How to choose a right back sheet for solar panel?

Now we have a full understanding for the solar Back Sheet...why back sheet is a must for solar panel? How to choose a right back sheet for manufacturing solar panel?

Actually back sheet is rear cover of PV modules or solar panel, the function of back sheet: isolation and seal , so there is no short circuit happen. And protect the solar panel or PV modules working effectively for 25 years even longer time.

At first, actually people use only PET as the back sheet, but normally PET can not bear the UV and water vapor for long time, in another word, we need back sheet with super weather resistance so we have to create back sheet that can bear UV and water vapor and the new back sheet is made with different layers and fluorine material used for anti- UV and Water Vapor... 

Fluorine film, there are two main type for back sheet, PVF film famous brand Tedlar of Dupont Company and PVDF film famous brand Kynar of Arekma Company. 

Actually, only the back sheet with structure of Tedlar film-PET- Tedlar film could be called TPT because TPT is protected by patent with the structure claimed by Dupont Company; And only the back sheet with structure of Kynar Film-PET-Kynar Film could be called KPK because KPK is protected by patent with the structure claimed by Arkema Company. And those two types of back sheet are considered as the best quality suitable for any weather conditions of the world, but the price is high, and comparing those two type of back sheet, KPK is much lower cost than TPT.

But you may see many suppliers say they provide you TPT or KPK, but actually not the real KPK and TPT, they even your fluorine coating skins on both sides of the PET, and told you the TPT or KPK and offer you lower price, but actually not the same quality items. So you shall know that differences.

Anyway, not any solar panel need real KPK and TPT, if the solar panel is not installed in the place where is too inclement weather like desert or seaside there is no need to use KPK or TPT. And we also need reduce cost so more people can use solar energy and buy the solar power plant system. So people create some lower cost back sheet, but also can work for 25 years.

KPE/TPE: those type back sheet consist of air side fluorine, PVDF film or PVF film and the cell side modified EVA or polymer materials, it save much cost, and with good quality PET as the middle layer, it can obviously work for 25 years, but it has a shortage: too much strength adhesion with EVA, so it is too hard to peel of if we found some defective solar cells after laminating the solar panel, so it is bad for rework... 

KPF/TPF: those type back sheet both sides with fluorine, Air side with PVDF film or PVF film and the other side with fluorine resin coating skin. This type with similar cost to KPE or TPE and it is easy to rework...but the shortage: the coating side easy to be scratched...

FPF: those type back sheet both sides with fluorine resin coating kin, it is a very low cost back sheet and easy to rework, but we still doubt the air side coating can bear wind and sands for such a long time...perhaps in some place it is ok, but for most of environment, I don't think it is good enough. And I have to remind you some friends, some suppliers offer you this type and tell you it is KPK or TPT... But it is actually no.

PPE: this is none fluorine materials back sheet, normally it can work for 10 years and lower cost, but it is still not good for rework.

Since the fluorine materials are also a kind of pollution and the back sheet with fluorine materials can not be degraded even for thousand years, till now there is no good way to recycle and dispose it... so we are still on the way to find a better solution for this, hope a new back sheet of non fluorine but can work for 25 years, right now there is some companies trying to improve the PET quality, make it ANTI-UV so it can work for 25 years, if it is finally created, then It should be the best choice for future back sheet, actually Dupont Company announcing that they find the sally port...But I guess Dupont Company won't provide low price rate even they find the perfect way....

So from the above descriptions, we can make a conclusion, right now, the best choice of back sheet: KPF or KPE...

Jingmao Technology can supply the full types of back sheet,not only for 1000VDC PV modules, but also we have item for 1500VDC PV modules , if any interests, feel free to contact me.