What are the reasons for the defects of woven fabrics in the finishing after printing and dyeing(2)?

(12) Migration (Migration)

Appearance: When the dyed fabric is dried, the water contained in the fabric evaporates, and the dye moves to the surface of the fabric with the movement of water, so that the color tone of the fabric surface changes.

Causes: 1). The pressure suction rate set during pressing is too large. 2). When preparing the dye solution, the dye used is excessive, that is, the concentration of the dye solution is too high. 3). The time is too long before drying after dyeing. 4). The drying rate is too fast. 5). No migration inhibitor is added, or the added amount is insufficient.

(13) Warp Stripe (Warp Stripe, YarnTexture Streak)

Appearance: Piece-dyed woven fabric with rain-like stripes in the warp direction. In severe cases, it can also be seen on the cloth surface of embryo cloth. Such flaws may show significant and insignificant differences due to differences in the brightness of the inspection site, the direction of observation, and the distance.

Causes: 1). It is formed due to the difference in the count, uniformity, twist number and cross-sectional shape of the yarn used for weaving. 2). Improper selection of dyes, especially when dyeing green is more likely to occur. 3). If it is polyester-processed silk fabric, the desizing treatment is improper before dyeing, and there is a residual paste in the local area. When dyeing, the color is less, the color is lighter, and there are warp stripes.

(14) Barry Dyeing, FillingBand in Shade

Appearance: In the weft direction of woven fabrics, or the horizontal continuous loops of circular knitted fabrics, the color is darker or lighter after dyeing.

Causes: 1). The woven fabric has dense or sparse defects. 2). During the weaving of knitted fabrics, the yarn feeding tension is uneven, or the number of loops is uneven. 3). Use filamentous chemical fiber yarns with the same specifications but different batch numbers when weaving. 4). Chemical fiber yarn for knitting, in the process of silk processing, the temperature of the heating process is not uniform.

(15) Dye Spot

Appearance: 1). On the fabric surface of dyed and light-colored fabrics, there are tiny color spots of the same color. 2). On the surface of bleached or light-colored fabrics, there are tiny color spots of other dyes.

Causes: 1). Poor dissolving of dyes, and there are still tiny particles that are not dissolved. 2). The dyes fly up during transportation and land on the fabrics to be processed. 3). When the mechanical equipment is not cleaned, continue to process the light color after the dark color is processed.

(16)Rope Mark

Appearance: During rope dyeing, because the fabric shrinks into rope shape, after dyeing, the cloth surface has irregular color and dark wrinkles along the direction of the cloth length.

Cause: When dyeing with Wenqi or liquid flow dyeing machine, the fabric is not pre-shaped or insufficiently shaped. The scroll bar malfunctioned and stopped working during dyeing. Sudden heating or cooling. The dye bath ratio is too small. The fabric is knotted in the vat, etc.

(17) Padding Mark

Appearance: When the woven fabric is dyed in open width, the fabric is folded in the warp direction between the two rollers. When it passes through the pressure line, the difference in thickness causes the suction rate to vary. The folded part is slightly lighter in color than the normal one. Occurs in two parts of a fabric.

Causes: 1). The fabric to be dyed has creases in the pre-treatment process, which cannot be completely eliminated during shaping. 2). The cloth spreader of the cloth feeding device of the dyeing machine fails, and the fabric cannot be opened. 3). The seam between each other is poor, and there is shrinkage or irregularity.

(18) Uneven Dyeing on Selvage

Appearance: After dyeing, the selvage shows a different color than the cloth surface.

Causes: 1). The edge of the embryo cloth is too loose or too tight. 2). During the setting before dyeing, the selvedge is clamped by the high temperature splint. 3). The edge of the cloth is curled during dyeing. 4). When dyeing with open width, the winding is uneven and the selvage is oxidized. 5). Insufficient reduction in vulcanization or urn dyeing in open width. 6). The pressure absorption rate of the selvage and the cloth surface is inconsistent during the open width pressing. 7). After dyeing, the washing is not enough, and there is residual medicine on the edge of the cloth.

(19) Fading of Selvage or Discoloration

Appearance: The finished fabric after dyeing and finishing, the color of the selvage is different than the normal one.

Causes: 1). When the resin is processed, the temperature of the needle plate or the splint is too high, and the dye sublimates and escapes. 2). When using the rotary cylinder dryer to dry the fabric, the temperature is too high, and the selvedge is too tight around the cloth cylinder.

(20) Edge Mark

Appearance: Refers to the circular knitted fabric, the part where the tube is flat folded and turned on both sides, showing abnormal dyeing.

Causes: 1). The oil added during weaving deteriorates. 2). If the fabric is stored improperly or for too long, the edge of the fabric will be changed or polluted by the action of air and sunlight. 3). When the cylinder is shaped, the temperature of the setting frame is too high.

(21) Drum pollution

Appearance: During the dyeing and finishing process of the cloth, when the cloth passes through the cylindrical device, the cloth surface is polluted due to the uncleanness of the cylindrical surface, such as oil, chemicals, dyes and other contaminants. The shape is mostly small flakes, and there is a certain distance between the two pollutions.

Causes: 1). There are oil stains on the cloth guide roller. 2). There are tar-like lakes on the pressing roller, or short fibers falling off from the fabric and other contaminants. 3). The drying cylinder has oil stains and dirt.

(22) Dyeing Stop Mark

Appearance: Along the weft or transverse direction of the fabric, there is a trace 2 to 10 cm wide, which is darker or lighter than normal, and there are watermarks on both sides.

Cause: During the normal operation period of the machine, when the machine suddenly stops running due to power failure, cloth rolling or other mechanical failure, the fabric is clamped between the two rollers, which occurs when the dyeing liquid or reducing liquid is pressed and sucked.

(23) Spots

Appearance: The finished fabric has been packaged, and there are darker spots of the same color on the fabric surface after opening.

Cause: After dyeing and finishing, the fabrics are packaged in a sealed package. Due to the condensation of evaporative water vapor, dyes and processing agents with weak wet fastness will move and form spot-like stains.

(24) Printed crease

Appearance: On the surface of the printed fabric, there are shuttle-shaped or elongated areas along the warp or longitudinal direction, and no pattern is printed.

Cause: During printing, the fabric surface is folded and folded, and the covered parts are not printed with patterns.

(25) Pollution of printing pulp cylinder

Appearance: The fabrics printed on white background are polluted evenly by a very small amount of printing paste, which mostly occurs in rollerized fabrics.

Causes: 1). The mirror surface of the printing roller is not enough, and it is easy to adhere to the printing paste. 2). The scraper is not in good contact with the printing roller, or the scraper is not often ground and not sharp enough. Black or dark patterns are most likely to occur on a white background.