Requirements for PET film for solar cell backsheets-film supplier
As the requirements of photovoltaic cell module manufacturers to extend battery life and photoelectric conversion efficiency further increase, the requirements for the supporting materials of photovoltaic cells—PET film are becoming more and more stringent. Such as electrical insulation, aging resistance, air permeability, and tear strength have high requirements. 3. 1 Electrical insulation performance The electrical insulation performance of solar battery backsheets mainly includes breakdown voltage and partial discharge voltage. Whether these two indicators can meet the standards mainly depends on PET film. The breakdown voltage of ordinary biaxially oriented PET film can reach the GB/T13542-2009 national standard or ASTMD-149 American electrical standard, but to reach the partial discharge voltage index of the battery backplane specified in the IEC60664-1/IEC61730 international electrotechnical standard. Research and improvement of the raw materials and production process of biaxially oriented PET film. 3. 2 Hydrolytic aging resistance Ordinary PET film is mainly tested for heat aging resistance, and generally can pass the UL94 certification RTI 105 ℃ temperature resistance standard. At present, to verify whether the PET film can reach the hydrolytic aging resistance of solar photovoltaic cells, the test method of hydrolysis resistance at 120 ℃ and 100% RH is generally adopted. The time for cracking and embrittlement of the PET film shall not be less than 96 hours. 3. 3 Water vapor transmission rate The water vapor transmission rate of the solar photovoltaic cell to the back sheet is less than 2 g/(m2·d) (ISO-15106-3 test method). At present, photovoltaic module manufacturers generally require that the 'water permeability' index of the battery backplane is less than 1. 5 g /(m2·d), even lower than 1 g/(m2·d). The 'water permeability' of the battery backplane mainly depends on the PET film, while the 'water permeability' of the ordinary 250 μm PET film is 2. 5 ~ 3. 5 g/(m2·d), PET film needs to work harder on modification of PET materials if it wants to meet the 'water permeability' requirements of solar cells. 3. 4 Dimensional stability The longitudinal shrinkage of PET film can generally be controlled at 1. 5% (150 ℃, 30 min) or less, because solar photovoltaic cells need to go through three high-temperature treatments (two solar backplane composites, solar module encapsulation high-temperature lamination once), this requires the base material of the battery backplane to have Excellent dimensional stability. At present, the longitudinal shrinkage rate of biaxially oriented PET film can be controlled to 0 in the world. Below 5% (150 ℃, 30 min). 3. 5 Tear resistance performance. Since solar cell modules need to be perforated (rectangular shape) from the battery backplane to draw the electrodes when encapsulating the solar cell module, this requires PET film to have good tear resistance and toughness, avoiding the process of module processing and outdoor It is easy to tear and brittle under wet, hot, dry and cold environment. In short, as a new energy source, solar photovoltaic systems have a wide range of applications. There are basically two types of applications, namely, independent power generation systems and grid-connected power generation systems. Its application fields are mainly in space vehicles, communication systems, microwave relay stations, TV differential turntables, photovoltaic water pumps, industrial and agricultural power generation, regional power supply, traffic signs, civil lighting, etc. As the main supporting material for solar cell backsheets, PET film was used in solar photovoltaic cells in 2010 by nearly 1%. 2 × 109 m2, becoming a new growth point in the application of PET film. It is a company specializing in the production of PET film with multiple functions, such as: transparent PET film, milky white PET film, release PET film, supply of PET motor film, etc. With a wide range of products, affordable prices, and environmental protection, we provide customers with excellent quality and service based on the service tenet of excellence in production, honesty and trustworthiness in distribution, warm and thoughtful service, and the spirit of assisting partners to achieve their own careers. Interested parties welcome to inquire!