solar backsheet

Type			Structure			Thickness
Backsheet ZX300/ZX350			PPE (PVDF Film+PET+PEVA Film)			300~350μm

Storage Methods:

● Storage to avoid direct sunlight, moisture in and keep packing condition;

● Room temperature in ambient humidity, (23±10°C, 55±15%RH) 12 Months

Why do we need a solar backsheet in a PV panel?

The solar backsheet plays a significant role in a solar PV panel. A poor quality solar backsheet can cause system degradation, unwanted maintenance, and replacements related to additional costs.
A quality solar backsheet must protect against:

● Ultra-violet radiation, which is harsh on most polymer materials

● Humidity and vapor penetration

● Dryness, wind, dust, sand, and chemicals

Besides, it must be scratch-resistant, especially during installation and maintenance. It should also be stable at a temperature range between -40°C and +85°C.
In bifacial solar PV panels, which are designed to allow sunlight to enter from both sides of the photovoltaic cell, the solar backsheet must be optically transparent.
Most solar panel manufacturers use TPT for a solar backsheet. TPT is the acronym of Tedlar film -PET- Tedlar film.
Tedlar is the brand name of the American chemical company DuPont and refers to polyvinyl fluoride (PVF), a thermoplastic fluoropolymer material. PET refers to Polyethylenterephthalat, a common thermoplastic polymer.
Only the solar backsheet with Tedlar film-PET- Tedlar film can be called TPT because TPT is protected by a patent claimed by the Dupont Company.

Alternatives to TPT solar backsheet
At present, TPT is the best backsheet material on the market. Therefore, TPT solar backsheets are more expensive than backsheets made from other materials.
When choosing another backsheet, it is recommended to use the following tips:

Choose a Tier 1 panel manufacturer; they are the leaders in the solar panel industry, and they tend to use premium materials in their solar PV panels.

1. It is better to avoid solar PV panels that use non-UV resistant solar backsheets to minimize risk.

2. Ask for the solar panel certifications, typically UL (UL1703) or IEC (IEC61215 and IEC61730).

3. When were the solar PV panels manufactured and how are they stored?

4. Make sure that the solar PV panels have serial numbers.

5. The warranty of solar PV panels and what the warranty does not cover.

Specification Data

			ZX300 / ZX350
Test Items	Test Standard	Unit	Standard value	Typical value
Thickness tolerance	GB/T6672-2001	---	±10%	300 / 350
Tensile strength (MD)	ASTM D 882-2002 GB/T 13542	Mpa	≥100	141
Tensile strength (TD)		Mpa	≥100	128
Elongation at break (MD)	ASTM D 882-2002 GB/T 13542	%	≥80	145
Elongation at break (TD)		%	≥80	118
Heat shrinkage 150℃,30min(MD)	ASTM D 1204-2002 GB/T 13542	%	≤1.5	-0.4
Heat shrinkage 150℃×30min(TD)		%	≤1.0	-0.2
Peel strength PVDF&PET	ASTM D 882-2002 GB/T 2790	N/cm	≥4	5.3
Peel strength Backsheet&EVA		N/cm	≥40	120
Breakdown voltage	ASTM D 149-1997 GB/T 1408	KV	≥18	21
Partial discharge vooltage	IEC 60664-1-2007 GB/T 16935	VDC	﹥1000	1181
Water vapor permeability (38℃,100%RH)	ASTM F 1249-2006 GB/T 21529	g/㎡.d	≤2	1.2
Damp-heat treatment (85℃,85%RH,2000h)	IEC 61215 GB/T 3979/7921		No bubble, no separation, no crack and significantly sticky	No obvious appearance defect
Hot and cold cycle processing (-40℃~85℃,6h/400 times)	IEC 61215 GB/T 1408		No bubble, no separation, no crack and significantly sticky	No obvious appearance defect
Wet frozen processing After 50 times Hot and cold cycle (-40℃~85℃,24h/20 times)	IEC 61215 GB/T 1408		No bubble, no separation, no crack and significantly sticky	No obvious appearance defect

Storage Methods:

Storage to avoid direct sunlight, moisture in and keep packing condition;
Room temperature in ambient humidity, (23±10°C, 55±15%RH) 12 Months

Roll Packing	Meter/Roll	Roll/Palle t	Sheet Packing	Sheet/Pack	Package/Pallet
Method 1	150	12	Method 1	100	10
Method 2	200	12	Method 2	200	20

Storage to avoid direct sunlight, moisture in and keep packing condition;

Room temperature in ambient humidity, (23±10°C, 55±15%RH) 12 Months

High sand scratch and corrosion resistance Excellent UV performance and hydrolysis resistance Outstanding electrical performance High inner layer reflectivity High moisture barrier and low power degradation Environmental aptitude:ROHS and REACH

High sand scratch and corrosion resistance
Excellent UV performance and hydrolysis resistance
Outstanding electrical performance
High inner layer reflectivity
High moisture barrier and low power degradation

Environmental aptitude:ROHS and REACH