting, and achieve the purpose of stabilizing the yarn twist.

Steaming yarn process

Steamed yarn technology was first used in wool spinning and wool-polyester blending processes. Used to solve problems such as fabric instability and static electricity. With the development of the textile industry, yarn steaming technology has involved cotton, linen, chemical fiber and other fields.

Steaming process

● Step 1: Warm up the fuselage.

During the yarn steaming process, water drop spots on the yarn are a common problem. Water drop spots can cause dyeing and other problems in subsequent processes. Therefore, the preheating process of steamed yarn is absolutely necessary, especially for wool yarn.

● Step 2: Vacuum.

Lower the boiling point of water to produce the required low temperature saturated steam.

● Step 3: Heating.

Let low-temperature saturated steam penetrate into the conical bobbin. Every production process (spinning, twisting, weaving…) will cause tension effects on yarns and fibers, and the effect of tension will cause entanglement of yarns. The stress relaxation in the molecular structure of man-made fibers causes the fibers to shrink. Tension and tangles can cause problems in subsequent processes.

● Step 4: Keep warm.

By Zhen�The transformation into a low-temperature saturated steam state enables the entire package including packaging materials to be completely processed. The moisture of the cold steam is transferred to the yarn, which distributes the moisture absolutely evenly, achieving consistent yarn strength and friction values. At the same time, the heat treatment also relaxes the twist.

During the yarn production process, the fiber moisture is constantly evaporating. From raw materials to cheese, the cumulative humidity reduction exceeds 4%. Different spinning mills have different yarn moisture indexes. Increasing the speed of the machine will cause a large loss of weight (moisture); the high temperature and friction inside the machine will evaporate the moisture in the yarn and reduce the quality of the yarn. , which is not conducive to subsequent processing steps.

● Step 5: Secondary vacuuming.

The unique secondary vacuum design of the yarn steaming machine can ensure the yarn processing effect.

● Step 6: Secondary heating and heat preservation.

Ensures compensation for yarn weight loss and improves yarn quality.

Yarn humidification treatment (yarn steaming) is done after winding and before the yarn is put into storage. If the storage time of the yarn is long, it will be done before delivery. good. Appropriate packaging of yarn during transportation, such as yarn bags or yarn reels, tensioned and sealed wrapping, can maintain the humidity of the yarn. In addition, knitting and weaving can also benefit from humidifying the yarn before use. Research on weaving supply and demand shows that humidified yarn is better than non-humidified yarn (dry yarn). When humidified yarn is used for weft weaving, the number of machine stops will be greatly reduced, and the strength of the yarn will be greatly reduced. And the elongation at break is improved, the hairiness is reduced, and the weaving efficiency is increased by 2%. In terms of knitting, it can be seen that flying flowers are significantly reduced.

In trade, buyers will never accept additional price increases. The increase in yarn weight is also the increase in profits. Generally, the investment return period for yarn humidification treatment equipment is less than one year, while the investment return period for cotton yarn humidification equipment is even less than half a year. In addition, the quality requirements of export trade also require continuous improvement of yarn quality. Therefore, the humidification treatment of yarn has become an important part of contemporary textile technology, which can compensate for the loss of yarn weight and improve the quality of yarn.

Recommended steaming temperature/℃

Pure wool (tube yarn) 78~80
Wool polyester (tube yarn) 90
Pure wool (bobbin yarn) 80~85
Wool polyester (bobbin yarn) 95
Super twisted yarn 90~95
Polyester filament 112~120
Spandex core-spun yarn 70~75
Polyester-cotton blended yarn 90~95
Man-made fiber (viscose) yarn 85~95
Polypropylene filament 130~140
Pure cotton (tube yarn) 80~85
Waxed cotton yarn 57~62

What is the role of steamed yarn?

1. The effect of steamed yarn on the mechanical properties of yarn

The breaking strength and breaking elongation of the yarn are closely related to the moisture regain of the yarn. Appropriately increasing the moisture regain is beneficial to improving the mechanical properties of the yarn. . This reduces end breaks in the subsequent weaving process and improves knitting and weaving efficiency.

2. Effect of steamed yarn on yarn friction coefficient performance

Yarn moisture regain Directly affects its friction coefficient uniformity, hairiness and static electricity problems. The yarn steaming process can balance the friction coefficient of the inner and outer layers of the spindle, while effectively reducing yarn static electricity, improving the yarn unwinding effect, improving weaving efficiency, and making the fabric soft to the touch.

3. The influence of steamed yarn on yarn twist setting

There will be torque in the yarn during processing, and the existence of torque will make the yarn strong Large fluctuations and uneven unwinding tension will reduce the efficiency of the knitting process and even cause quality problems. There are two ways to eliminate problems caused by torque. One is to rely on time and let the torque weaken naturally, but this process is long and the effect is not significant. Another way is to relax the internal stress through the yarn steaming process and twist the yarn at the same time. This method is short in time and has significant effect.

4. Other effects

The effects of factors such as high temperature, high humidity, and high pressure improve the stability of the yarn structure and the bulky performance. As well as the subsequent printing and dyeing process, the dyeing is more uniform and the color is brighter.

Generally speaking, the yarn steaming process improves the overall performance and quality of the fabric, making the fabric more dimensionally stable and softer and fuller to the touch. The yarn steaming process improves production efficiency, shortens delivery time, and adds advantages to enterprises in fierce competition.

Wide application of steamed yarn

  • ⒈, cotton spinning
    – Humidification and weight gain: increase the moisture regain rate by 1.5%-3%.

    ——Stable twist: the back twist of cotton and rayon is reduced by 40% and 60% respectively.

    ——Improve yarn quality: average yarn strength and elongation, improve the strength of weak yarns, increase breaking elongation and breaking work by 15%.

    ——Reducing hairiness can be reduced by about 40%.

    ——Add high count yarn, high twist yarn and other mixed carded yarn products Quality.

  • 2. Wool spinning

    ——Humidification and weight gain: increase moisture regain rate by 1.5%-4 %.

    ——Stable twist (bobbin).

    ——Reduce hairiness and improve downstream processes.

    ——Wool fiber restores elasticity and eliminates static electricity.

    ——Increase the yarn breakage limit.

  • 3. Linen

    ——Increased humidification: it can increase the moisture regain rate by 1.5%-3%.

    ——Improve yarn quality: increase yarn strength and elongation.

    ——Soft yarn.

  • 4. Silk

    ——Stable twist: stable high twist multi-count yarn.

    ——Silk is sensitive to humidity fluctuations, temperature setting