Dyeing and finishing defects refer to fabric defects caused by a certain processing process problem or transportation transfer between processes during the dyeing and printing process. There are many processing procedures for dyeing and finishing, and there are different processing methods according to customer requirements or techniques. Different processing methods will lead to different dyeing and finishing defects.
1 Warp willow
Phenomena: Shadow strips are formed due to differences in color absorption of the fabric during dyeing due to factors such as warp yarn raw materials or tension. The direction of the warp yarns shows that the entire warp yarns are bright and dark regularly or irregularly, with one or more shadow strips.
2 Trachoma and blockage
Phenomenon: The surface of the printed fabric is caused by blockage of the net. spot.
Cause: sticky lumps in the printing paste adhere to the printing plate, blocking the printing paste pass.
3 Colorless creases
Phenomena: During the printing process, due to fabric wrinkles, A clear streak with no coloration in the longitudinal direction on the printed fabric.
Cause: The wrinkles on the fabric surface overlap during printing, and the covered parts are not printed with patterns.
4 Line printing
Phenomena: During the printing process, due to residual yarn on the surface of the fabric It was not treated cleanly, resulting in a linear colorless streak on the surface of the printed fabric.
5 Missing flowers and pulp
Phenomena: Part or all of the original design pattern Not printed.
Cause: The printing slurry in the slurry tank of the printing machine is exhausted, the printing slurry is not added in time, or the automatic slurry supply equipment fails.
6 Bleeding
Phenomena: The color paste in the printed fabric bleeds out of the outline of the pattern.
Causes: 1. The printing paste is not thick enough. 2. The two colors of printing paste overlap.
7 Poor plate joining
Phenomena: Printed fabrics with continuous patterns, in their plate spacing The joint parts are not connected properly, and white horizontal stripes or transition between dark and light horizontal strips appear, which mostly occurs in outline printed fabrics.
Causes: 1. The plate used for plain printing is poorly made. 2. The distance between the printing front-loading plate and the front plate cannot be accurately controlled.
8 The pattern is incorrect
Phenomena: The printed pattern of two or more colors cannot be According to the original design pattern, the connection and combination may cause deviation or full-scale printing to appear white.
Cause: When printing patterns of more than two colors, the relationship between the pattern and the pattern is not accurately aligned.
9 “Through-through” phenomenon: often appears in light and thin printed fabrics, front printing Penetration, the obvious pattern color can also be seen on the bottom surface.
Cause: It usually occurs on steel plate (flat screen) printed fabrics. Due to the excessive pressure of the printing scraper, the printing penetrates.
10 Dragging
Phenomena: There are dragging marks in parts of the printing, causing some of the pattern edges Not tidy enough.
Causes: 1. Too much pulp is consumed during printing. 2. The lint on the surface of the fabric accumulates on the scraper. 3. There are wrinkles or holes in the pre-press fabric, resulting in residual printing paste on the bottom plate.
11 Dead creases
Phenomena: due to poor dyeing, finishing or voltage treatment, etc. This causes local folding damage to the cloth surface, which cannot be eliminated after ironing, leaving obvious creases. (Creases that flatten and disappear when tension is applied to the fabric surface are not regarded as defects.)
Cause: 1. The fabric to be press-dyed has already developed creases during the pre-processing process, which cannot be completely eliminated during shaping. . 2. The spreading device failed during dyeing and finishing and failed to open the fabric creases. 3. The seams between pieces are poor, with shrinkage or irregularity.
12 Oil stains
Phenomena: There are oil stains of different shapes on gray cloth or finished cloth.
Cause: 1. Lubricating oil was splashed during the weaving or printing and dyeing finishing process. 2. Contaminated by grease during transportation.
13 Water Damage
Phenomena: There are traces of natural air drying on the cloth surface after being soaked in water. (Under the light, the luster is generally lighter and more rounded than scratches.)
Cause: 1. Soaked by water. 2. When dyeing and fixing at high temperature, the equipment drips water on the fabric, resulting in a local light color due to less absorption of the dye solution at this location.
14 Rust stains
Phenomena: Traces left after the fabric is stained with rust.
Causes: 1. When the fabric is stored in a humid environment, it comes into contact with metal; 2. After weaving on a water-jet loom, if it is not processed in time, it is easy for the fabric to be damaged by metal due to moisture. pollute.
15 Mildew spots
Phenomena: Gray-black or light red moldy spots appear on the cloth.
Cause: The storage environment has high humidity, or the fabric is stored in a wet state for too long.
16 Holes in scouring and bleaching
Phenomena: After being treated with oxidant, the gray cloth surface contains Warp or weft yarns close to rust or mildew break, forming small holes.
Cause: The fibers at the rust stains or mildew spots on the cloth have been corroded and damaged, and are damaged after oxidation reaction.
17 Color Flower
Phenomenon: There are irregular flakes of color on the cloth surface.
Cause: Incomplete desizing and refining in pre-treatment or temperature change during vat dyeing shutdown, resulting in uneven coloring.
18 Head and tail color difference and tank color difference
Head and tail color difference: A batch contains several pieces or After dozens of pieces of fabric are continuously dyed under the same set conditions, the color of the cloth end and the end of the cloth will be different in shades.
Vat-specific color difference: When a large batch of fabrics are dyed in several vats or in one vat, the dyeing is not done in the same batch in the same vat, resulting in differences in shades. Although each cylinder has the same type, its functions will be slightly different. In the dyeing process, the operating conditions are not the same every time.
19 Pre-shrinking wrinkles
Phenomena: In the pre-shrinking process, because the tension of the pre-shrinking machine is too large, it causes wrinkles when the internal ironing roller rolls the cloth. Weft uneven wrinkles. (Similar phenomena such as “wooden roller wrinkles” on gray fabrics will not be deducted as defects, and subsequent processes will be required to shape and remove wrinkles. If the finished fabric has such a phenomenon, points will be deducted as defects.)
20 Scratches
Phenomena: Printed and dyed cloths appear scratches that are irregular and different from the normal cloth surface hue effect under fluorescent lights.
Cause: During the dyeing process, due to abnormal friction between the internal machinery of the dye vat and the cloth surface or burns due to high temperature during the drying process.
(Note the difference from water stains. The reflective surface of water stains is relatively rounded.)
21 Needle loss
Phenomena: When the fabric is being set, a section of the edge of the fabric is not inserted into the setting needle, resulting in deformation during setting and stretching.
22 “Loss of elasticity”
phenomenon: local loss of elasticity appears on the surface of high-elastic fabrics of wrinkles.
Cause: When the gray cloth is stored, the elastic fibers in some parts are corroded by rust or mold, and the high-temperature treatment of dyeing and finishing loses elasticity, causing wrinkles to form on the fabric surface due to the loss of elasticity.
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