Does alcohol damage polyurethane casters?

The impact of alcohol on polyurethane casters: Determined by concentration and usage scenario
Whether alcohol damages polyurethane casters depends critically on the alcohol concentration, duration of contact, and usage. In most cases, proper use will not cause noticeable damage, but improper use may affect caster performance. A detailed analysis is as follows:

Based on the properties of polyurethane materials, its molecular structure has a certain tolerance to low- to medium-concentration alcohol (such as 70%-75% medical alcohol). Alcohol at these concentrations is commonly used to disinfect the surfaces of casters used in food and medical applications. Brief contact (e.g., wiping and drying within 1-2 minutes) only slightly dissolves trace wax components on the polyurethane surface without damaging the molecular backbone or causing tread swelling, cracking, or discoloration. Furthermore, alcohol evaporates quickly after disinfection, leaving minimal residue, and its impact on the caster's overall performance is negligible.

However, caution should be exercised regarding the potential effects of high-concentration alcohol (such as 95% denatured alcohol). High-concentration alcohol has a stronger solvent property. Prolonged contact (such as when casters are soaked in high-concentration alcohol or repeatedly wiped without drying) will gradually penetrate the polyurethane tread, disrupting the hydrogen bonds between molecules and causing the tread to "harden." This loss of elasticity and a brittle feel can lead to increased wear and shortened service life. However, the likelihood of high-concentration alcohol coming into contact with casters in everyday situations is low, so improper use in industrial settings should be avoided.

Additionally, the way alcohol is used can affect the effects of alcohol on casters. Using alcohol directly to flush bearing seals or seeping into damaged bearing seals can dilute the lithium-based grease inside the bearing, causing lubrication failure and, in turn, causing the bearing to rust and seize. This damage is not due to alcohol corrosion of the polyurethane, but rather an indirect effect on the caster's structural components.

Therefore, there are two important points to keep in mind when using alcohol: First, prioritize 70%-75% medical alcohol and avoid using alcohol with a concentration higher than 95%. Second, simply wipe the tread with an alcohol-soaked cloth, avoiding the bearing area. Wait for the alcohol to completely evaporate after wiping; no additional water rinse is necessary. For daily cleaning, frequent alcohol treatment is unnecessary, as excessive disinfection can accelerate minor tread aging.