How to improve the high-temperature resistance of polyurethane casters?

To address the insufficient high-temperature resistance of polyurethane casters, three approaches can be taken: material modification, structural optimization, and process upgrades. These methods can be used to improve their high-temperature resistance and expand their application scenarios:

First, optimize the polyurethane formula and introduce high-temperature-resistant ingredients. During the polyurethane prepolymer synthesis stage, conventional polyols can be replaced with high-temperature-resistant types (such as polycaprolactone diol and polyethersulfone polyol). These polyols offer greater molecular chain stability and can raise the material's high-temperature resistance threshold to 120-150°C. Simultaneously, adding high-temperature-resistant additives, such as nano-silica and silicon carbide fillers, can strengthen intermolecular bonding and reduce softening and deformation at high temperatures. Isocyanate modifiers (such as xylylene diisocyanate) can also be introduced to increase the crosslink density of the polyurethane, further enhancing its high-temperature stability.

Second, improve the tread structure to enhance heat dissipation and deformation resistance. The caster tread is designed with a "honeycomb hollow structure" or "annular heat dissipation grooves" to increase the tread's contact area with the air, accelerating heat dissipation during rolling and preventing localized high-temperature accumulation. A steel or fiberglass reinforced skeleton is embedded within the tread. The skeleton's high-strength support prevents the tread from softening and collapsing or sticking under high temperatures, maintaining the caster's normal rolling shape.

Third, a high-temperature-resistant composite coating is used to isolate heat intrusion. High-temperature-resistant coatings, such as polytetrafluoroethylene (PTFE) or silicone resin coatings, are sprayed onto the polyurethane tread surface. These coatings, which can withstand temperatures exceeding 200°C, form a dense protective film on the tread, reducing heat transfer from external sources to the internal polyurethane material. They also prevent direct contact between the tread and oil and impurities in high-temperature environments, extending the caster's service life.

Fourth, the wheel hub and bearing configurations are upgraded to meet high-temperature requirements. Replace traditional steel wheel hubs with high-temperature resistant alloy materials (such as aluminum alloy and titanium alloy) to reduce the heat conduction efficiency of the wheel hub at high temperatures; use high-temperature resistant bearings, such as full-ceramic bearings and deep groove ball bearings filled with high-temperature grease, to avoid ordinary bearings from getting stuck due to grease failure at high temperatures, ensure that the caster can still rotate smoothly in high-temperature environments, and overall improve the caster's high-temperature resistance and adaptability.