A dielectric insulator is a material that does not conduct electricity and can withstand an electrical potential difference without allowing current to pass through. At SEG DIELECTRICS, our laminated insulators are designed to block the flow of electricity while maintaining excellent mechanical and thermal properties, essential for high voltage applications.
The choice of a dielectric insulator depends on several criteria: the required dielectric strength (breakdown voltage), the necessary thermal class, the environment of use (humidity, temperature), the mechanical properties (flexibility, tear resistance), and the standards to be met (IEC, ASTM). SEG DIELECTRIQUES offers a complete range to meet each specific application.
A laminated flexible insulation is a multi-layer composite material combining flexible films, paper, fabrics or non-woven fabrics (polyester, Kapton®, Nomex®, felt, glass fabric,…), with specialized adhesives. This structure allows for optimal flexibility while maintaining excellent dielectric strength. SEG DIELECTRICS’ flexible laminates offer maximum adaptability for complex geometries and windings.
SEG DIELECTRIC’s laminated flexible insulators are used in: electric motors (stator and rotor windings), distribution and power transformers, generators, converters, and electronic equipment. Their characteristics make them ideal for different applications: thin and flexible for complex shapes and small spaces, thick and rigid for mechanical reinforcement
SEG DIELECTRIQUES uses a selection of premium materials: polyester (chemical stability, cost-effectiveness), PPSU, PEN, Nomex aramid (high temperature, up to 220°C), Kapton/Zenimid/Polyimide (extreme performance, up to 240°C), insulating paper, and resins. These materials are selected for their dielectric strength and thermal properties.
The main thermal classes are: Class A (105°C), Class E (120°C), Class B (130°C), Class F (155°C), Class H (180°C), and Class C (>180°C). SEG DIELECTRIQUES offers laminates for each class, allowing an optimal selection according to the service conditions of your equipment.
The breakdown voltage is the maximum voltage that can be sustained by an electrical insulator before dielectric failure and arcing.
It guides the choice of high-voltage insulating materials (epoxy resins, polyethylene) and geometric design to avoid electrical breakdown in your industrial applications.
Laminated flexible insulation must meet IEC 60626 (Specifications for Flexible Combination Materials), IEC 60243 or ASTM D149 (Dielectric Properties) standards, as well as application-specific standards (IEC 60085 for thermal stability). SEG DIELECTRIQUES certifies all its products in accordance with the most demanding standards in the sector.
Dielectric strength is the maximum voltage that a material can withstand without breaking electrically (breakdown). It is expressed in kV/mm. SEG DIELECTRICS optimizes this property by selecting the right materials and thicknesses, ensuring the right dielectric strength for each medium or high voltage application.
The breakdown voltage of a polyester film laminate from SEG DIELECTRICS depends on the thickness and composition of the multilayer.
Typically, our polyester films offer a stiffness of 48 to more than 170 kV/mm depending on the configuration.
The relative permittivity of an insulation is measured according to ASTM D150 or IEC 60250. It indicates the material’s ability to store electrical energy. SEG DIELECTRICS provides permittivity data for all its products, which is essential for capacitance calculations in transformer and capacitor applications.
Nomex® (aramid) offers several advantages: excellent thermal resistance (up to 220°C), superior dielectric strength, better mechanical resistance to wear, and increased durability. SEG DIELECTRICS integrates Nomex® into its high-end laminates for critical applications requiring exceptional longevity.
Yes, aramid papers (Nomex® type) significantly increase thermal resistance. They allow for higher operating temperatures (200-220°C) compared to standard polyester films. SEG DIELECTRIQUES offers aramid laminates for high-performance equipment operating in extreme thermal conditions.
SEG DIELECTRIQUES designs optimal combinations such as Polyester + Nomex®, or Nomex® + Kapton®, depending on your thermal and electrical constraints. These multilayers combine high dielectric strength, flexibility and thermal resistance, offering the best performance ratio for each application.
Absolutely. SEG DIELECTRIC’s flexible laminates are specially developed for electric motor windings. They adapt to the complex shapes of stator and rotor windings, while providing reliable and durable insulation under dynamic and thermal conditions of motors.
Insulating films provide electrical insulation between the primary and secondary windings of transformers. At SEG DIELECTRICS, our high-voltage laminates guarantee maximum reliability in distribution and power transformers, with performance certified for IEC standards.
Yes, this is one of the main advantages of SEG DIELECTRIC soft laminates. Their flexibility allows adaptation to complex geometries: non-circular windings, small spacings, and special configurations. This adaptability ensures optimal insulating coverage in the most difficult-to-reach spaces.
Class F (155°C) is a very common industry standard. SEG DIELECTRIC’s Class F laminated insulation offers an excellent balance between thermal performance and cost. They are ideally suited for distribution motors and transformers operating at moderately high temperatures.
Yes, SEG DIELECTRICS Class H materials can withstand a continuous temperature of 180°C. This class provides better thermal life and allows for temporary overloads without accelerated degradation. Our Class H laminates are ideal for high-performance equipment in demanding industrial environments.
Class A can withstand 105°C, Class E 120°C, and Class B 130°C. These classes reflect the increasing thermal resistance of materials. SEG DIELECTRICS offers these three classes for traditional applications, with the option to upgrade to higher classes (F, H) if required for a longer service life.
SEG DIELECTRIQUES offers laminates based on Kapton® films in a thickness range from 120?. Depending on the application, we can offer laminates with higher thicknesses. The high-performance Kapton (up to 240°C) is available in multi-layer configurations to optimize dielectric strength while maintaining the correct mechanical characteristics.
Yes, SEG DIELECTRIQUES offers its laminated insulation in both formats: rolls for continuous applications and plates for cut parts. Our teams can also offer custom cutting according to your specific dimensions and production needs.
SEG DIELECTRIQUES uses precisely controlled lamination processes: uniform pressure and temperature, constant speeds, and quality control at every stage. This control ensures uniformity of thickness, dielectric strength and adhesion, which are essential for reliable performance.
SEG DIELECTRIC’s flexible laminated insulation offers good mechanical strength. Their multi-layered structure and flexibility absorb shocks. However, for applications with high impacts, we recommend reinforced configuratinos or specific classes according to your specifications.
Thermal ageing is measured according to IEC 60216: materials are subjected to increasing temperatures and their lifespan is estimated. SEG DIELECTRIQUES tests all its laminates according to this standard, guaranteeing maximum longevity even close to the thermal limits of each class.
The CTI (Comparative Tracking Index) is an index that measures the resistance of an electrical insulating material to the phenomenon of “creepage”. This phenomenon occurs when leakage currents create conductive paths on the surface of an insulation, usually in the presence of moisture and pollution, which can lead to electrical failure.
The CTI is measured according to IEC 60112. SEG DIELECTRIQUES offers ITC laminates suitable for harsh environmental conditions.
Initiated tear represents the ability of the laminated insulation to mechanically resist when a notch is accidentally made by a defect or roughness in the system into which the laminate is inserted. SEG DIELECTRIC’s laminated insulation has a high primed tear allowing it to be used with confidence.
The slipperiness of laminates depends on different factors (surface roughness, polarity, shape) and impacts the processability of the laminate in the motor notches. SEG DIELECTRIQUES performs slip tests to validate the behavior of its laminates in applications.
Vibration resistance is a very important trait to validate the ability of the insulation to stay in place and provide insulation in the motors. SEG DIELECTRIQUES develops pre-impregnated and hot-reactivatable solutions that allow adhesion to copper wires/bars and metal bodies in order to guarantee their stability in operation and improve the life of electric motors.
SEGPREGs are PRE-ImPREGned Insulators that can be reactivated when hot-tied. These are insulators on which a temperature-cross-linking adhesive varnish is deposited. The presence of this varnish ensures that the insulation sticks between the conductors. SEG DIELECTRIQUES offers a wide range of pre-preg laminated insulation.
Partial discharges (PDs) are localized electrical phenomena that occur in an insulating material (solid, liquid, or gaseous) when part of it is subjected to an electric field strong enough to cause ionization, but without causing a complete discharge (such as a total breakdown). SEG DIELECTRIQUES is actively working on partial discharge phenomena and offers solutions that are resistant to the voltages to which they are subjected.
For over 70 years, SEG DIELECTRIQUES has been designing and manufacturing high-performance insulation materials for industry. From laboratory formulation to the finished product, SEG DIELECTRIQUES controls every stage of its manufacturing process: lamination, coating, and cutting according to its customers’ requirements.