What is the installation and debugging process of POY spinning testing machine?

POY(Pre-Oriented Yarn) spinning testing machine is the core equipment used for small-batch research and development and process verification in chemical fiber field. Its installation and debugging should strictly follow the process of "basic preparation → mechanical installation → electrical connection → system debugging → process verification", and both equipment accuracy and safety specifications should be taken into account. The following are detailed operation steps and key points for attention:

First, preparation before installation: laying the foundation conditions

Before installation, it is necessary to confirm the qualifications of the site, equipment accessories, tools and personnel to avoid rework in subsequent processes.

Site and environment acceptance

Space requirements: reserve equipment operation space (front and back ≥1.5m, left and right ≥1.2m), reserve space ≥0.8m above it (convenient for subsequent maintenance and pipeline installation), level the ground (horizontal error ≤3mm/㎡), and do anti-skid and anti-corrosion treatment (to avoid leakage and pollution of spinning oil).

Environmental parameters: the temperature shall be controlled at 23 2℃ (to avoid the influence of equipment parts on accuracy due to thermal expansion and contraction), and the relative humidity shall be 45%-65% (to prevent electrical components from short circuit due to moisture and electrostatic accumulation of filaments), and an independent ventilation system shall be provided (to discharge trace volatiles generated during spinning).

Infrastructure: confirm that the site has reserved 380V three-phase five-wire power supply (power is matched according to equipment model, usually ≥50kW), compressed air interface (pressure is 0.6-0.8MPa, which is used for driving pneumatic components) and cooling water circulation interface (inlet water temperature ≤25℃, flow rate ≥10L/min, which is used for cooling heating components).

Inventory of equipment and accessories

Check the core components: extruder (including screw and barrel), metering pump, spinning assembly (spinneret and filter sand), cooling windshield, oiling device, drafting roller, winder, electrical control cabinet and oil circulation system one by one to ensure that there is no missing or transportation damage (such as screw deformation and scratches on spinneret).

Prepare special tools: level meter (accuracy 0.02mm/m), torque wrench (for torque control of fixed bolts), micrometer (for detecting the coaxiality of components), multimeter (for electrical wiring detection) and special cleaning tools for spinning (such as component cleaning basket and compressed air blowing gun).

Personnel and safety preparation

Operators should have chemical fiber equipment operation qualification and be familiar with POY spinning process principle; The installation team should include mechanical engineers (responsible for precision calibration) and electrical engineers (responsible for wiring).

Set safety warning signs in advance (such as "high pressure danger" and "high temperature area"), and equip with fire extinguishing equipment (dry powder fire extinguisher for oil fire), high-temperature gloves (contact with heating components) and insulating tools (electrical operation).

Second, mechanical installation: ensure accuracy and coaxiality.

Mechanical installation is the core of the stable operation of equipment, and it is necessary to control three key indexes: "levelness, coaxiality and spacing error".

Positioning and fixing of equipment main body

Hoist the equipment main body (integrated stand such as extruder and winder) to the preset position by forklift or crane, and pay attention to the "lifting lug" marked in the equipment manual to avoid the deformation of the stand.

Use level to detect the levelness of the frame: first adjust the longitudinal direction (extruder → winder direction), then adjust the lateral direction to ensure that the horizontal error of the four corners of the frame is ≤0.1mm/m, which is achieved by adjusting the adjustable anchor bolts at the bottom of the frame, and finally fix the frame on the ground with expansion bolts (the bolt torque is as required in the manual, usually M16 bolt torque is 50-60 nm).

Assembly and calibration of core components

The extruder is connected with the metering pump: the metering pump is installed at the discharge port of the extruder, and the parallelism (error ≤0.03mm) of the flange surfaces of the two is detected with a micrometer to ensure the coaxiality (radial runout ≤0.02mm) of the metering pump shaft and the extruder screw shaft, so as to avoid the decrease of metering accuracy or the abrasion of parts caused by different shafts during operation.

Installation of spinning assembly: put spinneret (to be cleaned by ultrasonic wave in advance) and filter sand (to be filled according to process requirements, such as 200-mesh+400-mesh double-layer filtration) into the assembly shell, tighten the assembly cover with torque wrench to apply force evenly in several times (to avoid the deformation of spinneret), and then fix the assembly in the heating box below the metering pump to ensure that the center of the assembly is aligned with the center of the cooling air window (deviation ≤1mm).

Positioning of cooling air window and oiling device: the cooling air window should be vertical below the spinneret (verticality error ≤0.5mm/m), and the distance between the air outlet of the air window and the spinneret should be adjusted according to the process requirements (usually 20-30cm); The loading tanker shall be located under the cooling wind window, so as to ensure that the strands can uniformly contact the loading tanker when passing by, and the axis of the loading tanker is parallel to the axis of the drafting roller (parallelism error ≤0.1mm).

Calibration of drafting roller and winder: when drafting roller (usually 2-3 groups of hot rollers) is installed, the levelness of roller surface should be detected (error ≤0.05mm/m), and the spacing between adjacent rollers should be adjusted according to the requirements of filament path (usually 50-80 cm); The winding shaft of the winder should be coaxial with the last group of drafting rollers (radial runout ≤0.03mm) to avoid irregular cake formation during winding.

Auxiliary system installation

Oil circulation system: connect the pipeline of oil storage tank, oil pump and oiling device to ensure that there is no leakage in the pipeline (pressure test can be used, and there is no pressure drop when the pressure is kept at 0.4MPa for 30 minutes), and install a filter (accuracy is 5μm to prevent impurities from blocking the oiling hole).

Cooling water system: the cooling water channel connecting the cooling water tank, the water pump, the extruder barrel and the heating box of the spinning assembly. The pipeline needs to be insulated (to avoid water temperature fluctuation) and installed with a flow sensor (to ensure that the cooling water flow reaches the standard).

Third, electrical connection: ensure safety and signal stability.

The electrical connection should strictly follow the electrical schematic diagram to avoid short circuit, poor grounding and other problems. The core is the accurate connection of "power circuit, control circuit and sensor circuit".

Power circuit wiring

Lead a special cable from the main distribution box of the site (the cross section is selected according to the power of the equipment, such as 16mm² copper cable for 50kW equipment), and connect it to the main circuit breaker of the electrical control cabinet of the equipment, so as to ensure that the terminal is tight (tighten it with a torque wrench according to the terminal specifications, such as the M6 terminal torque of 8-10 nm), and make phase marks (L1, L2, L3, N, PE).

Connect the power lines of extruder motor, metering pump motor, drafting roller heating tube and winder motor respectively. Pay attention to distinguish the phase line from the zero line when wiring the heating tube to avoid burning the single-phase heating tube. The wiring of the motor should ensure the correct steering (it can be confirmed by inching test, for example, the extruder screw should rotate clockwise, which is consistent with the instruction).

Control loop and sensor wiring

Control lines connecting PLC (programmable logic controller) and various executive components (such as solenoid valve, frequency converter and heating controller) shall be shielded (to avoid electromagnetic interference), and the shielding layer shall be grounded at one end (connected to the grounding bar of the control cabinet, with grounding resistance ≤4Ω).

Install and wire all kinds of sensors: barrel temperature sensor (PT100 platinum resistor, which needs to be inserted into the barrel temperature measuring hole to ensure accurate temperature measurement), spinning component pressure sensor (installed at the outlet of metering pump, with the measuring range selected according to the process requirements, usually 0-50MPa), filament tension sensor (installed between the drafting roller and the winder to ensure that the stress direction of the sensor is consistent with the filament tension direction), and cooling air speed sensor (installed at the wind window outlet).

Grounding and insulation test

Overall grounding of the equipment: connect the frame, electrical control cabinet and motor housing to the ground electrode of the site through the ground wire, and the grounding resistance shall be detected by a grounding resistance tester to ensure that it is ≤4Ω (to avoid the risk of electric leakage).

Insulation test: use megohmmeter (500V range) to test the insulation resistance of power circuit to ground ≥1MΩ, and control the insulation resistance of circuit to ground ≥2MΩ to avoid short circuit caused by poor line insulation.

Fourth, system debugging: step by step verification from no-load to load.

Debugging should be divided into three steps: "no-load debugging → no-load trial operation → load debugging", and problems should be investigated step by step to avoid equipment damage caused by direct load.

No-load debugging (no raw materials, no wires)

Self-inspection of electrical system: turn on the power supply of the control cabinet, start the PLC, enter the equipment operation interface, check whether the display of each sensor is normal (for example, the temperature shows "room temperature" and the pressure shows "0MPa"), and test the actions of each actuator, such as the start and stop of the cooling windshield (the wind speed can be adjusted, and the deviation between the displayed value and the set value is less than or equal to 5%), the rotation of the oil tanker (the rotation speed is stable without jamming), and the heating of the drafting roller (the set temperature).

No-load operation of mechanical system: start the extruder motor (without screw and raw material), and test the motor speed adjustment (0-50r/min, with stable speed and no fluctuation); Start the winding machine (no silk cake) and test the rotation of the winding shaft (the rotation speed is 0-3,000 m/min, without abnormal sound and vibration); Check the transmission parts (such as gearbox and bearing) for abnormal noise (it can be detected by sound level meter, and the no-load noise is ≤75dB).

No-load test run (continuous verification of stability)

Set the simulated process parameters, such as extruder temperature (according to the conventional POY raw material setting, such as PET raw material barrel temperature of 260-280℃), drafting roller temperature of 120-140℃, and cooling air speed of 0.5-1.0m/s, and let the equipment run continuously at no load for 4-8 hours.

Real-time monitoring key indicators: record the temperature of each heating zone (fluctuation ≤ 2℃), motor current (stable below 30% of rated current) and bearing temperature (≤60℃, detected by infrared thermometer) every hour, and check whether there are any problems such as overheating, abnormal sound and sensor drift.

Load debugging (adding raw materials, spinning sliver)

Raw material preparation and process setting: raw materials (such as PET chips, which need to be dried in advance until the water content is less than or equal to 0.02%) are selected according to the test requirements, and the formal process parameters are set: extruder screw speed is 20-30r/min, metering pump speed is 5-10r/min (calculated by filament size), cooling air temperature is 25℃, oiling rate is 0.8-1.2%, and drafting ratio is 2.5-.

Spinning start-up and parameter adjustment: add the raw materials into the extruder hopper, start the extruder, keep the temperature of the barrel at a set value for 30 minutes (to ensure that the raw materials are fully melted), start the metering pump, and observe the spinning situation of the spinneret of the spinning assembly:

If the filament breaks frequently: check whether the spinneret is blocked (it needs to be stopped for disassembly and washing), whether the cooling air speed is too low (appropriately increased), and whether the melting temperature of raw materials is insufficient (increasing the barrel temperature by 5-10℃).

If the oiling of the wire rod is uneven: adjust the contact pressure between the oil tanker and the wire rod, the concentration of oil agent (usually 10-15%) and the temperature of oil agent (25-30℃).

Winding and quality inspection of silk cakes: after the silk strips are stable, start the winding machine to wind 1-2 silk cakes (each cake weighs 500-1000g), and after stopping, check the quality of silk cakes, such as fineness deviation (measured by a fineness meter, the deviation is ≤ 2%), breaking strength (≥3.0cN/dtex) and elongation (15-25).

V. Final Acceptance and Document Filing

After debugging, it needs to be checked and accepted, and the documents should be sorted out to provide a basis for subsequent use.

Acceptance of continuous and stable operation: set qualified process parameters, let the equipment spin continuously for 24 hours, during which there is no broken yarn or equipment failure, and the fluctuation of the quality index (fineness, strength and elongation) of the silk cake is ≤ 3%, which is considered as qualified debugging.

Document filing: sorting out installation and debugging records, including:

Mechanical installation records (levelness and coaxiality test data), electrical wiring diagram and grounding insulation test report;

Debugging parameter records (process parameters at each stage, sensor data, troubleshooting records);

Silk cake quality inspection report (third-party inspection or self-inspection data);

Equipment manual, spare parts list and operation manual (distributed to operators).

Key considerations

Safety priority: the surface temperature of heating components (barrel, drafting roller) is extremely high (200-300℃), so wear high-temperature gloves when debugging to avoid direct contact; It is forbidden to open protective doors (such as extruder barrel protective door and winder protective cover) when the equipment is running.

Precision control: high-precision components such as spinneret and metering pump should be handled with care to avoid collision during installation; The coaxiality of drafting roller and winding shaft directly affects the quality of wire rod, so it needs to be calibrated repeatedly during debugging.

Raw material adaptation: The spinning process parameters of different raw materials (such as PET, PA6 and PP) are quite different. Before debugging, it is necessary to confirm the characteristics of raw materials to avoid carbonization of raw materials and equipment blockage due to parameter mismatch.

Through the above process, the POY spinning testing machine can be installed accurately and run stably, which can meet the needs of subsequent small batch research and development or process verification.