I. Safety Operating Procedures
1. Preparation for Loading: Operation must be stopped. Wet the fabric end with water and then smoothly attach it to the roller. Do not operate while the machine is running. If the fabric end falls off, stop immediately and reattach it.
2. Protection During Operation: Never handle defects such as curled edges or wrinkles on the front of the fabric roll to prevent hands from getting caught. The fabric roll core (square iron rod) must not be placed near the rotating roller.
3. Equipment Safety: The bevel gears and drive shaft on the roller must be equipped with fully enclosed safety covers. The dyeing machine should be equipped with an electrical or mechanical emergency stop device (such as a safety plate), which needs to be inspected and maintained regularly.
4. Personal Protective Equipment: When working, work clothes cuffs must be tightened. Skirts and neck towels are not allowed. When using acids, alkalis, and other toxic or harmful dyes and auxiliaries, appropriate protective equipment (such as goggles, rubber gloves, rubber boots, or respirators) must be worn.
5. Lifting Safety: When using an electric hoist to lift the fabric roll, the rollers must be kept horizontal and stable to prevent the rope from slipping and causing the fabric roll to fall.
II. Key Points of Dyeing Process Operation
1. Chemical Preparation: The dye must be fully stirred and dissolved in the chemical preparation tank before being injected into the dyeing cylinder; otherwise, color deposits or stains may occur on the fabric surface.
2. Temperature Control: The dyeing process must be covered and insulated to maintain a consistent temperature throughout the dyeing cylinder, both above and below the liquid level.
When using steam to raise the temperature, the fabric roll must not be moved, otherwise a temperature difference will occur, causing color variations.
Before operation, ensure that the temperature difference between the fabric roll temperature and the liquid level is minimal. In winter, it is especially important to prevent the fabric roll from becoming too cold, which could cool the fabric layer in contact with the roll.
3. Winding and Operation: Fabrics require pretreatment (such as desizing, scouring, bleaching, etc.) to remove impurities and sizing agents, improving dyeing uniformity and color fastness.
During the winding dyeing operation, the fabric needs to be evenly wound onto the dyeing beam, ensuring the winding tension is appropriate.
Start the winding dyeing machine, allowing the fabric to be repeatedly immersed in the dye bath. The immersion time and movement speed of the fabric in the dye bath are controlled by adjusting the angle of the guide rollers and the speed of the drive device.
The temperature and level of the dye bath are monitored in real time to ensure the uniformity of the dye bath and the stability of the dyeing process.
4. Uniformity Control: During the winding dyeing process, the fabric tension should be kept uniform to prevent uneven dyeing and fabric deformation. Especially during the winding process, fabric folding or overlapping should be avoided to prevent dyeing spots or streaks.
III. Common Problems and Prevention
1. Weft Color Difference: Check whether the flow rate of each outlet of the drain pipe is consistent. 1. If the flow rate is inconsistent, an adjustable water-blocking cover can be added to the outlet with the higher flow rate to ensure consistent flow rates at all outlets.
2. Shallow and Deep Edges: Shallow edges may be caused by the temperature inside the cover being significantly lower than the dye liquor temperature, causing the fabric edge to cool quickly. The dye only adheres to the fiber surface and fails to diffuse effectively inwards, or the required temperature was not reached during fixation. To address this, reduce the frequency of door openings and turn on the heating element at the top of the cover to bring the temperature inside the cover closer to the dye liquor temperature. Deep edges are mainly caused by uneven fabric winding. The exposed fabric edge is not compressed by the fabric roll, resulting in more dye adsorption and a deeper color.
3. Tension Control: When dyeing synthetic fiber fabrics on a roll dyeing machine, the tension should be tighter at the beginning and looser above 100°C. Avoid maintaining a constant tension.
IV. Equipment Maintenance
1. All components of the roll dyeing machine (such as the dyeing shaft, guide rollers, drive unit, etc.) should be inspected and maintained regularly to ensure normal operation.
2. The dye bath should be cleaned promptly to prevent dye sedimentation and auxiliary agent residue from affecting the dyeing effect.
3. When opening or closing the doors, no one should stand on either side to avoid injury or burns.
4. In case of emergency, the emergency stop switch should be turned off to stop the entire machine.
5. Carefully remove yarn ends and debris from the direct steam pipe to prevent uneven temperatures at both ends of the dye bath.
6. Check and adjust the curvature of the tension frame and adjust the fabric tension to prevent wrinkling during fabric operation.
7. Check if the track meter probe is loose or damaged; otherwise, the automatic turning mechanism will malfunction.
8. Check if the brake setting and tension settings are correct to prevent fabric runaway (dye slippage) during the dyeing process.
