Alkali Dosing Profiles and Mass Transfer in Jet Dyeing
Controlled progressive alkali dosing matches jet fabric loop velocity to eliminate surface fixation spikes and secure level shade fixation on cellulosic cloth.
Fabric Rope Marks
Surface Distortion
Linear creases or streaks that develop along the longitudinal axis of textiles during wet processing run parallel to the warp or wale direction. These fabric rope marks appear as permanent, irregular light or dark lines on the finished goods. They represent localized areas of physical deformation where the yarns have been compressed and bent during dye cycle operations.
Mechanical Origin
Mechanical action in jet or beck dyeing machines forces the textile into a rope form that experiences continuous flexing and folding. If the rope remains in a static fold configuration under high temperature, the thermal and chemical conditions set the yarn structure in this deformed state. When the fabric is posteriormente unfolded, the dyes have accumulated unevenly or the fibers have been permanently creased, creating visible streaks.
Process Avoidance
Process adjustments during textile preparation and finishing minimize the risk of these physical deformities. Continuous movement of the rope and frequent displacement of the folds are achieved by using chemical lubricants and adjusting machine speeds. These auxiliary agents reduce friction between the fabric folds and the metal surfaces of the machine, which helps the textile run smoothly.
Controlling the cooling rate after high-temperature processing prevents the thermal setting of accidental creases, ensuring that the yarn structure relaxes gradually without locking in the deformed positions.
Treatment Limitation
Once these permanent creases have been set during high-temperature dyeing, subsequent finishing treatments cannot fully restore the original flat surface of the textile. Chemical softening and mechanical stretching may reduce the severity of the deformation but do not eliminate the differential dye uptake associated with the marks. Prevention during the dyeing cycle is therefore the primary method for maintaining quality.