With years of experience in manufacturing polyurethane coated wheels, we frequently receive inquiries about why coated wheels are prone to delamination and tearing. Today, I’ll analyze the reasons from a professional perspective:
1. Raw Material Factors
First and foremost, the selection and quality of raw materials are critical. Polyurethane materials vary significantly in performance. If inferior polyurethane raw materials are used, their molecular structure may be unstable, greatly reducing bonding performance with the wheel core. For example, some low-quality polyurethane may contain impurities or have short molecular chains, which affects both the material’s performance and adhesive strength.
Additionally, improper polyurethane formulation is equally problematic. Different application scenarios require varying hardness and elasticity characteristics. If the formulation isn’t adjusted according to actual needs, the coated wheels become prone to delamination and tearing during use.
2. Substrate Treatment Issues
Second is substrate treatment. Incomplete or improper surface treatment – including oil stains, rust, poor primer quality, contamination during processing, or improper temperature control – will all affect the bonding strength between polyurethane and the substrate, leading to easy delamination.
3. Process Control Points
Process issues are another major cause of delamination and tearing. During the coating process, temperature, pressure, ratio, and equipment all play significant roles.
- Excessive coating temperature may cause polyurethane thermal decomposition
- Insufficient temperature leads to incomplete curing and weak bonding
- Inadequate pressure prevents proper integration between polyurethane and substrate, creating gaps that eventually cause delamination
- Coating speed is also crucial – too fast and the polyurethane won’t evenly coat the substrate, resulting in localized weak bonding
- Improper curing time and conditions similarly affect quality, making wheels prone to delamination and tearing
4. Environmental Influences
Usage environment and working conditions significantly impact polyurethane coated wheels.
- Long-term exposure to high temperature/humidity environments causes polyurethane aging, performance degradation, and weakened bonding
- Chemical corrosive environments can damage polyurethane structure and adhesive properties
- Excessive load beyond the wheel’s capacity creates fatigue in the bonding layer
- High rotational speeds generate excessive centrifugal force and friction that damages the coating
5. Maintenance Factors
Improper maintenance accelerates delamination and tearing problems.
- Poor cleaning allows dust/debris accumulation that affects operation and may scratch the coating
- Infrequent wear inspections mean small issues develop into major delamination problems
- Incorrect operation methods (sudden braking, frequent start-stop) create additional impact damage
Conclusion
In summary, polyurethane coated wheel delamination and tearing results from multiple combined factors. We must address materials, processes, usage environment, and maintenance to effectively prevent these issues and extend service life.
If my analysis is incomplete, please feel free to add your comments below.
