I. Core Preventive Measures
1. Strictly Control Dye Solution Quality to Reduce Corrosion Risk
Chloride ions are the main culprit for cracking the machine head. It is recommended to control the chloride ion content in the water used to prepare the dye solution to <500mg/L, and avoid using chlorine-containing dyeing accelerators (such as table salt) instead of industrial salt. Regularly clean the inner wall to prevent residue accumulation.
2. Optimize Operating Procedures to Reduce Stress Impact
Avoid frequent pressure increases/decreases and rapid heating/cooling. Maintain a stable heating and cooling rate to reduce thermal stress and mechanical vibration damage to the structure.
3. Select High Corrosion-Resistant Materials to Enhance Intrinsic Safety
When purchasing new or replacing parts, it is recommended to use duplex stainless steel instead of 321 austenitic stainless steel, as it has better resistance to stress corrosion. Perform stress-relief heat treatment on cold-worked parts to eliminate residual stress.
4. Establish a Regular Inspection Mechanism
Perform non-destructive testing (penetration or ultrasonic testing) on high-risk areas (such as the R-corner of the die head and welds) every 6 months to detect micro-cracks early.
II. 8 Key Areas to Check Daily
To help you quickly perform inspections, the following are the key areas that must be checked daily and their inspection points:
1. Die Head R-Corner Area
Check for seepage of dye, rust, or grayish-white crystals (signs of chloride ion corrosion).
Touch the surface to see if it is smooth and free of pits or micro-cracks.
2. Cylinder Head and Flange Sealing Surface
Check if the sealing ring is aged, deformed, or cracked.
Check if the flange bolts are tight and if there are any signs of leakage.
3. Circulating Pump and Pipeline Interface
Listen to the operating sound for any abnormalities (noise, vibration).
Check for leaks at the connections and whether the pressure gauge reading is stable.
4. Nozzle and Overflow Port
Confirm No blockages, scale buildup, or deformation.
Observe whether the dye liquor spray is uniform and whether there is any deviation.
5. Heat Exchanger Inlet and Outlet
Check for blockages, scale buildup, or deformation.
Observe whether the dye liquor spray is uniform and whether there is any deviation.
6. Lifting Roller and Guide Roller
Check whether the rotation is flexible and whether the bearings make any abnormal noises.
Check whether the surface is smooth to prevent scratching the fabric.
7. Electrical Control Cabinet and Temperature Control System
Check whether the instrument display is accurate and whether the PLC running light is normal.
Check whether the wiring terminals are loose or show signs of overheating.
8. J-Type Box Inner Wall and Plastic Pipe
Ensure that the inner wall is smooth and free of screws, burrs, or other foreign objects. Ensure that the plastic pipe is not cracked and the joints are not rough to prevent fabric abrasion.
✅ It is recommended to create an inspection card for the above 8 items and implement a "whoever inspects, signs, and is responsible" system to achieve closed-loop management.
