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What causes Transparent Film yellowing?

2019-04-19

Something used in almost every industry around the world is transparent PVC film, it is known for all its great and durable qualities. It can be used in just about anything from medical supplies to game consoles. It is, however, a polymer which means it brings with it certain properties that may cause a slight problem. It is important to know the advantages and disadvantage of a product, and also the scientifically proven solutions to any problems you may have.

 

PVC film is organically based, which means that it is at risk of breaking down and degradation through the natural oxidation process. This processes may be sped up depending on a few factors, these are; oxygen, heat, ultra-violet light, pollutants, ozone, visible light, manufacturing additives or if they are stored without the correct protective layers.

 

What are the main reasons transparent PVC film turns yellow?

Ultraviolet is one of the biggest culprits when it comes to this. It does not play well with polymers unless light stabilizers are added. This can not only change its color to yellow but can also causes it to break, crack, and shatter or even melt. It is vital to ensure that the transparent PVC film is not absorbing too much light; this gives you many options to help and trap the free radicals that are formed as the breaking down of plastic polymer chains occurs, and these formed by exposure and prevent them from causing damage.

 

When the temperature increases, the thermal oxidation process is accelerated, aiding in its degradation and so speeding up the process, causing the yellowing effect to come faster than anticipated. Which could mean all manner of damages and complications in the future? The industry has a form of sunscreen for polymers though, Ultra Violet Stabilizers that slow this process down drastically. And while these are great, eventually any stabilizer packages that have been used will eventually come to the surface or be consumed. Once this happens, the polymer will have lost its protection. This will speed up the process when it comes into contact with the atmospheric influences that were mentioned above.

 

While antioxidants can be used, and it helps to protect the transparent PVC film from the heat of extrusion when it is being produced, this is not guaranteed. It will not be of any help when the product is stored or when it is exposed. Some are even known to react more to UV more than any other antioxidant additives. It may be easier to see the yellowing when it has a larger density, but can be almost missed when it has been made into a flexible form. These cause no harm to your health or give off any other health concerns.

 

If you think of something that has been sitting getting some ultraviolet rays for quite some time, it is then packed away. This does not protect it from this fate, once the ultraviolet rays have made contact, it has already started the process so even when you take it out years later, you may have the same effect. What happens when a transparent PVC film starts to change? The way the plastic behaves may change once this degradation has started taking place and it may not be able to be used for its intended purpose.

 

The roll film may be quite obvious if it is yellowing due to the density, yet it may also be invisible to the eye once converted into a flexible package. If properly used, certainly it will not do harm to the human body even it is yellowing.

 

Nobody wants to buy a product that will be damaged within a few days of purchase, but rest assured that depending on exposure, the life span of this product is phenomenal, which is why so many people prefer to keep it out of landfills. There are various products and services on the market to help you with this, as long as you keep yourself educated on the possibilities, impacts, and solutions to this problem.


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