F-Class DMD Epoxy Prepreg Fabric | B-Stage Semi-Cured Electrical Insulation Material for Transformers & Motors

Product Introduction 

F-Class DMD Epoxy Prepreg Cloth is a high-performance B-stage semi-cured flexible insulation material engineered for demanding industrial electrical equipment. It is manufactured by uniformly impregnating a high-grade DMD (Polyester Non-woven Fabric / Polyester Film / Polyester Non-woven Fabric) composite substrate with a specialized, heat-resistant modified epoxy resin, followed by precision baking into a stable, non-sticky semi-cured state.

During the curing and assembly of electrical coils, this prepreg cloth fully cross-links at medium temperatures. It exhibits extremely low shrinkage and forms an incredibly tight, bubble-free, and permanent bond with metallic copper or aluminum surfaces, creating a unified, highly insulated solid structure.

Key Features & Advantages 

• Exceptional Metal Adhesion & Low Shrinkage: Chemically formulated to adhere tightly and securely to copper and aluminum foils during curing, minimizing the risk of voids, delamination, or air pockets.

• Eco-Friendly Curing Process: Cures smoothly at medium temperatures with virtually no low-molecular volatile emissions, resulting in an ultra-dense insulation profile without blistering.

• Superior Mechanical & Tensile Strength: Combines high tensile performance (up to ≥100 N/10mm) with strong tensile shear strength (≥23.0 MPa) to withstand intense electromagnetic and mechanical vibrations.

• Reliable Dielectric Performance: Outstanding breakdown voltage resistance (up to ≥10.0 KV) guarantees reliable safety parameters for low-voltage layer-to-layer applications.

• Excellent Class F Compatibility: Features a long-term thermal index (TI) of 155°C (Class F) and is broadly compatible with mainstream solventless insulating varnishes.

Typical Applications 

DMD Epoxy Prepreg Cloth is widely adopted in heavy-duty and high-temperature power equipment:

• Dry-Type Transformers: Specifically designed as the premier interlayer wrapping insulation for low-voltage copper or aluminum foil-wound coils.

• Class B & Class F Electric Motors: Widely utilized for slot liners, phase barriers, and turn-to-turn insulation padding in industrial generators and machinery.

• Reactor and Inductive Coils: Provides a perfect structural wrapping matrix for heavy-vibration electromagnetic and inductive components.