The following are the debugging details of the melt composite spinning machine:

1、 Equipment inspection and pre-processing

1. Cleaning and protection: After daily shutdown, clean the surface of the spinneret, distribution plate, and bundle of coking materials, and use a special copper brush combined with neutral solvent (such as acetone) to wipe to prevent residual polymer solidification and blockage. The screw feeding section needs to be cleaned carefully to avoid local overheating caused by the accumulation of raw material degradation products.

2. Mechanical transmission system calibration: Check the lubricating oil level and impurity content of the gearbox every week, and replace the fully synthetic gear oil (ISO VG68) every quarter; The tension of the synchronous belt needs to be adjusted to a pressing depth of 10-15mm. If the tooth profile of the severely worn synchronous belt deviates by more than 2mm, it must be replaced.

2、 Core parameter setting and calibration

1. Temperature control system debugging: Adopting zone heating design, the maximum working temperature reaches 350 ℃ (taking the 2025 M12 equipment as an example), and the temperature control accuracy is ± 0.5 ℃. Record the temperature curves of each zone every hour, and compare the deviation from the set value to be<± 2 ℃. If the heating coil turns red abnormally or the temperature control module alarms, immediately stop the machine to check for poor thermocouple contact or cooling fan failure.

2. Pressure and flow control: The screw extrusion pressure range is usually 5-15MPa, and precise flow control of 0.5-21.6g/min is achieved through Danfoss speed controllers. Regularly verify the sealing of the melt pump to ensure stable extrusion of high viscosity materials.

3. Optimization of spinneret and flow channel: Establish a "preventive replacement" mechanism, and immediately replace the spare spinneret when the fluctuation of single hole wire output exceeds 5%; The old board undergoes alkaline boiling, ultrasonic cleaning, and mirror polishing treatment. Qualified products are screened and returned to the warehouse using a laser micro hole detector. Install ceramic fiber insulation cover on the distribution board to reduce the difference in melt viscosity caused by radiation heat dissipation.

3、 Trial operation and dynamic adjustment

1. Low speed start-up and gradual loading: Run at low speed during start-up, gradually increase to working speed after the melt pressure stabilizes. During the process, attention should be paid to the speed ratio error of the stretching roller (<0.3%) and the winding tension (0.1cN/dtex).

2. Cooling system matching: Select the transverse blowing or water bath cooling mode according to the fiber specifications. After the initial fibers are rapidly cooled and shaped by 25 ℃ cold air or water bath, they are strengthened by 3-5 times stretching through a guide roller (500-1200m/min).

3. Abnormal working condition handling: If there are broken wires or uneven fiber webs, priority should be given to checking the blockage of the spinneret and the status of the static mixer. Disassemble the mixing components every half month and measure the gap between the spiral blades (standard value is 0.15 ± 0.02mm). If it exceeds the tolerance, laser cladding repair is used.

4、 Closing work and data archiving

1. Material emptying and rust prevention treatment: After spinning is completed, the remaining material should be squeezed out, the temperature control unit and transmission unit should be turned off, and the cooling water should be turned off after the temperature drops to a safe range. Spray rust inhibitor containing molybdenum disulfide on exposed metal parts, and coat the hydraulic rod piston rod with a hard chromium layer thickness of ≥ 0.05mm.

2. Maintenance file update: Connect to the DCS system for real-time monitoring of key parameters (such as screw speed fluctuation<± 1rpm, melt pressure standard deviation<0.2MPa), and use a vibration analyzer to detect the effective value of bearing vibration speed (RMS ≤ 4.5mm/s) every month. Establish equipment health records, recording the spare part numbers, fault codes, and solutions for each maintenance and replacement.