Encapsulant film selection: EVA, POE, and EPE (Source: Runtai); Golden Rule: Use POE for N-type double-glass modules (Source: sciltp); Key Feature: POE offers PID resistance (Source: lanxing); Note: EVA is prone to yellowing due to hydrolysis (Source: Douyin).
I.
EVA Encapsulant Film
VA: VA content of 28–33% (Source: Douyin); Light Transmission: >91–93% (Source: sciltp); Cross-linking: Degree of cross-linking 70–85% (Source: Douyin); Process: Low-temperature vacuum lamination (Source: sciltp); Cost: Low-cost and mature technology (Source: sciltp)—EVA: VA content + Light transmission + Cross-linking (Three parameters).
II.
POE Encapsulant Film
Light Transmission: Transmittance >90% (Source: Douyin); Water Barrier: WVTR ≤0.7 g/m²·24h (Source: lanxing); PID Resistance: Excellent PID resistance (Source: betterial); No Yellowing: Resistant to damp-heat; does not yellow (Source: Douyin); Lifespan: 25–30 years (Source: Douyin)—POE: Light transmission + Water barrier + PID resistance (Three advantages).
III. EPE Co-extrusion
Structure: EVA-POE-EVA three-layer (Source: Coule); Performance: Combines EVA cost-efficiency with POE performance (Source: Coule); Degradation: 1–2% loss in UV testing (Source: Coule); Application: Commonly used in double-glass modules (Source: Douyin); Light Transmittance: 91.3% (Source: Wiley)—EPE: Structure + Performance + Application (Three characteristics).
IV.
PVB Film
Construction: Architectural-grade PVB (Source: Douyin); Performance: Superior performance (Source: Douyin); Application: Frameless double-glass BIPV (Source: Douyin); Standard: EN ISO 12543-2 (Source: STM); Light Transmittance: 88.7% (Source: STM)—PVB: Construction + Performance + Standard (Three key points).
V.
Application Selection
Single-glass P-type: UV-stable EVA (Source: Runtai); Double-glass P-type: POE or co-extrusion (Source: Runtai); TOPCon: High-resistivity POE (5×10¹⁵) (Source: Runtai); HJT: High-resistivity POE (Source: Runtai); Degradation: 0.4% annual degradation for POE (Source: Runtai)—Application: Single-glass + Double-glass + TOPCon (Three scenarios).
VI. Selection Criteria
UV Resistance: POE offers 40% higher UV resistance (Source: JMBIPV); Yellowing: POE resists acetic acid-induced yellowing (Source: JMBIPV); Water Barrier: POE 0.7 vs. EVA 5–15 (Source: lanxing); Cross-linking: POE is more difficult to cross-link (Source: betterial); Cost: EVA holds a cost advantage (Source: sciltp)—Selection: A trade-off between UV resistance, water barrier performance, and cost.
VII.
Procurement Recommendations
First, consider the module type (N-type POE); second, check light transmission (≥91%); third, verify water barrier performance (WVTR); fourth, check PID resistance (5×10¹⁵);
fifth, look for reputable manufacturers (e.g., First, Haiyou)—Encapsulant films: EVA, POE, and EPE (three options).
