Warp defects are shadow strips formed by differences in color absorption during fabric dyeing due to factors such as warp yarn raw materials or tension. They appear in the warp direction of the...
Jingliu Defects not only limit the application scope of the fabric and affect its use value, but also reduce the added value of the product and cause losses to the company. Therefore, it is particularly important for enterprises to find out the causes of warping and carry out targeted prevention.
There are many reasons for warp willow. This article selects some common reasons for analysis, and shares with you the corresponding preventive measures that I have summarized based on many years of fabric development experience:
(1) The raw materials have different batch numbers. Even if the specifications are the same (such as the same denier and F number), their affinities for dyes are also different. If they are mixed and used as warp yarns, warp willow will be produced;
(2) Even if the raw materials are of the same batch number, due to the large difference in production time or being left for too long, subtle chemical changes have occurred inside the yarn, and its affinity for the dye has changed.And produce the willow tree;
(3) Improper storage of raw materials. Some raw materials will be affected by sunlight exposure or moisture or bad gas attack, which will affect their dyeing performance and cause warpage.
Preventive measures:When using warp yarns, it is necessary to distinguish the raw material batch numbers. Raw materials with different batch numbers must not be mixed. The origin and batch number of the raw materials must be checked before the raw materials are shipped out of the warehouse; they vary in size, softness and hardness. , bobbins with different gloss and poor molding should be removed, stored in a centralized manner, and processed separately.
(2) Reasons for the twisting process: During the twisting process, the difference in resistance of the spindle bearings may affect the twist of the twisted wire, and the twist Mixing different yarns will produce warp yarn;
(3) Reasons for the bobbin car winding process: If the bobbin tension piece is not adjusted in place (adjusted between 5-35 grams according to the denier of the yarn), it will cause the bobbin to be tightly wound and loosely wound. If it is mixed with Warping will cause warp in the fabric.
Preventive measures:
(1) Network equipment must ensure stable and sufficient air pressure and stable rotation speed. Ensure that the yarn mesh spacing is consistent, otherwise miscellaneous yarns with different mesh spacing will form warp willows;
(2) Raw material processing equipment must be timedInspect and refuel, especially the twisting machine, check the flexibility of the spindle regularly and add spindle oil regularly, clean the spindle bearings to ensure the flexible rotation of the spindle.
(2) The influence of the size of the bobbin: the sizes of the bobbin cannot be mixed. A small bobbin with a small radius will have a large tension, and a large bobbin with a large radius will have a small tension. Different sizes of bobbins of the same shape may produce warp; p>
(3) The impact of the fixed-width reed: The fixed-width reed is a tool on the warping machine to control the width of the warp, and it is also the passage for the warp. If used If it is rubbed by warp yarns for too long, grooves will form, which will create additional resistance when the warp yarns pass through, thus creating warp willows.
Preventive measures:During warping, the warp tension sheets should gradually decrease from the front row to the back row. Since the front row has fewer warp passages and less resistance, the weight of the tension sheets should be heavier (about 30 grams). The more you get to the rear passage, the greater the resistance. You may not need tension sheets at the end. The tension sheets will drop by about 5 grams for each row of retreats. In addition, the remaining yarn bottoms after warping should be reversed in batches to make the same type of yarn. Weft yarn, not used as warp yarn.
(2) The fixed-width reed channel must be smooth and wear-free, and the width and beam must be of the same size;
(3) The anti-static system device must be sensitive and reliable.
(2) The tension between each pulp shaft should be reasonably configured, and the warp tension should be completely consistent.
(2) New and old healds should be used separately. Since healds are the main passage for warp yarns on the loom, if different new and old healds are used, the mesh cleanliness of the healds will be different, and the warp tension will be different, resulting in warp tension. Willow;
(3) If the loom has a dropper, new and old droppers cannot be mixed, otherwise the warp willow will be caused by inconsistent resistance of the yarn;
(4) If the reed quality of the loom is poor, the distance between the steel sheets on the reed is inconsistent or some parts are rusty, obvious warp will appear, so if the reed is defective, it must be repaired in time;
(5) If a few warp yarns are missing during warping, it is necessary to tie a few warp yarns on the loom to supplement the yarn. Under the condition of ensuring that the yarn batch numbers and specifications are the same, The tension must be strictly adjusted to be consistent with the warp, otherwise tight warp or loose warp will occur;
(6) New and old healds should be used separately. Since healds are raw materials for looms, they should be stored in partitions according to batch numbers and specifications. First-in, first-use, last-in-last use should be maintained, and a stable inventory should be maintained. Dispose of useless yarn in a timely manner. It is better to dispose of it than to mix it into use. Otherwise, a single package of yarn may cause the loss of tens of thousands of meters of gray fabric;
(7) When setting the yarn after twisting, the process requirements of each variety should be consistent, and the time and temperature must strictly abide by the process requirements. If the setting time and temperature are too high, the dyeing properties of the raw materials will be changed and warp will be formed; p>
(8) The loom is a key equipment for fabric production. It is necessary to check whether the passage of each warp yarn is smooth and unobstructed, whether the let-off and curling mechanisms can remain stable and consistent, and the reed must be carefully checked without loss before use.
(1) Avoid sensitive colors, bleaching is the best way, or dye them in light colors and black (sometimes meridional stripes will appear even if you dye them black);
(2) When selecting dyes, try to choose dyes with good leveling effect and fine molecular particles or add leveling agents;
(3) Adjust the dyeing temperature and time, that is, extend the dyeing time and appropriately lower the dyeing temperature;
(4) The setting process should also reduce the temperature and speed accordingly. Since the finishing remedies are very subtle, just some remedies. The key is to control it in the previous process to prevent problematic gray fabrics from entering the dyeing and finishing process, which will be difficult to save.
The above points are my opinionsA little humble opinion on the occurrence and prevention of this. If there is any imperfection, please criticize and correct me.
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