Temperature of alkali liquor in cold mercerizing padding.

The temperature of cold mercerizing and padding lye is 12 to 20 degrees, and the specific reasons are as follows:

1. 1 cold mercerizing process of pure cotton knitted fabric

The alkali concentration of mercerizing treatment is 18~26? shellfish

The temperature of alkali tank is 12~20℃

The soaking time of fabric in alkali bath is about 30s.

The reaction zone of fabric alkali outlet tank is about 30s.

The machine speed is 8~ 12m/min.

The overfeed and transverse expansion tension of the fabric in the feeding area need to be adjusted according to the thickness and texture of the fabric. Ensure that the fabric enters the alkali zone in a completely expanded state. Because cotton fabric is an exothermic reaction in alkali solution, the temperature and residence time of alkali bath must be strictly controlled during cold mercerizing, otherwise it will have a certain impact on the mercerizing effect of fabric.

Mercerized cotton fabric

Mercerizing process of pure cotton knitted fabric: singeing, scouring (or pretreatment) cleaning, mercerizing and alkali dipping, alkali rolling, active expansion hot water washing twice, cold water washing (expansion) acid washing, water pad dyeing (bleaching), drying and shaping to make cloth. In order to improve the mercerizing effect of the fabric, it is best to carry out scouring (or pretreatment) before mercerizing to remove seed shells and impurities on the cotton fiber surface, improve the capillary effect of the fiber, make the mercerizing treatment of the fabric uniform and achieve good mercerizing effect.

Ensuring the good effect of mercerizing treatment is not only related to the process, but also related to the yarn (twist, raw cotton and blended fabric) and fabric structure. The corresponding mercerizing process can be fine-tuned according to the above factors, so that the fabric can achieve the best quality effect after cold mercerizing.

1.2 thermal mercerizing process of pure cotton knitted fabric

Mercerizing alkali concentration 30? shellfish

The temperature of alkali tank is 55~58℃

Additives in alkali tank

Rapid penetrant, mercerizing oil

Soaking time and residence time in alkali reaction zone: 50s.

Feeding tension: the width is expanded by 20%~25%.

Linear overfeeding: the overfeeding quantity will change according to the fabric variety.

The machine speed is 25~30m/min.

Many foreign knitting factories use hot mercerizing to treat knitted grey cloth. Because the concentration and temperature of caustic soda are higher than that of conventional cold mercerizing treatment, alkali molecules expand rapidly and uniformly under the action of rapid penetrant, thus shortening the mercerizing treatment time (residence time in alkali soaking zone and reaction zone), keeping the alkali rolling rate of grey cloth out of alkali tank within the range of 150%, making the fabric treatment speed reach 25~30m/min, and greatly improving the efficiency of mercerizing treatment. Compared with cold mercerizing, the speed of fabric treatment is increased by 30%~50%, the mercerizing effect is the same, and the cost is greatly reduced.

Textile machinery and equipment such as hank mercerizing machine made in Japan.

With the increase of alkali liquor temperature, mercerizing oil is added to the alkali liquor, so that the tubular fabric runs smoothly on the mercerizing machine, the tension is uniform, and the contact resistance between the grey fabric and the mercerizing machine is reduced, so that the knitted fabric can achieve good mercerizing effect after thermal mercerizing treatment.

2. Mercerizing treatment equipment

There are two kinds of mercerizing equipment for cotton knitted fabrics: cylinder mercerizing machine and open width mercerizing machine. In China, most knitted fabrics are mercerized by cylinder mercerizing machine, but some are treated by open width mercerizing machine. European and Japanese equipment factories produce open width mercerizing machines for knitted fabrics, and domestic knitting factories can choose.

Mercerizing process of mercerizing machine for open-width knitted fabric: The knitted grey fabric is overfeed, expanded, dipped in alkali and reacted under the clamping of machine needles, so that the fabric can be well stretched in the transverse direction under the condition of uniform tension in the longitudinal direction and the transverse direction. Under a certain bi-directional tension, the fabric has the best loop shape, uniformity and stability after alkali soaking, reaction and treatment.

Open-width mercerizing treatment can avoid excessive feeding, cloth scattering and cloth surface skew in the cylinder mercerizing feeding area, especially the uneven feeding reaction of fine alkali caused by the mechanical resistance at the upper part of the cold mercerizing cylinder mercerizing machine. When the particularly sensitive thin fabric is mercerized by cylinder mercerizing machine, the mercerized coil will be slightly deformed, but if it is treated by open width mercerizing machine, it can be completely avoided, so that the appearance of the coil is uniform and the luster is stable. The process is similar to that of cylinder cold mercerizing.

The disadvantage of mercerizing with open-width mercerizing machine is that in order to prevent the open-width fabric from curling, it is necessary to paste the edges before entering the cloth, and there will be some color difference after dyeing the gray cloth. Of course, this can be trimmed on the setting machine of the post-treatment process, so as not to affect the overall quality of the grey cloth.

Straight roller mercerizing machine

3. New progress in mercerizing treatment

Open width mercerizing is beneficial to liquid ammonia mercerizing treatment and meets the feeding conditions of knitted grey cloth. Liquid ammonia mercerizing finishing is a new technology of knitting finishing at present.

The technological process of liquid ammonia mercerizing finishing: drying the fabric, soaking it in liquid ammonia rolling liquid, then drying the fabric twice by hot drying guide roller (vaporization of liquid ammonia), twice by high-temperature spray washing, once by normal temperature spray washing, and drying the fabric. Among them, the liquid ammonia recovery area: the two pre-drying and hot drying guide rollers are two special blanket heating rollers, which heat and evaporate the liquid ammonia of the fabric and are sucked into the treatment recovery device by the upper strong suction device. Recovery of residual liquid ammonia: There are three ways, two of which are hot water spraying+drum washing machine and one is cold water spraying+drum washing machine. The residual liquid ammonia aft cleaning is convey to a liquid ammonia recovery device for purification.

There is a fabric drying area in the cloth feeding area, so that the drying of the fabric can evenly enter the liquid ammonia tank and the liquid roller, so that the liquid ammonia content of the grey cloth is even, and the ammonia molecules evenly enter the fibers, forming new groups with the fiber molecules, and the fabric forms a surface with good mercerizing effect and memory effect.

After alkali mercerizing and liquid ammonia finishing, the knitted fabric has a brighter luster, which is better than the conventional double-fired Mao Shuang mercerized knitted fabric. Washable with high gloss, softer hand feeling, skinny inside and good anti-wrinkle effect. Especially after more than two times of treatment and finishing, linen knitted fabric not only has good luster, but also has no itching feeling. The finished linen knitted fabric is suitable for making high-grade casual clothes and all kinds of underwear.

Straight roller mercerizing machine

In the conventional double-fired Mao Shuang mercerized knitted fabric treatment, the process of singeing and mercerizing the yarn is long, and the loss of the reverse winding process of the yarn is large, which affects knitting weaving, and easily leads to poor softness of the mercerized yarn and uneven friction coefficient of the yarn, resulting in weaving stripes, which has a certain impact on the first-class product rate of yarn-dyed fabrics. Liquid ammonia mercerizing technology for knitted fabrics has a long history in Europe, Japan and other countries and regions. It has been used in the finishing of woven fabrics for many years in China, but only a few enterprises are still in the experimental stage in the liquid ammonia finishing of knitted fabrics. This will become an excellent technology for knitting high-end varieties, making products comparable to international high-end varieties.

With the development and application of technology, new varieties appear constantly, especially liquid ammonia mercerizing finishing, which will make our knitted fabrics go to the top market in the world. At present, the new progress of finishing technology of mercerized high-grade products at home and abroad is summarized as follows:

A. After mercerizing, the fine cotton beaded fabric has strong three-dimensional effect of beaded particles, less shrinkage of the fabric and rough and soft hand feel. Clothing made of fabric does not shrink, is not easy to deform when wearing, and is cool and breathable. It is the first choice fabric for sportswear and casual wear of internationally renowned brands.

B. After alkali mercerizing and liquid ammonia mercerizing finishing, the linen knitted fabric not only has good luster, soft hand feeling, bone feeling, good air permeability and moisture conductivity, wrinkle resistance and no itching feeling, but also is not easy to pilling after repeated washing and is very cool.

C. Other light cashmere fabrics, viscose interwoven with lycra fabric (Modal lycra fabric) and cotton and linen, have good wrinkle resistance, luster and hand feeling after the above finishing.

D. After the above finishing, the quality of the new cotton-linen interwoven special mesh fabric is more unique, and the products have gone abroad.

give up

This article comes from the creator of Tencent news client, and does not represent Tencent news views and positions.