How oil-resistant are polyurethane (PU) coated casters?

Polyurethane (PU)-coated casters offer excellent oil resistance, making them an ideal choice for industrial oil-contaminated environments.

Dense Molecular Structure: PU is composed of rigid urethane groups and flexible segments (commonly known as the more stable polyether type). This high crosslink density prevents oil and grease penetration, resulting in significantly greater swelling resistance than standard rubber (which can swell by over 50%).

Optimized Formulation: Industrial-grade PU is enhanced with antioxidants and oil-resistant additives to further resist grease corrosion.

Mineral Oil (motor oil, lubricating oil, etc.): Long-term contact with PU exhibits no significant swelling (volume expansion <5%), maintaining wear resistance and stable elasticity. Suitable for: Machine shops and auto repair shops.

Plant/Animal Oil: Highly resistant, crack-resistant, and non-sticky. Some models meet food contact standards. Suitable for: Food factories and restaurant kitchens.

Mild Solvents (kerosene, diesel): Short-term splashes are acceptable; avoid long-term immersion in high concentrations (which may soften slightly).

Caster Type Volume Swelling in Mineral Oil Performance Changes After Long-Term Oil Contamination Applicable Applications

PU-Coated Casters: <5% No significant softening, stable wear resistance Long-term/heavy oil contamination environments (preferred)
Ordinary Rubber Casters: 30%-100% Severe swelling and softening, prone to falling apart Oil-free/light temporary oil contamination

Nitrile Rubber Casters: 10%-20% Slight softening, reduced wear resistance Moderate to light oil contamination

Strong solvent environments: Gasoline, toluene, acetone, etc. will damage the PU structure.

High temperatures combined with oil contamination (>60℃): Accelerated penetration aging; select high-temperature-resistant modified PU.

Long-term complete immersion: High-pressure penetration may cause separation between the rubber surface and the core.

Summary: PU-coated casters offer excellent resistance to mineral and vegetable oils (significantly better than rubber), maintaining wear resistance, elasticity, and structural integrity in oily environments. Their overall performance surpasses rubber, offering a better balance of quietness and floor protection than nylon, and they offer excellent value for money. Their advantages can be fully realized by avoiding strong solvents, high-temperature oil contamination, and long-term immersion.