When a castor is damaged, the common way to assess it is by checking how much the wheel surface has worn down. However, there is another completely different failure phenomenon observed in the field: the tire surface becomes sticky, soft, and develops fine cracks, even flaking off small chunks when scraped by hand, despite the castor not having been in use for an excessively long time.
What’s even stranger is that some devices, despite being used infrequently, also experience this issue.
At this point, the cause may not be the traditional sense of “wear,” but rather the hydrolytic aging of certain wheel surface materials under specific conditions.
1. What is the “hydrolysis” of castor wheel materials?
Simply put, it means that after prolonged exposure to moisture or a humid environment, the chemical structure of certain polymer materials gradually changes.
This change differs from the wheel surface being “worn down” by the ground.
Wear typically occurs in the contact area between the wheel surface and the ground, while hydrolysis involves gradual changes in the material’s inherent properties, so it may continue to develop even if the equipment remains stationary for extended periods.
This is why some stock casters appear “almost unused,” only to find their wheel surfaces significantly deteriorated when retrieved years later.
2. Are all polyurethane casters afraid of hydrolysis?
It cannot be generalized.
Polyurethane is not a completely rigid material but rather a broad material system. Different raw material systems, formulations, and manufacturing processes may exhibit significant variations in hydrolysis resistance.
Therefore, it is not accurate to simply conclude that “polyurethane wheels cannot be used in humid environments.”.
The key step is to clarify during the selection phase whether the casters will be in prolonged contact with water, high-moisture environments, cleaning solutions, or steam, and then choose a more suitable material system based on the actual working conditions.
Simply saying “I want a PU wheel” to the supplier does not provide sufficient information.
3. Why is a high temperature and high humidity environment more noteworthy?
Hydrolysis issues are closely related to environmental conditions.
If the casters are exposed to damp areas for extended periods while simultaneously facing higher ambient temperatures, the aging process of certain materials may become more noteworthy.
For example, production areas requiring frequent rinsing, long-term damp warehouses, cleaning equipment, certain food processing environments, and workplaces with moisture, should be specified in advance during the selection process.
Sometimes the mechanical load-bearing capacity of casters is not an issue at all, and it is the environment that truly limits their usage conditions.
4. What is the difference between hydrolysis and ordinary wear?
Normal wear typically exhibits relatively distinct contact characteristics.
After prolonged rolling of the wheel surface against the ground, the working surface gradually thins, which is a relatively straightforward mechanical wear phenomenon.
When the material exhibits significant aging, it may manifest as a sticky wheel surface, loss of original elasticity, surface cracking, localized powdering, or block detachment.
If the casters have not undergone high-intensity operation but exhibit extensive material condition changes, the investigation scope should be expanded from “wear” to the compatibility issues between materials and the environment.
5. Why can stock casters also have problems?
The fact that the casters are not installed on the equipment does not mean that the material condition will never change.
The storage environment in the warehouse is equally important.
If exposed to high temperatures, humidity, direct sunlight, or unsuitable environments for material storage for a long time, some polymer materials may still gradually age.
Therefore, for long-term inventory of casters, it is not recommended to only check whether the packaging is complete.
Before putting it back into use, the wheel surface can be checked for obvious sticking, cracks, hardening, softening, or surface abnormalities.
Especially for inventory that has not been circulated for a long time, it is worth conducting a simple inspection.
6. When selecting equipment for frequent cleaning, ask one more question
Many procurement personnel will tell suppliers:
The device is used indoors
But the condition of ‘indoor’ is too broad.
A regular warehouse is indoors, and the food processing area that needs to be washed every day is also indoors. The requirements for caster materials in the two environments may be completely different.
Therefore, if the equipment needs to be cleaned frequently, further explanation should be given on the cleaning frequency, whether there is long-term water accumulation, whether cleaning agents are used, and whether the wheels are in a damp state for a long time.
These pieces of information are often more valuable than simply telling suppliers’ indoor use ‘.
7. Found abnormal wheel surface, don’t rush to only replace with the same model
If a batch of wheels show similar sticking, cracking, or falling off, the simple solution is to replace them with new ones.
But if the new casters still use the exact same material system and the on-site environment remains unchanged, similar problems may occur again.
A more reasonable approach is to first confirm:
What humidity environment does the device remain in for a long time?
Do you frequently come into contact with water?
Is there a cleaning process?
Is there long-term water vapor near the wheels?
Are the storage conditions in the warehouse suitable?
After confirming these factors, evaluate whether the wheel surface material needs to be adjusted.
Write it at the end
The failure of casters is not always due to excessive use.
Some wheels run at high frequency every day, but the wheel surface remains stable; Some wheels may not be used frequently, but they may age prematurely due to mismatched environment and materials.
This is also a point often overlooked in the selection of casters:
In addition to asking how heavy the device is and what ground it runs on, you should also ask what environment the casters come into contact with every day.
When the wheel surface starts to stick, crack or even fall off, it is better not to immediately attribute it to “poor material quality”. Further inspection of the usage and storage environment often makes it easier to find the real cause.
For more information, please feel free to contact GLOBE Team!
Post time: Sep-11-2026
