I. Dyeing Quality-Related Faults
1. Excessive Foaming: Caused by high-speed fabric movement and high turbulence in the dye liquor; often linked to the foaming characteristics of dyes or auxiliaries. It leads to uneven liquor pickup on the fabric surface. Mitigation involves prioritizing low-foaming auxiliaries rather than directly using defoamers, which can stain the fabric.
2. Creasing/Wrinkling: Occurs when fabric remains stacked too long in the storage chamber and sets into permanent "chicken-foot" creases upon cooling below the glass transition temperature. Prevention requires keeping the fabric load within rated capacity, cooling slowly after dyeing, and using smoothing agents.
3. Uneven Dyeing: Caused by excessively rapid heating rates, insufficient holding time, or significant differences in dye uptake rates. Solutions include optimizing the heating curve, selecting dyes with compatible dispersion properties, and appropriately increasing fabric speed.
4. Oligomer Deposition: Oligomers released during polyester dyeing adhere to heat exchangers and fiber surfaces, reducing thermal efficiency and causing a "white frost" appearance on the fabric. This can be mitigated through solvent scouring prior to dyeing and the addition of oligomer control agents.
5. Dye Aggregation: Triggered by excessive electrolytes in the dye bath or improper auxiliary selection; leads to color spots and reduced dye uptake. Solutions include reducing electrolyte content, increasing dispersant dosage, and ensuring thorough equipment cleaning.
6. Fabric Tangling: Lightweight fabrics may stack haphazardly and knot inside the chamber, causing machine stoppages. Prevention relies on operators arranging the fabric correctly and maintaining an appropriate running speed.
7. Fuzzing/Abrasion: Caused by nozzle diameters that are too small, excessive jet pressure, or improper handling/unfolding procedures. Solutions include matching the nozzle to the fabric weight, lowering jet pressure, and handling the fabric gently.
8. Excessive Fabric Elongation: Caused by low fabric loads or excessively high liquor levels, which increase running resistance. Solutions include adjusting the load to standard levels and maintaining the minimum reasonable liquor level.
II. Mechanical Faults
1. Circulation pump abnormal noise/insufficient flow: Impeller wear or debris clogging the pump chamber results in inadequate dye liquor circulation power; the pump chamber requires regular disassembly and cleaning, and the impeller should be inspected for wear and replaced promptly.
2. Nozzle clogging: Accumulation of fabric lint or dye clumps in the spray orifices causes fabric movement to snag or stall; nozzles must be disassembled and scrubbed after every production batch.
3. Vessel/pipeline leakage: Caused by aging seals or loose bolts; gaskets require regular inspection, and aged components must be replaced promptly.
4. Fabric guide wheel jamming: Lack of lubrication or excessive bearing wear increases fabric running tension; grease must be replenished regularly, and bearings replaced promptly if wear exceeds 0.5 mm.
III. Electrical Faults
1. Inaccurate temperature control: Sensor drift or aging heating elements cause a discrepancy of more than 1°C between the actual vessel temperature and the displayed value; sensors require regular calibration, and the condition of heating elements must be checked.
2. Motor overload trip: Caused by jammed drive components or circuit short circuits; identify and clear obstructions causing jams and tighten loose wiring terminals.
3. Safety interlock failure: A high-risk fault where the vessel can still pressurize even if the door is not securely locked; the interlock function must be tested monthly, and any faults repaired immediately.
