How does the XY-axis manipulator achieve precise high-pressure foaming of two-component polyurethane?

In the fields of automotive interior, furniture filling, building insulation, etc., the requirements for precision and efficiency of the two-component polyurethane (PU) high-pressure foaming process are getting higher and higher. Traditional manual or simple mechanical infusion methods are difficult to meet the needs of complex shapes and high consistency products, and the intelligent combination of XY-axis manipulator + high-pressure foaming system is becoming a new industry standard.

1. System composition and core components

• XY-axis manipulator: high-precision motion control

Linear module: using servo motor + ball screw/linear motor, repeatable positioning accuracy ≤±0.05mm;

Multi-axis linkage: X/Y axis coordinated motion, supporting linear, circular, 3D trajectory interpolation (complex surface infusion);

Anti-shake performance: acceleration suppression technology avoids vibration during high-speed start and stop, ensuring injection stability.

• High-pressure foaming machine: precise mixing and injection

High-pressure metering pump: independent closed-loop control of material A (isocyanate) and material B (polyol), pressure range 150-250bar;

Dynamic mixing head: static mixer with high-speed rotation (3000-8000rpm); PID control of mixing chamber temperature (±1℃) to ensure stable viscosity of reactants; self-cleaning design to avoid residual solidification blockage.

• Intelligent control system

PLC+motion control card: real-time synchronization of robot trajectory and injection parameters;

Pressure-flow feedback: dynamic adjustment of metering pump output through pressure sensor, error <±1%;

Formula database: storage of process parameters of different products (such as ratio, temperature, injection speed).

2. Five key technologies for achieving precise high-pressure foaming

• Trajectory planning and speed matching

Path optimization: generate the optimal injection path according to the mold 3D model to avoid repeated/missed injection;

Variable speed injection: reduce speed at corners and increase speed in straight sections to ensure uniform foaming thickness.

• High-pressure mixing and instantaneous start and stop

High-pressure injection: pressure above 150 bar breaks the molecular chain of raw materials and improves mixing uniformity (pore diameter ≤ 0.3mm);

Millisecond switch: the response time of the mixing head solenoid valve is <10ms, ensuring that the discharge is instantly cut off to reduce dripping.

• Temperature-pressure-flow closed-loop control

• Ensure uniformity of pores

Vacuum degassing: pre-evacuate the mold (-0.08MPa) to reduce bubble defects;

Gradient pressure injection: adjust the pressure in stages (such as low-pressure filling first and high-pressure compaction later).

• Self-diagnosis and prevention of faults

Blockage warning: real-time monitoring of mixing head pressure fluctuations, automatic reverse flushing when exceeding the threshold;

Tank balance monitoring: ultrasonic sensor warns of material shortage to avoid imbalance.

3. FAQ of XY-axis manipulator two-component polyurethane high-pressure foaming machine

Basic principles

Q1: How does the XY-axis manipulator ensure the motion accuracy in high-pressure foaming?

A1: The XY-axis manipulator adopts servo motor drive + linear guide/ball screw transmission, with repeated positioning accuracy ≤±0.05mm, and anti-shake algorithm to suppress vibration during high-speed movement. All pipelines are protected by drag chains to avoid interference with the motion trajectory.

Q2: What is the core difference between high-pressure foaming and low-pressure foaming?

A2:

High pressure (12-18MPa): Mixing raw materials through high-speed collision, more uniform foam cells (diameter ≤0.3mm), suitable for high-precision products such as automotive interiors;

Low pressure (<5MPa): Relying on mechanical stirring, low efficiency but low equipment cost, suitable for simple filling.

Performance optimization

Q3: How to improve foaming uniformity?

A3:

Vacuum degassing: pre-evacuate the mold to -0.08MPa;

Gradient pressure: low-pressure filling first and high-pressure compaction later;

Trajectory optimization: the robot corner speed is reduced to 80mm/s, and the straight section speed is increased to 200mm/s.

Q4: How to reduce the energy consumption of the equipment?

A4:

Use servo motor + variable frequency pump, which saves 30% energy compared with traditional hydraulic system;

The heat recovery device uses the residual heat of reaction to preheat the raw materials.

Troubleshooting

Q5: What should I do if the injection pressure fluctuates abnormally?

A5:

Check the inlet and outlet pressures of the metering pump (standard: inlet 0.15-0.3MPa, outlet 6.5-12MPa);

Clean the filter or replace the worn plunger pump.

Q6: How to calibrate the positioning offset of the robot?

A6:

Adjust the injection point parameters on the station setting page (about 13plu=1mm);

Check the tension of the synchronous belt and the lubrication of the guide rail.

Maintenance and safety

Q7: Maintenance cycle of key components?

A7:

Mixing head: Check for wear after every 100,000 injections;

Metering pump: Replace seals every 500 hours;

Filter: Clean after daily production.