Prepregs are composite materials formed by impregnating a resin matrix into fibrous materials, combining the mechanical strength of fibers with the insulating properties of resins. They play a vital role in the field of industrial equipment insulation. With excellent formability and stable performance, prepregs can adapt to the complex structures and harsh operating environments of various industrial equipment, providing reliable guarantees for the safe and stable operation of equipment. The following explores the typical applications of prepregs as insulating materials in various industrial equipment.
Insulation Applications in Electrical Machinery
Insulation for high-voltage motor windings
During operation, high-voltage motor windings are subjected to both high voltage and high temperature, placing strict demands on the dielectric strength and heat resistance of insulating materials. Prepregs, with their excellent electrical insulation and high-temperature resistance, are an ideal choice for high-voltage motor winding insulation. In the winding manufacturing process, prepregs are wrapped or coated around the wire surface and cured under heat to form a dense insulating layer, effectively isolating windings at different potentials and preventing short circuits. For example, aramid fiber prepregs are suitable for motors operating in high-temperature environments above 200°C. Their mechanical strength resists friction caused by winding vibrations, ensuring the insulation layer remains intact during long-term use and guaranteeing stable motor operation.
Insulation for flameproof structures in explosion-proof motors
Explosion-proof motors are mostly used in flammable and explosive environments, and their flameproof structures must meet both insulation and explosion-proof requirements. By combining with metal enclosures, prepregs form an insulating barrier on flameproof joints, blocking current conduction while withstanding the impact of explosion pressure. Glass fiber prepregs, with their high mechanical strength and chemical resistance, are often used for lining enclosures and insulating components of flameproof motors. This ensures that in the event of internal sparks or explosions, the external environment remains unaffected, while insulation performance remains stable, complying with safety standards for explosion-proof equipment.
Insulation applications in transformers
Insulation for Dry-Type Transformer Windings
Dry-type transformers do not require insulating oil and rely on solid insulating materials to build their insulation systems, where prepregs play a key role. During the winding of dry-type transformers, prepregs are used for interlayer and end insulation. After curing, they form an integrated insulation structure, enhancing the integrity and mechanical strength of the windings. Epoxy glass fiber prepregs are suitable for medium and high-voltage dry-type transformers. Their high dielectric strength withstands the electric field stress during transformer operation, and their heat resistance rating matches the operating temperature of the windings, reducing insulation aging caused by local overheating and extending the transformer’s service life.
Insulating components for special transformers
In special transformers such as railway traction transformers and medium-frequency transformers, prepregs are used to manufacture insulating supports, partitions, and other components. These components must simultaneously provide insulation and structural support. After molding and curing, prepregs can be formed into complex-shaped insulating parts, meeting the compact design requirements of special transformers. For instance, in medium-frequency transformers, insulating partitions made from prepregs effectively isolate the iron core from windings, reducing eddy current losses while resisting electromagnetic forces generated by high-frequency currents, ensuring stable transformer operation under special working conditions.
Insulation applications in electrical enclosures and complete sets of equipment
Insulating supports inside enclosures
Electrical enclosures are core equipment in industrial power distribution systems, containing numerous high-voltage switches, busbars, and other components that require insulation materials to isolate them from each other. Insulating brackets and partitions made from prepregs are used to support busbars and fix switchgear. Their insulation performance prevents discharge between components at different potentials, while their mechanical strength bears the weight of equipment and electrodynamic forces during short circuits. Phenolic resin prepregs, with their moderate cost and good processability, are widely used in low-voltage electrical enclosures, while epoxy prepregs are suitable for high-voltage enclosures, meeting higher insulation and strength requirements.
Busbar insulation in complete sets of equipment
Busbar systems in industrial complete sets of equipment carry large currents, requiring reliable insulation between busbars and between busbars and enclosures. Prepreg tapes are wrapped around busbars to form insulating layers or made into busbar sleeves, effectively blocking current between busbars while withstanding high temperatures generated by short-circuit currents. In drawer-type switchgears, insulating sleeves made from prepregs can move with the drawers, maintaining insulation stability at busbar connections and ensuring safe operation of the complete set of equipment during frequent operations.
In the field of industrial applications of prepregs as insulating materials, Sui On Insulation has profound professional experience and can provide targeted solutions for customers. The technical team is familiar with the performance parameters and processing characteristics of different types of prepregs. Based on the voltage level, operating temperature, and structural design of industrial equipment, they recommend suitable prepreg products, such as aramid prepregs for high-temperature equipment, and Soflex DMD or Soflex BT epoxy prepregs for high-voltage equipment.
