TENCEL belongs to a new generation of cellulose fiber. Its most obvious characteristics are high wet modulus, high strength, easy fibrillation and high swelling property.As TENCEL is cellulose fiber, other dyes and finishing auxiliants used in cellulose fiber can be used as TENCEL.Because TENCEL fiber can be fibrillated, we can control the uniform occurrence and development of fibrillating, which is the difference in feel of the fabric.

Its basic process can be divided into two types according to the different effects produced:

1.Suede effect.Pretreatment -- primary fibrillation-enzyme cleaning (removing fibrils)-- dyeing -- secondary fibrillation-resin shaping.

2.Smooth effect.Pretreatment -- primary fibrillation-enzyme cleaning (removing fibrils)-- dyeing -- enzyme cleaning -- smoothing resin finishing.

Special attention should be paid to TENCEL fabric in dyeing and printing process:

1.Easy to fibrillate.Once the fabric is wet and swollen, and friction with the metal or itself, microfibrillar division will occur, and the cloth will appear fluff, which is difficult to repair.Different yarn twist, fabric structure, etc. can have a direct impact on fibrillating.Plants in the equipment under small stress, in the form of flat or steam lau jet processing, processing of the bath ratio, low temperature, low PH value, short processing time are conducive to reduce fibrillating.Using the right lubricant can also make fibrillation less likely.As far as the fabric itself is concerned, the yarns are tightly tightly twisted and the use of low-fibrillated TENCEL fibers and a reasonable blend ratio also helps to control the fibrillating.

2.Fibers swell easily.Unlike viscose fibers, TENCEL's swelling form is perpendicular to the fiber axis.The degree of swelling is close to 45%.The surface of the cloth becomes hard, making the fabric vulnerable to breakage during rope processing.Heavy fabrics bruise easily.This can be avoided by open-width machining and the use of lubricants.

onePreprocessing of TENCEL

Pretreatment is the basis of printing and dyeing, good pretreatment can make the fabric desizing thoroughly, whiteness, moisture absorption increase, color.Increase, evenness is good, is efficient dyeing and finishing, high quality guarantee.The first step of pretreatment is singeing, which is usually two heads and two tails.Singe is mainly a short fiber protruding from the surface of the fabric, which helps to improve the efficiency of removing fibril in the subsequent process.Because of the characteristics of the fibers, desizing after singling has also been carried out in the form of open width, and the intermittent desizing or continuous desizing award.Here I offer a one-step de-boiling and bleaching process:

Hydrogen peroxide stabilizer (ml/kg)8-- 11 sodium hydroxide (g/kg)40

Refining agent (ml/kg)3-- 5 hydrogen peroxide (ml/kg)8-- 15

Soak and roll at room temperature for 90-110%. Let the fabric stand for 6-22 hours. Then wash in hot water and cold water.Specific circumstances may be appropriately amended.

Second, the primary primitive of TENCEL

TENCEL fibers tend to be fibrillated, making dyeing and finishing difficult.The short fibers on the surface of the cloth should be removed first.After contact and friction, the short fibers remaining in singeing wool are generally longer and easily pilling, which must be removed.Cellulase can be used to remove them without damaging the strength of the fabric.If the enzyme treatment is carried out before dyeing, the dye anion can avoid the shadow of enzyme activity, so that the secondary fibrillator must be completely clear.Primary fibrillation is best done in an air jet dyeing machine.On the one hand, the fabric can withstand sufficient friction, on the other hand, it can prevent the formation of wrinkles.

Iii. Enzyme treatment of TENCEL

Enzyme treatment is the main way to remove TENCEL fibrils.The cellulase that USES should pay attention to two respects, it is normal dosage when go fibrillar effect;Second, fiber strength loss degree.Strict control of process, especially temperature and ph, is required.It is best to adjust the processing PH with a buffer. The buffer system is generally composed of acetic acid and sodium acetate.After the enzyme is treated, the enzyme can be inactivated by increasing the PH value or temperature, or the temperature and PH value can be changed at the same time. The PH value can be first increased and then heated with soda ash.This ensures that enzymes are inactivated.

The enzymatic treatment after dyeing is the only effective method to remove the secondary fibrils.

Iv. TENCEL staining

TENCEL is a cellulose fiber whose dyeing performance exceeds that of other cellulose fibers.Fabric dyeing requires the basic removal of fibrils, but as TENCEL is prone to fibrillating, fibrils can swell during dyeing and produce fibrils again after friction, which brings difficulties in controlling fibrils and preventing local over-fibrillating.Open width dyeing can avoid or reduce such problems, while rope dyeing cannot be avoided.This phenomenon can be alleviated by the use of reactive group dyes.

The ideal condition for the fabric to operate in the equipment should be the lifting roller, with the guide roller consistent with the linear speed of the fabric, but in fact the speed difference always exists and can only be adjusted to the minimum.At the same time, the fabric should be able to unfold again after a cycle, which can eliminate the local lasting wrinkle of the fabric.Liquid jet dyeing machines can't spread the fabric effectively, while air jet dyeing machines have proven to be very suitable for TENCEL fabrics.

Many factors can lead to fibrillation in rope dyeing, so efforts should be made to combine adjacent fibrils early in dyeing to prevent refibrillation.A stable chemical covalent bond is the best combination.First of all, the dye should be able to react with cellulose fiber to generate covalent bonds. Second, the number of bonds should be two or more than two, so that it is possible to effectively bridge between fibrin;The bonds should be strong, close to each other, so that the effect lasts.On the contrary, although the fixed color probability is the same, but the hinge is not fixed color, the effect is not lasting.Some multi-functional reactive dyes can reduce the fibrillation of fabric during dyeing and washing.

Multi-active group dyes have antigen fibrillating action, but do not include all varieties of this kind of dyestuff, they are related to the following aspects of characteristics: the position of reactive group on dyestuff molecule, the spacing of reactive group, the size and number of hair color group, the elasticity of dyestuff molecule bridge group, reactive group activity and dyestuff diffusion energy, etc.And the ability of the dye is directly affected by the depth of the dye.After the reaction of dyes and fibers, fibrinogenesis and fibrillating uniformity can be controlled to a certain extent. In most cases, the fabric needs resin hinge after dyeing. The effect of two effects can be lasting and obvious, but sometimes only using dyes can achieve good results.It is very important to use multi-reactive dyes for fabric dyeing that requires a bright and clean appearance, and we should give comprehensive consideration to the dyeing that requires suede.

At the end of dyeing, attention should be paid to the final appearance of the product and the corresponding processing method. For rope dyeing, if the appearance is required to be smooth, enzyme treatment of TENCEL fabric should be carried out to remove fibrils.Since the dye is treated with post-staining enzymes this involves whether the dye has a shade of color, a change in color light.Pretesting is usually required.

Fabric dyed with bright and clean surface requirements process is as follows: open width processing (rope dyeing - second enzyme processing) - open-width impregnating resin - drying - baking - not suede resin finishing, finished products in order to improve the rough handle, improving wear resistance, to properly add softener in the finishing bath, such as polyethylene emulsion, silicone softener.The effect of amino-silicone emulsion was better.

Five.Secondary fibrillation of TENCEL

If the finished product requires suede effect, secondary fibrillating should be carried out after dyeing.This kind of fibrillating is different from primary fibrillating. At this time, the yarn is easy to contact and friction at the intersection, so the fibrils are basically generated there. The fibrils are shorter, scattered around the intersection, and will not pilling.Because fibril is very fine, get color amount is same, but reflectivity is tall, the color is shallow on the vision, make the fabric has the feeling that sand washes or peach skin fleece.

1.Peach skin velvet style.

The process can be carried out in air jet dyeing machine or rotary cage equipment.Add 2-4% softener, control PH 5-6, bath ratio 1:5-20,30-40 ℃ treatment 20-30 minutes.This process can fully fibrillate the fabric, form the appearance of peach skin velvet, and make the fabric have corresponding feel by selecting appropriate silicone softener.

Sand washing style

Dyeing - rope impregnated resin - drying - secondary fibrillating - resin shaping - sand washing style.But when drying must control the fabric moisture rate of about 20%, and then in the rotary cage equipment according to the peach skin velvet style of secondary fibrillator, in order to produce a more fluffy feel, berkelium drying qualitative.The moisture content of the fabric and the operation of the rotary cage should be consistent, so as to maintain the same effect.

(Source: China Textile Network)