Use of Melt Flow Rate Test in Reliability Study of Thermoplastic Encapsulation Materials in Photovoltaic Modules

Moseley, J. ; Miller, D. ; Shah, Q.-U.-A. S. J. ; Sakurai, K. ; Kempe, M. ; Tamizhmani, G. ; Kurtz, S.

关键词: ACETATES;    CREEP;    CURING;    ENCAPSULATION;    FLOW RATE;    PERFORMANCE;    POLYMERS;    POLYOLEFINS;    POLYURETHANES;    POLYVINYLS;    RELIABILITY;    SAFETY;    STRESSES;    TESTING;    THERMOPLASTICS CREEP;    VISCO-ELASTIC FLOW;    DURABILITY;    RELIABILITY;    PV;    ENCAPSULANTS;    Solar Energy - Photovoltaics;   

DOI  :  10.2172/1027154
RP-ID  :  NREL/TP-5200-52586
PID  :  OSTI ID: 1027154
Others  :  TRN: US201123%%132

美国|英语

来源: SciTech Connect

【 摘 要 】

Use of thermoplastic materials as encapsulants in photovoltaic (PV) modules presents a potential concern in terms of high temperature creep, which should be evaluated before thermoplastics are qualified for use in the field. Historically, the issue of creep has been avoided by using thermosetting polymers as encapsulants, such as crosslinked ethylene-co-vinyl acetate (EVA). Because they lack crosslinked networks, however, thermoplastics may be subject to phase transitions and visco-elastic flow at the temperatures and mechanical stresses encountered by modules in the field, creating the potential for a number of reliability and safety issues. Thermoplastic materials investigated in this study include PV-grade uncured-EVA (without curing agents and therefore not crosslinked); polyvinyl butyral (PVB); thermoplastic polyurethane (TPU); and three polyolefins (PO), which have been proposed for use as PV encapsulation. Two approaches were used to evaluate the performance of these materials as encapsulants: module-level testing and a material-level testing.