Why Do Clear iPhone Cases Turn Yellow?

It’s not a hidden fact that most transparent iPhone cases turn yellow after a few weeks of use. But this condition is not limited to iPhone cases alone; all clear cases made of a particular material experience this. If you haven’t encountered what a yellowing case looks like, you can check the “before and after” image of a transparent iPhone case below.

No, this coloration is not something you can clean up using a damp cloth; it’s an irreversible change caused by some reactions. The color deepens with time and eventually leads to the breakage of the case.

As you probably can guess, a case like this makes your iPhone looks dirty and also defeats the purpose of purchasing it. But why exactly do most transparent covers turn yellow after a while?

Causes Of Yellowing Coloration In Clear Cases

The leading cause of yellowing in cases is the material. Many of the clear cases in the market are made of Thermoplastic Polyurethane (TPU) because of its tremendous benefits. The qualities of TPUs that make is a material of choice for fabricating clear cases include the following:

• Transparency
• Flexibility
• Resistance to oil and abrasion
• Elasticity
• Low cost

However, while TPUs are transparent, they are not as clear as the products presented to us. One can describe them as being transparently yellow, and manufacturers often tinge them with blue after other tweakings to give the crystal-clear view that we all see.

Under the appropriate conditions, these products will remain purely transparent forever. However, once there is a breach in these conditions, the case returns to its original state, which I earlier described as “transparently yellow.”

The conditions that lead to the yellowing of TPUs and their consequent degradation are primarily two. These are:

Ultraviolet Radiation from the Sun

Sunlight contains UV rays which is an electromagnetic wave. When this energy falls on finished TPUs, it breaks down the molecules, causing their degradation and removal. Of course, this process does not happen on the first exposure; it depends on the intensity and frequency of the sun. And in addition to the devastating effect of UV rays on TPUs, the second reason below seals the yellowing.

Moisture & Dirt

These two things are sure enemies of any transparent object because of the dirty coatings they leave on them. However, there is more to the damage they cause than the messy coatings. Most moisture that gets to transparent covers comes from sweat and other body perspirations consisting of salts, oil, and a degree of acidity.

Acids are corrosive, and even when mild, their additive effects are strong on TPUs. Combined with dust, dirt, and oily secretions, sweat and sun heat can quickly change the coloration of a transparent case.

Conclusion

Besides the general protection function, a clear case is responsible for highlighting your iPhone’s impressive design. However, with the yellowing coloration associated with most of them, you may be unable to achieve this.