How to classify the temperature resistance grade of high temperature adhesive tape in solar photovoltaic field?
In the field of solar photovoltaic, the classification of temperature resistance of high-temperature adhesive tapes focuses on the actual temperature requirements of the whole scene of photovoltaic production/application (from process high temperature to outdoor long-term temperature resistance), combining with the two core dimensions of short-term instantaneous temperature resistance and long-term continuous temperature resistance, and matching the tape substrate and process adaptability to make grade correspondence. There is no unified mandatory national standard in the industry, but a general classification standard is formed that fits photovoltaic production (lamination, sintering and welding) and outdoor operation and maintenance. And the classification will define the temperature resistance value+endurance time (the core is to distinguish between short-term process high temperature and long-term use high temperature). The following is the special temperature resistance classification for photovoltaic field and the corresponding application and substrate, which is the most suitable classification method for actual production in the industry:
Basic division principle
Short-term instantaneous temperature resistance: For the high-temperature process links of photovoltaic module manufacturing (such as sintering, lamination and welding), the adhesive tape can only withstand high temperature during the process, and the duration is from several minutes to several hours. It can be peeled/removed after the process, and the core requirements are short-term heat resistance, no residual adhesive and no deformation;
Long-term continuous temperature resistance: For outdoor use/long-term fixing links of photovoltaic modules (such as junction box bonding, edge sealing and insulation protection), the adhesive tape needs to withstand outdoor ambient temperature with the whole life cycle of the module, with a duration of 10-25 years (the design life of photovoltaic modules). The core requirements are long-term heat resistance, aging resistance and stable adhesive force, and it is suitable for outdoor temperature change cycle of-40℃~85℃.
Core temperature resistance grade of high-temperature adhesive tape in photovoltaic field (common in the industry)
Labeling with long-term continuous temperature resistance as the main factor and short-term instantaneous temperature resistance as the auxiliary factor is the core basis for the selection of photovoltaic enterprises, which is divided into four mainstream grades. Each grade has clear application scenarios corresponding to the substrate and photovoltaic, and there is no ambiguity interval:
1. Low-order high-temperature resistance: 80℃ for a long time/120℃ for a short time.
Core substrate: PET (polyester) substrate (coated with acrylic/silicone rubber layer)
Photovoltaic application: Non-core low-temperature processes in module manufacturing, such as temporary typesetting and fixing of battery cells, initial positioning of bus bars and temporary protection of equipment surface, are only suitable for routine operation at room temperature ~ 80℃, and can withstand the high temperature of 120℃ (1-2 hours) for short time, and can be directly peeled off after the process, with low residual glue rate.
2. Intermediate high temperature resistance: long-term 120℃/ short-term 150℃
Core substrate: thickened PET/glass fiber reinforced PET substrate (coated with silica gel/modified acrylic adhesive layer)
Photovoltaic application: The main heat-resistant grade of photovoltaic core lamination process is suitable for the high-temperature and high-pressure environment of 140-150℃ (withstanding 2-4 hours), and it is also the core selection grade of junction box base bonding and glue-pouring curing. It can maintain the bonding force at the extreme temperature of 120℃ for a long time without degumming and deformation, and is the most widely used heat-resistant grade in photovoltaic field.
3. High temperature resistance: 150℃ for a long time/200℃ for a short time.
Core substrate: PI (polyimide)/PTFE substrate (coated with silicone rubber layer, Teflon contains release coating).
Photovoltaic application: High-temperature precision process of module manufacturing, such as perforated Teflon tape used for exhaust demoulding of heating plate of laminator (withstanding long-term high temperature of 150℃), PI tape used for welding tape fixing/shielding in welding process, which can withstand short-term welding instantaneous high temperature of 200℃, meet the precise requirements of insulation, solvent resistance and no residual glue, and adapt to the protection of vulnerable parts such as battery cells and bus bars.
4. Ultra-high temperature resistance: long-term 200℃/ short-term 800-1000℃
Core substrate: glass fiber/ceramic fiber substrate (coated with high-temperature resistant inorganic adhesive/silica gel, partially self-adhesive without adhesive)
Photovoltaic application: The ultra-high temperature process of photovoltaic cell manufacturing, such as diffusion and sintering process, can withstand the high temperature in the furnace of 800-1000℃ (several minutes), prevent the edge of the cell from being polluted and ablated by high temperature, and ensure the photoelectric conversion efficiency of the cell. This grade of adhesive tape is only used in the cell process, and the component packaging link is rarely used.
Special label in photovoltaic field: composite grade of temperature resistance and weather resistance.
The temperature resistance grade of photovoltaic high-temperature adhesive tape will be marked in combination with outdoor weatherability (different from other industrial fields), such as 120℃/UV/ weatherability, which means that the adhesive tape not only meets the long-term temperature resistance of 120℃, but also has the characteristics of ultraviolet resistance, high-low temperature cycle resistance and high-humidity resistance, and is suitable for outdoor life-cycle use of components. This kind of composite marking is the core selection index of outdoor fixing/sealing/insulating adhesive tape, but only marks the pure temperature resistance value.
Key points of industry selection
When marking the temperature resistance grade of the adhesive tape, photovoltaic enterprises will specify the format of * * "℃/℃" * *, the former is long-term continuous temperature resistance, and the latter is short-term instantaneous temperature resistance, for example, marking "120/150℃" means that the adhesive tape can be used in the environment of 120℃ for a long time and can withstand the high temperature of 150℃ for a short time, which is a general marking specification for the photovoltaic industry.
