“When the cheese is dyed and matched, the printing and dyeing factory prepares the fabric pieces for color matching. But the bobbin is wet, so how does the printing and dyeing factory dry the fabric piece for color matching?”
Usually printing and dyeing factories use it. If you are pressed for time, you can use a hair dryer after dehydration. Blow-dry and color-match after dyeing; if you have enough time, you can dry it in the oven and then color-match.
The main factors affecting the drying quality of cheese yarn: The drying process of cheese yarn is a heat and mass exchange process. Due to the structure of the drying equipment, Factors such as the type of yarn, the type of dye, and the winding condition of the yarn may affect the drying quality, so they must be treated according to different situations.
01 Factors affecting package drying
Container drying The influencing factors of dryness mainly include the following 6 aspects:
02 Dye migration
The so-called dye migration refers to “the subsequent movement of dye molecules within the moist matrix”. Generally, only direct dye dyeing will show migration under drying conditions. Phenomenon.
Experiments show that when the inlet temperature of the drying process is around 110°C, the higher initial moisture balance is the cause of dye migration. Therefore, no matter what kind of dryer is used, using a suitable initial temperature and minimizing the moisture content are important means to avoid dye migration.
The coil structure and winding density of the bobbin also affect dye migration. Coils with larger mass, higher winding density, and hard edges have stronger migration phenomena, which are manifested as dyed annular bands on the upper and lower end surfaces. In order to avoid this phenomenon, on the one hand, it is necessary to ensure the forming quality and winding uniformity of the package yarn. On the other hand, it is necessary to pay attention to the fact that during the drying process of the package yarn dyed with direct dyes, the same batch should be kept of the same variety and quality. Specification.
03 The cleanliness of the air affects
If the drying air contains If the dust and dirt are not effectively filtered, the heat exchange surface of the heat exchange equipment and the surfaces of all parts in contact with the drying air will be scaled, thereby contaminating the dried yarn, especially white yarn and light-colored yarn. Yarn is the most harmful. Effective air filtration equipment is crucial to yarn drying quality.
04 Over-drying (over-drying) of fiber
Yarn The shorter the drying time, the less energy it consumes and the lower the cost. However, the drying time is closely related to the drying temperature. The higher the temperature, the faster the evaporation rate and the shorter the time. Since the thermal properties of various fibers are different, the temperatures at each stage of drying are also different. If the temperature exceeds the limit, over-drying (also called over-drying) will occur, which will cause changes in the structure of the fiber material.
Over-drying will affect the breaking strength and breaking elongation of the fiber, making it feel hard, brittle, and yellow. Ash (powder) dust is produced during winding. Over-drying will also cause dye migration in yarn dyed with direct dyes.
Selecting the appropriate drying temperature and time according to the fiber type and winding conditions of the package to be dried is a key step in preventing over-drying. The vacuum dryer will not cause over-drying.
05 Summary
To sum up, the influence of cheese drying There are many reasons for dry quality, and various types of dryers have different structures and characteristics. Drying processes should be formulated according to the machine model, fiber type and package yarn winding conditions to prevent dryness from the source. Uneven wetting, over-drying, dye migration and contamination of white yarn and light-colored yarn. </p
