A smartphone cover helps cover the back and sides of the phone, and sometimes the bump on the side of the device keeps even the phone’s screen protected. But, the same case can sometimes be a part of worry for smartphone users. We are specifically talking about transparent TPU cases. One of the emails from a smartphone user was about the same concern.

Hi, i have bought many cases in the past but this was first time that i chose a transparent case for my phone. It is a rubber like case so flexible and within three months itself it has got yellowish. i am not liking the look as i am using a galaxy s20 and thought that transparent case will make my phone looks good always. is there a reason or solution for this please? or should i settle getting a new non transparent case.

Transparent smartphone cover turn yellow

Firstly, thanks for bringing out this question as this has been very commonly seen on many smartphones. In fact, the Mi Note 10 that I am using comes with a case in the box itself, and that case has gone yellow already. I cannot complain about it, and can’t blame the manufacturer because of the nature of the material used in these cases.

The reason for the yellowing or discoloration of a transparent case (or coloring of a non-colored case) is the material – It is the Thermoplastic polyurethane (TPU) that is the material used in making these cases. The material is well resistant to falls and keeps all the sides and even the back protected from scratches and even falls. These are flexible unlike the ones made from silicone and plastic, which are actually hard but not chosen by everyone.

Why do TPU cases turn yellow over time?

It is said that the case turns yellow when it is exposed to sunlight, heat, or certain chemicals. The chemicals in the case get degraded and that makes the case yellowish and this is irreversible. While I haven’t found the actual reason or the chemical changes, it is claimed that the UV light from the sun easily changes the chemical composition and thus the yellow color is seen in the case.

Does this mean the durability of the case is also affected? No, certainly not. The durability doesn’t change at all, and the color is the only change. Some call the color change as the aging of the case but that doesn’t mean it has got weaker.

Another theory related to this also says that the sweat from your hand or the oils from your face skin can cause an oxidation reaction, turning the exterior of the case to yellow. This is an arguable one, but still, the claim also mentioned that it is only the color change, as with the previous ones, and there is nothing happening to the durability of the case.

yellow transparent phone cover

One more theory from one of the answers on Quora says that the clear was never transparent, and it was naturally yellow, and a bit of blue dye was added to it to make it look naturally clear. The post also tries to explain scientifically about the process that happens when exposure to UV rays or heat occurs. The long polymer molecule chains are not connected to each other in case of TPE cases and these wadded up chains start sliding apart if they are exposed to heat. The light refraction/reflection property of these chains results in that discoloration. In the case of UV light, these bonds, over time, are broken and that results in many short, disordered chains.

How to fix the yellowing of the phone case?

Now, you might be convinced about the reason. You might not. But then, there’s nothing you can do about it unless trying to fix the issue. The yellow stain or the yellow tinge on the entire case cannot be just washed away easily, especially if it is because of the oxidation, or due to molecular changes.

Soap water, or bleaching

These are things that you can try to use and wash off the cover only to try and remove any stains that have appeared externally due to reasons like grease, or oil from external sources. In fact, bleaching is a stronger way of cleaning the exterior of the case but it won’t be able to remove the yellowness if that was because of the oxidation.

You could also use toothpaste as it has some chemicals and substances that would rub off some of the strong external causes. Just apply some toothpaste and rub it vigorously with a cloth and see if that helps and changes, and we are asking you to try out these things as one cannot be certain of the actual cause of yellowing of your phone’s case.

No other way – Live with it, or replace the case

Remember, this is only aesthetic. The case isn’t going to get deteriorated in any way, so you won’t have to worry about the durability or the use case of it. But if you think it doesn’t look good (it obviously doesn’t), then only changing the case is an option. There are some colored options available in the market, or you could go with bumper cases that would solve more purposes.

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