EPGC308 Epoxy Glass Cloth Laminate: Ensuring Insulation Safety for Class H Motors

As industrial motors continue to evolve toward higher power, heavier loads, and more compact designs, the temperature rise in motor windings has been increasing steadily. This places ever more stringent demands on the thermal class and overall performance of insulating materials. In this context, EPGC308 epoxy glass cloth laminate, with its Class H (180°C) thermal rating and excellent electromechanical properties, has become an important material choice for insulation structural components in Class H motors.

Class H Heat Resistance – Effectively Handling High‑Temperature Challenges

EPGC308 epoxy glass cloth laminate is manufactured by impregnating electronic‑grade woven glass fabric with a high‑temperature‑resistant epoxy resin varnish, followed by drying and hot pressing. It achieves a thermal class of H (180°C) and a glass transition temperature of up to 180°C, enabling long‑term stable operation in high‑temperature environments. Compared with Class F products such as EPGC203, EPGC308 offers significantly improved heat resistance while maintaining excellent electromechanical properties. It retains high mechanical strength at elevated temperatures and continues to deliver reliable support and insulation performance under heat.

Outstanding Electromechanical Properties for Demanding Operating Conditions

EPGC308 not only withstands high temperatures but also combines excellent mechanical and electrical characteristics. In terms of mechanical performance, its normal‑state flexural strength (perpendicular to lamination) can exceed 500 MPa, and its impact strength (parallel to lamination) is above 51 kJ/m². Electrically, it exhibits a low dissipation factor of 0.02 at 1 MHz, and an insulation resistance after water immersion as high as 6.8×10⁶ MΩ. Its electric strength perpendicular to lamination reaches 17 kV/mm in transformer oil at 90°C. Furthermore, the material maintains stable electrical properties under high humidity and can be used in transformer oil, making it suitable for various complex environments encountered in motor operation.

Wide Range of Applications Covering Diverse Motor Scenarios

EPGC308 epoxy glass cloth laminate is suitable for insulating structural parts in Class H motors, traction converter motors, high‑power motors, transformers, carbon brush holders, rail transit vehicles, and other electrical equipment. In Class H motors, the material can be used for slot wedges, spacers, insulating supports, and ground insulation components. Thanks to its excellent machinability, EPGC308 can be fabricated into intricate insulating parts to meet the structural design requirements of different motors.

The product is available in thicknesses from 0.5 mm to 80 mm, with standard sheet sizes of 1020×1220 mm, 1020×2040 mm, and 1220×2470 mm.

Enabling High‑End Manufacturing and Building a Robust Insulation Barrier

In high‑end manufacturing sectors such as high‑speed railway traction motors, new energy vehicle drive motors, and wind turbine generators, motors often operate under prolonged high‑temperature and high‑load conditions. The reliability of the insulation system is directly related to equipment safety and service life. With its Class H heat resistance, high mechanical strength, stable electrical properties, and excellent resistance to moisture and oil, EPGC308 epoxy glass cloth laminate provides a dependable insulation solution for Class H motors. As industrial motor energy efficiency standards continue to rise and application scenarios keep expanding, EPGC308, as a representative Class H insulating material, will play an increasingly important role in advanced motor manufacturing.