Photovoltaic module manufacturers rely on PTFE-coated fiberglass release sheets to prevent molten EVA encapsulant from adhering to laminator heating platens during the lamination cycle. These release sheets operate under demanding conditions: continuous temperatures of 140–150°C, repeated vacuum and pressure cycles, and direct contact with adhesive materials that can migrate into the fabric structure if the coating is insufficient.
Single-sided PTFE fabric is common in the market. However, for photovoltaic lamination—where every cycle stresses both surfaces of the release sheet—the coating configuration directly affects service life, release consistency, and total consumable cost. This article explains why double-sided PTFE coating delivers measurable advantages in this application, based on a verified supply case for a solar panel production facility.
What the Lamination Process Actually Demands from Release Fabric
The photovoltaic lamination stack follows a defined material sequence: PTFE release fabric + glass + EVA + solar cells + EVA + backsheet + PTFE fabric. The fabric acts as both cover sheet and carrier sheet, creating a non-stick barrier between the molten EVA and the laminator’s heating surfaces.
During the lamination cycle, the release fabric faces:
- Continuous operating temperature of 140–150°C, with peak exposure potentially higher during initial heating stages
- Molten EVA overflow that contacts the fabric surface and must release cleanly after each cycle
- Vacuum and pressure cycling that can force adhesive residue deeper into the fabric if the coating structure contains pinholes or thin areas
- Mechanical handling as the sheet is removed, inspected, and repositioned for subsequent cycles
The fabric must maintain a smooth, imperfection-free surface throughout its service life. Any surface defect—coating wear, pinhole penetration, or localized adhesion—can transfer to the module surface and compromise the final product.
Case Reference: Solar Panel Lamination Release Sheets
This article is based on verified supply experience for a solar photovoltaic panel production facility. The application involved providing PTFE-coated fiberglass release sheets for the lamination process, where the fabric serves as both cover and carrier sheet in the module stack.
Key supply parameters for this application:
| Parameter | Specification |
|---|---|
| Coating configuration | Double-sided PTFE |
| Fabric type | PTFE-coated fiberglass |
| Application | Photovoltaic module lamination release sheet |
| Operating temperature | 140–150°C (lamination cycle) |
| Market compliance | RoHS, CE certified |
The critical validation for this application was not a single specification number, but consistent supply performance over repeated production cycles. The customer required release sheets that could be used, cleaned, and reused without progressive degradation in release quality or surface condition.
FAQ
Is double-sided PTFE coating necessary for all lamination processes?
Not necessarily. For simple, low-cycle applications with minimal adhesive migration, single-sided coating may suffice. Double-sided coating is recommended when both fabric faces contact adhesive, when penetration into the glass fiber substrate must be prevented, or when maximum service life is required.
What thickness is recommended for photovoltaic release sheets?
Industry practice for flat-bed photovoltaic laminators uses 0.25mm to 0.35mm total thickness. This range provides adequate thermal buffering, pressure distribution, and dimensional stability for repeated lamination cycles.
Can the same fabric be used for chemical expansion joints?
PTFE-coated fiberglass fabric is used in chemical processing applications, but the selection criteria differ. Chemical applications prioritize barrier performance and chemical resistance of the coating structure, while photovoltaic applications prioritize release consistency and thermal cycling durability. The same base fabric type may serve both, but coating weight and impregnation specifications should be matched to the application.
Request a Sample or Technical Datasheet
For photovoltaic lamination release sheets or chemical processing fabric specifications, contact us with your operating conditions:
- Lamination temperature range
- Adhesive or chemical media contacted
- Laminator dimensions or joint geometry
- Required cycle life or replacement interval
We will recommend the appropriate coating configuration and fabric specification for your application.
