Several key points of dyeing on a jigger

(1) The edges of the fabric entering the drum should be neat. No matter what kind of jigger is used for dyeing, first, push a car (roll) of fabric with the ends sewn in advance to the front of the drum, pull out a piece of joint cloth on the top, with the front of the fabric facing the guide roller outward to avoid being scratched by the dead roller, and then pass it through the expansion roller and the bottom guide roller (above the steam pipe) from one side, wrap it around the opposite cross roller, and then roll the fabric into the drum in the center, and wrap the lower joint cloth around the cross roller on the side of the fabric inlet. However, whether it is a wet fabric that has been pre-treated or a dry grey fabric, one side must be kept neat. It is normal for the other side to have some bumps (untidy), but it is not allowed for both sides to be uneven. Secondly, set the automatic turning (reversing) and counting device, start the machine to let the rolled fabric return (1 pass), and if the situation is normal, drain the residual liquid in the drum and replace it with new liquid to the specified bath ratio. After that, generally heat the blank bath in the drum to 40. C and add materials according to the process requirements.

(2) Dissolve the dyes and chemicals separately and add them evenly on both sides. To add any dye into the dyeing machine, you must pay attention to the following three points: ① If you are not skilled, you must stop the machine to add the dyes, and never add them while running; ② The dyes and chemicals must be dissolved in advance and ready for use; ③ When adding, they must be divided into two parts and added on both sides. After adding each side, it is necessary to use bamboo, wood or stainless steel rods to poke back and forth to make it even, and rinse the residue attached to the edge of the tank with an appropriate amount of water into the tank, maintain clean production, and develop good operating habits. (3) Adjust the expansion frame (shelf) according to the thickness of the fabric. It should be adjusted according to the thickness of the fabric. For thin fabrics such as nylon, polyester and pongee, the protrusion in the middle of the shelf can only be 1.5-2cm higher than the two ends. If the protrusion at both ends of the shelf is too different from the middle, the fabric will carry different amounts of liquid (scraping water), resulting in uneven color depth; on the contrary, if the protrusion at both ends of the shelf is too small (flat) from the middle, it is also easy to cause wrinkles in the fabric. Practice has shown that it is more appropriate to raise the protrusions of the two ends and the middle of the scaffold by 2-3cm. The protrusions of the two ends and the middle of thick fabrics such as canvas, corduroy, and velvet should not be greater than 5cm. In short, when changing the dyeing type, the expansion frame must be adjusted, either higher or lower, and it is best not to leave it unchanged.

(4) Adjustment of the reel tension. Dyeing on the roller dyeing machine relies on the compression between the fabrics. Therefore, the tension must be controlled during dyeing, and it must also be adjusted continuously with the change of fabric thickness. Because the tension of the reel is too large, the fabric will often be broken, and thin fabrics will even be pulled into cracks; on the contrary, if the tension is too small, the dyeing will produce color spots, especially for reduced dyes; in severe cases, the fabric will slip during the round-trip roller dyeing process, resulting in unevenness on both sides, and sometimes even "reversal" (that is, the fabric rolled on the cross axis is poured out again, and then the tension is adjusted, and the edges are neatly placed in the cylinder).

(5) During the dyeing process, pay attention to the following observations: ① Is the force (steam size) of the steam pipe sprayed out from both sides of the direct heating consistent? Sometimes it may be blocked by fiber debris. If you see this situation, you need to solve it yourself in time. Sometimes the hole will be enlarged due to long-term use. At this time, it needs to be replaced. For indirect heating, check whether the steam trap is malfunctioning, otherwise it will affect the insulation; ② Is each guide roller active and balanced? As long as 1 to 2 guide rollers are not flexible enough, scratches and weft skew will occur; ③ Is the liquid carrying rate of the fabric consistent, and is there any scraping phenomenon? ④ Is there any dripping phenomenon on the cylinder (drain plug) and sealing ring? When opening the cover of the dyeing machine with a cover, the operator and others should stand on the side and observe carefully. If you find a problem that you can solve yourself, you should solve it in time. Otherwise, you should report it in time and do not delay to avoid causing greater losses. Generally, each person can operate 2 ordinary roller dyeing machines; skilled workers can operate 3 (or more).