How to ensure the stability of multifunctional intelligent spinning experimental machine?

To ensure the stability of multifunctional intelligent spinning experimental machine, we need to start from hardware design, software control, process optimization and daily maintenance, and reduce the influence of mechanical wear, parameter fluctuation and environmental interference through the whole process control. The following are specific measures:

First, the hardware system stability guarantee

1. Mechanical structure optimization

Selection of key components:

Transmission system (such as drafting roller and metering pump) adopts high-precision servo motor and reducer (positioning accuracy ≤±0.01mm) to reduce mechanical clearance and vibration.

The frame is made of high-strength aluminum alloy or cast iron, and the structural stiffness is optimized by finite element analysis to reduce the resonance risk during operation (the natural frequency avoids the working frequency of the motor by 20%).

Installation accuracy control:

When installing the equipment, use a spirit level for calibration (levelness ≤0.1mm/m) to ensure the concentricity of each module (for example, the distance deviation between the spinning head and the receiving device ≤±0.5mm).

The pipeline connection shall be sleeve-type or flange-sealed (pressure resistance ≥ 1.2 times of working pressure) to avoid parameter fluctuation caused by liquid/gas leakage.

2. Temperature control and fluid system stability

Heating module design:

PID self-tuning temperature control algorithm and multi-point temperature sensor (one temperature measuring point is set every 10cm) are adopted to ensure the temperature uniformity ≤ 1℃.

The melt tank or spinning head is equipped with independent temperature control zones to avoid mutual interference between different temperature zones (for example, the temperature difference between the hot drawing roller and the electrostatic spinning module is ≥10℃).

Reliability of fluid transportation:

The metering pump is a positive displacement pump (such as a gear pump) and equipped with a pulsation damper to make the flow fluctuation ≤ 0.3%.

The spinning liquid pipeline is wrapped with thermal insulation material to reduce the influence of ambient temperature on the fluid viscosity (for example, the viscosity change is less than 5% when the temperature difference is less than or equal to 5℃).

Second, the stability of software and control system

1. Data acquisition and control algorithm

High precision closed-loop control;

PLC or industrial controller (such as Siemens S7-1200) and high-speed AD/DA module (sampling frequency ≥1kHz) are used to adjust the motor speed, temperature, pressure and other parameters in real time.

Fuzzy control or adaptive algorithm is introduced to dynamically compensate the parameter deviation caused by material viscosity change and environmental temperature and humidity fluctuation (for example, the pump speed is automatically corrected when the flow deviation is more than 1%).

Anti-interference design:

The signal cable adopts twisted-pair shielded wire, and the power wire and the signal wire are separately wired (the distance is not less than ≥30cm), so as to reduce the influence of electromagnetic interference (EMI) on the accuracy of the sensor (such as temperature signal noise ≤ 0.5℃).

The control system is equipped with Uninterruptible Power Supply (UPS) to ensure that data is not lost in case of sudden power failure, and key components (such as metering pumps) can stop safely.

2. Operation interface and fault diagnosis

Visual monitoring:

Man-machine interface (HMI) displays key parameter curves (such as temperature trend and flow fluctuation) in real time, and sets parameter threshold alarm (such as audible and visual alarm and recording when the temperature exceeds the upper limit).

Built-in historical data storage function (storage period ≥6 months), which can trace the running state of the equipment and help analyze the reasons for the decline of stability.

Intelligent fault diagnosis:

The system automatically recognizes abnormal signals (such as sudden change of motor current and disconnection of temperature sensor), and prompts possible fault points (such as "blockage of metering pump" and "damage of heating pipe"), thus reducing the time for downtime investigation.

Third, process parameters and environmental stability

1. Process parameter curing

Standardized process:

Establish a database of process parameters to record the best spinning conditions (such as temperature, drawing multiple and electrostatic voltage) of different materials (such as PLA and PAN) to avoid fluctuations caused by human misoperation.

Password authority management is adopted to restrict unauthorized personnel from modifying key parameters (such as the maximum speed of metering pump and the upper limit of high-voltage power supply output).

Parameter redundancy design:

Set the allowable range of parameter fluctuation (such as temperature 2℃ and flow rate 1.5%), and when it exceeds the allowable range, it will automatically trigger the backup scheme (such as switching to low speed mode to maintain operation).

2. Environmental condition control

Laboratory environmental management:

Maintain constant temperature and humidity (temperature 23 2℃, humidity 50±5% RH), and configure air conditioner and dehumidifier to reduce the influence of ambient temperature and humidity on the viscosity and electrostatic field of spinning solution (for example, the diameter of electrospun fiber fluctuates by ≤8% for every 10% change of humidity).

Keep away from vibration sources (such as compressors and large motors), and lay damping pads on the ground (vibration acceleration ≤0.5g) to avoid affecting fiber forming accuracy.

Air purification:

For precision spinning (for example, nanofiber preparation), the laboratory needs to achieve ten thousand levels of cleanliness (the count of dust particles ≥0.5μm ≤352000/m) to prevent impurities from blocking the spinneret hole or polluting the fiber.

IV. Daily Maintenance and Preventive Maintenance

1. Regular maintenance plan

Maintenance of mechanical parts:

Check the tension of the drive belt (sag ≤5mm) every week, and fill the bearings with grease (such as lithium grease, once every 200 hours) to reduce the accuracy decline caused by wear.

Clean the spinneret hole of the spinning head every month (using ultrasonic cleaning machine, frequency 40kHz, time 15 minutes) to avoid polymer residue curing blockage.

Electrical system inspection:

Check the grounding resistance (≤4Ω) every quarter, and tighten the electrical connectors (such as the torque of terminal row screws ≥ 2 nm) to prevent the control system from failing due to poor contact.

Calibrate temperature and pressure sensors every year (using standard measuring instruments, the error is ≤±0.5% FS) to ensure the accuracy of data acquisition.

2. Consumables and consumables management

Clear replacement cycle:

The seal of metering pump (such as fluororubber O-ring) should be replaced every 500 hours to avoid leakage caused by aging.

Clean or replace the air filter element every 3 months (according to the frequency of use) to ensure the stable air volume of the ventilation system (deviation ≤ 5%).

Spare parts reserve:

Key components (such as high-voltage power module and servo motor) are equipped with spare parts, which can be quickly replaced in case of failure, reducing downtime (replacement time ≤2 hours).

Five, personnel training and operation specification

1. Standardized operation training

Theoretical and practical assessment:

Operators need to master the start/stop sequence of equipment (such as preheating the temperature control system to the set temperature before starting the metering pump), parameter adjustment logic and emergency handling flow through training.

Organize regular operation competitions to strengthen the mastery of fine operations such as "low fluctuation start" (such as slowly increasing spinning speed to within 5% of the target value).

2. Emergency response to abnormal situations

Establish an emergency plan:

Compile the Equipment Stability Exception Handling Manual, and specify the troubleshooting steps (such as locating the fault point within 30 minutes) and solutions (such as switching to the standby heating module) for common problems such as "sudden temperature drop" and "frequent fiber breakage".

Conduct simulation drills on a regular basis (such as once every quarter) to improve the response speed of personnel to sudden fluctuations (such as restoring key parameters within 10 minutes).

VI. Stability Monitoring and Continuous Improvement

1. Real-time monitoring of key indicators

Establishing stability evaluation system;

Set core monitoring indicators: CV value of fiber diameter (target ≤8%), temperature fluctuation range (≤ 1.5℃) and flow deviation of metering pump (≤ 1%), and generate stability report every day.

SPC (Statistical Process Control) tool is used to analyze the data. When five consecutive samples exceed the average value of 1.5 σ, preventive maintenance (such as checking the transmission system in advance) is triggered.