Causes of holes in dyeing and finishing

There are several reasons for holes in dyeing and finishing

(1) The dosage of acid oxygen water is too high;

(2) There are many iron ions in the water;

(3) If the holes are regular, there is a problem with the equipment;

(4) The "temperature + time" parameter is improper;

(5) Holes appear in bleaching, which in most cases are caused by the reaction of hydrogen peroxide and iron ions;

(6) Excessive purity of hydrogen peroxide and alkali;

(7) Whether water softener is added in pretreatment and dyeing, and the metal ion content in the water may be too high;

(8) The local rapid decomposition of hydrogen peroxide caused by heavy metal ions causes holes.

Analysis of the reasons for holes caused by hydrogen peroxide bleaching

(1) Oil stains with heavy metal ions such as copper and iron on the cloth before bleaching; or contact with copper, iron and other equipment during the bleaching process.

(2) The concentration of hydrogen peroxide is too high, and the steaming time after bleaching is too long or superheated steam is used.

(3) If the grey cloth is mercerized before bleaching, the PH value of the cloth surface is too high and the alkali content is locally too much due to the uneven washing after mercerization.

(4) Improper selection of stabilizer or poor stabilization effect of stabilizer, resulting in accelerated decomposition of hydrogen peroxide.

Solution

(1) Ensure the optimum dosage ratio of hydrogen peroxide and alkali agent.

(2) Select high-quality refining agents with good comprehensive effects such as cleaning, emulsification, dispersion, penetration, and anti-sticking.

(3) Select high-quality hydrogen peroxide stabilizer and chelating dispersant to control the decomposition rate of hydrogen peroxide and adsorb and complex iron and other gold metals in the working fluid.

Causes of holes after dyeing textiles and how to prevent them

1. Needle hole

Cause of:

(1) The expansion is too large, causing damage to the selvage fibers,

(2) The stretch ratio of the needle chain track plate is out of balance

(3) There is a bent needle on the needle plate, and the needle is broken

How to overcome:

(1) Adjust the stretch to a reasonable level, and do not stretch and pull hard

(2) Correction of the stretch ratio of the track plate

(3) Replace the needle plate with bent needles and broken needles

2. Several forms of hole-breaking disease

After the fabric is dyed and finished, one or two yarns are broken on the semi-finished products or finished products, and large and small holes appear in serious cases. Defects are regular, sometimes irregular. The defect is generally a sudden defect. If neglected, a large number of secondary fabrics will be produced, which will seriously affect the quality and use value of dyed semi-finished products and finished products. Once the defect is caused, it cannot be remedied.

Causes: The reasons for the formation of holes in the fabric during the dyeing and finishing process can be summarized as burning, hooking, abrasion, pulling, rolling, and fiber brittleness.

(1) Burning: It mainly occurs on the singeing machine, which is caused by improper singeing process.

(2) Hook break: During the dyeing and finishing process, all parts of the cloth that pass through may have hook break. When the fabric is running, the hook is broken due to contact with protruding hard objects and broken parts. The needle eye puncture on the edge of the heat-setting cloth is mainly caused by the bent needle on the needle plate, and it must be checked and replaced in time.

(3) Scratching: The fabric may be rubbed by friction after passing through the hard and rough parts of the equipment.

(4) Stretch break: One case is that the fabric itself has small holes that are not found in time. After mercerizing tentering or dyeing and then tentering, the original small holes will expand; attention should be paid to finding holes that occur during the pre-processing process. the root of . Another situation is that the pre-treatment of the thin fabric is too large and the width of the door is too narrow. If the width of the tent is too large, the fabric is easily broken; in addition, the opening of the tenter clip is too late, and the angle between the clip blades Too sharp, etc. are easy to make the fabric to be pulled.

(5) Crushing: The fabric passes through a roller embedded with a hard substance, and is rolled into a hole by the roller. There are dry and hard lumps on the calender drum, causing calendering holes.

(6) The fibers are fragile; the fabric is broken as soon as it is pulled. The reason is due to improper chemical processing (such as bleaching and brittleness) in dyeing and finishing. 

Problems and solutions for holes in brushing and sanding

1. The problem of poor effect of brushing and sanding: inconsistent hair height, streaks, unable to be pulled, holes, etc.

2. Solution: Check whether the equipment's brushing, brushing roller or card clothing is damaged, whether the distance between the cloth surface and the brushing roller and the set process parameters are appropriate, and select suitable raising oil and special additives for brushing and brushing. .

3. Emphasized measures: the equipment should be inspected frequently, the covered card clothing should not be reversed, skewed, and the abrasive belt should not be damaged.

4. Prevent the metal ions from sticking to the cloth surface, prevent the ineffective decomposition of hydrogen peroxide and the brittleness, holes, strength reduction and weight loss of the fabric that may be caused by iron ions.

5. Mercerized scratches and holes are caused by improper operation. Check whether there are burrs, scratches or frictions on the cloth feed support plate, guide roller, needle plate and cloth clip of the equipment. Ensure the integrity of the equipment and avoid scratches on the cloth surface. Dimensionally selecting dyes, formulating process technical procedures, and then taking into account the fibers with weak chemical resistance and temperature resistance, formulating process parameters and selecting chemical auxiliaries, it is necessary to give priority to proofing, screening and optimization to formulate reasonable process and technical plans, and then lofting and adjustment. Promoting production gradually.

General description: To sum up, generally the grey fabrics are sent to the dyeing factory, and the seams should be turned over before the pretreatment, that is, the quality of the grey fabrics should be checked.