Failure of Polyurethane Pads upon Contact with Oil Contamination
Polyurethane pads are widely used in jacks and lifting equipment due to their high strength, resilience, and wear resistance. However, exposure to oil and other hydrocarbons can significantly compromise their mechanical and chemical properties, leading to premature failure.
1. Causes of Oil-Induced Pad Failure
Chemical Degradation: Oil can penetrate polyurethane, causing swelling, softening, or chemical breakdown of the polymer chains.
Loss of Mechanical Strength: Swelling or softening reduces load-bearing capacity and elasticity, making the pad more susceptible to deformation under load.
Surface Slippage: Oil on the pad surface reduces friction between the pad and the load or ground, increasing the risk of slipping.
Environmental and Operational Stress: Combined effects of oil contamination with temperature fluctuations or load cycles accelerate material fatigue.
Improper Material Selection: Using polyurethane grades not formulated for hydrocarbon resistance increases vulnerability.
2. Effects of Oil Contamination
Deformation and Swelling: Pads may bulge or permanently deform under load.
Cracking or Delamination: Chemical attack weakens adhesion to metal bases, leading to detachment or surface cracking.
Reduced Service Life: Continuous exposure accelerates wear and shortens operational lifespan.
Operational Hazards: Slippery pads compromise load stability, increasing the risk of accidents and equipment damage.
3. Preventive Measures
Use Oil-Resistant Polyurethane: Select grades specifically designed to withstand hydrocarbon exposure.
Surface Protection: Apply protective coatings or barriers to prevent direct contact with oil.
Immediate Cleaning: Remove oil contamination promptly to minimize chemical attack.
Load Management: Avoid overloading contaminated pads, which exacerbates deformation and failure.
Routine Inspection: Check for swelling, cracks, or adhesion issues, replacing pads when signs of oil-induced degradation appear.
4. Conclusion
Polyurethane pads can fail upon contact with oil due to chemical degradation, loss of mechanical strength, and reduced friction. Using oil-resistant materials, implementing protective measures, and regular inspection are essential to maintain pad performance, safety, and longevity.
References
Gent, A. N. Engineering with Rubber: How to Design Rubber Components. Hanser Publishers, 2012.
ASTM D471 – Standard Test Method for Rubber Property—Effect of Liquids.
Lake, G. J. “Fatigue and Fracture of Elastomers.” Rubber Chemistry and Technology, 2000.
ISO 1817 – Rubber, Vulcanized or Thermoplastic—Determination of the Effect of Liquids.
ASTM D2000 – Standard Classification System for Rubber Products in Automotive and Industrial Applications.
