What are the wearing parts of polyurethane spraying equipment?

Polyurethane sprayer is widely favored as a high-pressure spraying equipment commonly used for spraying polyurea and polyurethane in the industries of building insulation, automobile, and ship, with the advantages of high efficiency, uniformity of spraying, and strong adhesion. However, in the long-term use of polyurethane sprayers, some parts are prone to wear and tear or aging, affecting the spraying effect and equipment life. Therefore, understanding its wear parts and maintenance methods is the knowledge that every operator and manager must master.

I. Spray gun system: the most wearable key parts

Spray gun is the core component of polyurethane sprayer, which directly determines the spraying quality and efficiency. The wear parts in the spray gun system include:

1. Nozzle

   • Role: Control spraying flow and spraying angle.

   • Reason for wear and tear: Long-term flushing of high-pressure raw materials, crystallization and clogging.

   • Maintenance suggestion: Replace every 1-3 months and clean in time after construction.

2. Mixing Chamber

   • Role: Fully mix the A/B two-component raw materials.

   • Reason for fragility: High pressure flushing and residual materials lead to wear and tear or crystallization.

   • Maintenance suggestions: regular cleaning, inspection or replacement every 1-3 months.

3. Needle Valve & Seal (Needle & O-Ring)

   • Function: Controls gun on/off and seals against leakage.

   • Reasons for wear and tear: Frequent starting and stopping, high temperature corrosion of raw materials.

   • Maintenance suggestions: It is recommended to replace with the nozzle to keep the sealing.

Second, the pump system: to ensure accurate delivery of raw materials

Polyurethane sprayers usually use a proportional pump system (gear pump or piston pump), the wearing parts include:

1. Pump seal kit (Pump Seal Kit)

   • Role: Prevent leakage of A/B material.

   • Reason for wear and tear: Long-term high pressure, chemical corrosion.

   • Recommendation: Replace every 6 months.

2. Ball & Seat

   • Function: To control the flow direction and backflow of raw materials.

   • Reasons for wear and tear: material abrasion, particle scouring.

   • Recommendation: Replace every 6-12 months.

3. Pump piston rod (Piston Rod)

   • Role: Drive the pump body movement, transfer pressure.

   • Reason for susceptibility to damage: wear and tear or corrosion over a long period of time under high pressure.

   • Suggestion: Check regularly and replace if necessary.

Heating and Circulation System: Maintaining the fluidity of raw materials

1. Heating Rod / Heating Tube

   • Role: to ensure that the raw material to achieve the best viscosity, easy to spray.

   • Reason for wear and tear: long time high temperature erosion or aging of the heating wire.

   • Recommendation: Check and replace every 6-12 months.

2. Temperature Sensor (Thermocouple)

   • Function: Real-time monitoring of raw material temperature to ensure spraying accuracy.

   • Reason for wear and tear: Thermal fatigue or poor contact.

   • Recommendation: Periodic calibration or replacement.

3. Filter / Cartridge

   • Function: Prevents contaminants from entering the gun.

   • Cause of wear: build-up of material or clogging.

   • Recommendation: Clean weekly and replace 2-3 months.

High Pressure Hoses and Fittings

1. High Pressure Hose

   • Function: Conveying A/B material to the spray gun.

   • Reasons for wear and tear: high pressure pulse fatigue, lining aging.

   • Suggestion: Replace in 12-18 months.

2. Heated Hose

   • Function: Maintains material temperature and prevents viscosity increase.

   • Reason for wear and tear: aging or damage of electric heating wire.

   • Suggestion: Check the resistance or energization regularly.

3. Joints and Seals

   • Function: To prevent leakage of piping.

   • Reason for wear and tear: Frequent disassembly and reassembly.

   • Recommendation: Check or replace every 6 months.

V. Electrical and Control System

1. Relay / Contactor

   • Function: Controls the switching of equipment circuits.

   • Reason for wear and tear: Frequent starting and stopping causes wear and tear of contacts.

   • Recommendation: Inspect once a year.

2. PLC Module / Sensor

   • Function: Monitoring and automatic control of equipment.

   • Reason for wear and tear: Influence of high temperature, humidity and dust.

   • Recommendation: Regular testing of functional stability.

3. Touch Screen / Keypad

   • Function: Human-machine interaction.

   • Reason for wear and tear: long-term operation.

   • Recommendation: Replace as needed.

Maintenance Recommendations

1. Establish a record of replacement of wearing parts and maintain it according to the cycle to prolong the life of the equipment.

2. Clean the spray gun and pipeline in time after construction to avoid clogging by crystallization of raw materials.

3. Use original accessories to ensure equipment precision and spraying effect.

4. Regularly check the pump body, electric and temperature control system to avoid unexpected equipment shutdown.

5. Equip with common spare parts (nozzle, O-ring, valve ball, etc.) to improve the construction efficiency.