Elasticity Degradation of Polyurethane Pads
Polyurethane pads are widely used in jacks and industrial equipment for load distribution and shock absorption. Over time, their elasticity can degrade, affecting performance, stability, and safety. Understanding the causes, effects, and mitigation strategies is crucial.
1. Causes of Elasticity Degradation
Repeated Loading Cycles: Continuous compression and decompression lead to fatigue and permanent set, reducing rebound ability.
Overloading: Applying loads beyond the rated capacity accelerates material deformation and elasticity loss.
Environmental Factors: Exposure to high temperatures, UV radiation, moisture, or chemicals can chemically degrade polyurethane chains.
Aging: Natural aging of polyurethane results in hardening, embrittlement, or micro-cracking.
Poor Material Quality: Inconsistent curing, air bubbles, or inferior formulations reduce long-term elasticity.
2. Effects of Elasticity Loss
Reduced Shock Absorption: Pads lose their ability to distribute loads evenly, increasing stress on jack components.
Instability During Lifting: Loss of elasticity can result in uneven contact with the lifted object, increasing tipping risk.
Accelerated Wear: Hardened or fatigued pads wear faster, potentially damaging adjacent surfaces or the jack itself.
Safety Concerns: Degraded pads may fail under load, posing serious risks to operators and equipment.
3. Mitigation Strategies
Load Management: Operate within rated capacities and avoid sudden shock loads.
Material Selection: Use high-quality, properly cured polyurethane with additives for UV and chemical resistance.
Environmental Protection: Limit exposure to extreme temperatures, sunlight, and corrosive chemicals.
Regular Inspection: Monitor pads for signs of hardening, cracking, or permanent deformation, and replace as needed.
Proper Storage: Store pads in a cool, dry, shaded environment to slow aging and degradation.
4. Conclusion
Elasticity degradation in polyurethane pads results from mechanical fatigue, overloading, environmental exposure, aging, and material defects. Preventive measures, proper usage, and regular inspection are essential to maintain performance, ensure safety, and extend service life.
References
Gent, A. N. Engineering with Rubber: How to Design Rubber Components. Hanser Publishers, 2012.
Lake, G. J. “Fatigue and Fracture of Elastomers.” Rubber Chemistry and Technology, 2000.
ASTM D412 – Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension.
ISO 7619-1 – Rubber, Vulcanized or Thermoplastic — Determination of Indentation Hardness.
ASTM D2240 – Standard Test Method for Rubber Property—Durometer Hardness.
