Dark color wrinkle problem
Polyester microfiber brushed fabric is prone to wrinkles when dyed (chicken paw prints), especially red, navy blue and dark gray colors are difficult to repair once they occur. The composition of this kind of fabric is mostly 75D72F (warp direction) × 150D/228F (weft direction), the density is 144×93, and the width is 4000px.
Generally, the dyeing and finishing process is adopted: desizing → pre-forming → sanding → dyeing → stenter setting → finished product inspection.
Factors that cause wrinkles
There are many factors that cause wrinkles.
For example, after the fabric is desized, pre-shaped and sanded, its warp and weft tearing strength decreases by 11% and 50% respectively; if it is dyed at high temperature of 130℃, it will not be damaged. The molecular chain movement in the crystallization area of the fabric intensifies, coupled with the nozzle pressure on the dyeing machine and the high-speed friction of the cloth guide roller, the fabric forms folds in the machine and is fixed with different angles.
Especially the slower the fabric speed, the dye in the dye bath will accumulate in the deformation area of the fabric, and the greater the concentration, the deeper the wrinkle mark will be (obviously), even if it is taken slowly Measures such as cooling down are of no avail.
Measures to prevent wrinkle marks
To overcome this wrinkle mark, Improvements can be made from the following aspects:
1. Fabrics should use tight desizing equipment for desizing, such as open-width scouring machines and jigger dyeing machines to ensure that the fabrics are Roll flat.
2. Pre-setting must be regarded as final setting, that is, 190-200℃×30s, and the actual temperature of the main setting box in the heat-setting machine must be strictly controlled. The setting fabric must ensure The moisture content is 5%-7% and should not be too dry, especially when the climate is relatively dry in autumn and summer.
3. The sandpaper must not only be smooth and even, but also need to control technical parameters such as tension and speed. In practice, it is found that in order to select sandpaper and adjust the horizontal pressure roller, the technical parameters need to be determined according to the products and standard samples of different specifications. If the fabric is locally overheated during grinding due to poor levelness of the pressure roller, it will be difficult to ensure dimensional stability, and the strength of the fabric will be severely reduced.
The impact of different processes on fabric strength reduction
Process warp and weft direction
grey fabric 3.76 3.2
Before setting 2.16 2.08
After sanding 1.92 1.04
4. To choose good quality disperse dyes, the color fastness requirements If it is higher, you should choose disperse dyes with high fastness. When dyeing, you need to add high-temperature leveling agents and repair agents with good dye migration properties. The leveling agent has good dye migration properties. At the same time, a repair agent is added as a retarding agent, and 1%-1.5% of an anti-wrinkle agent in a high-temperature bath is added to ensure uniform dyeing.
In addition, special attention should be paid to the cooling speed in the dyeing process. Generally, 1℃/min is appropriate. Finally, in the dyeing operation, the mechanical nozzle pressure and cloth guide roller must be reduced to a minimum to minimize the friction between the equipment and the fabric. Fabrics are best dried in a short-loop track dryer before heat setting. This is also one of the ways to reduce the formation of wrinkles. </p