Huatao Group-Vibrating Screen Technology Solution and Service for Quarry & Mining Industry Since 2008.
Polyurethane Screen Blinding Problem: Cause Analysis and Practical Solutions
Polyurethane Screen Blinding Problem: Cause Analysis and Practical Solutions
In the screening operations of mining, metallurgy, coal, and other industries, polyurethane screens have become the preferred equipment component for many enterprises due to their advantages such as wear resistance, impact resistance, and high screening efficiency. However, recently, many companies have reported frequent screen blinding issues during the use of polyurethane screens, which not only significantly reduces screening efficiency and increases equipment energy consumption and maintenance costs but also affects the stability of subsequent production processes. To help enterprises address this challenge, we have conducted in-depth research into the causes and solutions of polyurethane screen blinding.
I. Core Causes of Screen Blinding (Ranked by Impact)
1. Material Characteristics: The Primary Cause
Particle Size and Aperture Mismatch: A high proportion of "near-mesh particles" (particle size within ±10% of the screen aperture) in materials like copper ore easily gets stuck in the screen openings.
High Mud Content: Fine mud (particle size < 0.074mm) tends to adhere to the screen surface in humid environments, forming a "mud layer" that blocks the openings.
High Material Moisture: When the moisture content of materials like copper ore exceeds 8%, fine particles agglomerate due to capillary action, forming "false particles" that cannot pass through the screen.
Low Open Area: If the open area of standard polyurethane screens is less than 40%, the material passage channels are insufficient, leading to accumulation and blinding.
Inappropriate Screen Opening Shape: Round openings perform poorly with irregular particles, while elongated openings (with an aspect ratio of 3:1 to 5:1) are more effective but are often not properly selected.
Smooth Surface Structure: The lack of "drainage grooves" or "protrusion structures" makes it easy for fine mud to adhere.
3. Incorrect Equipment Parameter Settings
Insufficient Vibration Frequency/Amplitude: When the vibration frequency is below 1200 r/min and the amplitude is less than 5mm, the vibration intensity is inadequate to dislodge stuck particles.
Improper Screen Surface Angle: An angle of less than 15° causes material to dwell too long on the screen, leading to accumulation; an angle greater than 25° causes material to flow too quickly, resulting in insufficient screening.
Lack of Auxiliary Cleaning Devices: The absence of real-time cleaning mechanisms such as ultrasonic systems, spray devices, or rubber ball anti-blinding systems prevents timely removal of blockages.
4. Improper Operation and Maintenance
Excessive Feed Rate: Surpassing the screen's capacity (typically the feed rate per unit area should be ≤5 t/(m²·h)) causes material buildup, preventing fine particles from passing through in time.
Uneven Screen Installation: Loose or uneven installation prevents effective vibration transmission, leading to localized blinding.
Untimely Cleaning: Residual material left on the screen after shutdown hardens upon drying, exacerbating blinding during subsequent use.
II. Emergency Measures for Existing Screen Blinding (Quick On-Site Implementation)
1. Temporary Unblocking: Rapidly Restore Screening Efficiency
Physical Unblocking:
For wet, muddy blockages: Use high-pressure water jets (pressure ≥8 MPa) to clean the screen surface, combined with soft wire brushes to remove residual mud from the openings.
For near-mesh particle jamming: After shutdown, gently tap the back of the screen with a wooden stick (avoid metal tools) to dislodge particles, or use compressed air (pressure 0.4-0.6 MPa) to blow backwards from the screen's reverse side.
For hardened blockages: Soak the screen in warm water (40-60°C) for 10-15 minutes to soften the mud before rinsing (avoid strong acids or alkalis to prevent corrosion of the polyurethane material).
Adjust Equipment Parameters:
Temporarily increase vibration frequency (e.g., from 1000 r/min to 1400 r/min) or amplitude (e.g., from 4mm to 6mm) for about 30 minutes to utilize high-frequency vibration for clearing.
Appropriately increase the screen surface angle (e.g., from 18° to 22°) to accelerate material flow and reduce accumulation (note: excessive angle may reduce screening accuracy; readjust after clearing).
Control Feed Rate: Temporarily reduce the feed rate by 30%-50% to allow the screen sufficient capacity to clear blockages, then gradually restore the feed rate once normal screening resumes.
Conclusion
By systematically analyzing the causes of screen blinding and implementing targeted measures, enterprises can effectively improve screening efficiency and extend equipment service life. It is recommended to combine daily maintenance with optimized design to prevent the recurrence of blinding issues.
Contact us ↓
Annie Lu
Huatao Group
Mobile: 0086 18032422676 ( Whatsapp/Wechat/Viber)