What is a truly clear phone case?
A clear phone case is a protective cover made of transparent materials such as TPU or polycarbonate (PC). Its core purpose is:
- Showcase device design – Retain the original beauty of your mobile phone without distortion.
- Provide basic protection – prevent your phone from being dropped and broken while maintaining a slim profile.
- Offer versatility – You can do more customized designs on the transparent phone case.
True clarity requires a light transmittance of over 92%, a metric measured by a spectrophotometer in a certified laboratory.
Clear phone case
Why do Clear Phone Cases Turn Yellow, and Why is It Important
Eighty-five percent of transparent phone cases will show obvious yellowing within six months (Journal of Polymer Science, 2024). This is because:
- UV radiation breaks polymer chains, creating yellow chromophores.
- Skin oils and cosmetics (such as sunscreen) seep into the shell, accelerating oxidation.
- Manufacturing impurities like residual sulfur compounds trigger chemical reactions.
For a brand, turning yellow means:
→ A return rate as high as 23%
→ Negative comments mentioned “discoloration” or “stains”.
Yellowing clear phone case
3 Steps for Phone Case Manufacturers to Prevent Phone Cases from Turning Yellow
1. Material selection: Beyond basic TPU/PC
- Medical-grade polymer (ISO 10993 certification) for sweat/oil absorption resistance.
- HALS (Hindered amine light stabilizer) at a concentration of 0.3%-0.5% neutralizes ultraviolet free radicals.
Avoid using cheap recycled materials – inconsistent purity increases the risk of yellowing.
TPU material
2. Precision Production Controls
| Process | Critical Parameter | Failure Risk |
|---|---|---|
| Material Drying | 4hrs @ 80°C ±2°C | Hydrolysis-induced yellowing |
| Injection Molding | Melt temp ≤175°C (TPU) | Thermal degradation |
| Oxygen Exclusion | Nitrogen purge <100ppm O₂ | Oxidation during molding |
3. Accelerated Aging Validation
Demand third-party test reports showing:
- QUV testing ≥200 hrs (ASTM G154)
- ΔE color shift ≤1.5 (measured by spectrophotometer)
YG Offers You A Solution for Clear Phone Cases that Resist Yellowing
We focus on measurable solutions:
- Co-injection molding: Coating anti-yellowing agents inside the material, not just the surface coating.
- GRS certification options: 30%-100% recycled components, without affecting clarity.
- Strict batch testing: Verify the stability of 5 units ΔE for every 500 pieces.
For the custom transparent phone case project, we offer:
- Free DFM analysis, highlighting yellow risks
- Sample and material certification documents for 15 days
Look for Partners that Meet Your Requirements
Inquire about potential clear phone case manufacturers:
- “Can you share the concentration of HALS in the MSDS table?”
- “Display the QUV test video with a timestamp.”
- “What is your tolerance for batch ΔE approval?”
Put transparency above the unit price.
FAQ
Q: Are the anti-yellowing cases environmentally friendly?
→ Yes. Use ISCC plus certified bio-TPU – combining UV resistance and reducing carbon footprint by 65%.
Q: How long should a quality clear case stay transparent?
→ For 18 to 24 months, with an appropriate formula. Demand guarantee supports this.
Q: Do colored clear cases (e.g., smoke black) yellow less?
→ Not necessarily. Dyes can temporarily cover up yellowing, but they cannot prevent degradation.
Key issues that brands need to pay attention to
- Yellowing is a chemical problem – it needs to be solved by applying chemical principles, not by coating.
- Verification is of vital importance – adhere to ΔE≤1.5 test data.
- Simplicity wins – Single-material TPU casings are usually superior to multi-layer designs.
Ready for Truly Clear Partnerships?
When purchasing transparent phone cases that do not turn yellow, contact YG. Let’s make a prototype for your vision
