Product Overview
Polyesterimide Enamel Wire (PEI Enamel Wire) – High Temperature Magnet Wire for Motors and Transformers
Product Overview
Polyesterimide Enamel Wire (PEI Enamel Wire) is a high-performance magnet wire designed for electrical applications that require excellent thermal resistance, mechanical strength, and long-term insulation reliability.
Manufactured with a polyesterimide resin insulation coating on copper or aluminum conductors, PEI enamel wire provides superior heat resistance compared with conventional polyester enamel wires. With a typical thermal class of 180°C, Polyesterimide enameled wire is widely used in motors, transformers, generators, compressors, and other electrical equipment operating under demanding conditions.
As a professional magnet wire manufacturer, LP Industry supplies customized Polyesterimide Enamel Wire with stable quality, precise dimensions, and reliable electrical performance to meet global industrial requirements.
Whether you need round enamel wire, rectangular magnet wire, copper magnet wire, or aluminum magnet wire, our engineering team provides customized solutions for different winding applications.
What Is Polyesterimide Enamel Wire?
Polyesterimide Enamel Wire is a type of insulated winding wire that uses polyesterimide enamel coating as the primary insulation layer.
Enameled varnishes, specifically Polyesterimide (PEI) is a high-performance insulating coatings applied to copper or aluminum winding wires. They are designed for specific thermal classes, mechanical strengths, and environmental resistances in motors, transformers, and industrial equipment.
Polyesterimide vs Polyamide-Imide vs Polyester Enamel Wire
Different enamel systems provide different performance levels.
| Type | Thermal Class | Main Advantages | Typical Applications |
| Polyester Enamel Wire | 155°C | Cost-effective, good general performance | General motors, transformers |
| Polyesterimide Enamel Wire | 180°C | Excellent heat resistance and mechanical strength | Motors, generators, transformers |
| Polyamide-Imide Enamel Wire | 200°C | Superior thermal and chemical resistance | High-temperature motors, EV applications |
Polyesterimide enamel wire offers an excellent balance between performance and cost, making it one of the most widely used high-temperature magnet wires in industrial applications.
Key Properties:
Chemical base: Modified Polyester
Solid Content: 24%-41%by weight
Viscosity: Ranges widely from 25–35 s (for fine wire/felt application) up to 15500-21500 mPa.s for specialized coatings.
Standard package new weight: approximately 210kg.
Applicable Wire Size (Round):
Fine Wires: 0.05 mm – 0.50 mm (e.g., Terebec TR 543-32).
Medium wire size range(dia): 0.2 mm – 5.0 mm (standard range).
Class of wire;130L
Flexibility & Mechanical Properties:
High Performance: Offers excellent mechanical strength, abrasion resistance, and thermal shock resistance.
Wind ability: While very tough, it is generally less flexible than PVA/Formvar, but modern THEIC-modified polyesterimides provide good flexibility, and in some cases, high flexibility suitable for high-speed winding.
Excellent flexibility.
Adhesion & Application:
Excellent Adhesion: Provides strong adhesion to copper especially in dual-coating systems (e.g., base coat PEI, top coat Polyamide-imide/PAI).
Usage: Ideal for motors, refrigerators, and high-temperature transformers.
Specifications: Often compliant with IEC 60317-8 (Class 180) or IEC 60317-13 (Class 200).
Excellent thermal stability (180°C) and heat resistance.
Good resistance to solvents, refrigerants, and moisture.
High cut-through resistance.
Suitable for high-speed winding machines.
Common Standards: IEC 60317-8, IS 13730-8.
Common Formulations: THEIC modified polyesterimide.
Applications: Motors, dry-type power transformers, refrigerators, and power tools.
Comparison of Key Specifications
| Property | Polyesterimide (PEI) |
| Thermal Class | 180°C – 200°C (up to 220°C) |
| Heat Resistance | Excellent; superior to PV |
| Flexibility | Good to excellent |
| Oil/Chemical Resist. | Very good refrigerant and solvent resistance |
| Mechanical Prop. | Very good to excellent, high cut-through temp |
| Typical Use | High-temp motors, industrial systems, heat-resistant transformers |
Key Performance Indicators (Tested on Wire)
Elongation: Ability of the coating to withstand stretching without cracking.
Flexibility & Adhesion: Tested by bending/winding; no peeling allowed.
Heat Shock: Resistance to cracking at high temperatures.
Cut-through Temperature: Resistance to thermoplastic flow (softening).
Dielectric Strength: High insulation capability
Common Additives and Solvents
Solvents: Phenol-based, cresol isomers, and aromatic hydrocarbons.
Modifiers: THEIC (Tris-2-hydroxyethyl isocyanurate) is often added to polyesterimides to
enhance thermal properties.
Topcoats: Polyamide-imide (PAI) is frequently applied over PEI to increase the temperature
rating to 200°C+ (Class C).
LP Industry Technical Specifications of Polyesterimide Enamel Wire
LP Industry manufactures Polyesterimide Enamel Wire (PEI Enamel Wire) according to international standards and customer-specific requirements. Our production process ensures accurate dimensions, uniform enamel coating, and stable electrical performance for demanding industrial applications.
The wire can be supplied in different conductor materials, shapes, and insulation thicknesses to meet various winding requirements.
Main Product Range
| Item | Specification |
| Product Name | Polyesterimide Enamel Wire |
| Insulation Material | Polyesterimide Resin |
| Thermal Class | Class 180°C |
| Conductor Material | Copper / Aluminum |
| Wire Shape | Round / Rectangular / Flat |
| Standard | IEC 60317, NEMA MW1000, GB/T Standards |
| Conductor Size | Customized according to customer requirements |
| Insulation Thickness | Standard / Heavy / Custom |
| Color | Natural enamel color or customized |
Why Choose LP Industry as Your Polyesterimide Enamel Wire Manufacturer?
Choosing the right magnet wire supplier directly affects product performance and manufacturing efficiency.
LP Industry provides professional PEI enamel wire solutions with decades of manufacturing experience.
30+ Years Magnet Wire Manufacturing Experience
Founded in 1993, LP Industry specializes in manufacturing:
- Enameled copper wire
- Enameled aluminum wire
- Rectangular magnet wire
- Paper covered wire
- Fiberglass covered wire
Our experienced engineering team understands different winding requirements across industries.
Frequently Asked Questions About Polyesterimide Enamel Wire
What is Polyesterimide Enamel Wire?
Poly esterimide Enamel wire a high quality magnet wire. With its using of polyesterimide resin coating, the wire shows good performances in high thermal resistance, mechanical, electrical insulation. This is equivalent to Class 180 degreesC.
What is the temperature rating of Polyesterimide Enamel Wire?
Almost all the Poyesterimide Enamel Wire products are Class 180 degrees C magnet wire to the global class insulation system.
Is intended for continuous operation at high ambient and product temperatures with reliable insulation.
What is the difference between Polyester and Polyesterimide enamel wire?
The most significant variation is that of thermal performance.
Polyester enamel wire offers usually Class 155 degreesC performance in insulation performance, while Polyesterimide enamel wire offers Class 180 degreesC performance in thermal resistance as well as provides better heat aging and chemical resistance.
Is Polyesterimide Enamel Wire suitable for motors?
Yes.
PEI enamel wire is widely used in electric motors because it provides:
Resistance to high temperature
Excellent mechanical durability
Superb insulation dependability
Industrial motor, automotive motor, high efficiency motor design.
Can Polyesterimide Enamel Wire be used for transformers?
Yes. Polyesterimide enamel wire is selected for transformer winding applications because of their high dielectric strength.
It can be used in:
Power transformers7ms
Distribution transformers
Dry-type transformers
What sizes of Polyesterimide Enamel Wire are available?
LP Industry will provide personalized PEI enamel wire sizes.
Available options include:
Round enamel wire
Rectangular magnet wire
Wire for flat winding
Can be ordered with specific conductor size, insulation thickness, dimensions.
Do you manufacture custom Polyesterimide Enamel Wire?
Yes. LP Industry provides OEM and customized magnet wire solutions based on:
Customer drawings
Technical specifications
Application requirements
We leverage our engineering team to support new product development and mass production.
